Science is the secret to sustainable seafood

By Orion McCarthy 

IT’S NO SECRET that marine ecosystems are in trouble. Overfishing poses a serious threat around the world, with 75% of fish stocks declining due to fishing pressures. Those who depend on fish as their primary source of protein, about 20% of the world’s population, are in dire need of sustainable marine resource management, as are those who generally enjoy seafood or depend on healthy marine ecosystems (Hint: that’s pretty much everyone).

We could all benefit from a little bit more sustainability in the sea.

Photo credit: Getty Images.

Photo credit: Getty Images.

Sustainable seafood is a nebulous term, but it generally refers to fishing practices that allow stocks to maintain stable population levels while avoiding damage to the surrounding marine ecosystem. In the long run, sustainable fisheries benefit everyone involved by providing a reliable source of income for fishers, a renewable resource for consumers, and a healthy marine ecosystem for wildlife.

Despite the benefits of sustainability, many fisheries around the world are poorly managed, unsustainable, or downright irresponsible. The tragedy of the commons, or the propensity for individuals to overharvest an unregulated communal resource, will ultimately lead to empty oceans without proactive, ecologically focused fisheries management using quotas, marine protected areas and regulations to restrict the harvest of marine organisms.

For many fisheries, the challenge of sustainability is rooted in scientific uncertainty. How can effective quotas or marine reserves be developed without adequate background information? Without population estimates, assessments of ecosystem health, or proper environmental baselines, the true effects of fishing practices may not be realized until the damage is done.

Wild caught Pacific Halibut in Homer, Alaska.

Wild caught Pacific Halibut in Homer, Alaska.

Amidst the many fisheries that struggle with overexploitation, the management of the Pacific halibut (Hippoglossus stenolepis) fishery can be considered a model of sustainability. A large species of flatfish capable of growing up to 8 ft long and reaching 500 lbs, Pacific halibut live on the sea floor along the continental shelf of the north Pacific. The International Pacific Halibut Commission, or IPHC for short, is an international organization established through a treaty between the United States and Canada in 1923 to manage populations of Pacific halibut from the coast of California up to the Bering Sea in Alaska.

To say the IPHC informs its management practices with scientific data is an understatement. The IPHC commandeers a fleet of fishing vessels to conduct annual research surveys throughout the waters of Alaska and Canada, and the organization has been collecting biological data on halibut growth rates and population trends since its inception, creating a valuable long-term data set. Such data informs complex, multivariable population models that allow the IPHC to more accurately predict trends and variations in halibut stocks, adjusting quotas accordingly.

In addition, annual scientific surveys provide an opportunity to collect other valuable ecological data, such as the effect of the fishery on marine mammals, the distribution of endangered sea birds, and oceanographic data such as water temperature and plankton levels across a wide swath of the Pacific coast.   Such large-scale research activities leave organizations like the IPHC better poised to understand the ecosystem effects of fishery activities, ultimately resulting in more sustainable fisheries management for the entire region.

The range of the Pacific Halibut is shown in yellow. Photo credit: Wikimedia.

The range of the Pacific Halibut is shown in yellow. Photo credit: Wikimedia.

The halibut fishery is a primarily long lining fishery, utilizing mile long ropes fitted with hundreds of hooks that are baited and left to sit on the bottom. While this method minimizes degradation to the sea floor that would be caused by trawling and other damaging methods, it has the potential to catch non-target species, a process known as bycatch. The ecological impact of long lining varies depending on the fishery and can lead to significant bycatch issues if not properly administered. Best practice methods, such as using circle hooks and seabird exclusion devices, are employed by the halibut fishery to reduce bycatch levels.  More destructive fishing methods such as trawling, gillnetting, and purse seining tend to result in more substantial environmental degradation or bycatch.

The Pacific Halibut is capable of growing up to 8 feet long and weighing up to 500 pounds, making it the largest flatfish in the world. Photo credit: NOAA.

The Pacific Halibut is capable of growing up to 8 feet long and weighing up to 500 pounds, making it the largest flatfish in the world. Photo credit: NOAA.

Aside from the stringency of quotas and the type of equipment used, many other factors contribute to the sustainability of a fishery. Regional variations in population stability, fishing pressure, and fishery legislation all effect sustainability in wild stocks. Increasingly fish stocks, particularly salmon and tilapia, are farmed in netted pens out at sea. While this relieves pressures on wild stocks of salmon and tilapia, smaller fish are still exploited to make fishmeal for farmed fish, and problems may exist with the spread of disease and escaped farm fish from such pens. Like everything else, the sustainability of each fishery varies based on local practices and regulations.

What YOU can do

With such regional variation and so many factors to consider, putting in the background research to eat sustainably caught seafood may seem like a monumental undertaking. Thankfully, expert marine biologists and fishery scientists have synthesized the dos and don’ts of sustainable seafood into an easily understandable reference for us consumers.   Apps such as Seafood Watch, created by the world renowned Monterey Bay Aquarium, offer clear and informative reviews of different types of seafood, labeling them as best choice, good alternative, or avoid. Fisheries are categorized by species, region, and harvest method in the app and are accompanied with compelling visuals and educational descriptions of fishery practices.

Use the free app Seafood Watch to check if your favorite seafood is best choice, a good alternative, or a species to avoid consuming. Photo credit: Monterey Bay Aquarium.

Use the free app Seafood Watch to check if your favorite seafood is best choice, a good alternative, or a species to avoid consuming. Photo credit: Monterey Bay Aquarium.

Whether it’s Pacific halibut (which just so happens to be listed as best choice) or farmed Atlantic salmon, eco-savvy shoppers that inspect products for a country of origin can use this app to learn just how sustainable their choices really are.

While initiatives like Seafood Watch allow ordinary consumers to support sustainability with their wallets, ecological research efforts by organizations such as the IPHC are ultimately responsible for the advent of sustainable fisheries grounded in sound science. Such science promises to keep our oceans healthy and our plates full for generations to come. So read up on your favorite fish, and find out if you can do the oceans a favor!

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  1. Couldn’t agree more with this post. It’s so important to get the information out there so people can start making the right choices when it comes to their seafood choice. Apps like Seafood Watch are a great start.

    The team @ You’re Eating Shark


    1. Thanks for reading! You are right, seafood watch is definitely a must have app. The more people use it the better off the oceans will be


  2. […] McCarthy, a graduate from the University of Maryland, wrote a lovely article summarizing the hardships facing fisheries today. From over fishing, to lack of scientific […]


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  5. […] the biggest hurdle to further progress has been a lack of scientific data for some fisheries. A sizeable minority of US fisheries still lack adequate data on stock levels […]


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