When searching for food to eat, people go with our appetites instead of our minds, and thus we are destroying our ecosystem. If you travel around the world and notice the products in the fish market, you will see the big 4: Shrimp, Tuna, Salmon, and Cod. The market has been shrunk to almost exclusively contain these fish and biodiversity has been reduced.
Sonar and lightweight polymers made during the ww2 era ushered in a war against fish. 80-90 metric tons are taken out of the ocean a year. This is equivalent to the human weight of china taken out of the sea a year. There has also been a huge boom in fish farming or aquaculture and within the last 2 years fish farming has outgrown the wild caught count.
The “perfect” fish for human consumption would have a vegetarian diet, be fast growing, adaptable to changing climates, have an oily fish profile we’re looking for, and provides us with a net gain of marine protein and omega 3s. Today, this fish does not exist.
McDonald’s filet of fish started w/ Halabit. They were forced to change to Alaskan Cod, then Pollock, and now Tilapia. Until 25 years ago, most people haven’t heard of Tilapia. Tilapia is a wonderful species because it can go from egg to adult in 9 months. However, Tilapia doesn’t have the oily fish profile (omega 3s) we crave.
Fishing for wild shrimp is carbon intensive and kills many fish in the process. 5-15 lbs. of fish are killed per lb. of shrimp brought to the market. And if you believe farming is the answer, you are wrong. Farming shrimp is a more carbon intensive processes. Millions of acres of coastal mangroves have been destroyed over the past 30-40 years due to farming shrimp. The bycatch fish and chicken farm byproducts (feathers, bones, etc.) are ground up and fed to shrimp. The ecosystem is literally eating itself to death.
One option to help our ecosystem is for people to start eating Mussels. They have similar nutrition when compared to canned tuna. Mussel fishing is 1/30th less carbon intensive to bring to the market relative to bring beef to market. Mussels have high concentrations of omega 3’s because they filter algae. In fact, this is where omega 3s comes from. Microalgae create omegas 3s and are simply bio accumulated in fish. In addition to having an oily profile, a single mussel can filter dozens of gallons of water a day.