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Aquaculture. Allain, Brooke, Amanda, Alexandra. Introduction.
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Aquaculture Allain, Brooke, Amanda, Alexandra
Introduction • “Seafood is one of the healthiest and most popular sources of protein worldwide. Almost half of the seafood we eat comes from farms, making aquaculture - seafood farming - the fastest growing food production system in the world…Despite a steep learning curve for this growing industry – learning in just 30 years what land farmers have garnered over 6,000 years – positive changes in the industry already are visible.” –worldwildlife.org
Total U.S. production is about $1 billion annually, compared to a $70 billion world market
Shellfish Farming • Shellfish including mussels, clams, and oysters are filter feeders. • They filter food and nutrients out of the water, including the nutrients that cause eutrophication and algae blooms. • One oyster can filter about 50 gallons of water per day.
Example: Chesapeake Bay Oysters • It is estimated that at their historic population peak, oysters filtered all of the Bay’s water in less than one week. It takes about one year for the current population to do so. • Farming the native oyster species has a threefold effect: it takes fishing pressure off native populations, helps filter the bay’s water, and the female farmed oysters that reach maturity can disperse 25-85 million offspring!
Example: Swedish Mussels • Nutrient emissions from agriculture and other diffuse sources were causing blooms of algae and phytoplankton off the coast of Sweden depleting water quality. • Mussels use these as food sources. • Farming mussels moves these problem nutrients from the sea back to land in the form of edible protein. • One kg of live mussels will remove 8.5 to 12 g of nitrogen, 0.6 to 0.8 g of phosphorous, and about 40 to 50 g of carbon. • Source Dr. Odd Lindahl, Kristineberg Marine Biological Station, Sweden.
Freshwater aquaculture • Catfish, tilapia, and trout are the most commonly farmed freshwater fish. • Tilapia are particularly good for the environment because they are herbivores and require no fishmeal to eat. • Freshwater fish farming has fewer environmental problems associated with it because it is usually self contained in manmade ponds. • According to the NOAA 70% of aquaculture in the United States is freshwater.
Coastal Aquaculture (Mariculture) • Aquaculture is often conducted in coastal environments and operations can be located on land with a nearby water source or in bays, estuaries, or marine waters. • Marine coasts are used because of high biological productivity and easy accessibility • Finfish, Shrimp, Shellfish, and Algae are grown and used for human consumption, pharmaceuticals and feed. • Aquaculture operations help meet consumer demand for seafood and generate jobs and income. • In Hawaii, the value of aquaculture products produced has increase from $13 million in the year 1995 to $28 million in 2003. • Coastal Aquaculture Authority Act, 2005 (India) – Large production of shrimp • Regulation of activities connected with coastal aquaculture in coastal areas • Mandates the Central Government to take all such measures for regulation of guidelines • Ensures that coastal aquaculture does not cause any harm to the coastal environment • Protection of the livelihood of various sections of people living in the coastal areas
Off-Shore Aquaculture (Mariculture) • Aquaculture moves off-shore because of less competition for space and the natural characteristics of offshore waters — deeper water, stronger current flow and superior water quality • The National Offshore Aquaculture Act of 2005 (U.S.) • Issuing of offshore aquaculture permits and environmental requirements • Not subject to fishing regulations that restrict size, season and harvest methods • Require the Secretary of Commerce to work with other federal agencies to develop and implement a coordinated permitting process and enforce policy to protect wild stocks and the quality of marine ecosystems • Establishment of a research and development program • Provide for enforcement of the Act.
What is overfishing? • Overfishing occurs when fish and other marine species are caught at a rate faster than they can reproduce • It can lead to depletion or extinction of fish populations • Most problems associated with overfishing have been caused in the last 50 years by the growing human population demanding food
Why is overfishing a problem? • Developing countries depend on fish • Marine biodiversity is in danger • Food chain diversity is severely affected • Shifts in ecosystem from large fish to smaller fish
How bad is it? • Scientists predict that if current trends continue, world food fisheries could collapse entirely by 2050 (Dr. Worm) • 70% of the world’s fish stocks are either fully exploited or depleted (FAO) • 3/4 of the world’s fish stocks are being harvested faster than they can reproduce (Dr. Worm) • One in five people on this planet depends on fish as their primary source of protein (FAO) • 90% of all large predatory fish - including tuna, sharks, swordfish, cod, and halibut - are gone.
How can aquaculture help? • Gives people more control of conditions • Restores depleted species of fish & shellfish • Boosts commercial catches and sports fishing • Complements wild catches to meet growing demand • Improvements of fishmeal • Nat’l Offshore Aquaculture Act of 2007 requires abidance of existing water quality laws and other pertinent laws
Damaging Fishing Techniques and Their Subsequent Effects • Sensitive habitats, endangered species, and marine food chain • 28.7 million tons of by-catch annually associated mainly with: • Trawling • Long Lining • Drift Nets
Factory Trawling • Every pound of commercial catch has 10-20 pounds of by-catch associated with it • Captures sea creatures that were not intended and clear-cuts everything in its path • May be the cause of recent collapse of ground fish stock • Stirs up sediments placing a lot of suspended solids into the water column
Trawling • Destroys everything in its path May be the most detrimental fishing technique to the environment, but is used most frequently
Long Lining • Thousands of baited hooks up to 80 miles long • Frequently catch non-intended species • 180,000 birds die on long lines each year • Sharks are severely impacted ,detrimental because they have slow reproductive rates
Drift Nets • Free Floating 29-49 feet deep and as long as 55 miles long • Largest amount of by-catch associated with drift nets • Great lengths of drift nets are lost every year (storms)- “ghost nets” creating problems
Final Thought • “It is vital that the United States further develop its own sustainable aquaculture industry, both to reduce its annual $9 billion annual seafood import deficit and to keep pace with the growing demand for seafood.” -National Oceanic and Atmospheric Administration
References • http://www.magazine.noaa.gov/stories/mag202.htm • http://coastalmanagement.noaa.gov/aquaculture.html • http://columbianewsservice.com/2010/04/awaiting-legislation-eco-friendly-fish-farms-in-federal-waters/ • http://www.akvagroup.com/index.cfm?id=319215 • http://aquaculture.tn.nic.in/ • http://www.encyclopedia.com/topic/aquaculture.aspx • http://fishery.about.com/od/BenefitsofAquaculture/a/Aquaculture-What-Is-Aquaculture_2.htm • http://www.csmonitor.com/Environment/2010/0224/Recirculating-aquaculture-systems-The-future-of-fish-farming/(page)/2 • http://www.bayoyster.com/eat.html • http://news.mongabay.com/2007/0709-interview_mike_sutton.html • http://www.theglobaleducationproject.org/earth/fisheries-and-aquaculture.php
How to avoid environmental impact • To better manage possible impacts from this growing industry, coastal managers can address the siting and management of aquaculture in a comprehensive manner. For example: • New policies, laws, and/or regulations can provide a mechanism to balance the needs of different marine resource users and protect the health of coastal and ocean resources; • Siting tools can help identify areas to site aquaculture facilities that will minimize conflicts with existing resource users; • Coordination mechanisms between regulatory agencies at the local, state and federal level can improve and speed decision making; • Accurately assessing environmental impacts can improve decision making.
Recirculation Aquaculture Systems • This new technology eliminates many of the environmental issues associated with aquaculture. • About 99.75 percent of the water in each unit is continuously cleaned and returned to the fish tanks, greatly reducing the water footprint. • These self contained systems prevent any possibility of fish, fish waste, antibiotics, or other chemicals to get out into the natural environment. • The excess nutrients in the waste can be used as fertilizer in local agriculture.
Replacing Fish Meal • Fish meal is traditionally used to feed carnivorous fish such as trout and salmon. • This fishmeal is attained by using fish by products and baitfish that is caught in the wild. • These baitfish are key to the health of wild ecosystems and they can also contain heavy metals which can be transferred to the farmed fish and then to humans. • Recently the USDA has developed a plant based fish feed using protein from soybeans, barley, and corn, with no fish or fish oil. • Studies have shown that this new food preforms as well or better than traditional fish feed using fish meal.