Saving Our Oceans by Switching Our Eating

 

Paul Greenberg gave an eye-opening TED Talk titled “The four fish we’re overeating - and what to eat instead.” Greenberg talks on the damage which overfishing has done to certain fish populations and consequently the ocean environment as a whole. First, he shares how in order to catch a pound of shrimp, which is a seafood commonly eaten in America and most of the West, up to 15 pounds of wild fish are killed. This wild fish bycatch is taken out of the ocean ecosystem and then turned into food for shrimp, which Greenberg describes as, “an ecosystem literally eating itself and spitting out shrimp.”  In addition, catching and selling shrimp is extremely fuel inefficient and carbon-intensive which further makes it environmentally unsustainable. The farming of shrimp also comes along with the destruction of wild habitats in mangrove forests, impacting even more of the natural world.

    

Shrimp and their extensive bycatch.

Furthermore, tuna has sustainability issues. Tuna is a global fish which means it must be managed globally in order to sustain its population, but the overeating of this fish has been harmful to its population. While growing tuna could have helped in this management, tuna is not good for aquaculture because it is warm-blooded and a fast swimmer. Attention must be given to this issue if we are going to be able to sustain this population.

Tuna swimming in the ocean.

Additionally, salmon has been harmed by human overeating. The dams which have been built in streams and rivers around the world have kept wild salmon from reaching their spawning groups which has negatively impacted the salmon population. In order to produce more salmon, aquaculture has been utilized. This process includes killing enough wild fish in order to feed this salmon, with a conservative ratio of two pounds of wild fish to one pound of salmon. This amount of life being removed from the ocean is unsustainable and must be changed or decreased all together.

Salmon being restricted by a dam.

The fourth fish which has sustainability issues is whitefish, which is an umbrella term used to describe fish such as halibut, Atlantic cod, Alaska pollock, and tilapia. The impact of overeating on whitefish is similar to the previous fish mentioned, and in order to sustain a healthy ocean as well as a healthy human diet, changes must be made.

Whitefish encompass many fish and unsustainable practices.

Greenberg suggests that in order to fix these sustainability issues, we must substitute these fish for seafood which can be sustained. First, clupeids are currently fed to salmon, but eating the clupeids directly would decrease the need for salmon farming and therefore the negative impacts of this. In addition, catching and selling clupeids are fuel and carbon efficient. Another possible substitution would be muscles. Muscles have many of the same benefits as tuna but it is incredibly fuel efficient and does not require other fish for food which make them even more sustainable. Muscles are also helpful in filtering water which is important for the world’s water. In addition, seaweed and kelp could be used as another substitution. They filter water similar to how muscles do and would therefore be another sustainable substitution that could also help feed cattle. 

Furthermore, Greenberg describes an aquacultured fish that could also be used as a substitute for the seafood which has sustainability issues. The attributes of this ideal aquacultured fish include it being vegetarian, fast growing, adaptable, and having an oily fish profile. In addition, this fish would have to have a net gain of marine protein. If this ideal fish can be made a reality, then more fish would be able to stay in the ocean.

After watching this TED Talk, I feel that Greenberg does seem optimistic about wild fisheries and our ability to practice sustainable aquaculture because his goal of sustainable substitution is plausible. He mentioned how institutions surrounding the aquaculture system have been able to make some changes, and since his recommendations are plausible, I believe that he seems optimistic that these recommendations could be implemented and lead to a more sustainable system which could benefit the ocean and people alike.