Understanding the Sustainable Seafood Industry

Worldwide, seafood is the largest traded food commodity. The consumption of aquatic animals ensures nutrition and food security for more than three billion people who depend on wild-caught and farmed finfish and shellfish as vital sources of protein.

Consequently, market demands have caused stocks of the world's large ocean fish, among them swordfish and tuna, to be nearly depleted—by some estimates as high as 90%. A 2022 report from the National Oceanic and Atmospheric Administration, the U.S. agency in charge of conserving and regulating marine and coastal ecosystems, reported that stocks of the most overfished species had reached an all time low in 2017.

So, what could possibly be "sustainable" about seafood? Has this phrase, like so many thrown about in the environmental movement, merely served as virtue signaling for overconsumption? Here, we'll explore the environmental problems and potential solutions within the seafood industry.

Overview of the Seafood Industry

The U.S. commercial fishing and seafood industry generates more than $200 billion in sales annually, with imports more than doubling the weight of exports. NOAA found that in 2020 the U.S. exported nearly 2.4 billion pounds of seafood; meanwhile, 6.1 billion pounds of foreign seafood wound up on American plates.

Imported seafood makes up a staggering 94% of seafood consumed in America. A big portion of that is fish caught or farmed in the U.S., then sent abroad for processing and returned. However, foreign-raised shrimp, salmon, and tilapia are inexpensive to import, and a growing percentage of it is farmed, not fished.

Aquaculture

Fish farms, also known as aquaculture, provide several benefits over wild-caught seafood: lower levels of pollution and disease, less damage to ecosystems, and greater ability to employ and monitor rigorous sustainability standards. If these conditions are met, sustainable aquaculture can solve the global demand for seafood without overtaxing irreplaceable natural resources.

The success of aquaculture can be measured by the increasing percentage of farmed aquatic animals that directly feed humans—currently around 50%.

However, if aquaculture is not well-planned or maintained, it can have disastrous consequences: Pollution and disease leaking from fish farms can decimate neighboring rivers, lakes, and other water sources. With proper filtration or fishing systems closed off to adjacent ecosystems, fisheries can successfully remove fish waste and prevent it from entering nearby waters.

Other Environmental Issues

As aquaculture continues to expand, the deforestation of mangroves also poses a threat to sustainable seafood. Along with recovering fish species, mangroves, too, require rehabilitation for long-term seafood sustainability.

Additionally, many farmed fish are carnivorous. Tuna, salmon, trout, and kingfish all feed on smaller fish rich in omega-3 fatty acids. To meet these high demands, farmed fish are fed pellets made partially from smaller fish that could have been used to feed people in developing nations.

This human-made fish feed generates its own set of carbon emissions, mostly during production. Fish feed is also quite expensive, swallowing up to 70% of all operational costs, thereby excluding many small-scale fisheries from affording it.

As a consequence of this vicious cycle, factory farm fishing also wrestles with the widespread use of antibiotics, like the livestock industry, another impediment to sustainability.

The Environmental Impacts of Fishing

Sustainable fishing requires environmental and economic justice for the communities that depend on the fishing industry, paying close attention to unsustainable practices—including overfishing, the unintentional capture of marine animals in fishing nets, water pollution from poorly managed fish farms, and the use of wild fish to feed farmed fish.

Overfishing

The heavy and recurring demand for a select few aquatic foods has led to the exploitation and overfishing of particular marine species. Thanks to recent sustainability efforts and cooperation with regulators, some American fish stocks, including gag grouper and North Atlantic albacore, have rebounded. Other populations are currently rebuilding under protection from U.S. law, while some species—bluefin tuna, Chilean sea bass, and Atlantic cod, among others—struggle to survive, according to Greenpeace's Red List. 

Enhanced technological innovations—like electronic monitoring systems on boats—promise to make available the data necessary for both scientists and governing bodies to determine the efficacy of sustainable fishing practices. 

Tracing Illegal Fishing

Closely related to overfishing is illegal fishing, which may make up some 30% of catch for high-value species. This pervasive practice harms the environment and can financially harm legally operating fisheries by moving tens of billions of dollars through untraceable supply chains. 

In the future, technology, including AI, could help track and determine the journey of seafood, which often travels overseas for processing before returning to the U.S. More transparency along the supply chain makes it easier for customers to support sustainable practices.

Bycatch

Of the marine food that is legally and illegally caught, nearly 40% is comprised of bycatch—including turtles, birds, dolphins, whales, sharks, and rays incidentally killed in fishing and lobster nets. Since this collection of non-targeted wildlife (and its subsequent disposal) occurs on the open ocean, these unsustainable practices often elude regulators and researchers, complicating marine conservation efforts. 

Habitat Destruction

Invasive fishing practices can also destroy ocean habitats, including coral. The seabed teems with life, and the practice of bottom trawling—dragging a fishing net behind a boat along the ocean floor—can cause irreparable harm to the biodiversity of an area. 

Coastal habitats benefit from the edge effect—the increased biodiversity that arises in the area between two separate ecosystems. These crucial ecologies also serve as the traditional home for aquaculture. When coastal habitats are transformed into farming operations, the industry can damage the surrounding ecosystems, including the edge. 

Creating and managing legally protected marine areas—what Monterey Bay Aquarium Seafood Watch describes as national parks for bodies of water—can help maintain necessary biodiversity in all corners of the globe and even restore overfished stocks. People and economies often thrive when coastal communities can care for these habitats using traditional practices. 

Farmed Fish Escape

When non-native fish, like salmon and shrimp, accidentally find their way into the ecosystems abutting aquaculture operations, they can negatively impact the local ecology by competing with local populations for territory, reproductive partners, and food, or possibly introducing disease.

Fisheries must take responsibility for any escapes that do occur by establishing plans to maintain and monitor facilities to prevent escape and respond quickly should an escape occur. Plans must also include structures that can withstand predator attacks and weather- and climate-related damage without risking escape.

Seafood and Greenhouse Gas Emissions

Transportation and refrigeration account for most of the carbon expenditures in wild-catch fishing. Before marine food ends up on your plate, it has often traveled the world—sometimes by plane but almost certainly by boat. Fishing vessels produce sulfur oxides and black carbon, short-lived pollutants, and those same boats’ refrigeration systems also emit dangerous hydrofluorocarbons. 

Aquaculture operations also typically run on electricity likely provided by coal. The rise of renewables will make the transition to carbon-neutral energy relatively straightforward for fisheries. 

Commercial vs. Smaller-Scale Fish Farming

The size of the fishing operation also plays a role in the ecological impact of seafood. Since 2012, the world has been producing more fish from aquaculture than from capture. With this in mind, consumers are left with a decision to support either small-scale or commercial-sized operations.

Small-scale fisheries use catch methods with a smaller impact on the surrounding environment. Instead of dropping trawling nets, these sustainable fish farmers use hooks and line or lay traps for their haul, leaving threatened megafauna at the bottom of the ocean in their rightful place. Supporting these smaller fisheries can boost the region's economy and create a demand for sustainable, local marine food. 

How to Shop for Sustainable Seafood

Sustainable fish and shellfish can find their way to your plate with a bit of vigilance. These sustainable seafood shopping tips can help keep fish stocks at reasonable numbers and reduce the overall environmental impact of your diet, ensuring a future that includes seafood for everyone—not just wealthy nations. 

Shop Domestic

Foreign-farmed fish not subject to U.S. laws is often contaminated with toxic substances, including veterinary drugs. (Machine learning is already assisting the FDA in determining the safety of imported seafood.)

Thanks to stringent sustainability and food safety regulations from NOAA, U.S. fisheries lead the world in sustainable wild-capture fisheries and aquaculture operations. Go hyper-local and join a community-supported fishery.

Shop Different Kinds of Seafood

Reduce pressure on finfish like tuna and salmon by embracing “trash fish” like carp. (Extra points for giving sustainably-sourced scup or herbivorous Hawaiian mullet a whirl.) 

Unlike larger fish, small seafood doesn’t suffer from bioaccumlation issues with mercury, a neurotoxin commonly found in fish at high—and getting higher—levels. Humans burn coal, which increases the amount of airborne mercury. Eventually, this heavy metal finds its way into bodies of water where seafood eventually consumes it. When bigger fish, like swordfish and tuna, eat smaller fish, the mercury intake is compounded, meaning that bigger fish have higher levels of contamination from eating fish lower on the food chain.

Choosing to eat smaller sea animals like sardines and squid can reduce your exposure to mercury as can opting for sea animals like scallops, mussels, and oysters that only feast on plankton.

Shop Certifications Labels

Look for seafood certified by the Marine Stewardship Council for wild-caught seafood and Aquaculture Stewardship Council for farmed seafood. These labels indicate responsibly sourced marine food from managed farms and fisheries.