New Bay Health, Restoration Efforts and Replacement

Indicators

MASC meeting

12/18/07

Objective: Report status of Bay-wide juvenile menhaden abundance

• 2006 Narrative: “Scientists currently do not produce Chesapeake Bay-specific population estimates of menhaden. Estimates are made on an Atlantic Coast-wide basis. Populations along the Atlantic Coast appear to be healthy, but scientists are concerned about low regional abundances in Chesapeake Bay. The number of juvenile menhaden in Chesapeake Bay has been declining in recent years, with current recruitment levels being about 50% lower than the mid-1980s. In 2006, Virginia placed a cap on the amount of menhaden that can be harvested annually from the Chesapeake Bay by the commercial fishing industry. Maryland currently prohibits the commercial industry from harvesting menhaden from Maryland waters. Since menhaden are an important forage species in the Bay food web, a number of studies are underway to assess their status in the Bay.”

New Bay Health Indicator: Menhaden Abundance

New Bay Health Indicator: Menhaden Abundance

Considerations• Data support the following 2006 statement: “The number

of juvenile menhaden in the Bay has been declining in recent years, with current recruitment levels being about 50% lower than the mid-1980s."

• Indices of menhaden recruitment address how well Chesapeake Bay is serving as a nursery area for the Atlantic menhaden population (a.k.a. coast-wide stock).

• However, recruitment is highly variable and not directly tied to the size of the menhaden population, nor to water quality conditions. Population abundance and water quality both influence recruitment but other factors (climate, predation, and disease) play a larger role in determining recruitment for any given year.

New Bay Health Indicator: Menhaden Abundance

Recommendations• The NOAA/MD DNR Cooperative Oxford

Laboratory recommends using a log geometric mean index based on Chesapeake Bay recruitment (juvenile) data.

• IWG expressed a concern about distinguishing an abundance index based on recruitment in the Bay from the metrics used by ASMFC to determine the coastwide stock for fishery management purposes. It may be useful to refer to coastwide stock abundance metrics in the CBP assessment, for reference purposes and to distinguish the two abundance measures.

New Bay Health Indicator: Menhaden Abundance

Recommendations (continued)• Option 1 – Use current juvenile menhaden

abundance index (GMI)– Not sure of relationship of beach seine to absolute

abundance in Bay– Non-linearity important

• Option 2 – Proportion of Positive Hauls (PPHL)– Not influenced by very few large hauls– More responsive at low levels – might help facilitate

precautionary management approach

New Bay Health Indicator: Menhaden Abundance

Comments

• Group preferred Option 2- (PPHL)

• Comments grouped as follows:– Determining health– Data analysis– Assigning letter grades

• Not recommended

New Bay Health Indicator: Menhaden Abundance

New Bay Health Indicator: Menhaden Abundance

New Bay Health Indicator: Tidal Wetlands Abundance

Background • Objective: Report status of Bay-wide tidal

wetlands, (not intended to speak about health of wetlands)

• UMCES Marsh Condition Index good but expensive

• Coastal Change Analysis Program (C-CAP) land cover and change maps

• Suitable for monitoring on 1 to 5 year cycle

New Bay Health Indicator: Tidal Wetlands Abundance

Issues• Defining tidal wetlands (includes estuarine

scrub/shrub, forested, emergent wetlands)• 30m resolution – may not detect small changes

(require 30,000 acre change to be significant). However, in future, CBP GIS will have capability to do high resolution verification.

• Baseline will be set upon 1984 and 1992 data analysis

• Probably most cost effective method

New Bay Health Indicator: Tidal Wetlands Abundance

Recommendations

• I

New Bay Health Indicator: Tidal Wetlands Abundance

New Bay Health Indicator: Tidal Wetlands Abundance

Objective: Report status of Bay-wide oyster recovery efforts

2006 Narrative: “Oyster reefs are an essential component of the Bay ecosystem, providing healthy habitat for other bottom-dwelling organisms as well as schools of fish. Reef restoration efforts include cleaning and placing oyster shells, planting hatchery-produced spat (juvenile) oysters, setting aside permanent sanctuaries, and placing alternate substrate materials. Thousands of acres have been treated in this way, sometimes with multiple efforts. The success of these habitat restoration techniques has been limited by numerous factors including disease, fishing pressure and resulting habitat destruction, and poor water quality caused by human population growth and land use changes. For more information on oysters, please see Part One: Ecosystem Health.”

New Bay Restoration Efforts Indicator: Oyster Recovery Efforts

New Bay Restoration Efforts Indicator: Oyster Recovery Efforts

Considerations • LIVRAW doesn’t support target/goal• Target level necessary to reach 10x

increase in biomass has not been determined

• Premature to establish an acreage goal• Acres of restoration is funding dependent• Option – “conduct x acres of restoration

per year.”

New Bay Restoration Efforts Indicator: Oyster Recovery Efforts

Recommendations• IWG recommends acres/year (stacked or solid

bars)• IWG suggested extrapolating line to 2010 or

annual target level equal to 1998• LIVRAW suggested existing annual average as

annual target• Both IWG and LIVRAW warn it is premature to

set any target now• LRSC recommends acres/year (stacked or solid

bars)

New Bay Restoration Efforts Indicator: Oyster recovery Efforts

New Bay Restoration Efforts Indicator: Oyster recovery Efforts

Potential Replacement Indicator: Shad Abundance

Considerations• Objective: Report status of Bay-wide shad

abundance• Original Shad abundance indicator (# fish lifted

at Conowingo) not accurate representation of Baywide abundance

• Proposed indicator combines peer-reviewed & historical data from four rivers (weighted) to provide bay-wide value

• Note: Abundance estimates not being used to make decisions about current moratorium

Potential Replacement Indicator: Shad Abundance

Considerations (Continued)

• Uses ASFMC shad stock assessment

• Includes two different metrics:fish passage goals (Susquehanna and James) and catch levels (Potomac and York).

Potential Replacement Indicator: Shad Abundance

Recommendations

• IWG and LRSC support this replacement indicator

Replacement Indicators: Shad Abundance

Replacement Indicator: Shad Abundance

Potential Replacement Indicator: Oyster Abundance

Considerations• Objective: Report status of Bay-wide oyster

abundance• Current MD monitoring not suitable to for

producing estimates of absolute oyster abundance with enough precision

• However, MD is funding two projects to address this concern and help move towards developing estimates of oyster abundance with adequate precision

Potential Replacement Indicator: Oyster Abundance

Recommendations

• Use existing indicator as interim measure until replacement has been approved (~after 2008)

Potential Replacement Indicator: Oyster Abundance