Climate Change is Reshaping Communities of Ocean Organisms: Study
Mon, April 19, 2021

Climate Change is Reshaping Communities of Ocean Organisms: Study

Marine species are the most affected in the warming of the ocean. / Photo credit by Inacio Pires via 123rf

 

 

For an ecosystem that covers 70% of the planet, oceans are often taken for granted. They provide most of the oxygen that people breathe in and feed us with its marine life. If not for the oceans, climate change and global warming would have already made this planet uninhabitable. Since the 1970s, the oceans have absorbed more than 90% of the warming created by humans. Had that heat gone into the atmosphere, today’s global average temperatures would have reached nearly 56 degrees Celsius.

Unfortunately, humans continue to abuse our oceans and the species living in them. National Geographic, an American pay television network and flagship channel owned by National Geographic Partners, reported that the top part of the ocean is warming up about 24% faster than it did a few decades ago. This rate is likely to increase, resulting in stronger hurricanes and tropical cyclones. The oceans are becoming more acidic as well, which makes ecosystems and marine species increasingly vulnerable.

A recent report by the UN’s Intergovernmental Panel on Climate Change (IPCC) revealed the state of the planet’s oceans and ice. The report projected that global warming will drastically alter the ocean and the cryosphere. Climate change has already reshaped both oceans and ice. Nathan Bindoff, a lead author on the report and an oceanographer at the University of Tasmania, stated that the rate of climate change has increased since 1993. Since then, the rate of the warming of global oceans has doubled. 

The report revealed that our oceans are expected “to transition to unprecedented conditions” with increased temperatures, increased marine heatwaves, upper ocean stratification, further acidification, and other factors. According to Eos, a weekly magazine of Earth science, the report cited significant measures to address climate change such as monitoring and forecasting, education and climate literacy, addressing social vulnerability and equity issues, and more. 

“Enabling climate resilience and sustainable development depends critically on urgent and ambitious emissions reductions coupled with coordinated sustained and increasingly ambitious adaptation actions,” the report stated. 

 

 

Marine Life More Sensitive to Warming

The most affected in the warming of our oceans are marine species. A recent study conducted by researchers from Rutgers University revealed that twice as many ocean-dwelling species as land-dwelling species have disappeared from their habitats due to global warming. The researchers analyzed worldwide research on nearly 400 species from lizards and fish to spiders. They wanted to compare the sensitivity to the warming of cold-blooded marine and land species. They did so to also compare both of their abilities to find refuge from the heat while staying in their normal habitats.

According to Science Daily, an American website that aggregates press releases about science, the researchers gathered and analyzed safe conditions for 88 marine and 294 land species. They also included the coolest temperatures available to each species during the hottest parts of the year. Lead author Malin Pinsky, an associate professor in the Department of Ecology, Evolution, and Natural Resources at Rutgers University-New Brunswick, stated that marine species are disappearing from their habitats twice as often as land species.

 

 

"The findings suggest that new conservation efforts will be needed if the ocean is going to continue supporting human well-being, nutrition, and economic activity,” Pinsky said. 

The researchers also found out that land species have something that marine species don’t: the ability to hide from the heat in forests, underground, or shaded areas. This explains why they are more in danger compared to animals on land. Unfortunately, it is expected that more marine species will disappear from local habitats due to the warming temperatures. 

Ocean Warming is Affecting the Mix of Species

Researchers from a recent study gathered and compiled the most comprehensive assessment to show how ocean warming has been affecting the mix of species in our oceans. They looked at invertebrates such as crabs, fish, and other crustaceans and plankton in the North Atlantic and North Pacific. At the same time, they analyzed three million records of thousands of species from 200 ecological communities across the globe from 1985 to 2014.

The findings of the study published in the journal Nature Climate Change revealed that there’s dramatic evidence that changing temperatures are already reshaping communities of ocean organisms. "We found that warm-water species are rapidly increasing and cold-water marine species are decreasing as the global temperature rises. Changes like this are often disrupting our fisheries and ocean food chains,” co-author Malin Pinsky, an associate professor in the Department of Ecology, Evolution, said.

 

Due to the rise of global temperature, warm-water species are rapidly increasing while cold-water marine species are decreasing. / Photo credit by Andrey Armyagov via 123rf

 

The study also recognizes temperature as a fundamental driver for change in marine systems. While it has been the reason for the restructuring of communities in the most rapidly warming areas, the researchers suggest that there’s a strong prognosis of resilience to climate change for these communities. Pinky stated that marine species can find their refuge by going in cooler, deeper water just like how land plants move to higher elevations to avoid heat. 

Also, the researchers noticed strong shifts toward the dominance of warm-water species in warm areas like the North Atlantic. Meanwhile, regions with stable temperatures show little change in species dominance. As of now, the team is trying to understand the changes in the oceans compared to those on land and in freshwater ecosystems. 

Indeed, climate change has been a driving force in altering our oceans and reshaping communities of ocean organisms. This could affect how marine species live and how they survive in the next few years.