We know that climate change is likely to bring about more frequent and intense extreme weather events that will have wide-ranging impacts on how people around the world live. But what about the other species and communities with which we share the planet? How will they react? It seems that for the marine environment at least, things are likely to shift north as the oceans warm and currents change.
In a new study published this week in PNAS, researchers have mapped the historic distributions of nearly 90 species of phytoplankton, and then mapped their predicted spread over the next 50 years. Phytoplankton are the tiny organisms that are crucial to most life in the oceans, and form the base of many food webs. The tiny organisms photosynthesize to obtain energy, and are in turn eaten by zooplankton, which are then fed upon by fish. This makes the phytoplankton the primary producers of organic compounds in the ocean, and thus an essential part of the marine ecosystem.
Phytoplankton, such as this species, form the basis of many marine food webs. NOAA MESA Project/Wikimedia
“Marine phytoplankton are crucial in marine food webs and global biogeochemical cycles and they are incredibly diverse but we don't really have a sense of what all the different organisms do when you modify climate, or even through natural climate variability,” co-author Andrew Barton explained to BBC News. Barton and his team found that most of the species of phytoplankton will shift north-eastward in the Atlantic, and at a much faster rate than was previously predicted.
But not only did they see whole communities move, they also predict that relationships between species of phytoplankton will be significantly altered. This could have profound impacts on the other organisms that rely on them, such as fish. A second study, published in Nature Climate Change, has looked at how the distribution of fish will be altered as the oceans warm, and as a result how the movement of fisheries will transfer their value and wealth to more northern nations.
“What we find is that natural resources like fish are being pushed around by climate change, and that changes who gets access to them,” says Malin Pinsky, who co-authored the second paper, in a statement. As the fish move north, communities that have conservation-orientated management of natural resources, such as those in the Northern Hemisphere, will derive more wealth from the fisheries than the communities who currently have access to them. This will ultimately exasperate the inequalities already seen between the developing nations and the developed.
These shifts in marine life to more northern climates have already been seen in the North Sea, as cod chase the colder water, and more exotic warm water species come into the south. It is also what is thought to be behind an increase in shark attacks along the eastern coast of the U.S., as the sharks move north into more populated areas. It seems that as climate change becomes more and more intense, the planet will be seeing more disturbances in its natural ecosystems.
