Carrie C. Wall Frank E. Muller-Karger Chuanmin Hu University of South Florida

1. Institute for Marine Remote Sensing Linkages between environmental conditions and recreational king mackerel catchoff west-central Florida Carrie C. Wall Frank E. Muller-Karger Chuanmin Hu University of South Florida College or Marine Science Mitchell A. Roffer • Roffers Ocean Fishing Forecasting Service, Inc.

2. Institute for Marine Remote Sensing Or: where to catch a king in the Gulf Mitchell A. Roffer • Roffers Ocean Fishing • Forecasting Service, Inc.

3. Study Focus • Pelagic Fisheries • Remote Sensing • Physical / Biological Oceanography Hypothesis: Stronger and persistent fronts have greater influence on fish abundance, increased catch efficiency

4. Fisheries • King Mackerel (kingfish) Scomberomorus cavalla • Highly migratory species • SST range (20 - 26°C) • Expected to concentrate in areas of high primary productivity and prey Catch data collected through interviews at local kingfish tournaments

5. Fisheries – SurveyWhere are the fish? • What pass did you leave from? • What time? • Where did you start fishing? • What time did you start? • What method of fishing was used? Troll? Anchor? Drift? • Number of fishing lines? • Number of fish hooked? • Number of fish caught? • Were bait fish present? • Did you see kingfish? • What time did you stop? • Did you fish anywhere else? • Did you run to the next site?

6. Remote Sensing • Sea Surface Temperature • AVHRR + MODIS • Chlorophyll concentrations • MODIS + SeaWiFS • Proxy for primary productivity • Turbidity • MODIS + SeaWiFS • Water-leaving radiance at 443 nm • Red Tide • MODIS • Fluorescence Line Height

7. DegC 25 17 Frontal Detection Sea Surface Temperature 9 April 2005 • Automated frontal detection algorithm • Measure gradients near fronts • Measure distance between catch and fronts

8. Detection of Bathymetric Gradients Areas of greater bathymetric gradient may influence frontal stability

9. High: 0.19 Low: 0.00 d. c. High: 0.67 Low: 0.00 Bathymetry Gradients and Sustained Fronts Sea surface temperature Chlorophyll a Locations where fronts are more likely to occur may aggregate more kingfish

10. i. j. Physical Oceanography • University of South Florida buoy data Wind Velocity Current Velocity Strong and variable winds and currents occurred throughout this study

11. Turbidity at Fishing Locations c. CPUE

12. Turbidity at Fishing Locations CPUE c. High fishing success associated with intermediate turbidity

13. Turbidity at Fishing Locations CPUE c. Low fishing success and turbid water during fall 2005

14. Effects of Fall 2005 Red Tide • Reduced kingfish catch • Spring 2004: 444 • Fall 2004: 818 • Spring 2005: 538 • Fall 2005: 208 • Increased fishing w/ no baitfish • Spring 2004: 46% • Fall 2004: 46% • Spring 2005: 49% • Fall 2005: 62% • Increased turbidity + chlorophyll FLH fronts November 12, 2005

15. Principal Component Regression Analysis • Environmental factors influencing kingfish catch: • Baitfish Presence (56%) • Turbidity Gradient (30%) • Chlorophyll Gradient (7%) • SST Front (6%) • Turbidity Front (2%)

16. Conclusions • High variability within fisheries data • Anglers • Strong and variable wind • Relationships observed between: • Bathymetry and fronts • Baitfish and fishing success • Water clarity and fishing success • Red tide in fall 2005 • FLH characterized features • Observed baitfish and kingfish abundance

17. Recommendations • Continue to characterize seasonal physical processes within the study area and relate to kingfish abundance • Pop-up satellite tags • Frontal probability • Apply findings to other pelagic migratory species • Aid in fisheries management • Continue to strengthen link between scientists and fisheries community