El Ni帽o, that extreme weather system聽known to wreak havoc on temperature, productivity and fisheries in the Pacific Ocean, as well as rainfall patterns around the world, has changed into something new.
Nicknamed the Modoki 鈥� a Japanese word meaning the same, but different 鈥� scientists have watched this new kind of El Nin虄o develop since the 1990s.
But while several papers have explained the Modoki鈥檚 physical effects on the tropical Pacific ocean, no one had examined how it affected ocean biology 鈥� until Dalhousie oceanography researcher Daniela Turk published a study in the journal .
Looking at El Ni帽o鈥檚 biological effect
鈥淲hile there has been significant research into the physical changes associated with El Nin虄o Modokis, there have been no studies prior to ours to determine whether they also induce a distinct biological response," she says.
In her 2011 paper, Dr. Turk and her co-authors used satellite data to compare decreases in biological productivity in the equatorial Pacific Ocean between El Nin虄o Modokis (also called Central Pacific or CP-El Nin虄o) and classical Eastern Pacific (EP) Nin虄os
This month, Dr. Turk continues her research, as a co-author on a follow-up paper by Michelle Gierach from the California Institute of Technology鈥檚 Jet Propulsion Laboratory. Published in Geophysical Research Letters, their paper received a Research Spotlight in the American Geophysical Union鈥檚 weekly electronic supplement.
鈥淭he interaction was very inspiring,鈥� she says of her collaboration with Dr. Gierach. 鈥淭he fact that I met a younger female colleague who continued on this research and I could help with my perspective as well learn from her was very rewarding for me.鈥�
El Ni帽o and the food chain
In her first paper, Dr. Turk tied the CP El Nin虄o to stronger declines in central Pacific phytoplankton and biological productivity, but found it had a less drastic effect on the eastern Pacific compared with EP El Nin虄os.聽 Her most recent paper further explored the responsible physical mechanisms behind these changes in biology.
Both studies suggests that a predicted future shift to more frequent CP El Ni帽os could alter ecosystem dynamics in the equatorial Pacific Ocean. It would enhance phytoplankton and biological productivity in the eastern basin and decrease in the central area.
鈥淭his changes in the basic building block of the ocean鈥檚 food chain could have an effect on distribution and abundance of zooplankton and fish.鈥�
This might prove a possible benefit for the eastern region鈥檚 fisheries, and Dr. Turk is interested in connecting with biologists in the Dalhousie-managed Ocean Tracking Network to look at the effect of changing El Ni帽o patterns on Pacific Ocean聽fisheries.
鈥淚 would like to find someone with data from the fisheries side, while I could provide oceangraphic perspective.鈥�
Her work is an important step in understanding the effects of this new weather event on many ecological levels around the world.
鈥淏ecause some scientists expect it to become the dominant El Ni帽o variant in response to global warming, understanding their differing effects is a pressing concern to us all,鈥� she says.