Marine biodiversity reshuffles under warmer and sea ice-free Pacific
Arctic

Date:
September 29, 2020
Source:
Hokkaido University
Summary:
Climate warming will alter marine community compositions as species
are expected to shift poleward, significantly impacting the Arctic
marine ecosystem.



FULL STORY ========================================================================== Climate warming will alter marine community compositions as species are expected to shift poleward, significantly impacting the Arctic marine ecosystem.


==========================================================================
The biodiversity of marine communities in the Pacific Arctic under
future climate change scenarios highlights profound changes relative to
their present patterns. Alterations in marine species distributions in
response to warming and sea ice reduction are likely to increase the susceptibility and vulnerability of Arctic ecosystems. The findings,
published by Hokkaido University researchers in the journal Science of
the Total Environment, also suggest that there will be potential impacts
on the ecosystem function and services.

Fisheries oceanographer Irene Alabia of Hokkaido University's Arctic
Research Center along with colleagues in Japan and the US investigated
how future climate changes will impact the marine biodiversity in the
Bering and Chukchi Seas. These seas extend from Alaska to Russia in the northern Pacific and southern Arctic oceans.

"This area forms a 'biogeographical transition zone': a biodiversity-rich region covering two distinct areas with specific features that encourage
the coexistence of species living at or close to their distribution
limits," explains Alabia. "These zones are vulnerable to climate warming,
and climatic disruptions can create favorable conditions for the shift of warm-water species into previously colder-water zones." Scientists are interested in understanding how species in biogeographical transition
zones are responding to climate changes and other human impacts.

This information could help in conservation planning, fisheries
management, and in studying the role of evolutionary history in shaping currently existing communities.

Alabia and her team mapped the present and future spatial distributions of
26 fish and invertebrate species in the Bering and Chukchi Seas. Using
species records, sea surface temperature, and sea ice concentration
data, the authors developed species distribution models to predict
the distributional ranges under the present-day (1993-2017) and future (2026-2100) climate conditions.

From the model outputs, the changes in species richness and compositional diversity in terms of species' phylogeny and functional traits between
time periods and across contrasting levels of warming were elucidated.

The findings suggest that larger, longer-lived and more predatory fish
and invertebrates will expand their ranges towards the pole in response
to warming waters and sea ice free conditions by the end of the 21st
century. These poleward shifts could alter the structure, composition and functions of future Arctic communities, which are currently dominated by smaller and short-lived species. The future species pool in the Arctic
waters will also have more similar functions within the ecosystem,
impacting regional food webs. It is also likely that there will be
considerable socioeconomic impacts, as commercially important species
shift northwards, which could increase operational fishing costs.

"These projected impacts are expected to raise challenges for ocean
governance, conservation and resource management of shifting fisheries,"
says Alabia. "Our results provided glimpses of potential futures of
the Arctic marine ecosystems, nonetheless, and some of these ecological
shifts are already being documented.

As such this highlights the need for continued monitoring and improving climate-ready strategies to buffer climate change impacts and maintain
the integrity and functioning of vulnerable ecosystems."

========================================================================== Story Source: Materials provided by Hokkaido_University. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Irene D. Alabia, Jorge Garci'a Molinos, Sei-Ichi Saitoh, Takafumi
Hirata,
Toru Hirawake, Franz J. Mueter. Multiple facets of
marine biodiversity in the Pacific Arctic under future
climate. Science of The Total Environment, 2020; 744: 140913 DOI:
10.1016/j.scitotenv.2020.140913 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200929123500.htm

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