Navigation Links
Predictions of climate impacts on fisheries can be a mirage
Date:3/25/2013

In the early 1940s, California fishermen hauled in a historic bounty of sardine at a time that set the backdrop for John Steinbeck's "Cannery Row" novel. But by the end of the decade the nets came up empty and the fishery collapsed. Where did they all go? According to a new study led by scientists at Scripps Institution of Oceanography at UC San Diego, the forces behind the sardine mystery are a dynamic and interconnected moving target.

Publishing in the Proceedings of the National Academy of Sciences, Scripps graduate student Ethan Deyle, professor George Sugihara, and their colleagues argue that problems lie in seeking answers one factor at a time, as scientists have done for decades. What is the impact of climate on sardines? What is the effect of overfishing on sardines? Focusing on single variables in isolation can lead to misguided conclusions, the researchers say.

"Studying ecosystems in this piecemeal way makes it hard to find quantitative relationships, the kind that are useful for management and stand the test of time," said Deyle.

Instead, using novel mathematical methods developed last year at Scripps, the researchers argue that climate, human actions, and ecosystem fluctuations combine to influence sardine and other species populations, and therefore such factors should not be evaluated independently.

The technique developed by Sugihara and his colleagues, called "convergent cross mapping," takes multiple variables into account and avoids the centuries-old "correlation does not imply causation" issue that has plagued single-factor studies (see: http://scrippsnews.ucsd.edu/Releases/?releaseID=1292). For example, based on data from the Scripps Institution of Oceanography Pier, studies in the 1990s showed that higher temperatures are beneficial for sardine production. By 2010 new studies proved that the temperature correlation was instead a misleading, or "mirage," determination.

"Mirages are associations among variables that spontaneously come and go or even switch sign, positive or negative," said Sugihara. "Ecosystems are particularly perverse on this issue. The problem is that this kind of system is prone to producing mirages and conceptual sand traps, continually causing us to rethink relationships we thought we understood."

By contrast, convergent cross mapping avoids the mirage issue by seeking evidence from dynamic linkages between factors, rather than one-to-one statistical correlations.

"Sustainable sardine fishing based on ecosystem-based management should adapt to dynamic changes in the ocean environment, and future policies should incorporate these effects to avoid another 'cannery row,'" said Deyle.


'/>"/>

Contact: Mario Aguilera or Robert Monroe
scrippsnews@ucsd.edu
858-534-3624
University of California - San Diego
Source:Eurekalert

Related biology news :

1. New method for greenhouse gas predictions
2. New Antarctic geological timeline aids future sea-level predictions
3. Missing polar weather systems could impact climate predictions
4. NOAA: Gulf of Mexico dead zone predictions feature uncertainty
5. Living in a sunny climate does not improve vitamin D levels in hip fracture patients
6. Dinosaur-era climate change study suggests reasons for turtle disappearance
7. Nevada climate, environmental data network to inform research, community
8. International conference to tackle climate-change threats to agriculture
9. Climate-smart strategies proposed for spectacular US-Canadian landscape
10. A game plan for climate change
11. March of the pathogens: Parasite metabolism can foretell disease ranges under climate change
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2017)... New York , April 19, 2017 ... competitive, as its vendor landscape is marked by the ... the market is however held by five major players ... Safran. Together these companies accounted for nearly 61% of ... of the leading companies in the global military biometrics ...
(Date:4/13/2017)... India , April 13, 2017 According to ... Proofing, Identity Authentication, Identity Analytics, Identity Administration, and Authorization), Service, Authentication Type, ... MarketsandMarkets™, the IAM Market is expected to grow from USD 14.30 Billion ... Growth Rate (CAGR) of 17.3%. ... MarketsandMarkets ...
(Date:4/11/2017)... , April 11, 2017 NXT-ID, Inc. ... technology company, announces the appointment of independent Directors Mr. ... to its Board of Directors, furthering the company,s corporate governance ... Gino ... we look forward to their guidance and benefiting from their ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... for two-dimensional representations of a complex biological network, a depiction of a system ... big mess,” said Dmitry Korkin, PhD, associate professor of computer science at Worcester ...
(Date:10/12/2017)... ... ... AMRI, a global contract research, development and manufacturing organization ... quality of life, will now be offering its impurity solutions as a stand-alone ... for all new drug products, including the finalization of ICH M7 earlier this ...
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit is ... and 8th June 2018 in San Francisco, CA. The Summit brings together current and ... distinguished CEOs, board directors and government officials from around the world to address key ...
(Date:10/11/2017)... ... October 11, 2017 , ... ... and pregnancy rates in frozen and fresh in vitro fertilization (IVF) ... maternal age to IVF success. , After comparing the results from the fresh ...
Breaking Biology Technology: