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Aquaculture Operations - Best Management Practices

Aquaculture Operations

Operating procedures, schedules of activities, maintenance procedures, and other management practices that aquaculture operations can use to prevent or reduce pollution.

National Strategy for the Development of Regional Nutrient Criteria

EPA is presenting a National strategy that describes the approach the Agency will follow in developing nutrient information and working with states and tribes to adopt nutrient criteria as part of state water quality standards. The strategy presents over enrichment assessment tools and recognizes current capabilities for conducting these assessments at the regional watershed and waterbody levels. The major focus of this strategy is the development of waterbody-type technical guidance and region-specific nutrient criteria by the year 2000. Once waterbody-type guidance and nutrient criteria are established, EPA will assist states and tribes in adopting numerical nutrient criteria into water quality standards by the end of 2003.

The National Water Quality Inventory: 1996 Report to Congress Executive Summary cites nutrients (nitrogen and phosphorus) as one of the leading causes of water quality impairment in our Nation's rivers, lakes and estuaries. Forty percent of the rivers were impaired due to nutrient enrichment, 51 percent of the surveyed lakes, and 57 percent of the surveyed estuaries were similarly affected.  Nutrients have also been implicated with both the large hypoxic zone in the Gulf of Mexico, hypoxia observed in several East Coast States, and Pfiesteria-induced fish kills and human health problems in the coastal waters of several East Coast and Gulf States. The national response to the nutrient problem has been limited primarily because of concerns over the scale of the problem, and because of the tremendous variability of nutrient conditions, both natural and cultural, throughout the nation.

Presently, the only national water quality criteria in existence are for nitrate nitrogen and phosphorus. In 1976, in EPA's  Quality Criteria for Water (also known as the Red Book), EPA presented ambient water quality criteria for nitrates, nitrites and phosphorus. The criterion for nitrate nitrogen was 10 mg/L for the protection of domestic water supplies. The nitrate criteria were intended to prevent over enrichment and to protect human and animal health. The phosphorus criterion was 0.10 ug/L elemental phosphorus for the protection of marine and estuarine waters. This criterion was based on a conservative estimate to protect against the toxic effects of the bioconcentration of elemental phosphorus to estuarine and marine organisms, and not on the potential to cause eutrophication.

In response to this effort to address nutrient assessment and over enrichment, EPA developed a peer reviewed national nutrient criteria strategy. The major elements of this strategy include: 

More information from EPA
–  National Nutrient Strategy
–  Federal Register Notice of National Strategy for the Development of Regional Nutrient Criteria
–  Contact EPA's Health and Ecological Criteria Division (4304)
    Ariel Rios Building
    1200 Pennsylvania Avenue, NW
    Washington, D.C.  20460 

More information from the States

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Marina Habitat Assessment and Scallop Farming

Ten years of private ecology research has demonstrated that recreational boat full-service marinas are productive artificial reefs and has led to the development of commercially viable bay scallop aquaculture under marina docks.

More Information from EPA
Cedar Island Marina, Inc.

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Model: Fishponds of Moloka'i, Hawaii

The south shore of Moloka'i island is blessed with the greatest number of relatively intact, ancient Hawaiian fishponds in the state and perhaps the strongest advocates of fishpond preservation and restoration. Moloka'i is popularly referred to as the "Last Hawaiian Island." Within the total 1990 population of 6,717, 49 percent were Native Hawaiian, the largest percentage of Hawaiians of any of the six major islands. With that strong native basis, the community has developed a vision of a Moloka'i that includes a rural subsistence lifestyle that relies upon existing and potential resources of the land and the people to stimulate local employment opportunities.

The community envisions that the fishponds, which have slowly deteriorated and are under-utilized, will be restored and managed by residents primarily for subsistence use. Secondary considerations to restoring the fishponds may include:  using them as a teaching tool for various disciplines (Hawaiian culture and history, marine sciences, resource management, etc.), eco-tourism, recreation, and community-oriented economic development. However, beyond these proposals is the overriding wish of the community to save the historic structures from further destruction as they embody an important spiritual, cultural, and historic link with the past. 

Unfortunately, community wishes to restore the historic ponds are running into the modern statutory and regulatory structure designed to protect Hawaii's present marine and coastal environment. At the moment, the restoration of coastal fishponds entails at least six major federal, state, and county permits. Costs to complete this process may range as high as $150,000. While these laws intend to balance the competing interests of protecting marine and coastal environments against its over-development and degradation, they also pose the latest, and some feel the greatest, impediment to attempts to restore the ancient Hawaiian fishponds. This level of cost to acquire permits unintentionally seems to favor projects that require substantial returns on investment, hence the trend for development within the coastal zone to favor major outside private interests rather than small, local community interests. 

The regulatory process also, unfortunately, has had the effect of transforming the original community vision for fishpond restoration. As each permit is granted, it has come with a number of preconditions to be fulfilled before restoration can commence. Such preconditions are inadvertently rewriting the plans and strategies of fishpond restoration as to how, and for what purposes, the fishponds can be restored. 

A number of techniques have evolved in an attempt to reduce delays, costs, and changes related to the regulatory process. These include: 

For many, it is hoped that the lessons learned from Honouliwai will pave the way to work on the other fishponds and provide a major step toward reviving the aquacultural legacy of Molokai's ancestors.

More Information from EPA
The Historic Fishponds of Moloka'i, Hawaii

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Recycling Sediment

America's waterways need to be--indeed, must be--dredged.  Strong national commerce and defense are critical reasons, yet environmental and public health concerns often restrict port and waterway dredging. After a century of industrial, agricultural, and other pollution discharged into our waters, dredging stirs up waste and yields contaminated material in large volumes. The problem is exemplified in the Port of New York which pays $118 a cubic yard to haul and dump contaminated material in Utah.

But dredged materials, either clean or contaminated, do not have to be a disposal problem; there are other options. Rather than looking at these materials as something to be disposed of, there are those who see them as a potential resource. Beneficial uses of sediment date to ancient times when dredged clay was used for dikes. One use is to create settling ponds or fish farms.

Of course, many issues make today's demands more difficult to resolve. To deal with modern complexities, there are a number of existing and emerging technologies to cope with contaminants in sediments, virtually all of which provide some form of de-contaminated end-product. Thus, the distressful "Where can we put dirty sediment? in the future may evolve into "How can we use cleaned sediment?"

More Information from EPA
Sediment Management

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