Issues

Environmental Impacts

In recent years a number of concerns have been raised about the environmental effects of aquaculture.These effects vary with the type of aquaculture system used, the species farmed, the scale and intensity of the operation, and the management practices employed. Potential impacts include: pollution in the form of uneaten food, fish waste and therapeutic drugs and chemicals affecting water quality around and below aquaculture facilities; escapes of farmed organisms and their interactions with marine wildlife; disease and parasite transfer to wild populations, and death or injury of marine mammals, seabirds and other wildlife from entanglement in or other contact with aquaculture facilities.

On the other hand, some forms of aquaculture can have positive effects on the environment. For example the farming of filter feeding shellfish in coastal waters can help remove excess nutrients, leading to improved water quality. Marine aquaculture can also produce juveniles for enhancement of depleted stocks of wild species. A better understanding of the effects aquaculture on the marine environment is needed and will be needed if marine aquaculture is to develop in an environmentally sustainable manner.

(http://www.pewtrusts.org/pdf/env_pew_oceans_aquaculture.pdf)

(http://www.frontiersinecology.org/specialissue/articles/Goldburg.pdf)

(www.wwf.no/core/pdf/wwf_escaped_farmed_fish_2005.pdf) 

Reducing Environmental Impacts of Coastal Aquaculture By the FAO Joint Group of Experts on the Scientific Aspects of Marine Pollution

(http://gesamp.imo.org/no47/index.htm)

The Environmental Status of Norwegian Aquaculture By the Bellona Foundation

(http://www.bellona.no/data/f/0/34/65/5_9811_1/Bellona_Report_No.7.pdf)

The Net-pen Salmon Farming Industry in the Pacific Northwest By the U.S. Department of Commerce, NOAA Technical Memorandum NMFS-NWFSC-49

(http://www.nwfsc.noaa.gov/publications/techmemos/tm49/tm49.pdf)

Economics

According to the U.N. Food and Agriculture Organization (FAO), most fisheries are either fully exploited or have been overfished. With global demand for seafood increasing, most experts believe that aquaculture is the only means to produce the additional seafood that the world’s consumers are demanding. In response, aquaculture has been growing at an annual rate of more than 10 percent worldwide and, by some estimates, now produces about a third of the fish and seafood eaten. For some species, such as salmon, aquaculture now accounts for more than 60 percent of worldwide production.

In coastal communities hit hard by the decline of wild fisheries, aquaculture can replace jobs in production, processing and sales. However, as the aquaculture industry grows, so has awareness of its effects on the marine environment. From an economic standpoint, many types of aquaculture have been criticized for the costs they impose on society as a whole in terms of pollution, escapes of genetically distinct or exotic farmed fish, the depletion of forage fish stocks used to produce aquaculture feeds, and the spread of diseases to wild fish, among other effects.

In determining whether or not an activity like aquaculture is sustainable, a critical issue is to ensure that all costs are accounted for fully. For example, if growers realize profits only by ignoring the social costs of pollution and escapes, then aquaculture cannot be deemed truly sustainable.

(http://usda.mannlib.cornell.edu/reports/erssor/livestock/ldp-aqs/)

(http://www.labor.state.ak.us/research/trends/oct03ind.pdf)

(http://www.ksg.harvard.edu/sed/docs/k4dev/hoagland_mre_2003.pdf)

Coastal Communities

As aquaculture expands into the marine environment, questions loom large for coastal communities that have traditionally depended on fisheries and have, in recent decades, increasingly depended on tourism. The jobs and revenue that aquaculture brings have been welcomed in many coastal communities, particularly those hit hard by the decline of wild fisheries. However, experience to date has shown that large-scale production of seafood depressed wholesale prices overall, making it harder for traditional fishermen to make ends meet. Secondly, aquaculture by its nature requires dedicated space for pens, cages or tanks, and these uses can compete with other, more traditional uses such as recreational boating and commercial and recreational fishing. Moreover, pollution from aquaculture facilities and escapes of cultured species can also have a detrimental effect on local business and cultural activities.

The large question looming as we begin to farm the sea is how and to what extent will it transform coastal communities? Will industrial-scale agriculture in the seas produce the same harmful effects to the environment that the green revolution produced on land or can we learn from the mistakes of terrestrial agriculture? Will jobs and profits remain in coastal communities, or will market-driven consolidation and integration export jobs and profits, leaving coastal communities to deal with the impacts but few of the benefits of aquaculture?

(http://dlc.dlib.indiana.edu/archive/00001045/00/suryanata.pdf) 

(http://www.fisheries.ubc.ca/publications/reports/report13_3.php)

(ftp://ftp.fao.org/docrep/fao/007/y1818e/Y1818e00.pdf)

(http://iis-db.stanford.edu/pubs/20270/salmon_environment_2003.pdf)

Seafood and Public Health

Per capita seafood consumption in the U.S. reached a record high of 16.3 pounds in 2003.As the population continues to grow and consumers look for healthy foods to eat, it is expected that seafood consumption will continue to increase. The benefits of eating seafood are well known. Seafood provides “good fats”—omega-3 fatty acids, which have been shown to protect against heart disease and are important in the development of infants. Seafood is also a low-fat source of protein, vitamins, and minerals.

Unfortunately there are also risks involved in the consumption of seafood, both wild and farmed.The amount of mercury and other contaminants in seafood has received a great deal of attention in recent years.Mercury, which is generally found in higher concentrations in large, predatory fish such as tuna and swordfish, is believed to be especially harmful to women and children because it can interfere with development. Recent scientific studies indicate that--like wild fish-- farmed fish can accumulate toxic contaminants such as PCBs and dioxins.Additionally, some imported farmed fish and shellfish have been found to contain chemicals and antibiotics, which could be harmful to consumers.

(http://circ.ahajournals.org/cgi/content/full/94/9/2337?ijkey=e7eae7a513f5bf4aa39d5d7edd1d7e74c4e70b23&keytype2=tf_ipsecsha)

(www.salmonstudy.org)

(http://epa.gov/waterscience/fish/forum/2004/)

A wide variety of marine species is currently farmed in the U.S. Farmed species range from filter feeding mollusks such as oysters, clams, and mussels, through omnivorous catfish to carnivorous fish such as salmon and cod.While filter feeding organisms require no feed inputs, concerns have been raised about the farming of carnivorous fish species because they require a high protein diet. From an energetic standpoint, the husbandry of carnivores is inefficient. It takes two or more pound of wild fish to raise carnivorous finfish for human consumption--a net loss of protein. Yet the high prices that these species command continue to drive growth in their culture. Currently, much of the protein in feeds for carnivorous fish comes from fishmeal obtained by catching wild fish, a finite resource that some have suggested is at its maximum sustainable yield.

Dramatic growth in the production of the carnivorous fish that western consumers prefer has raised challenging questions about the ecological sustainability of the industry.The dependence on wild fish for feed ingredients could result in increased pressure on wild fisheries used to make the feeds, with concomitant impacts on the ecosystems from which they are harvested. There is a growing realization that if aquaculture of carnivorous feeds is to expand, protein alternatives, most likely plant-based, will need to be developed.While much of this work has begun, it will be a major challenge for the industry to continue to grow while reducing its dependence on wild fish for feeds.

(http://www.rspb.org.uk/Images/fishmeal_tcm5-58613.pdf)

(http://iis-db.stanford.edu/pubs/12219/effect_aquaculture_nature_2000.pdf)

(http://emboreports.npgjournals.com/cgi/content/full/2/11/958)

(http://www.nautilus-consultants.co.uk/seafeeds/Files/Final%20Report.pdf)

(http://www.worldwildlife.org/cci/dialogues/salmon.cfm)

Many experts believe that growth of marine aquaculture in the U.S. is constrained by legal and regulatory issues.It has been suggested that the legal and regulatory regime governing marine aquaculture be modified to clarify rights and jurisdictions, harmonize overlapping and conflicting regulation and streamline permitting. A number of studies have suggested that the environmental impacts of aquaculture as well as conflicts with other uses of ocean space could be substantially reduced by moving facilities to the federal Exclusive Economic Zone, which generally extends from three to 200 nautical miles offshore.

Many federal regulations already apply to aquaculture, including permits for siting facilities, environmental impacts, waste discharge, chemical use, and interactions with wildlife. While these issues are likely to remain, the Administration is currently drafting legislation to provide the National Oceanic and Atmospheric Administration (NOAA) the authority to lease areas in federal ocean waters for aquaculture and coordinate the permitting process.

Aquaculturists operating in state waters, which generally extend three nautical miles offshore, face an array of regulations and processes that vary widely from state-to-state.Additionally, the federal Coastal Zone Management Act requires any development of aquaculture in the federal waters to be consistent with nearby state coastal management policies. This provides the states with an important ongoing role in the development of aquaculture in federal waters.

(http://www.whoi.edu/science/MPC/dept/research/SKAquaRegFinalRpt.pdf)

(http://darc.cms.udel.edu/sgeez/sgeez1final.pdf)

(http://www.olemiss.edu/orgs/SGLC/Offshore%20Aquaculture.pdf)

(http://www.oceanservice.noaa.gov/websites/retiredsites/natdia_pdf/15devoe.pdf)

(http://www.sab.noaa.gov/Meetings/2005/August/Presentations/Bunsick_final.ppt)

(www.oceanservice.noaa.gov/websites/retiredsites/natdia_pdf/16rieser.pdf )