Herbivores help protect ecosystems from climate change

October 11, 2017, University of British Columbia
Warming and limpet herbivores restructure marine communities. In the foreground, seaweed proliferates on a plate exposed to ambient temperatures in the absence of limpets. Just beyond, very little survives on a plate exposed to warm temperatures and where limpets are allowed to graze. Credit: Rebecca Kordas

Plant-eating critters are the key ingredient to helping ecosystems survive global warming, finds new UBC research that offers some hope for a defence strategy against climate change.

"The herbivores created space for other plants and animals to move in and we saw much more diversity and variety in these ," said Rebecca Kordas, the lead author of the study who completed this research as a PhD student in zoology at UBC. "We want variety because we found it helps protect the ecosystem when you add a stressor like heat."

For this study, Kordas, who is now a research fellow at Imperial College London, and her colleagues created mini-marine ecosystems on the shore of Ruckle Park on British Columbia's Salt Spring Island. The mini ecosystems were built on hard plastic plates that allowed researchers to control the temperatures. Some of the plates allowed voracious herbivores called limpets in, and some kept them out. Limpets are like snails, but with a cone-shaped shell.

The researchers were studying life in the intertidal zone, the area of the shore between the low tide and high tide. This area is home to a community of starfish, anemones, mussels, barnacles and seaweed. As the tide moves in and out, the plants and animals must cope with huge variation in temperature every day, sometimes as much as 20 to 25 degrees Celsius.

A limpet grazing on microscopic algae from the rocks in the marine intertidal zone. Credit: Rebeccas Kordas

"These creatures are already living at their physiological limits, so a two-degree change - a conservative prediction of the warming expected over the next 80 years or so - can make a big difference," said Kordas. "When heat waves come through B.C. and the Pacific Northwest, we see mass mortality of numerous intertidal species."

The researchers found that in the summer, when temperatures were at their warmest, communities could fare well even if they were heated, but only if limpets were present.

"When limpets were part of the community, the effects of warming were less harsh," she said.

The experimental plates installed on the shore in Ruckle Provincial Park, on Saltspring Island, B.C., Canada. Credit: Rebecca Kordas

Christopher Harley, a professor of zoology at UBC and senior author on the study, says consumers like limpets, sea otters or starfish are very important to maintaining biodiversity, especially in . Losing these species can destabilize ecosystems, but by the same token, protecting these species can make ecosystems more resilient.

"We should be thinking of ways to reduce our negative effects on the natural environment and these results show that if we do basic conservation and management, it can make a big difference in terms of how ecosystems will weather ," Harley said.

The study was published today in Science Advances.

Explore further: Marine biodiversity loss due to warming and predation: study

More information: R.L. Kordas el al., "Herbivory enables marine communities to resist warming," Science Advances (2017). advances.sciencemag.org/content/3/10/e1701349

Related Stories

Marine biodiversity loss due to warming and predation: study

November 28, 2011

The biodiversity loss caused by climate change will result from a combination of rising temperatures and predation – and may be more severe than currently predicted, according to a study by University of British Columbia ...

Species-rich food webs produce biomass more efficiently

October 5, 2016

Researchers at the Senckenberg have discovered a feedback in complex food webs: Species-rich ecosystems favor large, heavy animals. Even though this increases the amount of plants consumed, the plant biomass remains approximately ...

Climate change ripples through life on Earth

November 10, 2016

Climate change is affecting most life on Earth, despite an average global temperature increase of just 1C, say leading international scientists in a study published today in Science.

Recommended for you

Scientist launches hunt for Loch Ness 'monster DNA'

June 17, 2018

Tales of a giant creature lurking beneath the murky waves of Loch Ness have been around for more than 1,500 years—and one academic hopes the marvels of modern science can finally unravel the mystery.

Research shows diet shift of beluga whales in Alaska inlet

June 16, 2018

Beluga whales in Alaska's Cook Inlet may have changed their diet over five decades from saltwater prey to fish and crustaceans influenced by freshwater, according to a study by University of Alaska Fairbanks researchers.

Flatworms found to win most battles with harvestmen

June 15, 2018

A trio of researchers with Universidade de São Paulo has documented evidence of flatworms and harvestmen engaging in battle in the forests of Brazil. In their paper published in the Journal of Zoology, M. S. Silva. R. H. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.