Climate Wire | A new study reveals the unexpected consequences of climate change. Some crabs have lost their sense of smell.
As carbon dioxide seeps into the ocean and the water becomes more acidic, one of the most important senses we use to find food declines. It could deplete their population.
A study published Tuesday in the journal global change biologyfocuses on the economically important Dungeness crabs that live up and down the west coast of North America. Dungeness crabs make up some of the most valuable fisheries along the Pacific coast, including California, Oregon, Washington and Alaska.
However, Dungeness crab populations have declined in recent years. NOAA scientists cite factors such as algal blooms, hypoxia, and ocean heatwaves. These stressors may be exacerbated by the effects of climate change.
Now, new research has revealed another threat.
When humans release carbon dioxide into the atmosphere, some of it is absorbed by the ocean from the air. Also, as her CO2 concentration in the water rises, the ocean becomes more acidic.
That’s bad for a wide variety of marine life. Numerous studies have found that ocean acidification damages corals and crustaceans, making it harder for them to build and maintain the hard shells they need to survive. You can also change the behavior of fish.
It can also make it harder for Dungeness crabs to detect important odors in water.
Due to their poor eyesight, Dungeness crabs rely heavily on their sense of smell to detect prey and predators in the water. Each crab has a series of tiny rippling antennae that help it sniff out chemical signals in the water. When a crab encounters an important odor, it begins moving its antennae faster to process the signal.
But a new study finds that ocean acidification is impeding this process. The researchers exposed a group of Dungeness crabs to two different environments. The water was then pulsed with chemical signals intended to simulate the presence of food sources.
They found that crabs in normal aquatic environments flicked their antennae more frequently when confronted with food odors, just as they would when in their natural environment. However, crabs exposed to higher levels of CO2 were not. In fact, researchers had to hit them with about ten times the concentration of food chemicals before they reacted.
When the researchers examined the antennae, they found that increased CO2 levels appeared to interfere with the neural responses that encouraged faster flicks.
The researchers say they are part of the first evidence to show that ocean acidification can affect the olfactory system of crustaceans.
The extent to which this effect is affecting Dungeness crab populations is currently unknown. But it could add to the list of climate-related factors already threatening species.
Cosima Porteus, a scientist at the University of Toronto Scarborough and co-author of the study, said: statement. “If crabs are having trouble finding food, it’s no surprise that females don’t have enough energy to lay eggs.”
Reprinted from E&E News with permission of POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environmental professionals.
