draft eelgrass protection

Draft Eelgrass Protection & Management Plan (EPMP) for

Richardson’s Bay

Coastal Policy Solutions

coastalpolicysolutions.comPresentation by: Rebecca Schwartz Lesberg, President, Coastal Policy SolutionsPresentation to: Richardson’s Bay Regional Agency (RBRA) Board of Directors

http://coastalpolicysolutions.com


Outline:• About Richardson’s Bay (RB)• Environmental importance of eelgrass• Existing boundaries in RB• What is the EPMP? Why are we doing it?• What is in the draft report?• EPMP Framework

• Development of the EPMP• Summary of stakeholder feedback• Spatial Analysis• Plan Elements – Proposed Eelgrass

Protection Zone; monitoring and adaptive management; future moorings

• Final thoughts/next steps• Discussion


About Richardson’s Bay• 3,000-acre bay in Marin Co• Ancestral home of Coast Miwok • Today: Sausalito, Mill Valley,

Tiburon, Belvedere, Marin Co• Large ships anchoring since at

least 1890s• 19th/20th shoreline development

(marinas, industry, residences) = loss of historic bayland habitats

Photo: Sausalito Historical Society http://www.sausalitohistoricalsociety.com/sausalito-history


About Richardson’s Bay• Today: critical natural resource

bc of remaining eelgrass beds• 10s of 1000s of

migratory/waterbirds (Globally Important Bird Area)• Pacific herring, marine mammals

(harbor seals, porpoises)• Overlap between designated

Anchoring Area and eelgrass beds = natural resource conflict

Photo: Surf Scoters in Richardson’s Bay, courtesy of Audubon CA


Environmental Importance of Eelgrass• Seagrass, flowering plant• Shallow water bays and

estuaries• Habitat for baby fish, Dungeness

crab, food for birds• Spawning habitat for herring• Last commercial fishery in SFB• Reduces erosion, stabilizes

shoreline, sequesters carbon, reduces ocean acidification

Eelgrass covered in herring eggs.Photo: California Department of Fish and Wildlife


https://www.sfchronicle.com/local/environment/article/Underwater-meadows-of-California-seagrass-found-16065560.php


Threats Facing Eelgrass:• Human activity: shoreline

development, dredging, anchoring

• Climate change: changes in salinity, temperature, depth (sea level rise)

• Water quality: nutrient overload, contamination, turbidity• Probably not as big of an issue in

Richardson’s Bay – water quality testing shows pretty good WQ


Eelgrass in Richardson’s Bay:• Second largest bed in SF, variable in size

(~300-800 acres)• Ongoing damage: Up to 80 acres

removed due to anchor scour or “crop circles”1, approx. 2x size of Alcatraz Island

• Anchor scour is a threat to eelgrass regardless of length of stay/occupancy (though longer generally = worse scour) and the bed needs protection even from visiting vessels

• Certain anchor/mooring techniques can reduce damage, but to adequately protect need to move anchoring activities out of the eelgrass bed

1Kelly, J. J., Orr, D., & Takekawa, J. Y. (2019). Quantification of damage to eelgrass (Zostera marina) beds and evidence-based management strategies for boats anchoring in San Francisco Bay. Environmental management, 64(1), 20-26.Photo courtesy of Audubon California


Existing Boundaries in RB

Jurisdictional Boundaries Use Boundaries


What is the EPMP? Why are we doing it?• RBRA June 2020 Transition Plan,

Policy Direction #5: • “…develop eelgrass protection

measures and consider specific eelgrass restoration funding and projects”

• “The potential designation of up to four zones in RB for varying levels of vessel usage and eelgrass restoration and protection”

• Coastal Policy Solutions retained to implement Policy Direction #5 through development of an EPMP


EPMP – What is in it?1. Introduction: • Background• About RB• Eelgrass in RB• Regulatory/Policy Context

2. EPMP Framework• Development of the EPMP• Summary of stakeholder feedback• Spatial Analysis• Plan elements


Development of EPMP

Policy review

Spatial analysis

Stakeholder Engagement


Development of EPMP1. Policy review• McAteer Petris Act• San Francisco Bay Plan• RB Special Area Plan• CA Eelgrass Mitigation Policy• BCDC Enforcement Committee

direction• RBRA June Transition Plan


Development of EPMP1. Policy review2. Spatial analysis• GIS Analysis: eelgrass frequency

distribution, herring spawning


Development of EPMP1. Policy review2. Spatial analysis3. Stakeholder engagement



• Five 1.5 hr Zoom listening sessions• Targets: environmental groups,

scientists, elected officials, marina operators, resource/regulatory agencies, RB mariners

• 40+ people, 20+ organizations• No mariner participation in listening

sessions despite robust, targeted outreach

• Reviewed 2018/2019 community feedback from mariners



• Targeted outreach to mariners: • Links shared at three RBRA meetings,

posted to social media, and shared directly with key members of the mariner community.

• Mariner-focused Zoom listening sessions held on three separate occasions (two during the day, including during and after free lunch provided by Sausalito Presbyterian Church, and one in the evening).

• Email address set up where people could email their thoughts directly to project consultants. No emails were received.

• Significant input rec’d during Mooring Feasibility Study – reviewed here.

Summary of Stakeholder Feedback

Three main themes:

1. Threats to RB to consider during EPMP development

2. Uses to consider during EPMP development

3. Additional Feedback


Photo credit: Marin Independent Journal

Summary of Feedback by Theme (1 of 3): Threats

Sea level rise and other impacts of climate change

Damage from anchors, chains,

and other ground tackle

Loss of maritime culture,

herring/fishing culture

Natural fluctuation in eelgrass

determining static boundaries

Public safety Marine debris Shading and other impacts from docks

Lack of awareness about importance

of eelgrass

Stormwater runoff/water

quality

Regulatory burdens on marina operators


Summary of Feedback by Theme (2 of 3): Uses

Richardson’s Bay is an anchorage

Recreation, especially non-

motorized

RB as a sailing destination for cruisers/visiting

vessels

Education

Marinas Science/research

Eelgrass restoration and

bed migration with sea level rise

Birds and wildlife

Beneficial reuse of sediment/dredge

material

Opportunities for deeper water off

Belvedere/Tiburon


Summary of Feedback by Theme (3 of 3): Add’l

Vessel enforcement will be key to success

Should include monitoring on

ecological scale (10 years+)

Mooring program: Need for spatial analysis, not just

planning

Partnerships important

Don’t make marina operation harder

Eelgrass restoration and

bed migration with sea level rise

Include an alternatives

analysis


Safer, better for eelgrass; should be

considered now rather than a

separate planning process down the

line; visitor-serving, revenue generating

Spatial Analysis

NOAA Nautical Chart #18649

Eelgrass Frequency

Distribution –Years: 2003, 2009, 2013,

2014, and 2019

Herring Spawning

Occurrences –Years: 2013-

2020

Combined eelgrass +

herring data

• Chart – Used as base layer so any recs based on how space is used by mariners• Eelgrass – Insight re where

eelgrass most often occurs in RB, manages for spatial variability of bed across years• Herring – Insight re other

species use RB, protection of ecosystem function


Figure 6- Eelgrass frequency distribution in Richardson's Bay (2003-2019)

Eelgrass Occurrence Frequency

Notes:

Data are derived from side-scan sonar surveys conducted by Merkel and Associates in years 2003, 2009, 2013, 2014, and 2019.

The data layer exhibits the average extent of mapped eelgrass during survey years, regardless of cover class (percent cover/density).

Eelgrass Frequency


2014, and 2019

Notes:

Each purple polygon represents one spawning event. Multiple spawning events occur during each year. Areas of darker purple indicate repeated spawning events.

Eelgrass Frequency


2014, and 2019

Herring Spawning

Occurrences –Years: 2013-

2020

Notes:

The same eelgrass and herring data were used again, this time overlayed to provide a view of combined spatial use. Showed very similar patterns of use.

Eelgrass Frequency


2014, and 2019

Combined eelgrass +

herring data

Plan Elements

1. Proposed Eelgrass Protection Zone/No Anchoring Area

2. Monitoring and adaptive management

3. Future possible mooring program


Plan Elements – Proposed Eelgrass Protection Zone/No Anchoring Area

Description:

• EPZ/NAA proposed northwest of a line from Channel Marker 4 to Audubon Sanctuary

• Protects 90% of eelgrass from anchor damage

• Using existing boundaries/markers keeps things simple

• ONLY applies to anchoring; all other activities (kayaking, sailing, motoring, fishing, marinas, recreation, etc.) unaffected


Major changes:

• Reduces 72 hr Anchorage Area by ~2/3

• Reduces 10 hr anchoring (Belvedere water) by ~ 1/3

• Limits the number of boats the anchorage can support at one time

• Expands area available for non-anchoring activities (e.g., recreation)

• No change to shore access (Turney St.) but removes anchoring in area closest to boat ramp



Considerations:

• Proposed EPZ/NAA aligns closely with 5 ft MLLW contour – many transiting vessels can not anchor in such shallow water

• Majority of “Safe and Seaworthy” vessels already outside EPZ/NAA

• Boats can be anchored more closely together than they are; likely to meet demand for 72 hr anchorage



Alternative B (NOT proposed):

• Aligns with 6 foot MLLW contour

• Protects 100% of bed• Reasons for rejecting:

• Further reduced area for anchoring

• Signage would be difficult



Proposed (pending funding):• Annual – Aerial photography & GIS of

anchorage area, quantify damage/regrowth; longer of 10 years or 80% recovery

• Every 3 years – Sidescan sonar (or equivalent) bathymetric mapping, quantify density & spatial extent; continue until 80% recovery then decrease to every 5 years

• Water Quality – Continue twice/year monitoring with RWQCB

• Five Year Adaptive Management Review – Shift accordingly to ensure 90% of bed protected, may increase/decrease EPZ/NAA


Plan Elements – Monitoring & Adaptive Management

• EPMP consistent with future mooring efforts in consideration of 2019 Mooring Study

• Transitioning anchorage à mooring program has many benefits:• Higher density of boats

• Improved public safety

• Revenue generating• Protect bayfloor from anchor

scour• Easier enforcement of time limits

• No Mooring Program proposed here


Plan Elements – Possible Future Mooring Program

Final Thoughts/Next Steps: Feedback, requested changes

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