NOAACHESAPEAKEBAY OFFICE

Augmenting the Black Sea Bass Stock Assessment: Chesapeake and Mid-Atlantic Shelf Habitat Connectivity

2

Issue Statement

The Black Sea Bass Stock Assessment is considered to be “data-poor” and could be improved by incorporating Chesapeake Bay (and other MAB estuary) habitat information.

3

Black Sea Bass and the Northeast

4

Black Sea Bass and the Bay

BSB are often the dominant species on hardbottom communities in the estuaries and shelf of the Mid-Atlantic Bight

Historically, oyster reefs formed a significant proportion of hard bottom habitat in the Chesapeake Bay

5

Black Sea Bass & Habitat

The latest stock status report states “the current status of the stock relative to biological reference points cannot be determined at this time”

Given the precipitous decline of oysters, it is likely that BSB stocks have declined over the decades 1940 1950 1960 1970 1980 1990 2000 2010 2020

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

BSB (10^3 lbs) Oyster (10^6 pounds)

6

Chesapeake Bay Pilot Study

Linking Chesapeake Bay and shelf habitat-specific life history parameters for BSB to an ecosystem-based approach to management (habitat and stock assess)

1. Modeling• Ecosystem modeling to assess habitat impacts on predation

mortality• habitat suitability model to inform site selection

2. Mapping• high resolution survey of structured hardbottom

3. Monitoring• focused surveys to assess relationships

7

Modeling

1. Habitat suitability model and overlay with hard bottom/reef to assess where to sample/adaptively sample for BSB

2. Apply an ecosystem/habitat model of a typical oyster reef to project increase in oyster population and habitat-mediated increase in BSB and changes in predator-prey relationships

8

Mapping and Monitoring1. Apply water column habitat suitability model to identify potentially

available water column habitat areas for BSB in CB

2. Use acoustic seafloor habitat mapping to quantify structural hard bottom habitat in areas of interest (natural and artificial reef)

3. Deploy sensors to monitor environmental data in areas of interest

4. Fish sampling on identified structured hard bottom using suitable gear/methods to fill data gaps

9

Anticipated Benefits

1. Assessment: Improved BSB stock assessment using habitat indices for abundance or predation mortality

2. Monitoring: Improved monitoring/surveys for BSB (and other reef associated species) that is transferable to other parts of the Mid-Atlantic Bight

3. Habitat: Additional criteria for habitat protection and oyster restoration site selection

4. Multi-Species Management: Improved estimates of prey availability for BSB predators (e.g., flounder, dogfish, weakfish, bluefish and striped bass)

10

Questions?

NOAACHESAPEAKEBAY OFFICE

12

Vital Rates for Stock Assessments

Exploitable Stock Biomass

B

Recruits,R

Yield to People, Y

Recruitment Rate, r

Natural Mortality Rate, M

Fishing Mortality Rate, F

Growth Rate, G

Production, P/B

Total Mortality, Z

Competition for Food

-Reproduction-Egg Survival-Fry Survival and Growth-Pre-recruitment Survival and Growth

13

CHP – BSB Research Design – Document Relationship b/w BSB and Habitat

• Gather available BSB occurrence and associated data for CB and MAB (see datasets referenced in latest EFH documents)

• Apply water column habitat suitability model to identify potentially available water column habitat areas for BSB in CB

• Use acoustic seafloor habitat mapping to quantify structural hard bottom habitat in areas of interest (natural and artificial reef)o Mid-salinity tributary and adjacent mainstem (Choptank River area)o High salinity tributary/embayment in lower Chesapeake Bay (Poquoson//York River area)o Selected areas on the shelf (e.g., adjacent to mouth of CB, Ocean City)

• Deploy OBS sensors to monitor environmental data in areas of interesto Buoy-based sensor suiteo Profilerso Targeted AUV deploymento Existing sensors of opportunity (link up with upcoming hydrodynamics study, others?)

• Fish sampling on identified structured hard bottom using suitable gear/methods to fill data gapso Water column multi-beam/hydroacousticso Gill net sampling (original collection, groundtruth acoustics)o Visual observation/video