warmer waters

Climate change is taking a toll on forests, farms, freshwater resources, and economies all around the world. But ocean ecosystems remain the center of global warming.

Despite their vast ability to absorb heat and carbon dioxide, oceans are warming. In fact, according to scientists, the oceans have absorbed 90% of all the warming that has occurred during the past 50 years.

The ocean’s surface layer, which is home to most marine life, takes most of this heat. As a result, the top 2,300 feet of global ocean water has warmed approximately 1.5°F since 1901.

Well it turns out that a hotter ocean is also a hungrier ocean. According to a new study recently published in the journal Science, researchers discovered that predator impacts in the Atlantic and Pacific oceans peak at higher temperatures. The effects of more intense marine predation could disrupt ecosystem balances that have existed for millennia.

An international research team led by the Smithsonian Institution and Temple University analyzed predator and prey data collected from 36 sites, running along the Atlantic and Pacific coasts from Alaska in the north to Tierra de Fuego at the tip of South America. The research team found that, in warmer waters, predators’ more voracious appetites left outsized marks on the prey community. Total prey biomass plunged in warmer waters when prey were left unprotected. However, in the coldest zones, leaving prey exposed or protected made nearly no difference at all.

As the oceans continue to warm, more intense predation will create winners and losers and could jeopardize the overall health of marine ecosystems.

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As the ocean heats up hungrier predators take control

Photo, posted July 14, 2017, courtesy of Jonathan Chen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

As the oceans have warmed in recent decades, various marine species ranging from whales to corals have begun to shift poleward in search of cooler waters. But a new study, reported in the journal Nature Climate Change, found that many sedentary marine species – including snails, worms, and mussels – are actually being transported in the wrong direction.

What is happening is that bottom-dwelling species – also known as benthic species – in the northwest Atlantic Ocean are spawning earlier in the year because of the warmer water temperatures. But earlier in the year is when ocean currents travel southward. As a result, the larvae of these animals are being carried into warmer waters rather than cooler ones, threatening their survival and shrinking their ranges. These larvae grow into adults in these warmer regions and are basically trapped there. This creates a feedback loop where the situation for the species gets worse and worse. Species like common sand dollars and the economically important blue mussel have had a 30 to 50% contraction of their ranges.

The result is that a number of bottom-dwelling species that previously were quite abundant have entirely disappeared from the outer shelf.

The researchers at Rutgers University likened this “wrong-way migration” of bottom-dwelling marine life to so-called elevator-to-extinction events that have been taking place in mountainous regions. This is where species such as birds and butterflies move to higher and higher elevations to escape rising temperatures until there is nowhere else for them to go.

The essential fact that this research reveals is that species don’t necessarily move to places where the climate is congenial for them. They may unfortunately end up migrating to even worse conditions.

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As Oceans Warm, Some Species Are Moving in the Wrong Direction

Photo, posted June 10, 2016, courtesy of James_Seattle via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Marine Predation And Climate Change | Earth Wise

Climate change is taking a toll on forests, farms, freshwater resources, and economies all around the world. But ocean ecosystems remain the center of global warming.

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Marine Life Moving The Wrong Way | Earth Wise

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