This week, I read an article “What’s depleting salmon populations? ” by Jennifer Horton. In the article, Jennifer indicated that wild salmon is significantly reduced from the entire world. The essay also reminds me of Reut Elimelech’s project summary “Seafood Fraud”, which including the seafood crisis we are facing now. The picture of a jellyfish sandwich impressed me a lot. Reut addressed in her presentation that if there’s no more edible fish exist; jellyfish sandwich probably will soon be added to the menu and recipes.
Horton used “Four Hs”, which means harvest, hatcheries, habitat and hydropower to conclude the factors affect salmon population. Almost every condition for the salmon living and reproducing is essential.
Personally say, I love seafood especially the sashimi and sushi with fresh salmons. Suppose that each of individuals eat 50 gram of salmon per week, it means 15,000 tons of salmon fish are eaten in the United States. Actually, people prefer to eat salmon instead of other kinds of fish due to mercury. Commercials of salmon recipe or products are often to be seen on TV and magazines. Indeed, wild salmon has a little mercury and it is a good ingredient if you are trying to lose weight.
So, how many salmon are caught per year in fact? Much more than the assumption! The chart below reported by the Food and Agriculture Organization (FAO) shows commercial capture of all true wild salmon species from 1950-2010. We can easily find out that the number is continuing grow up, which is not a good sign for wild salmon reproduce. And nearly all captured wild salmon are Pacific salmon. The more we capture, the less salmon that are able to reproduce surplus.
Hatcheries and Habitat
I merge these two factors together to study because they are inextricably linked. Everyone knows that salmon is special than other fish due to it return to their habitat to spawn. The habitat river is where the baby salmons come from. If the environment of the habit degrades badly, salmon will not return back to reproduce. The population of salmon will decline soon. “Even small disturbances can make a big difference, since spawning is highly sensitive to things like increased sedimentation. Logging, agricultural practices, trash dumping and oil spills all contribute to poor water quality.” Said by Horton.
Today, most people cannot imagine just how little number of salmon would be migratory and spawn in the river. One of the reason why salmon taste delicious is they prefer cold and fresh water to live in. However, with the global warming and the deterioration of river conditions, most of the river is no longer to be the ideal habitat for salmons. The fish has to migrate further north in order to get a proper temperature to spawn, which means the more danger they probably are going to meet in the journey of going back. The data on Water Encyclopedia is undoubtedly startling:
“In California, Washington, Oregon and Idaho, salmon are extinct in nearly 40 percent of the rivers they were known to inhabit — at least 106 major stocks gone forever. In 1990, New Brunswick’s 108 salmon rivers supported healthy native Atlantic salmon runs. Ten years later, all are in decline and fewer than half have wild salmon populations at or above levels required to ensure survival. The Miramichi River was the world’s largest and most productive Atlantic salmon River; yet now, less than 1 percent of the salmon return to the river to spawn. The Atlantic salmon situation in the United States is also severe. Once, most rivers north of Connecticut were teaming with salmon. Today, it is estimated that only 50 to 100 native Atlantic salmon will return to a half dozen rivers in eastern Maine.”
Many examples show that the development of hydropower dams block salmons migratory. According to the study at Northwest Power & Conservation Council, “The Clearwater Coho salmon, once abundant in the Snake River Basin of Oregon, Washington and Idaho, became extinct in the early 1960s largely due to the construction of a dam that blocked the fish’s passage to and from its birthing grounds. ”
“Without modifications, hydropower dams block salmon from accessing vital habitsts.”
Resource: Joel Sartore/National Geographic/Getty Images
However, there are also studies addressed that dams and salmon can coexist. It demands us to take the needs of the fish to survive into considerations in the construction of the dams. Some modifications for salmons to migrate are enough to change the statue quo of the relationship between the fish and dam. We have the responsibility to think more, just than being human, but also for salmon, for fish and for our unique earth.