Ecosystem changes in tropics linked to declining upwelling of nutrient-rich waters, long-term study finds

Oct 17, 2012
Gordon Taylor, Professor of Oceanography, School of Marine and Atmospheric Sciences at Stony Brook University.

(Phys.org)—Reports of declining ice coverage and drowning polar bears in the Arctic illustrate dramatic ecosystem responses to global climate change in Earth's polar regions. But in this first-ever account of a long-term project in the southern Caribbean, a Stony Brook professor and his colleagues report in this week's Proceedings of the National Academy of Sciences. that tropical ecosystems are also affected by global climatic trends - and with accompanying economic impacts.

In an article entitled, "Ecosystem responses in the southern Caribbean Sea to ," Dr. Gordon Taylor and colleagues from Stony Brook University's School of Marine and Atmospheric Sciences (SoMAS), as well as the University of South Florida, University of South Carolina and two Venezuelan institutions (EDIMAR, Fundación de la Salle de Ciencias Naturales and Universidad de Oriente) provide an analysis of 14 years of continuous monthly oceanographic observations in the southern Caribbean off the coast of Venezuela. The research, known as the CARIACO Ocean Time-Series Program, has been continually funded by the National Science Foundation since 1995.

The researchers report how the complex food web overlying the Cariaco Basin has changed in this relatively short time frame. Microscopic plankton production has steadily declined and the species of plants supporting the food web have shifted. These ecosystem changes have affected the way this region exchanges carbon dioxide (CO2) with the atmosphere and, in part, caused local sardine fisheries to collapse and thus have a negative impact on Margarita Island economy.

The researchers link these ecosystem changes to declining upwelling of nutrient-rich waters caused by weakening Trade Winds in the region and an average sea surface warming of 1°C during their observations. According to the authors, all these changes trace back to the global heat budget, corresponding to in well-known indices of . This is the first report to link long-term, shipboard time-series oceanographic and local meteorological observations in the Tropics with global scale climatic changes.

The CARIACO Ocean Time-Series Program is currently funded by NSF to continue monthly sampling until the end of 2013 and has a five-year renewal proposal pending. "We will continue with the same measurements," said Dr. Taylor. "This also includes looking at ocean acidification, molecular characterization of microbial communities and cycling of major elements."

Explore further: Invisible helpers of the sea: Marine bacteria boost growth of tiny ocean algae

More information: www.pnas.org/content/early/2012/10/11/1207514109.full.pdf+html

Related Stories

Southern Ocean seals dive deep for climate data

Aug 11, 2008

(PhysOrg.com) -- Elephant seals are helping scientists overcome a critical blind-spot in their ability to detect change in Southern Ocean circulation and sea ice production and its influence on global climate.

The Arctic And Global Warming

Feb 28, 2006

A warmer Arctic Ocean may mean less food for the birds, fish, and baleen whales and be a significant detriment to that fragile and interconnected polar ecosystem, and that doesn't bode well for other ocean ecosystems in the ...

Warming in the Tasman Sea a global warming hot spot

Jan 30, 2012

Oceanographers have identified a series of ocean hotspots around the world generated by strengthening wind systems that have driven oceanic currents, including the East Australian Current, polewards beyond their known boundaries.

Recommended for you

Satellites catch the birth of two volcanic islands

5 hours ago

The birth of a volcanic island is a potent and beautiful reminder of our dynamic planet's ability to make new land. Given the destruction we've seen following natural events like earthquakes and tsunamis in t ...

Uncovering diversity in an invisible ocean world

6 hours ago

Plankton are vital to life on Earth—they absorb carbon dioxide, generate nearly half of the oxygen we breathe, break down waste, and are a cornerstone of the marine food chain. Now, new research indicates ...

Evolution of the Antarctic ice sheet

8 hours ago

ULB study sheds a new light on the stability of the Antarctic ice sheet. It shows for the first time that ice rises (pinning points that keep the floating parts of ice sheets in place) are formed during the transition between ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.