Biology 1229 Fisheries or Should fish be on
Biology 1229 Fisheries… or… Should fish be on the menu?
Fish on the menu… p At least 2. 5 Billion people depend on fish for more than 20% of the protein in their diet p 97 % of fishers are in developing countries
Why might fish be on the list? p Mercury
Why might fish be on the list? p Farming practices unsustainable Shrimp farming in Mexico destroys mangrove forests n Salmon farming n Escapes p Parasites p Eutrophication p
Why might fish be on the list? p Fishery unsustainable or environmentally damaging Bottom trawling Bycatch from a shrimp net!
Unsustainable fisheries
How does a harvested population work? Note: “sustainable” is economic, not based on the population!!! p It is possible to derive a MSY from population data using growth rate and harvest rate p
Orange Roughy Hoplostethus atlanticus p Slow, ugly, demersal fish (“Slimehead”) p Mature at 20 -30 p Live up to 156 years (depending on who you listen to…) p Harvested by bottom trawling around sea mounts p Fishing, or mining?
How much of the ocean is harvested?
Fishing down the food web
How many fisheries are sustainable?
What about recreational fishing? Commercial Fishery Including menhaden and pollock Recreational fishery as a %age of commercial But the vast majority of several high-value, threatened species (e. g. Red Snapper) are caught recreationally
We are catching too many fish!!
Not just fish suffer… p Effects on seabirds & other top predators p Effects on erosion and flood control (e. g. New Orleans) p Economic effects of fishery collapse (Newfoundland)
Top 20 countries for unsustainable fishing… 1. 2. 3. 4. 5. 18. China Peru Japan Chile USA Canada
What future? p Some authors predict the collapse of ALL fisheries by 2048 p Sustainable management is possible… requires Reliable data n Reliable fisherman n A pretty decent navy n p End of oil may result in reduced fishery pressure
Ownership of fisheries prevents collapse With ITQ Without ITQ Number of Individual transferable quota (ITQ) fisheries
See also http: //www. mbayaq. org/cr/seafoodwatch. asp
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