Showing posts with label phytoplankten. Show all posts
Showing posts with label phytoplankten. Show all posts

Friday, November 27, 2020

As giant ice shelves collapse amid global warming in the Arctic, experts call for more protection for the "Last Ice Area" (LIA). The vast communities of plants and animals living there could be lost, they warn, before we even get to understand them!

    by Larry Powell 
                                The vast Milne Ice Shelf broke up this summer. Animals found 
living within its ice cavity (red box), are shown on the right. 
Photo credits: Left: Joseph Mascaro, Planet Labs Inc. 
Right: Water and Ice Laboratory, Carleton University.

Using tools which included video taken by a robot submarine, a Canadian research team recently discovered an amazing array of plants and animals, living in the heart of Milne, the very ice shelf which broke apart just this summer north of Ellesmere Island (above), losing almost half of its mass.

Dr. Derek Mueller, Professor of Geography and Environment Science at Ottawa's Carleton University, is a team member who's worked in the area for decades. In an email to PinP, he can barely disguise his excitement over what they found.

"There are really neat microbial mats (communities of micro-organisms including cyanobacteria, green algae, diatoms, heterotrophic bacteria, and viruses) that live on the surface of the ice shelves. Similar microbial mats can be found in ponds on the bottom of shallow lakes... Inside the sea ice and clinging to its underside are communities of algae and lots of kinds of phytoplankton in the ocean as well." 
Small animals from marine waters under the sea ice in Tuvaijuittuq, a Marine Protected Area in the region. Photo credit: P. Coupel and P. Tremblay, Fisheries and Oceans Canada.
So what might the world lose if these organisms disappear with the ice?

"This Last Ice Area will hopefully serve as a refuge for ice-dependent species," Dr. Mueller explains, "both on land and in the marine environment.  We know relatively little about these organisms - how they are adapted to their surroundings, how unique they are (or perhaps how similar they are to their cousins in analogous environments in the Antarctic) and many more questions!  We won't get to ask these questions if global temperatures rise unabated and this ice melts away."

The images above come from just a tiny part of the vastness Mueller refers to, called the "Last Ice Area." And, in the face of a rapidly-warming Arctic, events involving the break-up of sea ice are all too common there.
What's left of the Ward Hunt Ice Shelf in the Last Ice Area 
after breaking apart in 2011Credit: CEN, Laval University.

Here's how Dr. Mueller describes the LIA. 

"'The Last Ice Area' means the region in the Arctic Ocean where sea ice is most likely to survive in a warming world." 

It sprawls for up to 25 hundred kilometres along the coastlines of northern Canada and Greenland and well out to sea. It's there that the thickest sea-ice in the entire Arctic can be found. Because of its importance as a home for ice-dependant marine life and its cultural significance to the Inuit people living there, they and the World Wildlife Fund have long promoted it as worthy of conservation. (Local Inuit elders call it “Similijuaq - place of the big ice.”) 

Dr. Mueller and a colleague, Dr. Warwick Vincent of Laval University in Quebec City, are now sounding the latest alarm bells over why additional measures are needed to protect the area from increased human activity.

While Dr. Mueller remains optimistic for the future, he suggests, further steps need to be taken to expand those existing, protected areas. 

"The good news is, we do still have a window to make a difference. We can augment the existing conservation areas - the marine one, Tuvaijuittuq MPA and the terrestrial one - Quttinirpaaq National Park,  with more optimal coverage of the LIA - from Greenland in the east to the NWT in the west and perhaps there could be more protection by expanding across the coastal region reaching both inland and offshore." 

The Government of Canada announced the creation of Tuvaijuittuq Marine Protected Area a year ago, aimed at protecting a large part of the LIA.
 It's not just marine life that will be vulnerable to melting ice. So, too will terrestrial (land) animals 
such as the Peary caribou, known to migrate across the sea ice. 
Photo by Paul Gierszewski - Nunavut.


"This would recognize the important interconnection between the terrestrial and marine environments. With vulnerable ice-dependent ecosystems protected from human activity, this will guarantee the removal of multiple environmental stressors.  The big stressor is, of course, climate change. But, if we can make good on our Paris commitments to reduce greenhouse gas emissions globally, then the chances of the LIA remaining, increase dramatically."   

The team's findings were published recently in Science Magazine.

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