Whether it’s sushi, in a bowl, or smoked, salmon is a popular food in all cuisines. But, the majority of salmon in your typical grocery stores are farm raised and not fished in the wild. In despite of its delicious taste, the way industrial salmon is farmed is becoming detrimental to oceanic environments. Originally, these farm-raised fish were an attempt to regulate overfishing, yet this type of harvesting is currently more harmful than is effective. Salmon farming has negative impacts on the salmon population, surrounding organisms, and even at the ecosystem level.

The way salmon is farmed is not as different as your typical cow and pig farms, except the fact that the waste from their enclosures bleed into the ocean around them. The life of a farm raised salmon begins in freshwater at the juvenile stage. Once they are adapted to saltwater conditions, the young adults are transferred to oceanic pens. These pens can hold up to 200,000 salmon at a time. When these fish are suitable for the market – typically determined by a certain weight – they are starved for a week to empty the digestive system and then slaughtered. Salmon, like other farmed fish, are not numbered by the individual, but by the ton. In 2019, the global salmon market reached 2.6 million tons and just six years later, it sprung to 3.1 million tons and is only expected to rise.

Salmon in the wild travel thousands of miles throughout their lifetime, while these caged fish live their lives trapped 50 meters wide and 150 meters deep. The cramped pens prevent salmon from natural behavior and often spread disease. Pathogens formed in the pens are treated with antibiotics which is another problem in itself, contributing to antimicrobial resistance. Not only that, but technical mistakes result in thousands of untracked fish escaping into the wild, increasing disease spread to wild fish. In 2023, 50,000 salmon escaped into Machias Bay, Maine and possibly impacted their critically endangered wild salmon.

In addition to disease, the rapidly growing salmon also produce feces, and a lot of it. In fact, several thousands of fish in the pens can produce one million pounds of waste annually. This waste is unregulated and untreated which results in the feces sinking to the ocean floor. This is where it decomposes to release nitrogen and reduce the amount of dissolved oxygen. Without dissolved oxygen, the conditions for fish and other organisms to live get much harsher and can even lead to hypoxia. It also creates an environment where toxic algal blooms can occur and wipe out all the fish, plants, and crustaceans. While some amount of nitrogen can be beneficial for the marine environment, the sheer amount of waste produced by these farms are extremely harmful to the surrounding ecosystem. Ocean farming, along with the warming of our climate, is becoming more destructive by decreasing biodiversity and disrupting whole ecosystems.

To put the problem locally, Maine is a leader in waste production with minimal regulation in place. The permits for Maine’s pens don’t require companies to track or limit their waste input in the ocean. The Department of Natural Resources in Maine is the company that is responsible for renting out locations to place the farms. In order to finalize a spot, the environmental conditions are supposed to be a certain way so that the impacts of the farm are few. However, The Department is currently failing to choose the right locations, they have approved farms that are too close to each other, in important fishing areas, and shallow water ecosystems in which the waste is more impactful. Another Department in Maine, the Department of Environmental Protection, doesn’t set any limits on the pollutants produced by the farms and doesn’t value monitoring how the pollutants affect the surrounding environment.

If the salmon farming industry is going to continue, it needs to continue their business safely. Marine ecosystems, especially in Maine’s waters, will not be able to sustain the amount of waste dumped into the ocean and we could see the loss of plant species like eelgrass, local fish species, and up to entire habitats. Fortunately, there are many environmental advocates fighting for the protection of our oceans and standing up against the negligent Departments. As advocates ourselves, we can purchase wild salmon instead of farmed, go to protests, sign petitions, and do what we can to serve our part in the Earth’s ecosystem.