The Fish That Got Away-- Improving Aquaculture

Open Ocean Fish Farm

Did you ever hear the one about the fish that got away? Aquaculture is one of the fastest growing food production sectors in the world, and has been heralded as perhaps the most promising solution for a planet whose population is outgrowing its ability to feed itself. Between offshore open ocean fish farming and land-based containment tanks, aquaculture has the potential to provide consistent, year-round nutrient-rich protein, relieve pressure on depleted natural fisheries and play a significant role in the economy by providing jobs and valuable export trade in a sustainable manner.

Despite its promise, aquaculture could be the one that gets away unless its problems are solved. Poorly managed aquaculture harms both humans and wildlife, but well managed fish farms are doable once the problems are identified and solved.

Challenges to be overcome…

Pollution from wastes and excessive use of chemicals. Aquaculture facilities are like giant aquariums that must flush out their dirty water. They can discharge significant amounts of waste water containing feces, antibiotics, bacteria, excess feed— even anti-foulants and pesticides used to keep pens and cages clean. Excess food and feces increase nutrient levels in the water leading to algae blooms which remove oxygen from the surrounding water. This, in turn, can cause fish kills in waterways and dead zones offshore. Antibiotics effect

Water filter for wastewater treatment

those who eat the fish and contribute to the development of super strains of bacteria that are resistant to antibiotics, making it more difficult to treat diseases, which perpetuates the ever increasing use of antibiotics. Studies indicate that farm-raised fish contain higher levels of chemical pollutants such as carcinogenic PCBs than wild fish. To avoid polluting the surrounding environment, aquaculture systems should be contained and/or its wastewater should be treated prior to discharge.

Atlantic Salmon commonly cultured
in offshore fish farms invades
the Columbia River

Escaped farmed fish endanger the health and genetic diversity of local natural fish. Offshore fish farming uses cages or pens which although well engineered, still allow escapes during storms or episodes of equipment failure or human error. Net pens in the open ocean are vulnerable to tears by attacking predators like sharks. Whether escapes occur on purpose or accidentally, aquaculture is the primary source of non-native invasive species that damage the environment and threaten native species with predation, and the transmission of viruses and parasites. They can jeopardize the recovery of depleted or endangered species as they compete for food and habitat. In the end, these invasive species can dilute the native gene pool and threaten the long-term survival and evolution of native fish. Solutions to this problem are limited at this writing.

The source of feed stocks for farmed fish undermines our natural fisheries. In an inefficient turn of insanity in a topsy-turvy world, farmed species are fed wild species. Fish caught to make fishmeal and fish oil, a primary ingredient in fishmeal, represent one-third of the global fish harvest. Increasingly, aquaculture depends upon natural food sources such as krill, squid and other small coastal pelagic fish like anchovy and herring which are the

Anchovies

primary food sources for many who inhabit the ecosystem— everything from birds, marine mammals like seals, sea lions and whales to larger depleted or threatened pelagic fish like mackerel, swordfish, tuna and sharks. Most farmed fish are carnivorous, but some freshwater species like tilapia can be raised and fed more sustainable fare like algae and other vegetable matter— a promising solution to a small part of the problem as long as they don't escape.

The profit motive leads to frankenfish. Since farm raised fish are bred for profit, it is inevitable that wise marketers will select for the most desirable, the most marketable traits. Selecting and breeding only fish with the most advantageous attributes like size and growth

AquaBounty GMO salmon in rear

rate, will alter genetic composition over time. A more direct path to that outcome is altering the genetic makeup of species in the lab— the creation of GMO fish which serves to heighten the dangers of escaped fish.

Aquaculture appears to be in its infancy and requires maturity-- fast. Adequate funds must be available to deal with emergencies, and emergency planning should be assured before any facility earns its permits. Since a number of threats to wildlife and the environment emanate from aquaculture, facilities should be protected from severe weather, unexpected disease outbreaks, human error-- and even terrorism. Damage caused by unplanned events can cause major escapes and chemical pollution.

What can be done?

A robust commitment to responsible, enlightened aquaculture by producers, investors, government and consumers would not only prevent many of the problems discussed above, but it would greatly improve faith in the system and its products. Here are a few nuggets toward that goal.

• Improved research and education about potential ecological impacts and/or negative social and economic side-effects of developing aquaculture.
• Localized and regional oversight, scrutiny and management of all facilities since they impact local communities and supports special consideration for sensitive habitats such as estuaries, mangrove forests, wetlands, riparian fauna and vegetation— and breeding grounds for natural fish and fauna.
• Along with localized oversight mentioned above comes smaller aquaculture facilities with more intensive use of fewer resources. Covers less area affording more manageable resource application, accident prevention and remediation.
• Environmental impact assessments at the outset and centralized collection of environmental data, farm performance and event response— along with regular environment monitoring. This would improve farm performance as well as prevent unplanned events.
• Deeper study leading to improved husbandry practices regarding selection and application of feeds and fertilizers, antibiotics, drugs and other chemicals-- or substitutes for them.
• Last but not least, development of self-regulatory codes of practice or guidelines for best practices for the entire global aquaculture industry.