Laura Palamara, John Manderson, Josh Kohut, Matthew Oliver, John Goff, Steven Gray

Laura Palamara, John Manderson, Josh Kohut, Matthew Oliver, John Goff, Steven Gray

Developing Ecological Indicators for Fisheries Management using IOOS Defined Habitat Characteristics in the Mid-Atlantic Bight

ObjectivesObjectives

Model fish distributions (multi- and single-species) using environmental data: benthic AND pelagic

See if we can use remotely sensed data as a surrogate for going out to sea

Apply model results to fisheries management

Important environmental indices EFH, MPA Curb by-catch

Statistical models of fish-habitat associations

NEFSC bottom trawls Spring 2003 - Fall 200765 Species

Bathymetry Sediment Grain Size

Ship Surveys:Bottom Habitat Data

• depth• median• standard deviation

• slope • median• standard deviation

• aspect• median• standard deviation

• profile curvature• median• standard deviation

• tangential curvature• median• standard deviation

• sediment grain size

Ship Surveys:CTD

• temperature• surface• bottom

• salinity • surface• bottom

• stratification• mixed-layer depth• Simpson’s potential energy

• entire water column• top 30 meters

Sea Surface Temperature

Ocean Color

Integrated Ocean Observation Systems:Satellite Data

• sea surface temperature• mean• standard deviation

• water-leaving radiance (ocean color)• 412 nm (M & SD)• 443 nm (M & SD)• 488 nm (M & SD)• 531 nm (M & SD)• 551 nm (M & SD)• 667 nm (M & SD)

• Chlorophyll a• mean• standard deviation

• water mass data

Integrated Ocean Observation Systems:HF radar - ocean currents

Current Velocity

Divergence Trend

• detided & filtered along-shore velocity• detided & filtered cross-shore velocity• variance in raw along-shore velocity• variance in raw cross-shore velocity• divergence

• average• trend

• vorticity• average• trend

Current Velocity

Current Velocity

Current Velocity

Current Velocity

Divergence & Vorticity

Seasonal Divergence Trends

Multivariate Analysis (CCA)Final Environmental Variables Used

Benthic

Depth (log-transformed)Profile curvatureSlope (residuals vs. depth)Sediment grain size

IOOS

SST488 nm reflectance551 nm reflectance (residuals vs. 488 nm)Cross-shore velocityVariance in cross-shore velocityDivergence trend

CTD

Mixed-layer depthSimpson’s PE (limited to top 30 m)Bottom tempBottom salinity (residuals vs. depth)

Community Axis 1

TempDepth

551 nm resids

Benthic IOOS

CTD

21.4% 16.8%

24.8%

5.2%

6.1%16.7%

8.9%

41.6% 47.6%

56.5%

27.5% 33.5%

14.1%

30.9%

22.0%

25.6%

Percent of Explained Community VariationPartial CCA

divergence trend488 nm reflectance

Simpson’s potential energy

bottom T SSTbottom salinity residuals SSTmixed-layer depth current velocity

Squid GAM• Used multivariate results as a guide• Explained approximately 85% of the variation in

squid abundance• Variables included:– bottom temperature– SST x depth interaction– sediment grain size– current velocity– divergence trend– water-leaving radiance: 488 nm

Conclusions

• Pelagic habitat is important• IOOS provides useful measures of the pelagic

habitat• IOOS increases explanatory power of

statistical habitat models