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FISHERIES MANAGEMENT AND THE ROLE OF APEX PREDATORS

FISHERIES MANAGEMENT AND THE ROLE OF APEX PREDATORS. Earth From Space. Satellite Image of North Central Gulf of Mexico. MS. AL. shelf. LA. TX. FL. shelf. shelf. Tan areas reflect continental shelf of Northern Gulf of Mexico. Ecosystem based fisheries management.

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FISHERIES MANAGEMENT AND THE ROLE OF APEX PREDATORS

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  1. FISHERIES MANAGEMENT AND THE ROLE OF APEX PREDATORS

  2. Earth From Space

  3. Satellite Image of North Central Gulf of Mexico

  4. MS AL shelf LA TX FL shelf shelf Tan areas reflect continental shelf of Northern Gulf of Mexico

  5. Ecosystem based fisheries management • Gulf of Mexico: a large marine ecosystem (LME) • An ecosystem: “the complex of a community of organisms and its environment functioning as an ecological unit” • How do we understand an ecosystem? Link (2002) Link J. 2002. Does food web theory work for marine ecosystems? Marine Ecology Progress Series 230: 1-9. Images from Large Marine Ecosystem project, Sherman et al.

  6. Red Drum or redfish were nearly depleted In the 1980’s Graduate student Matt Kenworthy studies red drum

  7. APEX PREDATORS IN THE NORTHERN GULF OF MEXICO

  8. Food Pyramid for the Oceans APEX or Top Predator Sharks Tunas and Mackerel Wolf of the ocean Anchovy-Sardines Cows of the ocean Copepods DIATOMS - Plants of the ocean

  9. NMFS Bottom Longline • Fishery independent bottom longline database: 1995 • Gulf wide random site selection out to 400 meters

  10. Blacktip shark Carcharhinus limbatus

  11. Blocks 1,2 West of Mobile Bay Block 3, 4, East of Mobile Bay Blue Line -North South Transect

  12. 2009 Survey

  13. Blacktip Shark Torpedo shaped for speed Camouflaged top and bottom Ampullae of Lroenzini-electric fields 1/3 to 2/3 of brain devoted to smell Mirror like reflective membrane to enhance light gathering Teeth are modified scales

  14. Buoy Long-line

  15. Hooks Shark Bait

  16. Long-line gangets with baited hooks

  17. Retrieving long-line with Shark

  18. Hammerhead Shark

  19. Sharks are brought on board to collect data

  20. Tag has a number that corresponds to a data sheet and statement that says REWARD with phone number

  21. Tagging Shark Tag

  22. Species Identification, Sex and Weight

  23. Tag Tetracycline is injected as a marker

  24. Marcus Dryman with Blacknose shark

  25. Not all sharks survive being caught on the long-line, many Samples from stomach to liver tissue are taken for further analysis Atlantic Sharpnose sharks have a low tolerance for oxygen deprivation

  26. Atlantic Sharpnose embryonic sharks, 4 in each uterus - 8 total

  27. Southern Stingray Circle hooks cause less mortality

  28. Red Drum are often caught on the long-line

  29. Rarely sea turtle like this Loggerhead are fouled hooked on long-line

  30. Nurse shark – hook being cut off to release shark

  31. Juvenile Tiger shark caught ¼ mile off Alabama-Florida line

  32. Tiger shark tagged and released

  33. Satellite Tags  DISL

  34. Acoustic Tagging

  35. We Are the Top Predators Gulp!

  36. Even sea birds fall prey to sharks APEX predator – means being on the top of the food chain

  37. Explosion and sinking of oil well Deep Horizon

  38. http://www.cosee-gom.org http://www.disl.org

  39. References That You Can Review Current-Journal of Marine Education Vol. 18 Number 1 2002 Harden, G. 1968. “The Tragedy of the Commons” Science 162:1243-1248 Husted, R., and R. Lent. “International Aspects of Atlantic Highly Migratory Species Management”. Current 14:22-24 Richards, W.J. & Edwards, R.E. (1986) “Stocking To Restore of Enhance Marine Fisheries” In : Fish Culture in Fisheries Management pp.75-80 American Fisheries Society Web sites: www.ifmt.nf.ca/mi-net/fishdeve/index www.ncdmf.net www.nmfs.noaa.gov/sfa/magact www.vims.edu/bridge/archive0100 www.vims.edu/bridge/archive0299

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