Species groups follow patterns reacting to climate change on US northeast shelf

February 22, 2016

Researchers studying marine fishery species grouped by similar depth and temperature distribution have found that those groups have similar responses to the effects of climate change. Interactions between individual species in those groups, however, may be affected by the amount of available habitat, predator-prey relationships, and competition for food resulting from shifts in range and distribution.

The study, published today in PLOS ONE, evaluates the pace and magnitude of climate change effects for bottom-dwelling fishery species found on the U.S. Northeast Shelf. Nearly 70 species were classified into four distinct "assemblages," a group of species sharing a common environmental niche - in this case temperature, depth and seasonal movement. The groups occurred in one of two distinct sub-regions of the Northeast Shelf. The northern region was defined as the semi-enclosed Gulf of Maine, and the southern region as the broad, shallower Mid-Atlantic Bight and Georges Bank.

"Regional differences in the effects of climate change on the movement and extent of species assemblages hold important implications for management, mitigation of climate change effects, and adaptation," said lead author Kristin Kleisner of the Northeast Fisheries Science Center (NEFSC)'s Ecosystem Assessment Program. "A number of studies have looked at impacts on individual species on the U.S. Northeast Shelf, but no one has really looked at how the ecosystem is affected at the assemblage level. Local climate variability plays a major role, as do topography and oceanographic conditions."

The study hypothesized that groups of species characterized by similar temperature and depth distribution would exhibit similar responses to climate effects. The team compared observed historical shifts in species distributions with concurrent shifts in temperature to determine whether consistent responses to climate change were visible within the species groups. The historical data examined was collected during the NEFSC's spring and fall bottom trawl surveys from 1968 to 2012.

Researchers found consistent patterns in the direction and rate of distribution shifts within the species assemblages in each region. Species associated with warmer, shallower waters in the Mid-Atlantic Bight and Georges Bank were shifting strongly northeast, tracking shifts in temperature bands along the shelf.

In contrast, species in the Gulf of Maine were shifting to the southwest, possibly tracking the cooler bottom waters in this area of the Gulf. Species in the Gulf of Maine associated with cooler and deeper waters also tended to shift deeper, taking advantage of the variable bottom topography in this region, but with little latitudinal change. Shifts in depth among the southern species associated with deeper and cooler waters are more variable, although predominantly shifts are toward deeper waters.

"Changes in the assemblage or group ranges that correspond to changes in the availability of desired temperature areas have consequences for species interactions and the level of fishing effort concentrated on fish stocks," said Kleisner. "The ability to distinguish regional climate responses at the community level provides important information for ecosystem-based fisheries management."

Differences in how species respond to regional climate changes may have implications for predator-prey interactions and competition as species shift into new areas and undergo range expansion or contraction. Fisheries management implications include new species entering or leaving traditional habitats. Increasingly concentrated species, for example, could result in increased vulnerability to capture by fishing, and potentially a decline in abundance.

Along the Mid-Atlantic Bight, economic impacts will be felt as shifting distributions of traditionally harvested species alter patterns of their availability to local fishing communities. The result is lost access to stocks managed with species-specific quotas, and rising fuel and travel costs as vessels seek out species in more distant areas.

"This study represents an important advance in our understanding of changes in fish assemblages in recent decades. The Nature Conservancy looks forward to continuing to work with researchers and managers to put this knowledge to work for the benefit of people and nature," said Sally McGee, Northeast Marine Program Director for the Nature Conservancy and one of the paper's co-authors.

The study was conducted through a joint partnership between NOAA's Northeast Fisheries Science Center and The Nature Conservancy, and was funded by a grant from the Gordon and Betty Moore Foundation.

NOAA Northeast Fisheries Science Center

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.