Navigation Links
New study reveals decline of marine phytoplankton over the past century
Date:7/28/2010

A new article published in the 29 July issue of the international journal Nature reveals for the first time that microscopic marine algae known as "phytoplankton" have been declining globally over the 20th century. Phytoplankton forms the basis of the marine food chain and sustains diverse assemblages of species ranging from tiny zooplankton to large marine mammals, seabirds, and fish. Says lead author Daniel Boyce, "Phytoplankton is the fuel on which marine ecosystems run. A decline of phytoplankton affects everything up the food chain, including humans."

Using an unprecedented collection of historical and recent oceanographic data, a team from Canada's Dalhousie University documented phytoplankton declines of about 1% of the global average per year. This trend is particularly well documented in the Northern Hemisphere and after 1950, and would translate into a decline of approximately 40% since 1950. The scientists found that long-term phytoplankton declines were negatively correlated with rising sea surface temperatures and changing oceanographic conditions.

The goal of the three-year analysis was to resolve one of the most pressing issues in oceanography, namely to answer the seemingly simple question of whether the ocean is becoming more (or less) green' with algae. Previous analyses had been limited to more recent satellite data (consistently available since 1997) and have yielded variable results. To extend the record into the past, the authors analysed a unique compilation of historical measurements of ocean transparency going back to the very beginning of quantitative oceanography in the late 1800s, and combined these with additional samples of phytoplankton pigment (chlorophyll') from ocean-going research vessels. The end result was a database of just under half a million observations which enabled the scientists to estimate phytoplankton trends over the entire globe going back to the year 1899.

The scientists report that most phytoplankton declines occurred in polar and tropical regions and in the open oceans where most phytoplankton production occurs. Rising sea surface temperatures were negatively correlated with phytoplankton growth over most of the globe, especially close to the equator. Phytoplankton need both sunlight and nutrients to grow; warm oceans are strongly stratified, which limits the amount of nutrients that are delivered from deeper waters to the surface ocean. Rising temperatures may contribute to making the tropical oceans even more stratified, leading to increasing nutrient limitation and phytoplankton declines. The scientists also found that large-scale climate fluctuations, such as the El-Nio Southern Oscillation (ENSO), affect phytoplankton on a year-to-year basis, by changing short-term oceanographic conditions.

The findings contribute to a growing body of scientific evidence indicating that global warming is altering the fundamentals of marine ecosystems. Says co-author Marlon Lewis, "Climate-driven phytoplankton declines are another important dimension of global change in the oceans, which are already stressed by the effects of fishing and pollution. Better observational tools and scientific understanding are needed to enable accurate forecasts of the future health of the ocean." Explains co-author Boris Worm, "Phytoplankton are a critical part of our planetary life support system. They produce half of the oxygen we breathe, draw down surface CO2, and ultimately support all of our fisheries. An ocean with less phytoplankton will function differently, and this has to be accounted for in our management efforts."


'/>"/>

Contact: Charles Crosby
charles.crosby@dal.ca
902-494-1269
Dalhousie University
Source:Eurekalert

Related biology news :

1. NJIT professor receives Fulbright to study at University of Salerno
2. Study suggests swimmers at sub-tropical beaches show increased risk of illness
3. Scripps research study shows infectious prions can arise spontaneously in normal brain tissue
4. Neiker-Tecnalia study use of oilseedrape and sunflower oils to produce fuel and feed for herds
5. Study recommends that parents, physicians share decisions in sex development disorder surgery
6. UT MD Anderson study ties abnormal cells in blood to lung cancer
7. Kids could get more whole grains from after-school snacks, University of Minnesota study finds
8. NIH awards National Jewish Health $31 million to lead study of infections associated with eczema
9. Study links African ancestry to high-risk breast cancer
10. Climate change causes larger, more plentiful marmots, study shows
11. LSU researchers secure NSF rapid response grants to study impact of oil spill
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/22/2016)... PUNE, India , March 22, 2016 ... new market research report "Electronic Sensors Market for ... Fingerprint, Proximity, & Others), Application (Communication & ... and Geography - Global Forecast to 2022", ... consumer industry is expected to reach USD ...
(Date:3/18/2016)... -- --> --> Competitive ... Unmanned Vehicles, Physical infrastructure and Perimeter Surveillance & Detection Systems ... security market and the continuing migration crisis in the ... has led visiongain to publish this unique report, which ... defence & security companies in the border security market ...
(Date:3/15/2016)... 2016 Yissum Research Development Company of ... of the Hebrew University, announced today the formation of ... of various human biological indicators. Neteera Technologies has completed ... private investors. ... of electromagnetic emissions from sweat ducts, enables reliable and ...
Breaking Biology News(10 mins):
(Date:5/24/2016)... , ... May 24, 2016 , ... ... diabetes, and traumatic injuries, will be accelerated by research at Worcester Polytechnic Institute ... engines of wound healing and tissue regeneration. , The novel method, developed by ...
(Date:5/24/2016)... ... 24, 2016 , ... Last week, Callan Capital, an integrated wealth management firm ... Future of San Diego Life Science event at the Estancia La Jolla Resort and ... event with speakers Dr. Rich Heyman, former CEO of Aragon and Seragon, and Faheem ...
(Date:5/23/2016)... ... ... The need for blood donations in South Texas and across the nation is growing. , ... Center, blood donations are on the decline. In fact, donations across the country are at ... South Texas in the last four years alone. , There is no substitute for blood. ...
(Date:5/23/2016)... 2016 Zimmer Biomet Holdings, Inc. (NYSE and SIX: ... its Board of Directors has approved the payment of a ... 2016. The cash dividend of $0.24 per ... to stockholders of record as of the close of business ... to approval of the Board of Directors and may be ...
Breaking Biology Technology: