Slippery As A Fish: Selecting Sustainably Sourced Seafood

April 19, 2018 Brad Peebler

Slippery As A Fish: Selecting Sustainably Sourced Seafood

By Sophia FitzMedrud 

In its essence, something that is sustainable can be continued. A sustainably caught fish is one that is caught in a way that can be continued indefinitely. (2) 

There are a number of factors influencing the ultimate sustainability of seafood. The way I think about it, they are: first, species caught; second, the practice used;
third, location; and fourth, the number of handlers between you and the fishermen. Let’s go through these factors in order. 

First: species caught.
The species of seafood affects sustainability in a profound way. Some fish mature and reproduce both quickly and in great numbers. These species can rebuild populations quickly. Others take years to mature and reproduce in smaller numbers. These take a long time to rebuild 

1 “Sustainable.” Dictionary. Merriam-Webster, Inc., 13 June 2017, https://www.merriam-
2 “Learn About Sustainability.” United States Environmental Protection Agency, United States Environmental Protection Agency, 18 October, 2016, 

their populations. Eating lower on the food chain is often a better choice, since these species are more abundant and can often rebuild faster. (3) 


Knowing the species of the fish you’re eating is imperative. Ideally, knowing the scientific name would be a given, since there can be multiple fish by one name. For example, Atlantic Bluefin Tuna (thunnus thynnus), Pacific Bluefin Tuna (thunnus orientalis), and Southern Bluefin Tuna (thunnus maccoyii) all share the “Bluefin tuna” name, but have slightly different population statuses. 

Once you know the scientific name, do a little research before eating–check the conservation status, maturation, and reproduction. If you can, make sure the fish you’re eating has had a chance to reproduce, especially if it’s a species that rebuilds more slowly. 

Second: practice used.
Fishing practices are a huge part of sustainability, and also one of the more obscure. Knowing the exact practice used to catch the fish you’re eating is very important. The same fish 

3 “Sustainable Seafood: How Do We Balance Our Tastes With What’s Right for the Oceans?.” National Geographic. National Geographic, 13 June 2017, action/sustainable-seafood/.
4 Pauly, Daniel and A. Atanacio. “Fishing Down the Food Web.” webs–biodiversity.html. 

could have been caught using a pole-and-line, which has very little impact on the ecosystem outside of the direct result of removing that particular fish, (5) or a dolphin-set purse seine, which kills hundreds of dolphins every year, (6) or even a gillnet, which are so notorious for their by-catch that they are called “walls of death.” (7) 

And even within a practice–purse seining, for example–there can be a range of variation as to the exact impacts it has. An open-set purse seine has a minimal impact on the ecosystem, and can be a sustainable choice. Associated purse seining, using fish aggregation devices (FADs), and dolphin-set purse seining, are often both problematic. (8) 

Drift Net B-ycatch (9)

Even a usually problematic practice, like long-lining, can be made more sustainable through the use of modifications like streamers to warn off seabirds, circle hooks to reduce by- catch of marine mammals and non-target fish, or even using whole fish as bait rather than squid 

5 Brown, Elizabeth. “Fishing Gear 101: Handlines – Entice and Hook.” Safina Center, June 7, 2016,
6 Brown, Elizabeth. “Fishing Gear 101: Purse Seines – The Encirclers.” Safina Center, June 6, 2016, 7 Brown, Elizabeth. “Fishing Gear 101: Gillnets – The Entanglers.” Safina Center, June 6, 2016,
8 Brown, Purse.
9 U.S. Fish and Wildlife Service Headquarters and uploaded by Dolovis. “Drift net with bird, 2.” [CC BY 2.0 ( or Public domain], via Wikimedia Commons,,_2_(8080506763).jpg. 

to reduce by-catch of sea turtles (since turtles have a tendency to eat fish off the hook in small bites, whereas they will eat the whole piece of squid–with the hook–at once). (10,11) 

Take time to familiarize yourself with fishing practices used to catch the fish you’d like to eat. Find out which were used to catch the fish you’re eating, and which modifications were used to lessen negative effects, like by-catch or damage to the sea floor. 

Third: location.
Where a creature was caught will also affect the sustainability of your meal. A species that’s doing well in one area could be nearly gone in another, and the regulations can vary. For example, while dolphin-set purse seines aren’t used by US fishermen, this method is used in other areas of the Pacific.(12) Knowing where the fish you’re eating came from is important to know the sustainability of your food. 


10 Brown, Elizabeth. “Fishing Gear 101: Longlines – The Snaggers.” Safina Center, June 6, 2016,
11 Gilman, Eric. “Bycatch governance and best practice mitigation technology in global tuna fisheries.” Marine Policy 35(5):590-609, June 2011, gy_in_global_tuna_fisheries.
12 Brown, Purse.
13 Strebe. “Winkel triple projection: [CC BY-SA 3.0 (], via Wikimedia Commons. 

Fourth: number of handlers between you and the fishermen.
An unfortunate aspect of eating seafood is that the information one needs to determine the sustainability of a meal can be lost in the transactions between the fishermen and your table. There can be miscommunications, mistranslations, and sometimes even straight up misinformation. 

  Tuna are caught, frozen, and shipped to the fish market in Japan. They will be auctioned off here, then shipped to the buyer, who might represent a restaurant or a fish supply company that would then sell to the restaurant. This process is repeated daily. 

Tuna are caught, frozen, and shipped to the fish market in Japan. They will be auctioned off here, then shipped to the buyer, who might represent a restaurant or a fish supply company that would then sell to the restaurant. This process is repeated daily. 


The ideal place to buy seafood is from the fishermen themselves. They are the best informed to answer any questions you have about how the fish was caught, what species it is, or anything else you have concerns about. Plus, fishermen earn more for their catch when it is sold with fewer middlemen. (15) 

14 Fisherman. “Tuna sale at Tsukiji Fish Market.” [GFDL (, CC-BY-SA-3.0 ( or CC BY-SA 2.5-2.0-1.0 ( sa/2.5-2.0-1.0)], via Wikimedia Commons.
15 Mustain, Patrick and Avery Siciliano. “Fish Stories: Success and Value in Seafood Traceability.” Oceana, March 2016,, pp 1 and 18. 

  Fish market in Italy (16)

Fish market in Italy (16)

Another thing to be aware of is hidden seafood, or products made from seafood that one wouldn’t necessarily think of as being seafood, such as supplements or salad dressings containing fish or fish oil. 

In conclusion, there is no list or magic formula to find out whether a fish was caught sustainably. Every fish is different, and “sustainable” is just a label. The only way to know is to determine it for yourself, from the information you have. If you’re not certain that the fish you’re eating was sustainably procured, then eat something else. In the United States, we don’t need fish as a protein source, and, therefore, we can make another choice. 

Our generation depends on healthy oceanic ecosystems, and that means that we need everyone to make responsible seafood choices in order to maintain or rebuild healthy fish populations. Get informed about the fish you’re eating and do your research before buying it– or don’t buy it at all. 

16 “Italy-Fischer-Fish-Market-Fishing-Boats-Chioggia-238404.jpg.” Max Pixel, public domain photo under liscence Creative Commons Zero – CC0, Chioggia-238404.