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Fishing Techniques http://www.seafoodwatch.org/ocean-issues/fishing-and-farming-methods Fishing End of the Line Video: http://endoftheline.com/ Oceans provide about 1% of the world’s food Provide 10% of the world’s protein source There are over one million large-scale fishing vessels, twice as many as in 1970 Worldwide catch peaked in 1989 when 86 million tons of fish were harvested from the sea Since then, after experiencing a five-fold increase within 40 years, the annual take began to decline before stagnating This is due to overfishing: a rate of depletion that exceeds the rate of recovery Fishing Economics In the US Techniques Bottom Trawling – boats drag large nets along seabed, catching almost everything in the path. This can damage coral reefs, seagrasses, oyster beds, and sponges. Bottom Trawler Realizing the problems with bottom trawls, one of the first recorded laws against them was passed in 1499 to prevent trawls that “rooted up and swept away the seaweeds which served to shelter fish” However, still today, the continental shelves, bays and estuaries are the most heavily trawled. In 2005, General Fisheries Commission for the Mediterranean banned trawling below 1,000 meters US has closed deep-sea areas in Alaska to trawling UN General Assembly began discussions to completely ban bottom trawling South Pacific nations banned all trawling over an area that amounts to 14% of Earth Bottom Trawler (continued) Bottom Trawler (continued) Bottom Trawler (continued) Drift Net Drift Net – also called gill nets. Nets up to 40 miles long usually set up on buoys that typically catch fish by the gills. Hang as deep as 50 feet below the surface Due to mostly organic materials used prior to the 1950s, mesh sizes were larger allowing smaller fish to pass through. However, with increased use of synthetic material used beginning in the 1960s, mesh size was decreased. Near invisibility also increased catch Due to effectiveness, in 1987, the U.S. limited the length of drift nets to 1.5 nautical miles (~1.7 miles) In 1992, the UN banned the use of nets longer than 1.6 miles Drift Net (continued) Drift Net (continued) Drift Net (continued) Long Line Long Line – method commonly used to catch swordfish, tuna, and halibut where hundreds or thousands of baited hooks hang at intervals along a single fishing line sometimes up to 80 miles in length Main source of sashimi tuna since the 1980s Marine birds which dive after bait on longlines become entangled and drown. Approximately 44,00 albatrosses are killed each year in the Southern Ocean An estimated 20,000 loggerhead turtles are caught as bycatch each year, and estimated 4,000 of which die once released with hooks still in their mouths Some nets are now equipped with features to allow certain types of bycatch to escape. Acoustic pingers warn marine mammals away but have little effect on keeping turtles, sharks, rays, or birds away. Long Line (continued) Long Line (continued) Purse Seine Purse Seine – A large wall of netting deployed around an entire area or school of fish. Seine has floats along top line with a line threaded through rings at the bottom. The threaded line is then pulled in “pursing” the net closed on the bottom. This prevents fish from escaping by swimming downward. Purse Seine (continued) Purse Seine (continued) Purse Seine (continued) Troll Fishing Troll fishing (Trolling) – several baited fishing lines are strung from the boat. Does not use nets as trawling does. Typically conducted by small-scale operations but can be used on a large scale with the use of special equipment such as a trolling motor and outriggers. Most popular pelagic fishing method in many places Used mostly in small-scale operations to catch marlin, yellowfin tuna, and mahimahi Relevant Laws Federal Aid in Fish Restoration Act of 1950 Set up to help state agencies conserve and restock game fish through tax on fishing equipment (managed by Texas Parks and Wildlife) Fish and Wildlife Act of 1956 Comprehensive policy on fish and shellfish resources directed primarily to industry Fish and Wildlife Coordination Act of 1980 Assistance in training of state fish and wildlife enforcement personnel and assistance to states in the development and revision of conservation plans for nongame fish and wildlife Relevant Laws (continued) Sustainable Fisheries Act of 1996 The biggest obstacles and reasons for the need for regulations include: Population growth - more demand for fish, more people to feed, greater number of fishing vessels Improved technology - greater ability of fishing vessels: GPS, sonar, materials (monofilament plastic lines rather than cotton or cables/wire), better ships to withstand more extreme weather and temperatures, onboard refrigeration units Further understanding of aquatic systems has shown majority of areas fished as well as practices of fishing are not sustainable Regulation Requires regulations for: times of day or year when fishing for certain species can occur maximum number of certain fish that can be caught per day/season/year types of fishing methods that can be used (ie. no cyanide or blast fishing) established no fishing zones (for spawning as well as known pollution areas) Regulation (continued) Restrictions for methods of fishing such as escape nets to allow escape of certain types of bycatch (although proven not completely successful) Specified net mesh maximum or minimum depending on target species Aquaculture Fish as agriculture is what is called aquaculture This practice was brought about due to the relative ease of “farming” fish in a given area rather than having to go find the fish in a large lake or ocean Aquaculture in captivity (fish farms) can be good in that it lessens the need for overharvesting in native habitats such as the ocean which can have a Trophic Cascade effect depending on which species of overharvested Fish as Agriculture Provides about 5% of the total worldwide food production Raises: 80% of all mullusks 40% of all shrimp Kelp makes up about 17% of agricultural output In the wild, Maximum Sustained Yield (MSY) is the largest amount of marine organisms that can be continually harvested without population crashes Fish as Agriculture (continued) Currently, aquaculture is practiced with over 220 species of aquatic life, from fish, to shrimp, clams and even seaweed (kelp/algae) Left over fish scraps are used as a fertilizer on food crops Alternately, food waste can be used as food for fish Overall, aquaculture can produce as much as 10 times more fish per unit area than is harvested from waters on the continental shelf and up to 1,000 times more than is harvested from the open ocean Aquaculture: The Down Side As with many things in dense populations, aquaculture can result in an increase in diseases, which reduces food security, necessitates antibiotic treatment, and raises the cost of production Aquaculture has a large ecological footprint. A lot of waste is produced, both in the form of waste directly from the organisms, to wastewater, but also the uneaten food that decomposes in the water. Additionally, most aquaculture fish are still fed fish meal made from wildcaught ocean species such as herring and anchovies, which can place a stain on the wild fish populations that would typically eat them in their native habitat If farmed fish escape into ecosystems where they are not native ((such as Asian carp have), they can spread disease to native populations or outcompete the native organisms for food or habitat. This is the problem with invasive species. Overfishing Occurs when species depletion rates exceed recovery rate China is responsible for 1/3 of all global fishing 1/3 of all catches are for purposes other than human consumption 1/3 of all catch is Bycatch Bycatch is the “unwanted fish and other marine creatures caught during commercial fishing for a different species” Overfishing (continued) Bycatch Reduction Devices (BRDs) such as shown, are required in shrimp trawl nets in federal water of the Gulf of Mexico and South Atlantic Ocean Overfishing (continued) Turtle Extruder Devices (TEDs) typically consist of a grate through which sea turtles and large fish can use to escape but smaller fish will pass through net further into netting Overfishing (continued) Sea Lion Exclusion Device (SLEDs) allow larger marine mammals such as sea lions and seals to escape through similar means a sea turtle grates but usually include larger grates Article Post: NOAA Fisheries proposes requiring streamer lines to protect birds: http://www.westcoast.fisheries. noaa.gov/stories/2014/10_0910 2014_saving_seabirds_bait.html Sustainability Sustainable Fishing Video: https://youtu.be/lTWeIRky7Bc For sustainability, more than “overfishing” or “overconsumption” must be considered Sustainability is “an integrated approach to Environmental, Social, and Economic impact issues that lead to long-term, sustainable growth and profit The three main factors: Social (People): Standard of living, education, community, equal opportunity Environmental (Planet): Natural resource use, environmental management, pollution prevention Economic (Profit): Cost savings, economic growth, research and development Sustainability (continued) Other diagrams include “Viable” between Economic and Environmental; “Bearable” between Society and Environmental; and “Equitable” between Economy and Society Sustainability (continued) Sustainable Fisheries Sustainable Fisheries – Marine Stewardship Council Video: https://youtu.be/3rVeSBdpO6Q Article: “McDonald's USA first national restaurant chain to serve MSC certified sustainable fish at all U.S. locations” https://www.msc.org/newsroom/news/mcdonalds-usa-first-restaurantchain-to-serve-msc-certified-sustainable-fish-nationwide January 24, 2013 Article: “McDonald’s Sustainable Filet-O-Fish Threatens Alaska Fishermen’s Livelihood” http://www.huffingtonpost.com/entry/mcdonalds-sustainablefilet-o-fish-threatens-alaska-fishermenlivelihood_us_559ed33be4b096729155caee July 9, 2015 Global Fishing Watch Google and Global Fishing Watch Article: https://www.washingtonpost.com/news/energyenvironment/wp/2016/09/15/from-space-a-new-effort-to-crack-down-on-illegalfishing-across-the-globe/?utm_term=.31c2444a1f13 Summary Global Fishing Watch Map: http://globalfishingwatch.org/ Bozeman Science, Fishing: http://www.bozemanscience.com/apes-020-fishing/ (7:31)
