Acidifying Oceans Could Dissolve Shark Scales

14347752190_da041b2ba6_o (1).jpg

The puffadder shyshark. Image: Graeme Kruger

South African researchers from University of Duisburg-Essen and Heinrich-Heine University have published a new study showing that increasing concentrations of CO2 in the ocean are damaging shark scales, known as denticles.

What’s Happening: CO2 in the ocean dissolves in the seawater to create carbonic acid that acidifies the oceans. This acid can corrode shark denticles which are small tooth-like scales that give sharks several of the evolutionary advantages.

The Study: As Smithsonian Magazine explained, to test how acidity affects shark skin, they housed 80 puffadder shysharks in tanks full of pH 7.3 water, simulating projected future conditions, or pH 8 water.

  • Exposed to acidified water, sharks quickly began to pump bicarbonate, a base, into their blood to counteract the acid.
  • But the longer the sharks spent bathing in the harsh liquid, the worse off their denticles were.
  • When the researchers examined three specimens that spent nine weeks in the acidic tank, they found damage on 25 percent of the sharks’ denticles under a microscope, compared to just 9.2 percent in a group that had remained in more neutral water.

*a pH of 7.3 in the world’s oceans would be catastrophic for most marine life (as Luiz Rocha, curator of fishes at the California Academy of Sciences told Wired) but this experiment nonetheless highlights one more way in which humans are threatening sharks.

Why This Matters: Sharks have been around for 450 million years and have learned to adapt to countless environmental threats, but humans are likely their biggest threat yet. In addition to overfishing, habitat degradation, and human-caused pollution, sharks are now having to adapt to a rapidly warming planet. While some species may be more resilient to climate threats, since sharks have long generations they may not have time to adapt to threats like ocean acidification. Sharks are critical for maintaining healthy marine ecosystems and it’s time we got serious about maintaining their populations.

Go Deeper: There are more than 500 known species of sharks that keep our oceans healthy and we’re still discovering more! As New Atlas reported, scientists have discovered four new species of shark in Indonesia with a surprising way of moving through the water. The team observed the tropical marine creatures using their fins to walk across the sea floor, a motion rarely seen in sharks and one that affords them a strong advantage over the smaller creatures they prey on.


Up Next

Dogs Can Sniff Out COVID-19

Dogs Can Sniff Out COVID-19

Scent detection dogs may be the best tool for finding and fighting the spread of COVID-19, according to some promising new research at the University of Helsinki.

Why This Matters:  COVID-19 detecting dogs could be immensely helpful in rooting out the disease in places where it might otherwise be hard to detect, such as sporting events, airports to find the virus on surfaces, and border crossings, and places where early detection is important, like nursing homes and retirement communities, and by helping to screen people within the medical care sector who test positive so as to avoid unnecessary quarantines for those who have been exposed.

Continue Reading 366 words
We Need Animals to Survive—But First, We Need to Include Them

We Need Animals to Survive—But First, We Need to Include Them

By Beth Allgood, U.S. Country Director, International Fund for Animal Welfare It’s often said that dogs are man’s best friend. This common phrase may seem simple to most, but it holds a very important lesson: animals are important to human wellbeing. IFAW’s newest report, Animals are Key to Human Development: A Guidebook for Incorporating Conservation […]

Continue Reading 1003 words
One Cool Thing: Wildlife Comes Out At National Parks

One Cool Thing: Wildlife Comes Out At National Parks

Park Rangers at National Parks that have been closed for many weeks have observed things they had never seen before.  For example, pronghorn antelope in the sun-scorched lowlands of Death Valley National Park, and at Yosemite, with traffic a distant memory, deer, bobcats, and black bears have made their way into Yosemite Valley and are […]

Continue Reading 173 words