According to the State of World Fisheries and Aquaculture (SOFIA) 2022 report, per capita, apparent consumption of fish has been on a steady increase since 1950. However, despite innovations in capture technology and fishers working harder than ever around the world, it has been observed since 2003 that the amount of fish captured in major fisheries has been declining. This is attributed to fishery collapses—a reduction of a fish population within a fishery by 90 percent or more.
The major cause is overfishing; aquatic populations have become strained due to an ever-increasing demand for oceanic products. Many of these fisheries lie in international waters, and despite the advent of the United Nations and their Convention on the Law of the Sea, the only tangible protection that these fisheries have is through regional fisheries management organizations (RFMOs). These are international entities comprised of various States organized in the interest of regulating a region of international waters. Amongst these regulations are EU sustainable fisheries partnership agreements (SFPAs), which are considered “a benchmark for good fisheries governance” that ensures “equal rules, scientific management and social empowerment, with a focus on environmental sustainability, local growth, human rights and shared accountability,” according to the European Commission.
With that being said, the SOFIA report still indicates that fishery resources have still declined substantially in the past few years, and this decline may be exacerbated by the growth in the global population, a factor that is expected to ramp up aquatic food consumption by 15 percent. A solution to these demands is the growth of aquaculture, the industry of farming sealife through breeding and cultivation of aquatic populations. It has already played an important role in filling consumer demand for seafood without the environmental setbacks of any capture method.
Indeed, an example of its success in promoting sustainable consumption is the salmon industry. The 2021 Sector Sustainability Update from the US-registered Sustainable Fisheries Partnership states that 79.9% of all salmon produced is sustainable (their precise definition of sustainable can be found here), and approximately 82.6% of farmed salmon is considered to be improving.
However, aquaculture has many environmental risks depending on the quality of the operation. Firstly is the matter of chemical usage in aquaculture operations. Farmed salmon and other fish are treated with antibiotics, as given the confined nature of these operations, bacterial infections would be rampant otherwise. This contributes to bacteria becoming increasingly resistant to antibiotics. Additionally, pesticides, such as emamectin benzoate to ward off sea lice and other infestations are used; this practice has the potential to create pesticide treadmills, a phenomenon already occurring in Atlantic salmon farms around the world (e.g. Scotland, which has also been observed to have contributed to bee loss of life). These chemicals are ultimately not treated out of the water in open net-cage operations, as one of the economic benefits of these operations is the fact that ocean currents are used to flush the sites of wastewater. This has potentially dangerous effects on surrounding fish populations, such as certain crustacean species that are harmed by emamectin benzoate.
Secondly is the matter of waste treatment. As already established, most open net-cage operations do not have any form of wastewater treatment, instead opting for ocean current flushing. Organic waste from such operations, therefore, flushes out into ocean waters. Sometimes, pollutant feces is able to disperse and dissipate without much harm to the environment. However, if it flows into regions that have less powerful currents, the waste can lead to harmful algal blooms and/or promote bacterial pollution of waters, reducing overall water quality. This also has effects on clam gardens; organic wastes from salmon and other aquaculture farms have been observed to affect the quality of clam shells and meat in Canadian and US regions.
This is particularly harmful to indigenous North American tribes; in the US, as per the precedent set in the 1974 U.S. v. Washington ruling, the tribes of the Northwest Indian Fisheries Commission are entitled to 50% of all seafood caught in regional waters, and in general, indigenous tribes across western North America are economically and culturally dependent on salmon, clams and other aquatic life.
Robert Mountain, a Local Outreach Coordinator from the Musgamagw
Tsawataineuk Tribal Council, stated in a First Nations brochure that “waste from [salmon] farms can flow onto beaches where there is not enough tidal flow or water currents to dissipate or disperse the pollutants. Our people are the only clam diggers in the area and they sounded the alarm in the early 1990s. The clam diggers noticed the beaches near farms had changed. There was a sulphuric smell, unchecked algal growth, the clams had brittle dark shells and mushy dark meat.”
Thirdly is the introduction of a nonnative fish species through aquaculture farms. This often holds risks to biodiversity, especially in the context of surrounding native fish populations being in decline. For instance, if a substantial amount of Atlantic salmon escapes into Pacific waters, they could displace native wild Pacific salmon or interbreed with their populations. The latter could result from native wild populations being endangered; genetic intermingling with farmed fish can lead to the complete elimination of wild populations in a given area and, in their place, escaped farmed fish which are less fit to survive in a natural environment. This results in a loss of genetic diversity, arising from farmed fish’s faster rate of reproduction that overtakes that of wild fish.
Semi-closed fish farming, although a relatively new innovation, can prevent the risks posed by open net farming from becoming reality. It involves the use of giant containers that encapsulate the schools of fish, preventing wastewater from simply flowing out to the ocean.
This has a number of advantages, not just environmental. Sea lice are physically unable to enter through these barriers, and as a result, money is not spent treating the fish with pesticides, and the environmental effects of regular pesticide use are not felt by the surrounding waters and their organisms. This economic benefit is offset by the high costs associated with establishing and maintaining these containers and their wastewater systems.
This solution, and many others, remain either experimental or unadopted by the aquaculture industry at large. With an expected steady increase in aquatic food demand, it is critical that we continue to develop alternatives to wild catch operations in order to conserve aquatic ecosystems and fisheries around the world.
Informal bibliography (for the sources not explicitly cited within the article)
FAO. 2022. The State of World Fisheries and Aquaculture 2022. Towards Blue Transformation. Rome, FAO. https://doi.org/10.4060/cc0461en
https://www.oecd.org/sd-roundtable/papersandpublications/39374297.pdfhttps://oceans-and-fisheries.ec.europa.eu/fisheries/international-agreements/sustainabl e-fisheries-partnership-agreements-sfpas_en
https://heyzine.com/flip-book/2f80bae4af.html#page/2 https://www.annualreviews.org/doi/full/10.1146/annurev-ecolsys-112414-054339
