Presearch by the Federal University of Rio Grande do Norte (UFRN) foresees changes in the configuration of coral reefs and the migration of fish from the Caribbean and the Brazilian coast in the coming decades due to the warming of the oceans. The fall in the amount of fish that feed on algae in the tropical region may cause the reef ecosystems to lose their species diversity and have algae predominance as early as 2050.
The work projected the trophic interactions – related to the feeding – of the fish in relation to the increase in the temperature of the oceans. The results demonstrated that the interactions will decrease and that in some regions there will be a geographic displacement of these interactions: those that occurred, for example, in the tropical region, will migrate to the extratropical region, as explained Kelly Inagaki, researcher at the Laboratory of Marine Ecology at UFRN.
“We made these projections from North Carolina to Santa Catarina [ao longo do Atlântico Ocidental], then it can be said that the reefs of this entire region are threatened or are prone to change, according to our results ”, said the researcher.
She pointed out that records from bodies such as the Intergovernmental Panel on Climate Change (IPCC) and NASA, the US space agency, show that the average temperature of the oceans has increased over the years. “Actions that reduce the progression and impact of climate change are urgent. Otherwise, we will be taking the risk of losing the reef environments and all of its benefits ”, he added.
The reef fish that will potentially migrate from the tropics are herbivores and feed mainly on algae, controlling the abundance of these organisms in the reefs. As the researcher stated, with the warming of the ocean, this control would be impaired due to the migration of fish to regions outside the tropics, in search of more pleasant temperatures.
One possibility is that coral reefs in the Caribbean, for example, can be turned into algae-dominated reefs. “The fish that are controlling these algae, that are eating these algae, they will decrease. We will see an increase in these algae and the competition with corals or other organisms will become stronger and will make algae dominate these environments ”. She explained that algae live alongside corals, but if they compete for space or some other resource, algae usually win the competition.
“And an environment that is now dominated by algae will have changes in relation to sediments, so there may be more cloudy water, there may be changes in nutrients, PH or even the organisms that are living there. Not everyone likes to live with algae or like to eat algae and, if this environment is becoming dominated by algae, these fish and other organisms will look for other places to live ”, he said.
With the impact on the reef ecosystem, the benefits that reefs offer are also affected, such as fishing, coastal protection and tourism. “For example, in the Northeast, where we have a very strong economic activity in tourism: if these environments are going to change, perhaps this tourism activity will not be as strong as it is today, and it is necessary to think about alternatives for that or prepare in case these changes happen, ”noted Kelly.
According to the researcher, these situations – like the one observed in the research – are the result of living, living together and human existence. “If we want to change anything, we have to rethink the way we live. We have been using natural resources incessantly, without giving nature time to reorganize itself in relation to this ”. She cited society’s relationship with carbon dioxide production, food production and consumption, pollution and energy production as elements to be rethought.
With information from Agência Brasil.