It's a Fish Eat Fish World

By Shanna Luster
NAMA's Intern
The Lab School of Washington

As part of my internship with NAMA, I'm learning about the marine ecosystem. And in the process I have learned that the ocean is a fish-eat-fish world and at the heart of that food web are pelagic fish.

Pelagic fish are the food source of most bony fish, and other ocean animals, like sea birds and sharks. Pelagic fish live in the pelagic zone, which goes from the surface almost to the bottom of the ocean. The pelagic zone can have up to five horizontal layers defined by the amount of light they reserve from the surface. These layers from top to bottom include Epipelagic (sunlight), Mesopelagic (twilight), Bathypelagic (midnight), Abyssopelagic (lower midnight). Pelagic fish range in the size from Blue fin Tuna to a sardine. Pelagic fish numbers are dropping at an alarming rate because of industrial scale purse seines and midwater trawl equipment. Also, global warming is changing the temperature of the ocean, meaning pelagic fish migration patterns change. Since many animals eat pelagic fish, this would also impact there migration patterns.

Humpback whales travel many miles to eat herring. Humpback whales lunge out of the water forcing the herring to go down their throats. When the humpback lunges out of the water to catch the herring most of the herring fly out of the water which gives the sea birds, like the brown pelican a chance to grab the flying  fish. The herring that is left over from the whales' feast is then taken by big schools of bluefin tuna. This symbiotic food chain is an example of how essential pelagic fish are. If all of the Pelagic fish leave the oceans, all of the ocean life will be affected, as will we.