The study was published in the journal Progress in Oceanography by leading author Maria Vernet of the University of California Scripps Institution of Oceanography in San Diego.
This finding adds to the understanding of the carbon cycle and the availability of nutrients in this rapidly warming and changing environment.
Phytoplankton are arguably the most important organisms in the ocean. Directly or indirectly, almost all life in our global waters depends on their operation. In a new study, a team of researchers has mapped how the activity of these microscopic plants affects Greenland’s critical waters, affecting important regional fisheries and even nutrient availability around the world.
The researchers found that the seasonal availability of carbon produced by phytoplankton is shifting towards the poles and is visible for longer than in previous decades. The discovery will improve researchers ’understanding of the carbon cycle and the availability of nutrients in this rapidly warming and changing environment.
During photosynthesis, all plants convert carbon dioxide into food by utilizing energy from the sun. The food they create in the form of organic carbon is vital. This process is called primary production and plays an important role in the global carbon cycle. In the sea, almost all primary production is carried out by phytoplankton.
“It all depends on the carbon produced by phytoplankton no matter where you are in the ocean waters,” said a senior researcher at Bigelow Laboratory. Paty Matrai, one of the authors of the magazine. “If there is no primary production, no new carbon will be generated, and many of the animals that depend on it will have nothing to feed.”
The growth patterns of Arctic phytoplankton have already changed significantly due to climate change. The fish that feed on them have had to adapt, as have the industries that rely on them. These changes need to be better understood in order to plan ahead.
Researchers looked at the 10-year period 2008-2017 in seven areas of Greenland to understand where and when primary production takes place. They found that prices were higher in the southern regions, where the North Atlantic is more affected by water. They also found that phytoplankton blooms began in the south around April and in the north around June.
“These waters have extreme seasonality and great diversity in terms of primary production,” Matrai said. “Greenland has an influential location, and understanding the waters around it can give us unique insights into global ocean processes.”
Greenland is at the intersection of complex interactions between Arctic and Atlantic currents, and its coastal waters are part of both systems. As the planet warms, milder conditions and the nutrients and organisms that favor them move from the south upwards.
Its waters are also a mixing point for salt water and melting fresh water. More than 80% of its land area is covered by the Greenland ice sheet. As it melts due to global warming, it sends a stream of cold fresh water from the north into the ocean. This can have significant impacts on the physical and biological processes in the North Atlantic, including ocean convection, nutrient availability, and primary production.
The waters around Greenland are known to be difficult to study. Severe weather, complex sea conditions and changing sea ice make sampling dangerous. Although the fjords to its west have been better studied, less is known about the fjords to the east and the continental shelf.
The researchers used two independent mathematical models to calculate primary production around the island. One was based on the color of the ocean, which can be used as a substitute for phytoplankton and other life, and the other on the biology and physical properties of the ocean.
The team also found that most of the carbon from Greenland’s primary production is sinking, affecting ocean ecosystems below surface waters. In contrast, scientists have long thought that unused carbon that remains on the surface is converted to carbon dioxide and returned to the atmosphere.
The study showed that as much as 75 percent of annual production is exported deep into the ocean, with the largest amounts sinking closer to the Arctic. This means that coal could play an extra, unexpected role in global cycles as it swept into deep ocean currents moving around the planet.
Most organisms live in the surface waters of the oceans, where sunlight feeds photosynthesis. Scientists have used this area as a model for the operation of food webs and nutrient cycles. However, as the carbon generated near the surface sinks, it becomes accessible to a variety of organisms. This opens up new possibilities for ecosystem dynamics and discoveries.
Researchers are working to capitalize on these results to understand long-term patterns of primary production, how they are affected by climate change, and how it affects marine life.
“Because melting sea ice allows more sunlight to enter ocean waters, it creates new habitats for photosynthetic organisms and increases the potential for primary production,” Matrai said. “A better understanding of the role of primary production can help us anticipate and adapt to change in this critical environment.”
Source: ANI
Source: The Nordic Page