An international team of researchers from France's National Center for Scientific Research or CNRS monitored clownfish in the lagoons of Kimbe Bay. Kimbe Bay is known as a biodiversity hot spot in Papua New Guinea, and they recorded their research for 10 years.
They used genetic analysis of the population's DNA, and they were able to calculate their ability to adapt to habitat changes and renew their population. Clownfish and anemone tenants rely on coral for their survival. However, those are under threat from warming seas, pollution, and human intrusion. These situations can make adapting very difficult for them. Big families of clownfish were linked to high-quality habitats, instead of shared genes.
Clownfish are in danger due to climate change
Simon Thorrold, a WHOI biologist, said that the findings that they reported in their study were made possible by a massive sampling and DNA sequencing effort that had not been attempted for any marine species before. The biggest surprise to use was also the most troubling because numerous conservation efforts can't rely on genetic adaptation to protect clownfish from the effects of climate change. He also said that it seems that clownfish won't be able to save themselves.
Anemone contributes significantly to the survival of clownfish. Clownfish relies 50% of their life on anemones to be able to renew their population. If anemones remain healthy, then the clownfish population will continue. But if the coral reefs and anemones are impacted by climate change, then the clownfish population is in danger.
Benoit Pujol, an evolutionary geneticist at CNRS said that clownfish are at the mercy of a habitat that is degrading every year. To expect a clownfish to genetically adapt at a pace that would allow it to continue living in lagoons would be unreasonable, and the ability of these fish to remain in the lagoons in the next decade will depend on the human's ability to maintain the quality of their habitat.
Effects of climate change in marine life
Due to climate change, the oceans are getting hotter. The changes in water temperature can affect the environments where marine species live. Climate change causes oceans to become warmer. The populations of some marine species may adapt by shifting toward cooler areas.
Black sea bass, American lobster, red hake, and hundreds of other populations of marine species have already shifted to the north to cooler waters, according to the fourth edition of EPA's Climate Change Indicators in the United States report. These important species have shifted their average center of biomass northward by an average of 109 miles over the past 32 years. For all 105 marine species that were studied, the average center of biomass along the U.S coasts shifted northward by about 12 miles between 1982 and 2014. At the same time, these 105 species moved an average of 18 feet deeper.
Another effect of climate change is the acidity in the ocean. The acidity is increasing because of the increasing carbon dioxide levels in the air from human activities such as burning fossil fuels. The concentrations of carbon dioxide are higher than in the last 800,000 years. Carbon dioxide dissolves in water, changing seawater chemistry, and decreasing the pH in the water, thus making it more acidic. The increased acidity in the ocean results in thinner shells, and more shellfish die because they become easier for predators to eat.
The corals are also very sensitive to acidity because it is difficult for them to make and maintain the structures that are needed for their protection and support. The corals provide important fish spawning habitat and support for thousands of marine species.
If no action is taken on climate change, we can no longer see clownfish in our lagoons in the next decades to come.
