Climate change reduces the richness of marine life. TUCHONG
Ever since Earth formed roughly 4.5 billion years ago, its climate has gone through a number of incredible changes.
All you have to do is look at images of the Jurassic Period to know that at one time, much of our planet was covered in extremely hot and humid jungle. Skip ahead a couple million years and you get to an ice age event, when global temperature experienced a huge drop. While many species were not able to deal with these changing climate patterns, others successfully adapted, and some are even still with us today.
Now, as humanity pushes the planet closer to another extreme climate event, scientists are eager to find out how the world’s species will react.
The idea was highlighted in a study published on April 6 in the journal PNAS, which showed that between 1970 and 2010, open water species such as lobsters and fish had declined by about half in tropical marine zones across the globe because over the 40-year time period, sea temperatures in those regions had risen by roughly 0.2 C.
The lower numbers aren’t a sign of all the sea creatures dying off though. In fact, the scientists found some of them outside of their traditional habitats, meaning that if a species can migrate to cooler waters and adapt in a new environment, they will.
However, those movements aren’t always a good thing; species that can’t move, such as coral, which is fixed to the seabed, rely on the fish and other sea creatures to contribute to the natural food chain and stay healthy. Additionally, when a non-native species moves into a new area, it threatens to disrupt the ecosystem that already exists there.
Depending on the species, it can take anywhere from one generation to thousands and thousands of years to properly adapt, so the changes that have occurred in just the last 40 years are very troubling for scientists. As Sebastian Ferse, an ecologist at the Leibniz Centre for Tropical Marine Research, Germany, explained: “In geological history, this has occurred in the blink (眨眼) of an eye. To see such changes occurring so rapidly is something quite alarming.” He added, “One of the big questions is ‘Will coral reefs as ecosystems and corals as species be able to move north or south fast enough to adjust to a changing climate?’”