What is Aquaculture?
Aquaculture involves the rearing of aquatic animals or the cultivation of aquatic plants, and often involves the production of shellfish or finfish for human consumption. San Diego is home to aquaculture projects of various sizes and purposes, though most are either land-based or considered “nearshore aquaculture” and are located in our lagoons or bays. Existing local projects largely operate under established permits and standards designed to protect the region’s water quality.
Currently, offshore aquaculture of finfish doesn’t exist in the United States’ federal waters, which start at three miles offshore and extend 200 miles from our coastline. However, in recent years, notable attempts have been made to explore the feasibility of large, open-ocean aquaculture projects in the federal waters just offshore from San Diego. Marine finfish aquaculture, or “open ocean” aquaculture specifically involves the production of fish for food in the ocean environment, usually in nets, pens, or cages. Because open-ocean aquaculture often involves the large-scale production of food akin to factory farming, aquaculture projects throughout the world have been shown to degrade the surrounding marine environment in various ways.
Environmental Considerations with Large-Scale Aquaculture
The following environmental considerations have yet to be comprehensively addressed by the federal government. Currently, there is no system in place to measure the environmental impact of such large-scale open-ocean aquaculture projects and mitigate those impacts.
- Feeding operations
Producing a single kilogram of high-value carnivorous marine fish such as yellowtail, cod, sea bass, or tuna typically uses two to five kilograms of wild-caught fish processed into fish meal and fish oil for feed. From an ecological perspective, using wild-caught fish to produce a smaller amount of farmed fish is incredibly inefficient, and encourages unsustainable wild fish harvesting. Supplementing fish feed with land-based nutrients from corn, soybeans, or grains raises additional environmental concerns.
- Sourcing and selecting farmed species
Farming non-native fish species locally poses an unacceptable risk to native ocean ecosystems. In the past, escaped fish from aquaculture operations have introduced new and often effective predation, competition, and disease into local ecosystems. Transporting juvenile fish used to populate or repopulate the farm raises energy and efficiency questions.
Aquaculture is known to amplify disease and parasites due to crowded conditions within the farmed population, which transmits these back to wild fish. Disease can spread at a rapid pace; as water flows through the cage, parasites are washed out and can infect wild fish. Antibiotics, other drugs, and chemicals to prevent disease are passed into the environment and may be passed to the consumer.
- Predator and wildlife interruptions
Sharks, whales, seals, and other predators attracted by the captive fish may become entangled in the cages, nets, or related equipment. This could result in incidental death, damage to net pens, and escaped farm fish.
- Nutrient pollution
Nutrient pollution is one of America’s most widespread, costly, and challenging environmental problems, and is caused by excess nitrogen and phosphorus in the water. Excess nutrients from residual feed, fish waste, and other products used in aquaculture contaminate the surrounding environment. This may lead to algal blooms, unhealthy dissolved oxygen levels, or “dead zones” near the operations.
- Cumulative impacts
Multiple aquaculture operations in a given geographic region may have unintended or unforeseen significant cumulative impacts.
- Location concerns
Offshore aquaculture facilities could potentially interrupt marine life migration routes if they are not properly sited. In places where oil rigs exist, offshore aquaculture on or near oil rigs poses significant environmental and consumer risks, and complicates matters of oil company responsibility in the event of future damage or liability caused by the rig.
Lack of current regulation
If domestic offshore fish aquaculture is to be pursued in federal waters, the critical first step toward ensuring responsible execution of aquaculture projects is for the United States Congress to establish a national federal framework for the review, permitting, leasing, and regulatory oversight of projects that leads to robust best management practices to address environmental impacts and monitoring requirements. Once that framework is in place, we encourage continued transparency and public debate regarding all proposed offshore aquaculture facilities and their ongoing operations.
A Local Example: Rose Canyon Fisheries
On February 25, 2015, Rose Canyon Fisheries, Inc. submitted an application to the Army Corps of Engineers (the government body currently in charge of approving navigational obstruction permits) for a permit to establish the structures related to a proposed commercial aquaculture project off the San Diego coast that could produce 11 million pounds of fish annually. In response, San Diego Coastkeeper called for congressional action to establish a clear federal regulatory framework for all aspects of the offshore aquaculture permitting process to precede any individual permit. In addition, Coastkeeper advocated for an extensive overhaul to the environmental protections proposed for this project. The Rose Canyon Fisheries aquaculture project is currently on hold, and we continue to monitor its progress. Coastkeeper advocates for sustainable, wild fish populations that produce healthy food and support fishing businesses in balance with good water quality and a healthy ecosystem.
Download this PDF to access all scientific citations related to the information above and to read our March 11, 2015 comments on the Army Corps permit application.