Mail Buoy: May 14

Question:

How much of the carbon (brought in by phytoplankton) do the fish eat? How do you (researchers) keep track of the poop? How do you sample/ know how much there is?

-Yusef B.H.M., Clarke Middle School

Answer:

Great questions! Relatively speaking, there isn’t much carbon getting to the fish. With every step up the food chain, carbon is lost. Only a small percentage gets to fish, but there’s an incredible amount of plankton to begin with that supports all of the fish.

To get more specific, fish that eat zooplankton are step three of the food web. Roughly 10% of phytoplankton becomes zooplankton biomass. Then 10% of that goes to fish that eat zooplankton. So, about 1% of phytoplankton biomass becomes fish biomass.

Scientists use sediment traps to catch poop that’s raining down in the water as marine snow. A sediment trap is essentially a cylinder under water that works like a rain gauge on land.

-Helena, Joel and Ken

Question:

What kind of fish are you researching?

-Wyatt S., Tremont Middle School

Answer:

Whatever we catch! The mesopelagic is still unexplored for the most part. The most common fish we catch are bristlemouths. (They're estimated in the quadrillions, yes with a "q"!)

The twilight zone is home to more fish than the rest of the ocean combined. Most of these fish—and other organisms that live in the zone—are tiny, measuring just a few inches long or less.

-KR Baltes, OTZ Project Manager