This post is part of KQED’s Do Now U project. Do Now U is a biweekly activity for students and the public to engage and respond to current issues using social media. Do Now U aims to build civic engagement and digital literacy for learners of all ages. This post was written by Ben Lokken, Anna Herff, Tim Jenkins and Sara Wolf, students in Juk Bhattacharyya’s “Environmental Geology” class at University of Wisconsin-Whitewater.
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Fish on a Farm
Get a brief introduction to fish farming, including some environmental concerns and how scientists are helping to address those impacts.
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Do the benefits of aquaculture and fish farming outweigh the negative impacts? #DoNowUFishFarm
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Learn More About Aquaculture
Aquaculture has emerged a popular and efficient way to grow and rear marine and aquatic life for consumption. Various species of fish, shellfish and even plants are grown in tanks, ponds, man-made inland systems or open water cages in the ocean until they reach market size. On a large scale, aquaculture could lessen the need for finding and catching wild fish for food or ornamental purposes (i.e. aquariums) and also help us more efficiently harvest underwater plants for uses in pharmaceuticals, nutritional supplements and other products. Aquaculture has grown exponentially in recent years. For example, according to the Food and Agriculture Organization of the United Nations, 44.1 percent of total fish production worldwide in 2014 came from aquaculture, an increase from 42.1 percent in 2012 and 31.1 percent in 2004. Aquaculture shows tremendous promise in being a long-term source of food to sustain a growing population. However, it has its fair share of problems.
There are many reasons why aquaculture is good for the environment. In 2009, the total seafood consumed in the world was more than117 million tons. Of this, 90 million tons were taken out of freshwater and marine habitats. This practice can lead to overfishing, which happens when more fish are caught than can be replenished naturally. This can cause certain fish species, like Atlantic bluefish tuna, to become extinct. Overfishing can impact marine ecosystems as well. For example, cod feed on herring. If herring are overfished, the cod population is adversely affected. Upsetting links on the food chain has consequences up and down the line. Aquaculture could help decrease the effects of human consumption of fish on freshwater and marine water habitats by producing food without taking away from overfished environments. Fish, plants and shellfish produced in aquaculture farms are also used to rebuild species populations in freshwater and saltwater habitats. A lesser-known benefit is that plants grown in aquaculture provide material used in pharmaceutical, nutritional, and biotechnology products. Aquaculture can also potentially be used for treating sewage and wastewater. For example, in India, treated sewage is first passed through ponds of duckweed and next through ponds of prawns and carp. These animals gain nutrients from the waste as they clean the water. The water can then be used for agricultural purposes. These are just some of the ways aquaculture is beneficial not only to habitats and wild fish, but also to humans.
Along with the positive aspects of aquaculture come some negative ones. Fish farms can impact wild fish populations by transferring disease and parasites to migrating fish. Aquaculture can also pollute water systems with excess nutrients and fecal matter due to the large numbers and concentrations of farmed fish. Sometimes equipment used in aquaculture can be problematic. For example, in the Puget Sound, geoduck clam farming has affected the coastal ecosystem—the amount of PVC piping and netting has changed the landscape for marine life, although the farmed geoducks, themselves, did not have a negative effect. Also, raising farmed fish can cost a lot in resources. For example, many species of fish raised by aquaculture, such as salmon, are predatory fish. They are fed pellets made from other fish like anchovies or sardines. So, wild fish are being caught to feed farmed fish. In some places, the practice of trawling the bottom of the ocean for marine life in order to make fishmeal scrapes the sea floor, thus harming the sensitive ecosystem. The increased amount of pollutants in fishmeal, caused by toxins from ocean pollution, is also raising concerns because these harmful toxins make their way into food targeted for human consumption.
There are some great benefits to fish farming, but before continuing on, we must be aware of the potential harmful effects it could have on us as consumers as well as the environment. What do you think? Is aquaculture a good alternative to wild harvesting of fish and shellfish?
Website: Bren School of Environmental Science & Management, University of California, Santa Barbara
Learn about key aquaculture species, the cost and benefits of aquaculture, and community and industrial aquaculture practices.
Website: Monterey Bay Aquarium
Read about some of the effects of aquaculture, including pollution and disease, how fish that escape pens affect wild populations, and potential damage to habitats.
Scientists See Aquaculture in America’s Future
Hear why the U.S. is behind other countries in aquaculture even though demand for seafood is growing.
KQED Do Now U is a biweekly activity in collaboration with SENCER. SENCER is a community of transformation that consists of educators and administrators in the higher and informal education sectors. SENCER aims to create an intelligent, educated, and empowered citizenry through advancing knowledge in the STEM fields and beyond. SENCER courses show students the direct connections between subject content and the real world issues they care about, and invite students to use these connections to solve today’s most pressing problems.