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 |
How do muscles know what time it is?
21.08.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Materials Sciences
20.08.2018 | Information Technology
20.08.2018 | Life Sciences