Subtle and short-lived differences in ocean salinity or temperature function as physical barriers for phytoplankton, and result in a patchy distribution of the oceans' most important food resource. The new research from the Center for Macroecology, Evolution and Climate at the University of Copenhagen may help explain the large biodiversity in the sea.
Phytoplankton are microscopic algae that live free-floating in the sea, transported around by ocean currents. The composition of phytoplankton communities affect other microscopic organisms, fish and even whales, as they constitute the base of the food web in the sea.
Small differences in salinity and temperature lead to the formation of weak and ephemeral fronts with different phytoplankton communities on each side. Researchers found that several species of the genus Chaetoceros (shown on photo) constituted the majority of the biomass on one side of the front but were virtually absent on the other side.
Credit: Niels Daugbjerg
"The oceans are full of invisible barriers that occur when temperature or salinity changes. Our new research shows that even short-lived barriers of just a couple of days or weeks, are enough to influence phytoplankton communities. This provides us with new insight into how the high biodiversity of phytoplankton is maintained and how the food web might be affected", says lead author and Postdoc Erik Mousing from the Center for Macroecology, Evolution and Climate at University of Copenhagen.
In recent decades, researchers have increasingly understood how small organisms are separated by relatively permanent fronts in the sea caused, for example, by large ocean currents. However, this is the first time researchers demonstrate that short-lived changes in salinity or temperature also lead to changes in the composition of algae communities.
While it is known that physical barriers on land, such as rivers and mountains, can lead to the development of new plant and animal species over time, the oceans have primarily been perceived as a homogeneous environment. Therefore, it has been difficult to explain the large biodiversity of small algae.
"Our results show that the distribution of phytoplankton is much patchier than previously assumed as a result of these commonly occurring weak fronts. Coupled with the short generation time of phytoplankton the local barriers caused by these fronts could help explain why phytoplankton diversity is so large. Thus, at least in terms of the overall mechanisms controlling biodiversity, the terrestrial and marine systems are not fundamentally different", says co-author and Professor Katherine Richardson, from the Center for Macroecology, Evolution and Climate.
In the study, which was published today in the Journal of Ecology, the researchers analyzed 30 samples of phytoplankton from 16 locations in the North Atlantic. They also measured temperature and salinity in different water depths. Based on the samples, the researchers were able to map out a front with different salinities on each side. The species composition of phytoplankton was significantly different on either side of the front.
"Although our results are based on samples in the North Atlantic, weak and short-lived fronts occur in oceans all over the world. Therefore, there is every reason to believe that the influence of these small scale fronts on phytoplankton is a common feature in the world's oceans", concludes Erik Mousing.
The study has been conducted in cooperation with the Danish ClimateLab, NASA and the University of Maine.
Erik Askov Mousing |
Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)
Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Information Technology
13.12.2017 | Physics and Astronomy
13.12.2017 | Health and Medicine