Remote sensing techniques to assess linkages between environmental conditions and recreational king

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Remote sensing techniques to assess linkages
between environmental conditions and recreational
king mackerel catch off west-central Florida
Institute for Marine Remote Sensing

• 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.

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Where to catch a king in the Gulf
Institute for Marine Remote Sensing

• 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.

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Study Focus

• Pelagic Fisheries
• Remote Sensing
• Physical / Biological Oceanography

Stronger and persistent fronts have greater
influence on fish abundance, increased catch
efficiency
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Fisheries

• King Mackerel (kingfish) Scomberomorus cavalla
• Highly migratory species
• SST range (20 - 26C)
• Expected to concentrate in areas of high primary
  productivity and prey

• Catch data collected through interviews at local
  kingfish tournaments

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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?

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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

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Frontal Detection
Sea Surface Temperature 9 April 2005

• Automated frontal detection algorithm
• Measure gradients near fronts
• Measure distance between catch and fronts

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Detection of Bathymetric Gradients
Areas of greater bathymetric gradient may
influence frontal stability
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Bathymetry Gradients and Sustained Fronts
Sea surface temperature
Chlorophyll a
Locations where fronts are more likely to occur
may aggregate more kingfish
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Physical Oceanography

• University of South Florida buoy data
• Wind Velocity Current Velocity

Strong and variable winds and currents occurred
throughout this study
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Turbidity at Fishing Locations
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Turbidity at Fishing Locations
High fishing success associated with intermediate
turbidity
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Turbidity at Fishing Locations
Low fishing success and turbid water during fall
2005
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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
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Principal Component Regression Analysis

• Environmental factors influencing kingfish catch
• Baitfish Presence (56)
• Turbidity Gradient (30)
• Chlorophyll Gradient (7)
• SST Front (6)
• Turbidity Front (2)

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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

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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