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Food Resources G. Tyler Miller’s Living in the Environment 13th Edition Chapter 13 Catching and Raising More Fish • Fisheries – concentrations of aquatic species suitable for commercial harvesting in a given body of water • 55% of annual commercial catch comes from the ocean. • 33% from aquaculture. • 12 % from inland freshwater fishing. Commercial Fishing Methods Trawler fishing Fish farming in cage sonar Spotter airplane Purse-seine fishing trawl trawl flap lines fish school trawl bag Long line fishing lines with hooks Fish caught by gills float Drift-net fishing buoy Potential to harvest more fish • 1950-1982 + Fish catch increased 5-fold + Per capita seafood catch doubled • Since 1982 – Little increase in commercial fish catch – Per capita commercial fish catch falling Potential to harvest more fish The primary cause of depletion of fish stocks is too many fishing boats pursuing too few fish or OVERFISHING (Tragedy of the Commons) • Habitat destruction • Global warming Aquaculture • Fish farming – Cultivating fish in a controlled environment. – Harvesting them when they reach the desired size. – Catfish are the leading aquaculture product in the US Aquaculture • Problems – Raises demand for ocean fish as fish meal to feed aquaculture species – Creating vast amounts of animal waste in coastal areas – Farming of carnivorous fish increases over-fishing of smaller marine species. Future • Increasing wild catch and aquaculture will not increase world food supplies significantly. • Fish and shellfish supply only 1% of the energy and 6% of the protein in the human diet.