Graphic by Elise Fero
Graphic by Elise Fero

Finding a trace in whales

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Welcome to the Humboldt Coast, home of nudibranchs, crabs, and of course, whales. The water we know to be so cold is actually a large reason why the whales are here in the first place.

Claire Till from Humboldt State University’s Chemistry Department concentrates on the research of trace metals in marine environments and investigating their impact. She believes it’s important to realize our cold water has a purpose.

“We also get some really cold water that gets brought up from deep and with it, it often brings iron,” Till said. “And then when iron comes up to the surface, a bunch of phytoplankton start growing and then the whales have learned that there are going to be big phytoplankton blooms off our coast and they come by and eat. So the iron is really kind of the catalyst in a lot of places that lead to more phytoplankton growing and more whales.”

These elements in the food chain are extremely important to the ecosystem and its inhabitants. Without one, the ecosystem could change very quickly.

Matthew Hurst from HSU’s Chemistry Department studies trace metals and nutrient cycling in aquatic ecosystems. He believes climate change could have an affect on the good trace metals.

“The good trace metals, they are being affected by climate change because how the wind blows affects the way in which these metals can be brought up to the surface or it would perhaps change the pH of the ocean which would change the way these micronutrients can be acquired by biology,” said Hurst.

Till worries the whales will lack food when climate change causes temperatures to rise.

“One of the big things I’m worried about with climate change and the ocean is there’s not going to be as much mixing of the ocean water because the surface water is going to be heated more than it is currently and that will make it stay on top of the ocean and be it less inclined to mix with deep water,” said Till. “Usually the nutrients are coming from deep… so if we aren’t having as much mixing we aren’t going to have as much nutrients coming to the surface ocean and we aren’t going to have as much phytoplankton and that could be a problem for whales not getting enough to eat.”

Not only are the whales not getting enough to eat, but they aren’t receiving enough nutrients either.

“Whales eat the phytoplankton and incorporate all kinds of elements including the iron into the whales bodies,” said Till.

On the other hand, there is such a thing as too much trace metals, which scientists refer to as heavy metals. One of the concerns is mercury.

“I would be most concerned with mercury,” said Hurst. “I would say although others exist and are present in the ocean, mercury is extremely toxic and bioaccumulates in the environment and given that whales are at the top of the food chain, they have elevated concentrations in their body and we probably don’t quite understand how it’s affecting them.”

Heavy metals are from pollution, mainly caused by human beings and coming from coal and other fossil fuels. NOAA Fisheries reports pollution as one of the most common threats among species of whales, some including heavy metals.

“This pollution is in the runoff, it’s in the rivers going into the ocean, but it’s also deposited through the air,” said Hurst.

Now studies are being performed to understand what this means for whales and other marine mammals.

“When they do find whales that are dead, they measure the elemental content of their tissue and again, at least in terms of mercury, it’s extremely high given that it bioaccumulates,” said Hurst.

All around the globe whales are being found stranded with toxic heavy metals in their tissues, but research is still needed to understand the damage it does.

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