Manta Rays and Global Warming

Manta Rays and Global Warming

Climate change and global warming

Modern times are marked by multiple environmental problems, but a major concern is that global warming has caused climate change on planet Earth.

Global warming is defined as the increase in temperature of the atmosphere, mainly as a result of the excessive emission of greenhouse gases given off by many human activities. This heating is evidenced by the abrupt and unprecedented changes in climate in many geographical regions, the increased frequency and intensity of unusual natural phenomena such as hurricanes and tornadoes, and rising sea level.

The oceans are home to millions of living beings that make up the food chain. However, the lives of these beings is in danger because the oceans absorb some of the heat from the atmosphere and their temperature also increases, the polar ice melts and gradually increase the water level, and excess carbon dioxide in the atmosphere is absorbed by the water which forms carbonic acid and ocean acidity increases with decreasing pH.

All this is a cluster of changing factors that can be beneficial or may be harmful, but the adverse effects could overtake the benefits as aquatic creatures may not adapt to change.

The effects of global warming on manta rays

The base of the marine food chain is plankton, a set of mostly microscopic organisms that serve as food for many animals such as larvae, crabs, fish and crustaceans which in turn are food for other animals, however, some whales and sharks also consume plankton, along with the two species of manta ray.

In this sense, climate change affects the availability of plankton to feed the manta rays. The increase in sea temperature can disrupt the life cycles of these microorganisms and begin to dwindle, so manta rays would be in trouble because they are eminently filter feeders. Eventually, they would face problems in finding adequate supplies of plankton.

Scientists include global warming and climate change among the major threats to members of the genus Manta. And no wonder, since besides the possibility to affect the availability of their staple food, it can have consequences on their distribution, behavior and migration.

It is known that the habitat of manta rays is the warm waters of tropical, subtropical and temperate zones. A significant increase in ocean temperatures could expand their range, and can be extended to areas where they are not today. But the oxygen dissolved in the water may decrease, complicating the process of breathing and cause water acidification damages to their immune system, preventing the defensive response to disease.

Indirectly, this will harm manta rays because they are animals normally associated with coral reefs, especially the reef manta (Manta alfredi). Regardless of the species, individuals tend to visit cleaning stations that may be located on coral reefs, but they tend to die when in response to stress by high temperatures and their colors fade. The reef species is also vulnerable to sea level rise because their habitats are usually closer to the coast than those of the giant manta ray (Manta birostris).

Some scientists suggest that manta rays could be biological indicators of the impact of climate change on the oceans as their feeding habits, migration and movement becomes understood deeply. This issue becomes of vital importance as it has relevance not only on manta rays, but in all aquatic animals.