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Published byGraham Keach Modified over 10 years ago
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How Effective are No-Take areas on Current and Historic Nassau Grouper Spawning Grounds? P. Bush B.X. Semmens, P. Bush, S.A. Heppell, B. Johnson, C. McCoy, C. Pattengill-Semmens, L. Whaylen, S.S. Heppell
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Nassau Grouper: Conservation Status Protected in Bermuda since 1970s Protected in Florida since the 1980s IUCN Red Listed as endangered B. Semmens
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Spawning Aggregations Easy target for fishing Few large (functional?) aggregations left P. Bush In order to manage spawning aggregations, we need to understand how they work
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Study Objectives Identify the full geographic and demographic ‘sphere of influence’ of a functional aggregation Look for evidence that spawning behavior changes (depensation) after spawning sites have been fished to exhaustion P. Bush
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Cayman Islands Are the spawning site MPAs warranted? Sphere of influence of a healthy SPAG? Evidence for behavioral depensation?
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Questions For a Functional Aggregation Where are they coming from? Do all fish aggregate every year? Do older fish aggregate more often?
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Study Design Ring the island of Little Cayman in hydrophones Acoustically tag 50 fish –30 from the aggregation –20 from various sites around the island Follow them for 2-3 years
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Questions For a Functional Aggregation Where are they coming from? Do all fish aggregate every year? Do older fish aggregate more often?
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Fish Locations Blue – Aggregation Red – Off Aggregation
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Questions For a Functional Aggregation Where Are They Coming From? Do All Fish Aggregate Every Year? Do Older Fish Aggregate More Often?
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LC Spawning Season 2006
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Questions For a Functional Aggregation Where are they coming from? Do all fish aggregate every year? Do older fish aggregate more often?
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Big, Old Fish Bigger fish showed up earlier and stayed longer B. Semmens
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Questions For a Remnant Aggregation Do fish migrate to spawn? Can fish find the spawning site? If they find the spawning site, do they spawn?
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Questions For a Remnant Aggregation Do fish migrate to spawn? Can fish find the spawning site? If they find the spawning site, do they spawn?
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Brac Spawning Season 2007
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Questions For a Remnant Aggregation Do fish migrate to spawn? Can fish find the spawning site? If they find the spawning site, do they spawn?
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Do Remnant Aggregations Spawn? BIG NEWS: Spawning observed on all three islands in 2009!!
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Management Implications? Preserving local spawning sites preserves local spawning stocks (in entirety!) Protecting spawning sites even after exhaustive fishing is a really good idea Given the excessive use of ‘corridors’, conservation of this species may require more than just SPAG site MPAs P. Bush
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Support Provided By CI Businesses: Little Cayman Beach Resort Head of Bay Pete Hillenbrand McCoy’s Dive and Fishing Lodge Pirate’s Point Southern Cross Club REEF Volunteers Funding: Pew Lenfest Ocean Program NOAA International Coral Reef Conservation Fund PADI Project Aware J. Edward Mahoney Foundation REEF CIDOE Oregon State University Hey Baby!
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