Something fishy: How climate change reaches into the ocean
Climate change could have devastating consequences for the world鈥檚 fish.
As global temperatures rise, the resulting ocean acidification and warming may hurt the diversity and population of fish species across the globe, say researchers.
鈥淭his 鈥榮implification鈥� of our oceans will have profound consequences for our current way of life, particularly for coastal populations and those that rely on oceans for food and trade,鈥� said Ivan Nagelkerken, Australian Research Council (ARC) Future Fellow with the University of Adelaide鈥檚 Environment Institute in .
Professor Nagelkerken and his colleagues in a paper Tuesday in the journal Proceedings of the National Academy of Sciences.听
Although researchers predict diversity and population among fish to decrease, that may not be true across all species.
Tiny plankton may increase production in the warmer water. But an increase of these creatures low on the food chain may not translate up to larger animals.
鈥淲ith higher metabolic rates in the warmer water, and therefore a greater demand for food, there is a mismatch with less food available for carnivores 鈹� the bigger fish that fisheries industries are based around,鈥� said Nagelkerken. 鈥淭here will be a species collapse from the top of the food chain down.鈥�
Using data from 632 published experiments across a range of marine environments, the researchers looked at the impact of warming water and acidification on the underwater ecosystems.
The researchers found that either condition exacerbated by climate change could impact coral, oysters, mussels, and other habitat-forming species.听
Coral, for example, might become bleached by warmer ocean temperatures. Just in the past couple of years scientists have seen significant bleaching events across the globe.听
When coral becomes stressed by the warmth it releases the algae that it typically co-exists with and that gives the reef-forming organism its color. When coral bleaching occurs, it is difficult for the reef to recover and many of the corals die. 聽
Habitat-forming species, like coral, shape the reefs that other fish live in, magnifying the impact of such marine changes throughout the ecosystem.听
Other marine life has been shifting its range in response to warmer water temperatures. Some tropical species have been spotted a ways from the tropics, like some black sea bass, unique squid, and blue crabs that have been eyed by fishermen in the Gulf of Maine.
King crabs are on the verge of moving into ecosystems that haven鈥檛 seen such shell-crushing predators in tens of millions of years. The royal crustaceans seek out warmer waters, and the Antarctic shelf has now reached suitable temperatures for the king crabs.
鈥淲e know relatively little about how climate change will affect the marine environment,鈥� said University of Adelaide marine ecologist Sean Connell, a fellow author on the current study.
鈥淲e need to know what we are doing to our world,鈥� Richard Aronson, lead author of the study on king crabs in Antarctica and head of the department of biological sciences at Florida Institute of Technology told 海角大神. 鈥淲e need to know the full extent of climate change effects.鈥�
