Many environmentalists dream of a world where producing food in a way that benefits the environment is possible. With commercial agriculture pushing pesticides, fertilizers, methane, and other pollutants into the environment, food production generates an oversized share of pollution. Looking at the food production problem through this lens, concepts such as restorative aquaculture appear to be the epitome of feeding two birds with one scone—producing food while improving the environment. The process of restorative aquaculture is explained in a piece by Darian Mizuta as “commercial or subsistence aquaculture that supports initiatives to provide/or directly provides ecological benefits to the environment, leading to improved environmental sustainability and ecosystem services, in addition to the supply of seafood or other commercial products and opportunities for livelihood”. While this explanation makes restorative aquaculture sound like a win-win solution, the many factors involved in manipulating environments have led to strong feelings both for and against restorative aquaculture practices.

Aquaculture practices can be a polarizing topic. In Puget Sound alone, there is a history of water quality degradation, marine disease, and non-native species introductions associated with aquaculture. In commercial aquaculture practices for finfish in particular, there is significant waste generated that can cause eutrophication and increased nitrogen levels in the environment. In addition, the rearing of species in higher-than-natural densities can lead to increased disease and parasitism from things like sea lice. In Puget Sound, we have experienced each of these consequences, as well as environmental catastrophes when aquaculture infrastructure fails, such as in the case of Cooke Aquaculture in 2017. In one infrastructure breakdown, over 250,000 non-native fish were released from Cooke’s pens into Puget Sound, threatening native stocks and their habitats. With a history like this, it’s easy to understand why there are negative views of aquaculture. 

While these events have led to some having a negative perception of aquaculture, aquaculture can also have positive outcomes. The Puget Sound region has a significant shellfish aquaculture industry presence that contributes to the region’s economic and community health. Aquaculture has the ability to improve food security and boost the supply of nutritious food to communities across the globe. In addition, shellfish and seaweed aquaculture can improve water quality. While traditional aquaculture can be beneficial in many ways, the practice of restorative aquaculture takes these benefits a step further.

The concept of restorative aquaculture goes beyond the traditional aquaculture goal of production; it aims to improve the environment while still producing seafood products for harvest. The Nature Conservancy praises restorative aquaculture as a practice that can improve the ecosystem while benefiting the economic development and food production potential of a region. The ecosystem and social services that restorative aquaculture provides can be worth billions of dollars annually, a figure that includes the market value of species produced as well as the ecosystem services created, such as nitrogen remediation. The Nature Conservancy’s site on restorative aquaculture claims that just under two and a half acres of shellfish or seaweed aquaculture can remove more than half a ton of nitrogen from the water. They value this ecosystem service at around $50,000, or the cost that a community would otherwise have to pay through water treatment in lieu of aquaculture. This decreases the cost of water treatment for the community while simultaneously providing a food source and market good. 

In addition to the human benefits that can be derived from restorative aquaculture, it also offers a whole suite of environmental benefits. Different forms of restorative aquaculture can provide different ecosystem improvements, from habitat creation to water filtration to carbon sequestration. Locating restorative aquaculture projects near areas where habitat has been degraded can provide new habitats for local species and nursery space for juveniles. This can boost stocks of native species and jumpstart habitat restoration efforts in the area. Even in cases where the aquaculture practice does not include a habitat-forming species, the gear used can provide benefits. Aquaculture pens and infrastructure suspended near the surface can provide wave attenuation services, protecting shorelines and intertidal habitats from extreme wave force. It is important to note, however, that these benefits are only helpful where extreme wave action is present. Restorative aquaculture may provide a number of ecological benefits that have positive impacts on the ecosystem and human communities that surround them.

While there are many potential benefits of restorative aquaculture, there remain some concerns and potential hazards from the practice. Restorative aquaculture, like traditional aquaculture, frequently involves introducing non-native species to an ecosystem. This practice can expose native stocks to contamination by parasites and diseases such as oyster herpes. Other threats include the introduction of new genetic material to local populations. This can be problematic because many farmed stocks are genetically modified to favor traits that make them more marketable, like faster growth or higher yield. These traits can be helpful in production settings, but can diminish a native species’ ability to compete or survive in their native environment. Even when performed in a cautious and conscientious way, the process of restorative aquaculture poses risks to ecosystems.

Here in Puget Sound, multiple groups are trying to create practices of restorative aquaculture. One example can be seen in the Swinomish Shellfish Company’s practices. Swinomish Shellfish Company grows native Olympia oysters and other species on their Fidalgo Island farm, generating food for commercial sales, subsistence, and use in traditional practices. In addition to the oyster farm, Swinomish Shellfish Company dedicates space to clam gardening, a practice that attracts shellfish larvae by developing protected sedimentary habitats within the intertidal zone. The company also works with regional restoration teams to create pocket estuaries, habitat that is critical to juvenile salmon. This production approach emphasizes food security, sustainability, and ecosystem restoration while also embodying the goals of restorative aquaculture.

Another Puget Sound group focused on restorative aquaculture is Blue Dot Sea Farms. Blue Dot grows kelp and oysters using suspension aquaculture techniques with a goal of supporting “marine ecology, enhanc[ing] water quality, and creat[ing] habitat for salmonids”. The oysters and kelp that they produce are commercially available and mostly sold to restaurants, yet their focus appears to be more on the sustainable potential of their approach. The team at Blue Dot contributes to research on enhancing ocean health, using kelp as biofuel, marine agronomy, and more. Their practices aim to positively contribute to the environment beyond simply creating habitat for salmonids and food for humans. While the potential of Blue Dot as a restorative aquaculture practitioner is high, the farm remains only 5 acres in size at Hood Head, WA. 

One of the more niche examples of restorative aquaculture in Puget Sound can be seen at the Port Madison Community Shellfish Farm on Bainbridge Island, a project developed and supported by the Puget Sound Restoration Fund. The Community Shellfish Project aims to create a sense of shared ownership over marine resource health with local communities while also providing food and improving ecosystem health. The oyster project provides habitat for juvenile fish, crabs, and other species while the oysters themselves filter microalgae and other particles from the water. This can help improve water quality while increasing species diversity. In addition, the farm is run by volunteers and all proceeds go toward regional water quality projects. The farm thus creates direct ecosystem benefits and also supports initiatives that benefit the larger environment, meeting both of the qualifications of a restorative aquaculture practice. 

While there are justified opinions of aquaculture as a positive and a negative force, the goals of restorative aquaculture are admirable. When developed in a way that complements the native ecosystem, restorative aquaculture can provide a number of environmental and societal benefits. As aquaculture practices continue to evolve to meet human demand, restorative practices can help the industry feed communities both in the sea and on land.