Presentation is loading. Please wait.

Presentation is loading. Please wait.

Bonefish Ecology and Conservation in The Islands of the Bahamas By: Justin Lewis Supervisor: Dr. Jim Williams Summer Work Term For my AQUA 400 work term.

Similar presentations


Presentation on theme: "Bonefish Ecology and Conservation in The Islands of the Bahamas By: Justin Lewis Supervisor: Dr. Jim Williams Summer Work Term For my AQUA 400 work term."— Presentation transcript:

1 Bonefish Ecology and Conservation in The Islands of the Bahamas By: Justin Lewis Supervisor: Dr. Jim Williams Summer Work Term For my AQUA 400 work term I interned at the Cape Eleuthera Institute (CEI) located on the Island of Eleuthera in the Bahamas. At CEI the main project that I was involved in focused on juvenile bonefish and the habitats that they utilize post settlement as a part of CEI’s Flats Ecology and Conservation Program. Apart from the juvenile bonefish study, I was a co-advisor for the Island School summer term flats research class. I taught the Island School students about the importance of flats environments with an emphasis bonefish ecology and conservation. With the Island School students and various other local and visiting groups, one of my main goals during the summer was to get students out on the water and have them actively seek bonefish for capture either by flyfishing or seine netting. Once mature fish were captured they would be tagged so to track their movements and growth rates, in accordance with the Bonefish and Tarpon Trust’s (BTT) Bahamas initiative. Students also had the opportunity to meet and learn from seasoned bonefishing guides. The Bonefish Albula vulpes Bonefish are an ecologically and economically important species of fish that reside in tropical shallow waters worldwide. Bonefish are one of the most sought after sport fish in the world, attracting anglers from all over the world to the search the flats of the Bahamas for these elusive fish. Anglers targeting bonefish contribute $141 to the Bahamian economy annually. Bonefish are important to Bahamians as both a symbol and food source. There are three different species of bonefish found in the Bahamas. The most common being Albula vulpes followed by Albula sp. B and Albula nemoptera. Juvenile Bonefish Research There is very little known about bonefish with the majority of research being focused on the mature and the larval life stages and little to nothing known about the juvenile stage of the bonefish’s life history. The goal of our research was to capture juvenile bonefish and identify the areas they use a nursery habitats. Prior juvenile research in Belize and Florida focused their efforts along windward sandy beaches and captured over 1,000 juvenile bonefish, 95% of which were Albula sp. B and the remaining 5% was Albula vulpes. To help us identify where juvenile bonefish might be we utilized traditional ecological knowledge (TEK) from bonefish guides and local fisherman. The identification of the habitat(s) that juvenile bonefish use is very important when it comes to the conservation of not only bonefish but also a variety of other flora and fauna that take residence on the flats. Methods We used two distinct sampling approaches in our search for juvenile bonefish; exploratory qualitative sampling and systematic quantitative sampling. Collection methods included the use of beach seine nets, multimesh gill nets, cast nets, and fish traps. After our exploratory phase we concluded that the most effective sampling method was the 50ft inch mesh beach seine with no bag. Juvenile bonefish that were captured were catalogued and dissected in lab. The otoliths and stomachs were removed for analysis and fin clips were taken for dna analysis. Results Juvenile Bonefish Of total 342 hauls, 39 (11%) caught juvenile bonefish Total 143 juvenile bonefish caught Number of JBF per haul ranged from 1 to 35, (median = 1) Sizes of juveniles ranged from 21 to 117 mm FL (<1” – 4.5”) (Mean=70, SD=14.8) Habitat Depths range: feet (Mean = 1.25, sd=.75) Water Temp range:29 – 36° C (Mean = 31.2, sd= 2) 69% of hauls in calm conditions, remainder in <1 ft chop 77% substrate dominated by fine sand or silt 23% mixture of sand, algae, seagrass 74% adjacent to mangrove (within ≈ 25m) 31% adjacent to dense seagrass and/or algae Bycatch 97% contained mottled mojarra (a.k.a shad) ( , median = 68) 31% contained Barracuda (1-5, median = 1.5) 18% contained silversides (1-14, median=9) Laws Protecting Bonefish Bahamians are allowed to catch bonefish using hook and line for personal consumption. Buying or selling bonefish and using nets to catch them is illegal. Individuals can be fined up to $3,000 and/or spend a year in jail for selling and netting bonefish. Anthropogenic Threats Coastal degradation and illegal fishing pose the biggest threat to the stability of the bonefish population in the Bahamas. The construction of hotels and the dredging of canals is highly destructive and disrupts various habitats like mangrove forest and sea grass flats that bonefish and other coastal flora and fauna depend on. Illegal netting of bonefish cannot only capture whole schools of bonefish but as well capture commercially important juvenile reef fish that use the shallow flats as nursery habitat. Traditional Ecological Knowledge A shift in recent decades towards ecosystem-based management practices and subsequent efforts to identify essential fish habitats have brought about a considerable movement towards the acceptance and utilization of fishers’ ecological knowledge in fisheries research and management efforts. To date, there has been no organized effort made to record or utilize the potentially valuable ecological knowledge of local fishermen or bonefishing guides in The Bahamas. Given the limited knowledge available on bonefish life history, and largely unsuccessful attempts thus far to elucidate juvenile habitats of bonefish, it seemed obvious that all possible sources of information should be considered in our attempt to focus sampling efforts on habitats and locations most likely to harbour juveniles.Their knowledge was an effective tool in helping us locate juvenile bonefish and their nursery habitats. Diet 88% comprised of invertebrates Main food source is bivalves Common shrimp Swimming crabs Snapping shrimp Mud and Spider crabs Mantis shrimp Benthic worms Snails Polychaetes Small fishes Catch Locations 3 sheltered embayment's that had easy access to the open ocean. 1 open beach Conclusions Habitat? Large, sheltered embayments (East & West sides of Eleuthera) Relatively shallow water (1/2 - 3 ft) Fine Sand/Silt Mud (feeding/protection?) Proximity to mangroves (related to fine sediment?) Co-occuring with mottled mojarra Social mimicry (protection)? Mutually beneficial? Shared muds for protection Increase foraging effectiveness Acknowledgements: Chris Haak (UMass), Luke Griffin (College of Charleston), Aaron Shultz (CEI), Dr. Andy Danylchuk (UMass) and Dr. Aaron Adams (BTT)


Download ppt "Bonefish Ecology and Conservation in The Islands of the Bahamas By: Justin Lewis Supervisor: Dr. Jim Williams Summer Work Term For my AQUA 400 work term."

Similar presentations


Ads by Google