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:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
(Date:4/26/2016)... 2016 Research and Markets has ... Market 2016-2020"  report to their offering.  , ,     ... The analysts forecast the global multimodal biometrics market ... the period 2016-2020.  Multimodal biometrics is ... as the healthcare, BFSI, transportation, automotive, and government ...
(Date:4/15/2016)... 15, 2016  A new partnership announced today ... underwriting decisions in a fraction of the time ... and high-value life insurance policies to consumers without ... With Force Diagnostics, rapid testing (A1C, Cotinine and ... (blood pressure, weight, pulse, BMI, and activity data) ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... HOUSTON , June 23, 2016 ... agreement with the Cy-Fair Sports Association to serve ... of the agreement, Houston Methodist Willowbrook will provide ... education and connectivity with association coaches, volunteers, athletes ... partner with the Cy-Fair Sports Association and to ...
(Date:6/23/2016)... ... , ... Supplyframe, the Industry Network for electronics hardware design ... Located in Pasadena, Calif., the Design Lab’s mission is to bring together inventors ... and brought to market. , The Design Lab is Supplyframe’s physical representation of ...
(Date:6/23/2016)... , June 23, 2016 ... Hematology Review, 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 ... , the peer-reviewed journal from touchONCOLOGY, Andrew ... escalating cost of cancer care is placing an ... result of expensive biologic therapies. With the patents ...
(Date:6/23/2016)... FRANCISCO , June 22, 2016  Amgen (NASDAQ: ... sponsorship of the QB3@953 life sciences incubator ... human health. The shared laboratory space at QB3@953 was ... overcome a key obstacle for many early stage organizations ... part of the sponsorship, Amgen launched two "Amgen Golden ...
Breaking Biology Technology: