HomeMy WebLinkAboutSS4 - Appendix BAPPENDIX B
Eelgrass Capacity and
Management Tools
HARBOR AREA MANAGEMENT PLAN
EELGRASS CAPACITY AND MANAGEMENT
TOOLS
Technical Report
Prepared for:
Harbor Resources Division
City of Newport Beach
829 Harbor Island Drive
Newport Beach, CA 92660
Prepared by:
Rick Ware, Principal /Senior Marine Biologist
Coastal Resources Management, Inc.
PMB 327, 3334 E. Coast Highway
Corona del Mar, CA 92625
a
With HAMP Team
April 2008; Revised June 2009
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
TABLE OF CONTENTS
1.0 EELGRASS CAPACITY AND MANAGEMENT TOOLS ............... ...............................
I
1.1 Introduction ............................................................................... ...............................
l
1.2 Objectives .................................................................................. ..............................1
1.3 Organization ............................................................................... ..............................1
2.0 EELGRASS BIOLOGY AND DISTRIBUTION IN NEWPORT BAY ............................
2
2.1 Importance of Eelgrass .............................................................. ..............................2
2.2 Key Issues .................................................................................. ..............................3
2.3 Eelgrass Distribution and Abundance ........................................ ..............................4
2.3.1 Sediments ...................................................................... ..............................4
2.3.2 Depth Distribution ....................................................... ...............................
5
2.3.3 Wave /Current Energy .................................................. ...............................
5
2.3.4 Light Penetration .......................................................... ...............................
5
2.3.5 Temperature ................................................................. ...............................
6
2.3.6 Salinity .......................................................................... ..............................7
23.7 Oxygen .......................................................................... ..............................7
2.3.8 Nutrients ........................................................................ ..............................7
2.3.9 Synergistic Effects ....................................................... ...............................
8
2.3.10 Summary of Other Relevant Scientific Information Regarding
Eelgrass Structure and Function .................................. ...............................
8
2.3.11 Nutrients and Macroalgae ............................................ ...............................
9
2.3.12 Invasive Algae ............................................................. ...............................
9
2.3.13 Effects of Bottom Disturbances on Eelgrass ............. ...............................
10
2.3.14 Historical Range of Eelgrass in Newport Bay ........... ...............................
10
2.4 Eelgrass Regulatory Overview ................................................. .............................29
2.4.1 Clean Water Act ......................................................... ...............................
29
2.4.2 Magnuson— Stevens Fishery Management and Conservation Act
(FR 62, 244, December 19, 1997 — Essential Fish Habitat and
Habitats of Particular Concern ................................... ...............................
29
2.4.3 Southern California Eelgrass Mitigation Policy ........ ...............................
30
2.4.4 California Department of Fish and Game Regulations. 2008
Department of Fish and Game Ocean Fishing Regulations. Section
4 Ocean Fishing ......................................................... ...............................
30
2.4.5 California Code of Regulations, Title 14, 650. Natural Resources.
Division 1. Fish and Game Commission — Department of Fish and
Game. Subdivision 3, General Regulations. Chapter 1. Collecting
Permits....................................................................... ...............................
30
2.4.6 City of Newport Beach Local Coastal Plan ............... ...............................
30
3.0 CURRENT CHALLENGES TO ESTABLISHING SUSTAINABLE EELGRASS
POPULATIONS IN NEWPORT HARBOR ..................................... ...............................
32
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4.0 DEVELOPING AN EELGRASS MANAGEMENT PLAN ............. ............................... 33
4.1 Current Guidelines for Conducting Eelgrass Transplants ........ .............................33
4.1.1 Current Specific Mitigation Success Criteria from the Policy
(NMFS 1991 as amended) ......................................... ............................... 33
4.1.2 Eelgrass Mitigation Success in Newport Bay ............ ............................... 35
4.2 Eelgrass Threshold Capacity ..................................................... .............................35
4.3 Recommended Areas in Newport Bay to Create A Sustainable Eelgrass
Population( SEP) ....................................................................... .............................36
4.4 Development and Implementation of a Long -Term Eelgrass Management Plan..37
4.5 Steps Forward ........................................................................... .............................39
5.0 REFERENCES .................................................................................. ............................... 41
LIST OF TABLES
Table 1. Eelgrass Abundance in Newport Bay, 2003 -2004 and 2006 -2007 Surveys ................. 23
LIST OF FIGURES
Figure 1. Eelgrass (Zostera marina) .. ...............................
Figure 2. Narrow- Bladed Eelgrass ..... ...............................
Figure 3. Wide - Bladed Eelgrass ........ ...............................
Figure 4. Invasive Algae, Caulerpa taxifolia ....................
Figure 5. Newport Bay Eelgrass Distribution 2003 -2004
Maximum Distribution ..... ...............................
.............................. ............................... 6
.......................... ...............................
and 2006 -2007 Surveys
Figure 6. Area 1, Eelgrass Habitat, Entrance Channel ...................... ...............................
Figure 7. Area 2, Eelgrass Habitat, Corona Del Mar Reach .............. ...............................
Figure 8. Area 3, Eelgrass Habitat, Balboa Island ............................. ...............................
Figure 9. Area 4, Eelgrass Habitat, North Harbor ............................. ...............................
Figure 10. Area 5, Eelgrass Habitat, Northwest Harbor .................... ...............................
Figure 11. Area 6, Eelgrass Habitat, Northwest Newport Harbor ..... ...............................
Figure 12. Area 7, Eelgrass Habitat, Soutwest Newport Harbor ...... ...............................
Figure 13. Area 8, Eelgrass Habitat, Upper Newport Bay. Note: Eelgrass Patches in the
Newport Dunes Marina were mapped by Chambers Consultants (2005) .......
Figure 14. Tidal Flushing Rates in Newport Bay... ....................... ..................................
Figure 15. Relationships between Eelgrass Acreage and Tidal Residence Times in
Newport Bay, 2003 -2004 and 2006 -2007 ...................... ...............................
Figure 16. Relationships between Eelgrass Habitat Loss and Tidal Residence Times in
NewportBay, 2003 -2007 ................................................ ...............................
Figure 17. Eelgrass Habitat Zones in Newport Bay .......................... ...............................
Figure 18. Eelgrass Turion Density in Newport Bay, 2004 - 2008 ..... ...............................
Figure 19. Potential Eelgrass Sustainability Locations in the Stable Eelgrass Zone........
10
12
13
14
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1.1 Introduction
The marine resources of Newport Harbor are extremely diverse and rich and are extremely
important to the health and maintenance of nearshore coastal resources. The City of Newport
Beach is committed to achieving a sustainable Newport Harbor area through the projection and
improvement of harbor marine resources, including marine plants, invertebrates, fishes, seabirds,
marine mammals, and the habitats that they are associated with.
One of the most important biological resources within Newport Harbor is eelgrass (Zostera
marina). It is considered wetland habitat by state of California and federal wetland defmitions
and is protected by a no net loss wetlands policy. Any development that has a potential to
adversely affect eelgrass must include provisions to avoid, reduce the level of impacts, or
compensate for losses of eelgrass habitat values.
1.2 Objectives
The objectives of this technical report are as follows:
• Identify historical and current eelgrass distributions in Newport Bay.
• Identify key issues related to resource management conflicts between eelgrass and the
management goals of Newport Harbor.
• Provide recommendations for developing and implementing an Eelgrass Management
Plan for Newport Harbor.
• Provide information and data requirements needed to develop a long -term
management program of eelgrass bed resources in Newport Bay.
1.3 Organization
This technical report provides a detailed review of eelgrass biology and its distribution and
abundance in Newport Bay. Data are then presented to determine the regions within the Bay
where the potential for future eelgrass sustainability sites are the highest. A plan for the long-
term mitigation requirements related to harbor infrastructure projects impacts on eelgrass bed
resources is presented. The report concludes with data requirements to implement a long -term
mitigation program.
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2.1 Importance of Eelgrass
Eelgrass (Figure 1) is a marine flowering plant that grows in soft sediments in coastal bays and
estuaries and occasionally offshore to depths of 50 ft. Eelgrass forms meadows on mudflats and
subtidal sediment in bays and estuaries. The presence of eelgrass in Newport Harbor is a
biologically important feature because of the high biological productivity associated with
eelgrass beds. Eelgrass meadows form a basis of primary production that supports ecologically
and economically important species (Orth et al., 1984; Thayer et al., 1984).
Source: CRM, Inc.
Figure 1. Eelgrass (Zostera marina)
As a primary producer, eelgrass fixes carbon at rates that are equivalent to or exceed the rates of
the most intensively farmed agricultural crops (Thayer et al., 1984). Epiphytes such as diatoms
and green algae that attach to eelgrass blades add to this high level of productivity (Thayer et al.,
1984; Phillips and Menez, 1988). The organic matter in the form of shoots, blades, and roots is
transferred to both invertebrate and vertebrate secondary consumers that feed on the particulate
matter through the detrital feeding pathway. In addition, invertebrate and fish predators forage
upon the diverse types of detrital feeding invertebrates which congregate within eelgrass habitat.
Eelgrass meadows (and subunits called "beds" and "patches ") are important habitat for
invertebrates as a source of food and attachment and for marine fishes that seek the shelter of the
beds for protection and forage on invertebrates that colonize the eelgrass blades and sediments in
and around eelgrass vegetation.
Eelgrass canopy (consisting of shoots and leaves approximately 2 -3 ft long) attracts many
marine invertebrates and fishes, and the added vegetation and the vertical relief it provides
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enhances the abundance and the diversity of the marine life compared to areas where the
sediments are barren. Juvenile California halibut (Paralichthys californicus) and California spiny
lobsters (Panulirus interruptus) —which are of sports fish and commercial value as adults —use
eelgrass beds as a nursery habitat. The vegetation also serves a nursery function for many juvenile
fishes, including species of commercial and /or sports fish value (e.g., California halibut and
barred sand bass) and federal Fishery Management Plan (FMP) groundfish species (e.g., lingcod,
and Boccaccio rock fish).
A diverse community of bottom - dwelling invertebrates (e.g.., clams, crabs, and worms) live
within the soft sediments that cover the root and rhizome mass system. Eelgrass is an important
contributor to the detrital (decaying organic) food web of bays because the decaying plant
material is consumed by many benthic invertebrates (e.g., polychaete worms) and reduced to
primary nutrients by bacteria. This carbon is then transported offshore and becomes important
sources of nutrients for coastal food webs.
Eelgrass coexists and competes for bottom habitat and sunlight with benthic algae. For example,
eelgrass meadows in Newport Bay often co -occur in the low intertidal or shallow subtidal zone
with green algae (Enteromorpha spp) and in deeper parts of the meadow, with brown algae
(Ectocarpus), and red algae (Acrosorium and Gracilaria). Eelgrass in Newport Bay and other
Southern California bays also support unusual or rare species, including Pacific seahorse
(Hippocampus ingens) that became established as a result of warm water intrusions into
Southern California produced by El Nino conditions and the juvenile broad -eared pecten
(Leptopecten latiauratus) which attaches to eelgrass shoots and blades.
Eelgrass meadows are also foraging centers for endangered seabirds, such as the California least
tern (Sterna albifrons browni) and California brown pelican (Pelecanus occidentalis), that feed
on topsmelt and anchovy that congregate within eelgrass meadows.
From a recreational standpoint, eelgrass meadows in Newport Bay provide fishing opportunities
for boat and kayak fishermen; this translates into a consistent economic base for businesses
within Newport Beach, including the recreational fishing industry, boat and kayak rental/retail
stores, and food concessions. Detailed fishing charts of Newport Harbor were recently produced
that include the Coastal Resources Management, Inc. (CRM, Inc.) 2003 -2004 eelgrass habitat
maps produced for the Harbor Resources Division ( http: / /www.bajadirections.com).
2.2 Key Issues
From a resource management perspective, the presence of eelgrass within Newport Harbor often
conflicts with the development and the maintenance of federal, state, city, and residential
infrastructure. From a geological perspective, eelgrass beds dampen wave and current action,
trap suspended particulates, and reduce erosion by stabilizing the sediment (National Marine
Fisheries Service (NMFS) 1991, as amended). Once established, eelgrass colonization will
promote additional shoaling that can be a navigational hazard. Dredging of these shoals;
maintenance of navigational channels, bulkhead, pier and dock construction and/or maintenance;
and beach nourishment along the shoreline of Newport Harbor directly affects eelgrass through
burial or removal of vegetation and a loss of eelgrass function as a wildlife habitat. Other
activities may also indirectly affect the distribution and abundance of eelgrass. Dredging activity,
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pile driving activity, and stormwater flows via street -end storm drains and Upper Newport Bay
that discharge into Newport Harbor increase water turbidity and decrease the amount of
underwater irradiation that reaches the bayfloor. Secondary effects from boat dock and pier
construction will permanently shade soft bottom habitat. Because eelgrass is considered wetland
habitat by state of California and federal wetland definitions, it is protected by a no net loss
wetlands policy. Any development that has a potential to adversely affect eelgrass must include
provisions to avoid, reduce the level of impacts, or compensate for losses of eelgrass habitat
values.
These projects are undertaken as federal, state, local agency projects, or individual resident's
projects which do not qualify under the City's Regional General Dredging Permit (RGP 54) due
to the presence of eelgrass within 15 ft of their docks, bulkhead, piers, or beach nourishment
projects. More detailed and, to the homeowners, more costly analyses are required under these
circumstances if they do not qualify for inclusion in the RGP.
The City of Newport Beach has an adopted a Coastal Commission- approved land use plan
(LUP). The LUP acknowledges that the need to maintain and develop coastal- dependent uses
may result in impacts to eelgrass. To mitigate the potential impacts to eelgrass of dredging and
development, the LUP requires the avoidance where possible and restoration where avoidance is
not practical:
The City and all the stakeholders need to develop an eelgrass mitigation program to allow the
City to go forward with dredging and construction activities that are necessary and will impact
eelgrass.
2.3 Eelgrass Distribution and Abundance
Many factors, both abiotic and biotic, have an influence on eelgrass distribution and abundance.
These factors are discussed below.
2.3.1 Sediments
Eelgrass colonizes a range of sediments varying from firm sand with moderate wave action to
soft muds in quiet bays (Phillips, 1974). In Newport Bay, eelgrass colonizes in sediments that
range from fine sands to silt /clay (Coastal Resources Management, Inc., in progress). Eelgrass
grows in predominantly fine sand sediments between the entrance channel to Harbor Island. In
most other areas of the Bay, eelgrass colonizes siltier, less compact sediments. Results of
sediment grain -size analysis in eelgrass beds and in sediments where eelgrass is not found in
Newport Bay (CRM, Inc. in progress) indicate that on the average, eelgrass can grow in a wide
range of sediment types with as little as 4% sand (Linda Isle Inlet) and as much as 97% sand
(near the harbor entrance). On average however, sediments tended to consist of approximately
10% more sands in eelgrass beds than in unvegetated sediments, although the proportions of
sand and silt/clay can be highly variable. Typically, sediments exhibit a decreasing grain size
with increasing depth in Newport Bay (Ware, 1993; Chambers Group Inc. and Coastal Resources
Management, 1998; Chambers Group Inc. and Coastal Resources Management, 1999) as well as
lower velocity current regimes.
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2.3.2 Depth Distribution
The upper elevational range limit of eelgrass on naturally sloped shorelines is primarily regulated
by desiccation, sediment stability, and wave shock (Phillips, 1974). In Newport Bay, this limit
appears to be approximately at the mean lower low water (MLLW) mark (0.0 ft), although it can
occur as high as +1 ft MLLW. However, in many areas of Newport Bay and other modified
Southern California embayments, its upper range limit is also affected by dredging and
bulkheading activity that eliminates natural intertidal slopes and eelgrass meadows. Within
Newport Bay, eelgrass is found at depths as great as -25 ft MLLW in the entrance channel,
although it more typically occurs in other areas of Newport Bay at depths from 0.0 ft and -8.0 ft
(Ware, 1993; NMFS, 2003; CRM, Inc., 2005 and 2008; CRM in progress; Chambers Consultants
Inc. and Coastal Resources Management, 1998 and 1999).
2.3.3 Wave /Current Energy
Some water motion is needed to supply nutrients to the plants, cool the flats, and prevent the
buildup of floating organic matter that can smother eelgrass (Thom et al., 2003). Strong waves
and currents will erode the sediment in an eelgrass bed (Phillips, 1984).
Light, temperature, and salinity also control growth and productivity of seagrasses (Thayer et al.,
1984; Backman and Barilotti, 1976; Zimmerman et al., 1991). Of these, light is the factor which
often controls the depth, distribution, density, and productivity of seagrass meadows (Backman
and Barilotti, 1976; Zimmerman et al., 1991).
2.3.4 Light Penetration
In Newport Bay, as in other shallow -water embayments, light penetration is affected by
parameters, such as time of day and year, tidal condition, suspended organics and sediment input
into the bay from dry - season runoff, winter storms, plankton blooms, shading from docks and
boats, and in -bay activities such as dredging and boating activity (ACOE, 1998; 1996; MBC
Applied Environmental Sciences and SCCWRP, 1980; CRM, Inc. in progress).
Light penetration is better during the incoming tides compared to outgoing tides which carry
higher levels of suspended organics and sediments out of Newport Bay. Zimmerman et al. (199 1)
estimated that eelgrass in San Francisco Bay required between three and five hours a day of
irradiance to maintain carbon balance and growth and suggested that eelgrass is adapted to
extremely low light availability.
Higher water turbidity in coastal embayments limits eelgrass depth distribution to intertidal and
shallow subtidal environments (Zimmerman et al., 1991). This is reflected in Newport Bay with
eelgrass exhibiting a greater depth range nearer the harbor entrance compared with eelgrass beds
located near Harbor Island, Balboa Island, Linda Isle, and Upper Newport Bay where water
clarity is poorer and sediments are much finer (CRM, Inc., 2005). Generally, the compensation
depth for seagrasses is approximately 11% of the available surface irradiance (Duarte, 1991).
Eelgrass growth and distribution is also affected by a decrease in solar radiation resulting from
seafloor shading from docks, piers, and vessels. Studies indicate that shoot densities of
seagrasses decrease near docks and pilings and that the construction of docks and piers can lead
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to a permanent loss of seagrass vegetation (Beal and Schmit, 2000). In addition, the height of
pier structures will affect how much light can penetrate beneath the piers. In locations such as
Corona del Mar where piers are elevated several feet off of the sediments, eelgrass will grow
underneath the piers. In other areas, structures (e.g., along Balboa and Harbor Island piers and
gangways) are not as elevated and allow less light penetration beneath. Consequently, eelgrass
may not grow as well or may be absent altogether underneath these structures (Coastal Resources
Management, Inc., 2005).
2.3.5 Temperature
Eelgrass is a eurythermal species (Phillips, 1984). Its optimal temperature distribution is between
10° Celsius (C) and 20 ° C (50-68 ° F). Its extreme temperature ranges may vary from -6 ° C in
Alaska to 40.5 °C (21.2-104.9' F). Therefore, water temperatures in Newport Bay are generally
not a limiting factor for eelgrass growth and distribution. During late summer, water
temperatures in Newport Bay can exceed 21 ° C for sustained periods of time (CRM, Inc., in
progress) that promote seasonal biofouling of the blades. The heavy blades then bend and come
in contact with the sediments that lead to eventual burial and loss of eelgrass above - ground
biomass.
Eelgrass may display some genetic and/or environmentally associated variations in response to
water temperature and/or light requirements. For example, wider - bladed meadows of eelgrass
occur primarily in the deeper, cooler entrance channel waters of Newport Bay, whereas a
narrower- bladed variant is found throughout the other regions of Newport Bay in shallower,
warmer conditions (Figures 2 and 3). Recently, wide -blade eelgrass in the Channel Islands was
identified as a different species (Zostera pacifica) (Coyer et al., 2007), whereas before it was
considered either a subspecies (Z. marina var latifolia) or a separate species (Z. asiatica)
(Phillips and Wyllie- Echeverria, 1990). Currently, it is not known if the wide -blade variant form
in the entrance channel is the subspecies Z. marina var latifolia or if it is considered to be Z.
pacifica. The genetic differences and the relative differences in depth and geographical
distribution of the two forms within Newport Bay suggest that future mitigation efforts need to
take into account the morphological and genetic differences when collecting donor material for
specific projects and the selection of the eelgrass mitigation site.
Figure 2. Narrow - Bladed Eelgrass
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Figure 3. Wide - Bladed Eelgrass
2.3.6 Salinity
Eelgrass is also a eurysaline species, tolerating a wide range of water salinities, including the
range of salinities that Newport Harbor experiences. It has been documented to grow at stream
mouths when the water is fresh at low tide (Phillips, 1984) but does not grow in persistent
freshwater. At the other extreme, eelgrass can grow in waters of extreme salinity (42 ppt). In
Puget Sound, eelgrass grows best in a salinity of 20 to 32 ppt. Phillips (1972) found that most
(70 %) eelgrass seed germination occurred at 5 to 10 ppt at all temperatures, although at 10 ppt,
seed germination often doubled from 10° C to 15° C but did not do so in full strength seawater
(30 ppt). Newport Bay salinity, on the average range between approximately 30 to 33 ppt,
although during wet periods, surface salinity may decrease to below 25 ppt for short periods of
time. In addition, salinity is typically lower in the Upper Bay due to runoff from the Newport
Bay Watershed.
2.3.7 Oxygen
Under normal growing conditions, oxygen is not a limiting factor for eelgrass. However, during
periods of high turbidity which may result in significant light limitation and decrease in
photosynthesis and oxygen production, eelgrass root and rhizome tissue may experience periods
of anoxia. While eelgrass tissue apparently can withstand periods of 24 hrs of anoxia (Smith,
1989), the long -term cumulative effects of prolonged anoxia are not known, but it is possible that
eelgrass distribution, particularly at its deeper limit, may be negatively affected (Zimmerman et
al., 1991).
2.3.8 Nutrients
Eutrophication is one of the main causes for decreased light availability that can lead to a decline
of eelgrass populations. As excess nutrients stimulate phytoplankton growth, light penetration to
the plants growing at depth is reduced. Increased epiphytic (and benthic) macroalgae growth
from excessive nutrient loading can shade and suffocate eelgrass plants. As light diminishes, the
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plants develop thinner blades, leading to lower rates of productivity and a decrease in biomass
and lower shoot densities (Denison, 1987).
2.3.9 Synergistic Effects
There is a lack of available data that compare submarine light levels, turbidity levels, eelgrass
compensation depths, and temperature variations within vegetated and unvegetated regions of
Newport Harbor. These data are required to understand the observed differences in eelgrass
cover and density among the various regions of the bay, and to identify areas that may or may
not be suitable for future eelgrass transplants. Consequently, studies are currently being
conducted that will address these parameters and how they influence eelgrass distribution in
Newport Bay (CRM, Inc., in progress).
2.3.10 Summary of Other Relevant Scientific Information Regarding Eelgrass
Structure and Function
Few studies have directly approached the biological diversity and habitat value of eelgrass within
Newport Bay. These studies are critical to understand the relative habitat importance and value
of eelgrass habitat within the various regions of Newport Bay, and to be able to make informed
management decisions relative to eelgrass mitigation. For example, do sparse, low- density, and
patchy eelgrass beds along Mariner's Mile provide the same habitat value for marine life as
eelgrass beds near the Harbor Entrance Channel, and should all eelgrass areas of Newport
Harbor be treated the same from a harbor management perspective?
While not comprehensive or quantitative, a list of organisms observed during the 2003 -2004 bay
wide eelgrass habitat surveys included 63 species. Of these, one was a sulphur bacterium, nine
were algae species, two were seagrasses, 31 were invertebrates, and 20 were fishes. Data were
not analyzed by region with the harbor. During eelgrass surveys conducted in July 1999, 28
species of macro invertebrates were observed living on eelgrass or in sediments of eelgrass beds.
The most common forms were speckled scallops (Argopecten aequisulcatus), anemones
(Pachycerianthus fimbriatus), snails and sea slugs (Bulla gouldiana and Navanax inermis) and
nudibranchs (Anisodoris nobilis). During both the 2003 -2004 and 1999 surveys, commonly
encountered fish included topsmelt (Atherinops affinis), spotted sand bass (Paralabrax
maculatofasciatus), barred sand bass (P. nebulifer) and round string ray (Urolophus halleri).
Fourteen of 16 species of fish observed during July 1999 eelgrass bed surveys were associated with
eelgrass habitat (Chambers Group Inc. and Coastal Resources Management, 1999).
Directed research in other Southern California embayments concerning the value of eelgrass
beds as a nursery or wildlife habitat not received high priority, although several studies (MBC,
1986; Hoffman, 1986; Hoffman, 1990; Hoffman, 199 1) suggest the marine life of eelgrass
meadows is enhanced in numbers, species, and standing crop compared to unvegetated soft
bottom habitat. Infaunal and epifaunal invertebrate studies conducted in Mission Bay, Sunset
Bay and Huntington Harbour eelgrass meadows suggest vegetated bay sediments support a
higher diversity of invertebrates compared to unvegetated bay sediments because of the added
structure and habitat (MBC Applied Environmental Sciences, 1986). Ninety-seven species of
epifauna (plants and invertebrates living on the blades and shoots of eelgrass) were collected
from in Mission Bay, Sunset Bay, and Huntington Harbour. Community composition and
abundances were dominated by crustaceans (39 species), polychaete worms (23 species) and
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mollusks (13 species). Other common epifaunal invertebrates included nemertean worms,
ectoprocts, hydrozoans, nematodes, and ascidians. The benthic community living amongst the
root - rhizome mass included 216 species of invertebrates, dominated in richness and abundance
by 87 species of polychaete worms, 63 species of crustaceans, 28 species of clams, and 17
species of snails. Dominant organisms in both the epifauna and infaunal communities were
species that occur commonly throughout embayments of Southern California.
2.3.11 Nutrients and Macroalgae
Relationships between nutrients and macroalgae abundances and species compositions have been
examined in Upper Newport Bay (SCCWRP, 2003; County of Orange, 2003; County of Orange,
2004; County of Orange, 2005). Findings of these studies indicate that nitrate, rather than
organic nitrogen is the most common and most bioavailable nitrogen source. Between 1996 and
2003, the incidence of nuisance algal blooms in the Upper Bay diminished (County of Orange,
2003). In addition, algal biomass decreased along a gradient between San Diego Creek and the
Pacific Coast Highway Bridge. The decline in nuisance seaweeds in Upper Newport Bay was
similar to those found for all kinds of algae when the limiting nutrient(s) are reduced. The most
obvious explanation for the reductions in seaweeds in Newport Bay was the reduction in nitrate
entering from San Diego Creek.
Eelgrass competes with macroalgae for space and sunlight, and seasonal blooms of green algae
can blanket eelgrass beds (R. Ware, pers. observation). Such events can contribute to year -to-
year variations in celgrass abundance throughout Newport Bay. In areas of poor water circulation
where tidal residence times are high, green algae is abundant; in other areas, the red algae
(Acrosorium), particularly in mid -bay (Harbor Island) and Mariner's Mile areas compete with
eelgrass for space and light. The combination of poor water circulation, warm water
temperatures, and high algal productivity in areas like Newport Shores and West Newport Bay
likely affect the ability of eelgrass to colonize these areas. However, observed water quality
improvements in the Newport Bay watershed, like the reduction in nitrates (County of Orange,
2003) over the long term, will benefit eelgrass by reducing competition and shading.
2.3.12 Invasive Algae
Invasive algae (Figure 4) has a potential to cause ecosystem -level impacts in Newport Bay and
nearshore systems due to its extreme ability to out - compete other algae and seagrasses. Caulerpa
taxifolia grows as a dense smothering blanket, covering and killing all native aquatic vegetation
in its path when introduced in a non - native marine habitat. Fish, invertebrates, marine mammals,
and sea birds that are dependent on native marine vegetation are displaced or die off from the
areas where they once thrived. It is a tropical/subtropical species that is used in aquariums. It was
introduced into Southern California in 2000 (Agua Hedionda Lagoon) and (Huntington Harbour)
by way of individuals likely dumping their aquaria waters into storm drains, or directly into the
lagoons. While outbreaks have been contained, the Water Resources Board, through the National
Marine Fisheries Service and the California Department of Fish and Game require that when
projects that have potential to spread this species through dredging, and bottom - disturbing
activities preconstruction surveys must be conducted to determine if this species is presence
using standard agency- approved protocols and by National Marine Fisheries Service / California
Department of Fish and Game Certified Field Surveyors.
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
Source: NMFS
Figure 4. Invasive Algae, Caulerpa taxifolia
2.3.13 Effects of Bottom Disturbances on Eelgrass
Eelgrass is susceptible to physical damage from activities that disturb the seafloor. Dredging will
remove all vegetation and change bottom depth and sediment characteristics. Deployment of
anchors and anchor chains will remove eelgrass vegetation and create furrows within eelgrass
beds, as will damage from vessel propellers. Single -point mooring anchor systems can "crop and
thin" eelgrass within a defined radius around the anchor chain as ebb and flood tides change the
position of the mooring. Some bottom disturbances are temporary while others will result in a
sustained, long -term loss of eelgrass, particularly where depth and light requirements for eelgrass
are permanently altered.
2.3.14 Historical Range of Eelgrass in Newport Bay
Pre -1900s — It is difficult to asses whether eelgrass was present in Newport Bay prior to the time
of the development of Newport Harbor. However, there are indications that eelgrass was present
in the vicinity of Newport Bay dating back to at least 600 A.D. (Weide, 198 1) as evidenced by
the presence of eelgrass in local midden (refuse areas) remains along the shoreline of what is
now Upper Newport Bay (Attachment 1). Prior to the mid 1800s, "Newport Harbor ", or "Lower
Newport Bay" did not exist and the coastline was an open coastal sandy beach and rocky
shoreline. Eelgrass was only present in what is now referred to as "Upper Newport Bay ".
Following the formation of a sand spit that formed the Balboa Peninsula in the mid to late 1800s,
quiet water conditions in Newport Lagoon were likely conducive for eelgrass growth and
establishment.
Recent History — In Upper Newport Bay, eelgrass was reported to be present in the 1950s and
1960s, although not abundantly, from the Coast Highway Bridge to the southern tip of Upper
Island near Big Canyon (Barnard and Reish, 1959; State Water Quality Control Board, 1965;
Stevenson and Emery, 1958; Posjepal, 1969; Hardy, 1970; Allen, 1976). The bulk of eelgrass
was located in the main channel on the west side of the Bayside (DeAnza) Peninsula to the
10
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
entrance to the Dunes Aquatic Park. The estimated amount of eelgrass in the Upper Bay was
estimated to be approximately 8 acres (Posjepal, 1969). See Attachment 1 which illustrates
where eelgrass was located in the Upper Bay. Comparatively, in 2003/2004, the mapped area of
eelgrass in the same vicinity was 1.2 acres and in 2006/2007, the mapped area of eelgrass
diminished to 0.001 acre (CRM Inc., 2005 and 2008).
Stephenson and Emery's work, conducted in 1950, indicated that eelgrass was "confined to
rather deep, -4 It channels with mud bottoms and to narrow fringelike patches along the main
channel. In Newport Lagoon (the fixture Newport Harbor), almost continuous expanses of this
eelgrass line the deepened channels. In the main channel, with high velocity, the bottom is swept
clean of mud, leaving coarse sand and shell. Sparse colonies are found where mud is either
beneath the shelly bottom or in small hollows of the channel." Stephenson and Emory (1958,
page 35). A California Department of Fish and Game survey of Lower Newport Bay, conducted
in 1951 (CDFG, 1953) found eelgrass fragments in several locations: the south side of Balboa
Island, the southeast corner of Balboa Island, within the Balboa Channel, the northwest side of
Balboa Channel near Harbor Island, two locations along Mariner's Mile, off of the Kerckhoff
Marine Laboratory in the entrance channel, and on the east Balboa Peninsula. Allen (1976) found
dense eelgrass beds in Newport Harbor off of Bayside Drive and in the entrance channel during
1974 and 1975 while conducting fish studies throughout Newport Bay. Locations of all of the
sites where eelgrass was reported present pre -1976 are shown in Attachment 1.
Eelgrass beds all but disappeared in Newport Bay between the late 1960s and the mid 1970s.
Although the reason for its disappearance was never conclusively determined, increased siltation,
higher turbidity, dredging, and the effects of destructive floods in 1969 likely contributed to the
disappearance of eelgrass.
Eelgrass transplants conducted along the DeAnza Peninsula did not survive in 1984 (Ware,
1993). A small subtidal eelgrass bed however, was located near the Castaways Site at a depth of
-5 ft MLLW in 1990 and 1992 (Ware, pers. obs). Eelgrass surveys conducted in Upper Newport
Bay channels between Coast Highway Bridge and Jamboree Road during December 1997 and
January 1998 immediately prior to Upper Bay dredging failed to locate any surviving eelgrass
beds (Coastal Resources Management, 1998). Eelgrass acreage in Newport Bay was roughly
estimated to be 3 acres in 1993 (Hoffman, pers. comm. in Ware, 1993). In 1999, eelgrass was
estimated to cover over 18 acres of shallow underwater habitat (CRM, 2002).
Small patches of eelgrass were located in the Dunes Marina facing Shellmaker Island during
predredge surveys in December 2004 (Chambers Group, Inc., 2005). No eelgrass was observed
in Upper Bay during extensive surveys conducted prior to the Upper Newport Bay Restoration
Project (MBC Applied Environmental Sciences, 2004) or within the Dunes Marina or Aquatic
Park in October 2007 (Chambers Group, 2007; CRM, Inc., 2007).
Bay -wide mapping surveys were conducted in 2003 -2004 and again in 2006 -2008 (CRM Inc.,
2005, CRM Inc., 2008; CRM in progress) using diving biologists and GPS technology to map
the distribution of shallow water eelgrass between bulkhead -to- pierhead lines at depths to -10 ft
MLLW. During 2003, the National Marine Fisheries Service mapped eelgrass in the deeper
portions of the entrance channel and Corona del Mar Reach using a single beam acoustic sonar
unit. In 2008, CRM, Inc. mapped eelgrass in the deeper portions of the same areas at depths
between -10 and -25 ft MLLW using sidescan sonar technology. The distribution of eelgrass in
11
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
the Bay during these surveys is summarized on Figure 5, and presented by region on Figures 6-
13. These results suggest that eelgrass acreage increased from approximately 3 acres in 1993 to
over 100 acres in 2003 -2004, and then decreased to 70.7 acres in 2006 -2008. Variation can be
high over the short term (two to three years) depending on storm events and other extrinsic
factors.
Areas of greatest eelgrass abundance in Newport Bay during 2003 -2004 included the harbor
entrance channel, and the shorelines of Corona del Mar, Balboa Island, Harbor Island / Beacon
Bay, Balboa Channel yacht and marina basins, and the channels that surrounded Linda Isle
(Areas 1 -4). Upper Newport Bay (Area 8) had a significant eelgrass meadow around the southern
one -half of the DeAnza/Bayside marsh peninsula and nearby the Castaways Site on the west side
of the Channel. Eelgrass was substantially less abundant in West Newport Bay (Areas 5, 6, and
7) along the shoreline of Mariner's Mile, Lido Isle, the Balboa Peninsula shoreline west of Bay
Island.
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and 2006 -2007 Surveys Maximum Distribution
12
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In 2003 -2004, 30.4 acres of shallow water eelgrass were mapped within the bulkhead -to -pier
head lines (CRM, Inc., 2005) and 93 acres in the deeper navigational channels between Corona
del Mar and Balboa Island (NMFS unpublished data). Some of the CRM and NMFS mapping
areas overlapped in the main channel, so the total amount in the bay was less than the 124 acres
when the data for the two surveys were summed.
The increase in eelgrass acreage in Newport Bay since 1993 may be the result of several factors:
an improvement in water clarity, highly favorable growing conditions during prolonged dry
weather years (i.e., La Nina years of low rainfall and low concentration of suspended sediments),
better management of dredge and fill projects in the last decade, increased environmental
awareness of the importance of eelgrass, and more systematic, repetitive methods of mapping
eelgrass vegetation (CRM, Inc., 2005).
CRM conducted shallow water eelgrass surveys again in 2006 -2007 (CRM, Inc., 2008) and
mapped 23.1 acres -a decline of 7.4 acres within a three -year period (Table 1). Losses occurred
primarily in Upper Bay (Area 8), in the channels surrounding Linda Isle and Harbor Island, and
along the north shoreline of Balboa Island (Area 4). While the overall loss in Newport Harbor
was 24% compared to 2003 -2004, losses in these particular regions ranged from 31 % and 100%
compared to 2003 -2004. Exceptions to the eelgrass loss patterns included both the inlet of Linda
Isle and the Grand Canal, both of which exhibited increases rather than losses. Both of these
areas are shallow, with relatively narrow openings.
CRM, Inc., using sidescan sonar methods, surveyed the deeper navigational channels originally
surveyed by NMFS (2003) and mapped 47.6 acres of eelgrass at depths between -10 and -25 ft
MLLW in Areas 1 -3 (Figures 6, 7, and 8). This represents a decrease of 46.1 acres compared to
the NMFS 2003 survey results. This may be reflective of differences in survey methods used and
data interpretation (single beam sonar vs sidescan sonar) or an actual loss of eelgrass. Two large
sections of the navigation channel contained eelgrass: the harbor entrance channel and the main
channel between Corona del Mar and Balboa Island. However, the recent CRM surveys, using
sidescan sonar technology, were ground- truthed by divers and remote video methods that
provided a high degree of confidence in the data and the interpretation of the sidescan sonar
records.
The distribution of eelgrass appears to be heavily influenced by the amount of time it takes to
fully flush the bay based upon tidal flushing rates (Figures 14, 15a and 15b, and 16). Longer
periods between complete tidal flushing reduces water quality by increasing water temperatures,
lowering dissolved oxygen, and increasing the length of time that suspended sediments prevent
light from illuminating the seafloor. The reduction in eelgrass area observed during the 2006-
2007 survey was likely related to overlapping factors: tidal flushing rates combined with region -
wide rainfall and runoff events that occurred during late 2004 and Winter 2005 period, which
was one of the wettest rainfall years on record. In addition, heavy plankton blooms were present
in the harbor during Spring and Summer 2005 (R. Ware, pers. observations). Eelgrass losses
were associated with increased suspended material that remained in the harbor for long periods
following extremely heavy rainfall in areas where tidal flushing rates exceeded six to eight days
(Figure 16) and secondly, prolonged reduced light levels due to heavy plankton blooms.
21
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
The pattern of eelgrass habitat loss around Linda Isle and Harbor Island may also suggest that
events related to Upper Bay restoration activities such as dredge -scow and tug movement
through Newport Harbor may have created higher than normal suspended sediment loads in
areas of low tidal flushing rates over the last few years (Figure 14). While in the long run, Upper
Newport Bay restoration activities will benefit eelgrass. In the short term however, secondary
effects related to dredging have a potential for limiting eelgrass recovery in Lower Bay and near
the PCH Bridge in Upper Newport Bay.
The one exception where eelgrass has not receded is Linda Isle basin where eelgrass has actually
increased in acreage compared to 2003. This area may have been excluded from effects of
rainfall events and higher turbidity in 2004 -2005, and increased turbidity from dredge scow
movement because of the physiographic setting of the area; the entrance to the basin is relatively
narrow, it has a single entrance opening, and the tidal current flows from Upper Newport Bay
pass perpendicular to the opening to the basin. It is atypical compared to other areas of high
eelgrass abundance because the tidal residence time in Linda Isle basin is more typical of areas
that do not support extensive eelgrass beds, and sediments are extremely high in silt (96 %)
compared to other areas that support eelgrass.
22
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
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Hushing time scale (days)
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Figure 14. Tidal Flushing Rates in Newport Bay
24
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
Source: CRM, Inc., 2008
Figure 15. Relationships between Eelgrass Acreage and Tidal Residence Times in Newport
Bay, 2003 -2004 and 2006-2007
25
Relationship Between Eelgrass Acreage and Tidal Residence Time In Newport Bay. 2003 -2004
(n =17 eelgrass regions)
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Figure 15. Relationships between Eelgrass Acreage and Tidal Residence Times in Newport
Bay, 2003 -2004 and 2006-2007
25
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
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2003 and 2007 )m17 eelgrass regions)
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Figure 16. Relationships between Eelgrass Habitat Loss and Tidal Residence Times in
Newport Bay, 2003 -2007
Based upon these studies, eelgrass distribution in Newport Harbor can be divided into three
zones: a Stable Eelgrass Zone that includes areas where tidal flushing is between approximately
zero and six days; a Transitional Zone where eelgrass acreage is susceptible to large -scale
variability and tidal flushing is approximately seven to 14 days; and an Unvegetated Eelgrass
Zone where tidal flushing ranges between 14 days and 30 days and the amount of eelgrass
present is either insignificant or lacking.
Eelgrass within the Stable Eelgrass Zone provides longer -term critical habitat for more
organisms than within the Transitional Eelgrass Zone, where organisms are highly susceptible to
short-term and long -term losses of vegetation. Stable Eelgrass Zone shallow water acreage based
on the average of the two bay -wide eelgrass habitat mapping surveys is approximately 20 acres
and 47 acres of deeper channel eelgrass (based on the 2008 deeper channel surveys. Shallow
water Transitional Eelgrass Zone habitat, on the other hand, accounts for approximately 10 acres
of eelgrass and no deeper channel eelgrass habitat exists in the Transitional Eelgrass Zone.
Eelgrass Turion Density — A turion is an above ground unit of eelgrass growth that consists of
an eelgrass shoot and associated eelgrass blades. Eelgrass density refers to the number of turion
units per area of bayfloor. Turion density can be highly variable as a result of water temperature,
water currents and tidal exchange rates, sediment characteristics, light availability, and water
depth. A combination of low and high density canopy, and open patches of unvegetated sediment
may contribute to a greater diversity of organisms and a more complex ecological system.
26
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
Stable Eelgrass Zane
Transitional Eelgrass Zone
WNegetaled Eelgrass Zone
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Figure 17. Eelgrass Habitat Zones in Newport Bay
For example, open, unvegetated areas in eelgrass beds are frequented by demersal (bottom)
fishes such as sand bass, staghorn sculpin, turbot, California halibut, and round stingray. Some
disrupt the bottom sediments (bioturbation) and create their own open habitat in eelgrass beds as
they forage in the muds (Merkel, 1990). Dense, long - bladed canopy will provide a greater degree
of protection and shelter for cryptic, resident species (canopy- associated pipefish and kelpfish),
and shelter or foraging habitat for transients (surfperch and topsmelt).
Mean turion density in Newport Bay eelgrass meadows during late Spring to Summer 2004
period was 231.2 turions per sq in (n =600 replicates) (CRM Inc., 2005). By sampling area, turion
density ranged between 102.3 (Orange Coast College Boat Basin) to 323.4 per sq in (Outer
DeAnza Peninsula). In most areas of Newport Bay, eelgrass turion density exhibited a significant
negative correlation to sampling depth (t =2.8, 12 deg freedom, r2 = 0.72). While this is true for
most areas, deeper areas with better water clarity near the ocean entrance channel support higher
density eelgrass beds than regions farther back in the harbor at similar depths (i.e., Lido Yacht
Club and the Orange Coast College Boat Basin).
In 2008, Newport Bay eelgrass turion density was 136.1 turions per sq in (n=415 replicates;
CRM Inc., in progress), which is 60% of the average density observed in Newport Bay in 2004
and ranged between no eelgrass (where it previously was present) to 234.8 turions per sq in
along Corona del Mar shoreline. Substantial density decreases occurred at stations in the
Transitional Eelgrass Zone; five of the sampling stations in 2004 lacked eelgrass in 2008 (two in
Upper Newport Bay, at Lido Yacht Club, and within the Orange Coast College boat basin).
27
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
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Harbor Area Management Plan
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2.4 Eelgrass Regulatory Overview
Environmental legislation under the National Environmental Policy Act (NEPA) and State of
California Environmental Quality Act (CEQA) dictates that project designs for coastal projects
(1) make all possible attempts to avoid impacts to eelgrass, (2) minimize the degree or magnitude
of impacts, (3) rectify, or compensate for unavoidable eelgrass habitat losses by restoring soft
bottom habitat with eelgrass using transplant techniques, and (4) reduce or eliminate impacts to
eelgrass over time by preservation and maintaining eelgrass over the life of the project. Eelgrass
is considered a protected resource by California Department of Fish and Game, U.S. Fish and
Wildlife Service, and the National Marine Fisheries Service although it does not have a formal
listing as a state or federal rare, sensitive, endangered, or candidate species.
2.4.1 Clean Water Act
Eelgrass, as a vegetated shallow water habitat, is protected under the Clean Water Act, 1972 (as
amended), section 404(b)(1), "Guidelines for Specification of Disposal Sites for Dredged or Fill
Material ", subpart E, "Potential Impacts on Special Aquatic Sites." This area includes sanctuaries
and refuges, wetlands, mudflats, vegetated shallows, coral reefs, riffle, and pool complexes.
2.4.2 Magnuson— Stevens Fishery Management and Conservation Act (FR 62,
244, December 19, 1997 — Essential Fish Habitat and Habitats of Particular
Concern
Newport Harbor and Upper Newport Bay are estuarine and eelgrass habitats, which are
considered habitat areas of particular concern (HAPC) for various federally managed fish species
within Coastal Pelagic (i.e., northern anchovy) and Pacific Groundfish Fisheries Management Plans
(IMP), (i.e., rockfishes) under Essential Fish Habitat (EFH) provisions of the 1996 amendments
to the Magnuson— Stevens Fishery Management and Conservation Act (FR 62, 244, December
19, 1997).
EFH is defined as "those waters and substrate necessary to fish for spawning, breeding, feeding,
or growth to maturity". An adverse effect is "any impact which reduces the quality and/or
quantity of EFH." Adverse effects may include direct or indirect physical, chemical, or
biological alterations of the waters or substrate and loss of or injury to benthic organisms, prey
species, and their habitat, and other ecosystem components. Adverse effects may be sites specific
or habitat -wide impacts, including individual, cumulative, or synergistic consequences of actions
(50 CFR 600.910(a)).
HAPC are described in the regulations as subsets of EFH which are rare, particularly susceptible
to human induced degradation, especially ecologically important, or located in an
environmentally stressed area. Designated HAPC, including eelgrass, are not afforded any
additional regulatory protection under the Magnuson— Stevens Fishery Conservation and
Management Act (1997). However, federally permitted projects with potential adverse impacts
to HAPC are more carefully scrutinized during the consultation process (National Marine
Fisheries Service, 2008).
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2.4.3 Southern California Eelgrass Mitigation Policy
Mitigation for impacts to celgrass bed vegetation and potential celgrass habitat is addressed in
the Southern California Eelgrass Mitigation Policy (NMFS, 1991 as amended, Revision 11).
This document provides the current standards for all mitigation projects and includes information
regarding habitat replacement ratios, timing and methods for celgrass habitat mapping surveys,
eelgrass transplants, monitoring and maintenance, and success criteria. Eelgrass management is
on a project -by- project basis, so that individual homeowners and applicants are responsible for
implementing surveys, assessing project impacts, conducting transplants, and monitoring
transplants for a five -year period. This policy is described in more detail in Section 4.1.1.
2.4.4 California Department of Fish and Game Regulations. 2008 Department of
Fish and Game Ocean Fishing Regulations. Section 4 Ocean Fishing
30.00. Kelp General — (a) Except as provided in this section and in Section 30.10 there is no
closed season, closed hours or minimum size limit for any species of marine aquatic plant. The
daily bag limit on all marine aquatic plants for which the take is authorized, except as provided
in Section 28.60, is 10 pounds wet weight in the aggregate. (b) Marine aquatic plants may not be
cut or harvested in state marine reserves. Regulations within state marine conservation areas and
state marine parks may prohibit cutting or harvesting of marine aquatic plants per subsection
632(b). 30.10. Prohibited Species. No eelgrass (Zostera), surf grass (Phyllospadix), or sea palm
(Postelsia) may be cut or disturbed.
2.4.5 California Code of Regulations, Title 14, 650. Natural Resources. Division 1.
Fish and Game Commission — Department of Fish and Game. Subdivision
3, General Regulations. Chapter 1. Collecting Permits
(a) General — Except as otherwise provided, it is unlawful to take or possess marine plants, live
or dead birds, mammals, fishes, amphibians, or reptiles for scientific, educational, or propagation
purposes except as authorized by a permit issued by the department.
2.4.6 City of Newport Beach Local Coastal Plan
The City of Newport Beach has an adopted, Coastal Commission- approved land use plan (LUP).
The LUP acknowledges that the need to maintain and develop coastal- dependent uses may result
in impacts to eelgrass:
"Dredging and dock and bulkhead construction projects have a potential to impact eelgrass
resources within several areas of Newport Bay through direct habitat loss or secondary effects of
turbidity or vessel anchor scarring. However, ongoing maintenance of harbor structures and
periodic dredging is essential to protect Newport Harbor's value as a commercial and
recreational resource. A comprehensive and balanced management plan is necessary to maintain
the recreational and commercial uses of the harbor while protecting its natural marine
resources..." LUP at 4 -40.
To mitigate the potential impacts to eelgrass of dredging and development, the LUP requires the
avoidance where possible and restoration where avoidance is not practical:
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"Avoid impacts to eelgrass (Zostera marina) to the greatest extent possible. Mitigate losses of
eelgrass at 1.2 to 1 mitigation ratio and in accordance with the Southern California Eelgrass
Mitigation Policy. Encourage the restoration of eelgrass throughout Newport Harbor where
feasible." LUP Policy 4.2.5 -1.
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KIII=«111VV=1ki 1191y:r_1444► CC] 4:1 fell :'I r_1 3116y:11MCIMI' Mr_II►r_l3114
EELGRASS POPULATIONS IN NEWPORT HARBOR
The most critical challenges to eelgrass populations and their establishment are (1) the presence
of availability of suitable intertidal and subtidal soft- bottom habitat (2) maintaining adequate
water quality and underwater light conditions to promote eelgrass growth and health and (3)
maintaining a balance between the natural resources within Newport Harbor with the uses of
Newport Harbor as a viable recreational boat harbor so that the areal cover and health of eelgrass
vegetation continues to serve an important function as a habitat for marine life.
These challenges are particularly important because eelgrass mitigation projects cannot be
successful unless specific habitat requirements are met for the establishment and growth of
eelgrass. In addition, biodiversity associated with eelgrass beds is directly influenced by the
conditions that govern eelgrass growth and habitat characteristics. Dredging, bulkheading, and
other waterside infrastructure projects affect the abundance and distribution of eelgrass through
direct losses (i.e., removal or burial) and secondarily, light - limitations through sediment
resuspension and construction of structures that impede light from reaching the bayfloor.
Infrastructure projects are undertaken as federal, state, local agency projects, or individual
resident's projects that don't qualify under the City's Regional General Permit (RGP) 54 due to
the presence of eelgrass within 15 ft of their docks, bulkhead, piers, or beach nourishment
projects. If residents do not quality for inclusion in the RGP, they are responsible for individually
obtaining the necessary state and federal permits from the regulatory agencies.
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4.0 DEVELOPING AN EELGRASS MANAGEMENT PLAN
Current and future harbor infrastructural improvement projects such as maintaining safe
navigable waters, the renovation and construction of piers, docks, seawalls, and replenishing the
harbor's beaches will affect the distribution and abundance of eelgrass and will require programs
to compensate for eelgrass habitat losses. Thus, understanding governing regulations, the
constraints for eelgrass success in various regions of the bay, and identifying specific mitigation
options for eelgrass losses are important to review.
4.1 Current Guidelines for Conducting Eelgrass Transplants
The Southern California Eelgrass Mitigation Policy (SCEMP) (NMFS, 1991 as amended) is the
basis for current eelgrass mitigation throughout the Southern California region.
Eelgrass transplants "shall be considered only after the normal provisions and policies regarding
avoidance and minimization, as addressed in the Section 404 Mitigation Memorandum of
Agreement between the Corps of Engineers and Environmental Protection Agency, have been
pursued to the fullest extent possible prior to the development of any mitigation program.
Mitigation will be required for the loss of existing vegetated areas, loss of potential eelgrass
habitat, and /or degradation of existing /potential eelgrass habitat as well as for boat docks and/or
related work" (NMFS, 1991 as amended).
The policy requires that eelgrass habitat losses be successfully mitigated at a 1.2:1 mitigation -to-
impact ratio (i.e., successful mitigation over a period of five years requires an additional 20%
more eelgrass habitat than the amount originally impacted by the project). Also, the policy
defines the methods by which eelgrass transplants will be conducted, despite the possibility that
other, more cost - effective and efficient methods have been developed since the inception of the
SCEMP.
The SCEMP does recognize that "There may be circumstances (e.g., climatic events) where
flexibility in the application of this Policy is warranted. As a consequence, deviations from the
stated Policy may be allowed on a case -by -case basis.
4.1.1 Current Specific Mitigation Success Criteria from the Policy (NMFS 1991 as
amended)
Criteria for determination of transplant success shall be based upon a comparison of vegetation
coverage (area) and density (turions per square meter) between the adjusted project impact
area (i.e., original impact area multiplied by 1.2) and mitigation site(s). Extent of vegetated
cover is defined as that area where eelgrass is present and where gaps in coverage are less than
one meter between individual turion clusters. Density of shoots is defined by the number of
turions per area present in representative samples within the original impact area, control or
transplant bed. Specific criteria are as follows:
a) The mitigation site shall achieve a minimum of 70% area of eelgrass and 30% density as
compared to the adjusted project impact area after the first year.
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b) The mitigation site shall achieve a minimum of 85% area of eelgrass and 70% density as
compared to the adjusted project impact area after the second year.
c) The mitigation site shall achieve a sustained 100% area of eelgrass bed and at least 85%
density as compared to the adjusted project impact area for the third, fourth and fifth
years.
Should the required eelgrass transplant fail to meet any of the established criteria, then a
Supplementary Transplant Area (STA) shall be constructed, if necessary, and planted. The size
of this STA shall be determined by the following formula:
STA = MTA x (At + Dtl - IA, + D,p
MTA = mitigation transplant area.
At = transplant deficiency or excess in area of coverage criterion ( %).
Dt = transplant deficiency in density criterion ( %).
A� = natural decline in area of control ( %).
Dc = natural decline in density of control ( %).
The STA formula shall be applied to actions that result in the degradation of habitat (i.e., either
loss of areal extent or reduction in density).
Five conditions apply:
1) For years 2 -5, an excess of only up to 30% in area of coverage over the stated criterion
with a density of at least 60% as compared to the project area may be used to offset any
deficiencies in the density criterion.
2) Only excesses in area criterion equal to or less than the deficiencies in density shall be
entered into the STA formula.
3) Densities which exceed any of the stated criteria shall not be used to offset any
deficiencies in area of coverage.
4) Any required STA must be initiated within 120 days following the monitoring event that
identifies a deficiency in meeting the success criteria. Any delays beyond 120 days in the
implementation of the STA shall be subject to the penalties as described in Section 8.
5) Annual monitoring will be required of the STA for five years following the
implementation and all performance standards apply to the STA.
Eelgrass transplant programs cannot be conducted within areas where eelgrass has occurred in
the past or where it currently is present since the transplant would only be considered "habitat
enhancement' by National Marine Fisheries Service (Bryant Chesney, NMFS per. com to R.
Ware, April, 2007). Therefore, eelgrass transplants for mitigation purposes must be conducted at
sites where eelgrass has historically not been present or in areas `created" within Newport Bay
by dredging or in- filling of bay habitat to depth ranges and with sediment types that are known to
support eelgrass vegetation.
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4.1.2 Eelgrass Mitigation Success in Newport Bay
Eelgrass mitigation was initiated in the late 1970s and early 1980s in Newport Bay. These have
taken place in the Harbor Entrance Channel for U.S. Army Corps of Engineers dredging projects
(Noel Davis, Chambers Consultants, pers. com. with R. Ware, January 2008); on De Anza
( Bayside) Peninsula in Upper Newport Bay as mitigation for eelgrass losses in Huntington
Harbour (MBC Applied Environmental Sciences, 1987) and for the 2004 U.S. Army Corps of
Engineers Harbor Entrance Channel / Balboa Channel Dredge Project (MBC Applied
Environmental Sciences, 2004); for a pier and dock project at a private residence on Bayside
Drive (Mike Curtis, MBC Applied Environmental Sciences, pers. com. with R. Ware, 1998); and
in the Grand Canal on Balboa Island for losses associated with dredging and seawall protection
in 1999 (CRM, Inc., 2000). In addition, under a joint program conducted by the City of Newport
Beach, the U.S. Army Corps of Engineers, and the County of Orange, a Newport Harbor
Eelgrass Pilot Restoration Project was undertaken by Chambers Group, Inc. and CRM, Inc. in
August and September 2004 under Section 206 of the Water Resources Development Act (1996).
Six sites in Lower and Upper Newport Bay were experimentally transplanted to determine if
these sites could be used as eelgrass mitigation banking sites for future federal, city, and county
eelgrass mitigation projects. These were undertaken in Transitional Eelgrass Zones of the harbor.
Of the major eelgrass transplant projects conducted in Newport Bay since 1982 only three were
successful; all were conducted within the Stable Eelgrass Zone (Figure 16). These included the
1982 entrance channel transplant, the 1998 Bayside Drive (Corona del Mar) transplant, and the
1999 Grand Canal eelgrass transplant. The remaining transplants were successful for less than
one year. Because there were no concurrent studies abiotic parameters at the successful or
unsuccessful transplant sites, there are no clear indications of the physical, chemical, or
biological conditions that were responsible for either success or failure. However, the failure of
the City of Newport / County of Orange / ACOE pilot eelgrass transplants was likely attributable
to heavy rains in the months following the transplants, extremely warm temperatures during the
late- season planting period, and the long tidal residence times that diminish water quality in the
areas that were transplanted.
Eelgrass is capable of recovering from habitat disturbances without mitigation measures being
implemented. For example, following a dredging project in the Grand Canal during the mid -
1980s, eelgrass successfully recolonized the area (R. Ware, pers. com with Robert Hoffman).
After dredging the Balboa Channel in 2004, eelgrass was reported to have naturally grown back
on the dredged slope (R. Ware, pers. com. with Tom Rossmiller, City of Newport Beach Harbor
Resources Department). Alternatively, it is possible that patches of eelgrass were left untouched
during the dredging operation.
4.2 Eelgrass Threshold Capacity
Eelgrass threshold capacity can be defined as the acreage of eelgrass within Newport Bay that is
sustainable over time taking into account short-term and long -term temporal and spatial
variability. The goal of identifying eelgrass threshold capacity is to provide harbor resource
managers a tool by which to evaluate appropriate long -term eelgrass mitigation options relative
to future maintenance of harbor infrastructure.
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Projects such as maintenance dredging, beach nourishment, dock and bulkhead renovation
projects that are within bulkhead and pierhead lines are generally accomplished on an
incremental basis, account for the majority of harbor infrastructure projects, and have a high
potential to affect eelgrass habitat stability on a year -to -year basis in Newport Bay.Based upon
the results of bay -wide shallow water habitat mapping surveys between 2003 and 2007 (CRM
Inc., 2005 and CRM, Inc.,2008) the "average threshold capacity" (the average amount of
eelgrass mapped in the 2003/2004 and 2006/2007 surveys) in Stable Eelgrass Zones was
approximately 20.4 acres. This zone exhibited very little variation between surveys (20 acres in
2003/2004 and 21 acres in 2006/2007). Transitional Eelgrass Zones, where eelgrass habitat is
more susceptible to temporal and environmental disturbances than Stable Eelgrass Zones,
accounted for an average eelgrass threshold capacity of approximately 6.3 acres, with a range
between 2.2 (2006/2007) and 10.4 acres (2003 /2004).
Eelgrass in the deeper channels of Newport Harbor are susceptible to less frequent episodic
dredging impacts but when dredging occurs, the potential for wide -scale damage to dense and
large eelgrass meadows is high. Based on the most recent 2008 survey data set, the threshold
capacity of eelgrass in the federal navigational channel is approximately 47 acres
These estimates of eelgrass threshold capacity can be refined, over time, with additional data
acquired from bay -wide eelgrass distributional studies.
4.3 Recommended Areas in Newport Bay to Create A Sustainable
Eelgrass Population (SEP)
While eelgrass occurs throughout many regions of Newport Bay, its structure and function varies
widely from region -to- region and from year to year. Mitigation for losses of eelgrass habitat
must be focused in areas where suitable habitat requirements are met for size of the habitat,
sediment types, depth, and light intensity) and where eelgrass will survive and flourish over the
long term.
Based on the historical distribution changes of eelgrass in Newport Bay, on the results of
eelgrass mitigation successes and failures, and the realization that the amount of habitat that meet
eelgrass establishment and growth criteria in Newport Bay is extremely limited, high priority
should be given to maintaining and creating a sustainable eelgrass population (SEP) in the Stable
Eelgrass Zone (Figure 17) . The long -term potential for successful eelgrass population
sustainability is highest in this zone, where tidal residence times are less relatively short (less
than six days), tidal currents are moderate to high, and there is a history of long -term eelgrass
sustainability with minimal year -to -year natural variation
Conversely, maintaining sustainable eelgrass populations in the Transitional Zone is difficult.
Creating eelgrass populations in this zone increases the risk of failure because this zone is
susceptible to large -scale natural variability due to episodic events such as El Nino and the
effects of extremely heavy rainfall and runoff (which occurred in 2004 and 2005). And, in these
areas where tidal residence times are already decreased, events such as plankton blooms can
push the light threshold limits below that which can sustain eelgrass reproduction, growth, and
survival. The potential for the highest risk of mitigation failure is within the Unvegetated
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Eelgrass Zone where tidal flushing ranges between 14 days and 30 days and where virtually no
eelgrass is currently found.
4.4 Development and Implementation of a Long -Term Eelgrass
Management Plan
Eelgrass within both the Stable Eelgrass Zone and the Transitional Eelgrass Zone will be
continually susceptible to infrastructure improvements within Newport Harbor. Consequently, it
is in the interest of the City to develop and implement a long -term Eelgrass Management Plan to
maintain and create a sustainable eelgrass population (SEP) where eelgrass populations have the
highest potential for long -term survival.
The City of Newport Beach would be responsible for developing, overseeing, and enforcing
compliance with the Eelgrass Management Plan, and be responsible for eelgrass surveying,
implementing programs to establish eelgrass populations, monitoring the success of the
programs, and conducting periodic, baywide eelgrass surveys. Under such a concept, the City
would protect and promote a shallow water eelgrass population and as long as the sustainable
eelgrass population is above 20 acres, no more than 2 acres of eelgrass impacts would be
permitted per year conditioned on compliance with best management practices (BMPs) for
avoiding eelgrass disturbance where possible. Should the shallow water eelgrass population drop
below 20 acres, increased mitigation measures and decreased allowable annual impacts will be
implemented in a phased manner.
The purpose of the BMPs would be three -fold: (1) To avoid and minimize damage to existing
eelgrass bed resources. Such BMPs would include reviewing the need for beach nourishment,
dredging and dock projects, identifying alternatives that would minimize impacts on eelgrass;
using Best Available Technology (BAT) to minimize dredging and dock construction effects;
using materials on docks and piers that could promote eelgrass growth beneath these structures;
(2) Educate boat owners and property owners as to the importance of eelgrass within Newport
Harbor so that they take "ownership" in their project and view eelgrass as a positive outcome of
their project; and (3) Maintaining and creating a sustainable eelgrass population in the Stable
Eelgrass Zone should the threshold value of eelgrass populations in Newport Harbor fall below
the minimum amount of 20 acres.
Close coordination will be needed between the City of Newport Beach, the Department of Fish
and Game, and the National Marine Fisheries Service to develop special conditions that will be
effective in making the Newport Beach Long -Term Eelgrass Management Plan a success, and at
the same time, responsive to agency concerns.
To achieve this goal, eelgrass sustainability populations should be maintained and if needed,
eelgrass sustainability areas created for future public and private sector projects in Newport
Harbor. The concept would involve (1) maintaining a base amount of eelgrass based upon
identified eelgrass threshold capacity measurements and using BMPs to ensure this threshold
capacity is maintained, (2) implementing programs to maintain and establish sustainable eelgrass
populations in areas affected by disturbances, or into the created habitat using innovative and
cost - efficient methods if necessary to maintain a critical eelgrass mass (20 acres), and (3)
monitoring over the long term, the success of the sustainable eelgrass population.
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Traditionally, eelgrass transplants for small to medium -sized projects have been conducted by
using an anchor - bundle method by which eelgrass is collected from donor sites, bundled into
units, and then replanted by divers in predetermined planting grids (Fonseca et al., 1982).
However, for large -scale mitigation and restoration projects (on the order of small to large
projects it may be necessary to utilize alternative transplant methodologies using eelgrass seed
banks and seed dispersal methods (Granger et al., 2002) that will have less environmental
impacts than collecting large amounts of eelgrass donor material. Safety concerns for deploying
teams of divers to conduct eelgrass transplant using the anchor /bundle method may also require
the implementation of alternative transplant methodologies such as the remote deployment of
prefabricated eelgrass structural units (Short et al., 2002). Labor costs can potentially be reduced.
Such experimental programs have been initially established for San Francisco Bay (Michael
Josselyn, Wetland Research Associates, Inc. pers. com with R. Ware, March 2008). Due to the
expected large size of the mitigation site, transplant methodologies should be evaluated and
tested within Newport Bay prior to the creation of the shallow water habitat to determine the
most effective and cost - efficient methods to employ for large -scale eelgrass transplants.
If needed, sustainable eelgrass population could be established in the Stable Eelgrass Zone
(Figures 17 and 19). For example, the deeper channel waters beneath Mooring Area B seaward
of the southern perimeter of Balboa Island encompass a maximum of approximately 28 acres of
bayfloor that could be modified to support a sustainable eelgrass population(Figure 19) although
several sites within the Stable Eelgrass Zone could be utilized for this purpose. Being within the
Stable Eelgrass Zone, this site exhibits good water circulation, and the nearby shoreline along
South Bay Front is colonized by high eelgrass cover. While depths within this area are currently
too deep to support eelgrass, a selected site(s) could be engineered to provide for (1) long -term
stability from the effects of sediment scour and/or sediment deposition, (2) appropriate depth
ranges to support a sustainable eelgrass population, and (3) adequate depths to maintain safe
navigation and boating. The creation of new shallow -water habitat in the harbor would also
present an opportunity to establish both a confined disposal site to manage contaminated, dredge
sediments from Newport Bay dredging projects as well as maintain a sustainable eelgrass
population. Similar sites have been created in San Diego Bay near North Island Naval Air
Station (Pondella et al., 2006). A 40+ acre shallow water eelgrass mitigation site is proposed
within Outer Los Angeles Harbor as mitigation for loss of shallow water habitat associated with
the Port of Los Angeles Pier 300 project.
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Figure 19. Potential Eelgrass Sustainability Locations in the Stable Eelgrass Zone
4.5 Steps Forward
1. Identify appropriate needs relative to future watershed and harbor activities to
gauge the extent of required sustainable eelgrass management. Develop an
ecosystem approach Eelgrass Management Plan (EMP) rather than managing
eelgrass project on an incremental basis.
2. Meet with stakeholders and identify concerns, constraints, and permitting issues
based on what will be required for future dredging and infrastructure
improvements in Newport Harbor. It will be critical to assess the environmental
permitting and fiscal constraints of the program early on to assess the ability of the City
to implement an Eelgrass Management Plan. Early agency involvement with the Coastal
Commission, U.S Army Corps of Engineers, State Lands Commission, State Water
Resources Control Board, and resource agencies (NMFS, USFWS, and CDFG) is critical
to ensure that there is sufficient agency understanding and support for such a critical
undertaking.
3. The EMP will promote a system -based approach; the key metric of eelgrass
protection is the maintenance of a sustainable shallow water eelgrass population of
at least 20 acres. The focus of the City's management will be to protect and promote
shallow water eelgrass populations and as long as the sustainable eelgrass population is
above 20 acres, no more than 2 acres of eelgrass impacts will be permitted per year
conditioned on compliance with best management practices for avoiding eelgrass
disturbance where possible. Should the shallow water eelgrass population fall below 20
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acres, increased mitigation measures and decreased allowable annual impact will be
implemented in a phased manner.
4. The City of Newport Beach will assume lead responsibility for the preparation and
implementation of the Eelgrass Management Plan. The City will enforce compliance
with the plan, subject to agency oversight. Consistent with its management role, the City,
rather than individual residents, will be responsible for surveying and data gathering,
while relieving individual property owners of a burden they generally lack the expertise
to effectively carry.
5. The City will of Newport Beach will identify primary and alternative locations in
the Stable Eelgrass Zone capable of supporting the maximum amount of sustainable
eelgrass required for future projects should it be necessary to create additional
Stable Eelgrass Zone eelgrass populations. Conduct coastal engineering and marine
biological surveys to identify those areas with the Stable Eelgrass Zone that have a
potential to be utilized for mitigation bank sites. Conduct side scan sonar mapping
surveys, physical modeling, and field studies in potential sustainable eelgrass areas to
evaluate erosion, sedimentation, and other process that will be required to refine site
selection.
6. The City will prepare a draft Eelgrass Management Plan (DEMP) and negotiate a
Final Stable Eelgrass Zone Management Plan (FEMP) with the National Marine
Fisheries Service, the California Department of Fish and Game, the U.S. Army
Corps of Engineers, and the California Coastal Commission. Upon completion of the
FEMP, the City shall commence review of the plan for consistency with provisions of the
City of Newport Beach Local Coastal Plan and the Regional General Dredging Permit
(RGP).
7. Once in place, the City will implement and manage the FEMP. Following
implementation, the City will review the success of the EMP at five -year intervals to
determine the effectiveness of the program, identify any required changes to the
program, and implement if necessary, adaptive management to ensure the key
program metrics are being met.
8. Establish an Eelgrass Management Plan Website. Lastly, the City should consider
establishing a website that will track project implementation and achievement of key
metrics for public review. This will also assist the City in providing suggested public
educational outreach for the project
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5.0 REFERENCES
Allen, L. A. 1976. Abundance, Diversity, Seasonality and Community Structure of the Fish
Populations of Newport Bay, California. M.S. Thesis, California State University,
Fullerton. 108 pp.
Backman, T.W. and D. C. Barilotti 1976. Irradiance and reduction: Effects on standing crops
of the eelgrass Zostera marina in a coastal lagoon. Mar. Biol. (Berl) 34:33 -40.
Barnard, J. L., and D. J. Reish 1959. Ecology of Amphipoda and Polychaeta of Newport Bay,
California. Allan Hancock Foundation Publication. Occasional Paper No. 21. 106 pp.
Beal, J. L. and B. S. Schmit. 2000. Chapter 4. The effects of dock height on light irradiance
(PAR) and seagrass (Halodule wrightii and Syringodium filiforme) cover. Pages 43 -63
in: Stephen A. Bortone, PhD, ed. Seagrasses: Monitoring, Ecology, Physiology, and
Management. CRC Press, Boca Raton. 318 pp.
CDFG (California Department of Fish and Game). 1953. Biological survey: Lower Newport
Bay. Report to the Santa Ana Regional Water Pollution Control Board. Feb 10, 1953.
Code No. 58 -8 -8.
Chambers Group, Inc. and Coastal Resources Management. 1998. Pre - dredging eelgrass survey
in Lower Newport Bay. Prepared for the U.S. Army Corps of Engineers. Los Angeles
District. 15 pp. plus figures and appendices.
Chambers Group, Inc. and Coastal Resources Management. 1999. Lower Newport Harbor
eelgrass restoration project field reconnaissance report. Prepared for the U.S. Army
Corps of Engineers. Los Angeles District. 18 pp. plus figures and appendices. August
1999.
Chambers Group, Inc. 2005. Newport Dunes eelgrass survey, December 2004. Prepared for
Moffatt & Nichol Engineers. February 2005.
Chambers Group, Inc. 2007. Newport Dunes eelgrass, Caulerpa, and oyster survey. Prepared
for Moffatt & Nichol Engineers. November 2007.
Coastal Resources Management, Inc. (CRM) 1999. Grand Canal post - dredging eelgrass impact
analysis. Prepared for the City of Newport Beach Public Works Department. May 3`a
1999.
Coastal Resources Management, Inc. (CRM) 2002. City of Newport Beach Local Coastal
Plan. Biological Appendix. Prepared for the City of Newport Beach Planning
Department. Various Paging. December 2002.
Coastal Resources Management, Inc. (CRM) 2005. Final report. Distribution and abundance of
eelgrass (Zostera marina) in Newport Bay. 2003 -2004 eelgrass habitat mapping
project. Bulkhead to pierhead line surveys. Prepared for the City of Newport Beach
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Harbor Resources Division. April 2005. 30 pp. Maps on the City website:
http: / /www6.city.newport- beach .ca.us /website /InteractiveMap /map. asp
Coastal Resources Management, Inc. (CRM) 2008. Distributional maps of eelgrass (Zostera
marina) in Newport Bay. 2006 -2008 eelgrass habitat mapping project. Shallow water
(bulkhead to pierhead line surveys) and deeper channel survey results. Prepared for the
City of Newport Beach Harbor Resources Division and the City of Newport Beach GIS
Department. Maps on the City website:
http: / /www6.city.newport- beach. ca .us /website /InteractiveMap /map. asp
Coastal Resources Management, Inc. (CRM). (In Progress). Eelgrass (Zostera marina)
distribution and abundance in Newport Bay and abiotic influences on its distribution,
2003 -2009. In preparation under contract to the City of Newport Beach Harbor
Resources Department.
County of Orange, 2003. Report of the Regional Monitoring Program for the Newport By /San
Diego Creek Watershed Nutrient TMDL (Resolution No 98 -0 as amended by Resolution
No 90 -100. Prepared with the Cities of Irvine, Tustin, Newport Beach, Lake forest,
Santa Ana, Orange, Costa Mesa, and the Irvine Company and the Irvine Ranch Water
District. November 2004. 99 pp.
County of Orange, 2004. Report of the Regional Monitoring Program for the Newport By /San
Diego Creek Watershed Nutrient TMDL (Resolution No 98 -0 as amended by Resolution
No 90 -100. Prepared with the Cities of Irvine, Tustin, Newport Beach, Lake forest,
Santa Ana, Orange, Costa Mesa, and the Irvine Company and the Irvine Ranch Water
District. November 2004. 82 pp.
County of Orange, 2004. Report of the Regional Monitoring Program for the Newport By /San
Diego Creek Watershed Nutrient TMDL (Resolution No 98 -0 as amended by Resolution
No 90 -100. Prepared with the Cities of Irvine, Tustin, Newport Beach, Lake forest,
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45
Harbor Area Management Plan
Eelgrass Capacity and Management Tools Technical Report June 2009
ATTACHMENT 1
SITE LOCATION MAP WHERE EELGRASS WAS RECORDED PRIOR TO 1976
Source: CRM, Inc.
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