The water in the Bay of Mazatlan is warming faster than the average for the world’s oceans. Over the last 40 years, an average warming trend of 0.57 degrees Celsius per decade is estimated, which is higher than the global average, reveals a study by the Institute of Marine Sciences and Limnology (ICML).
If the current trend continues, the temperature of the water in the area could increase up to seven degrees Celsius by 2100 and radically transform the ecosystem of the bay, details the study “Rapid surface water warming and impact of the recent (2013 –2016) temperature anomaly in shallow coastal waters at the eastern entrance of the Gulf of California”, published by the scientific journal Progress in Oceanography.
A team of researchers from the University participated in the investigation, made up of Joan Albert Sánchez Cabeza, José Luis Carballo Cenizo, Benjamín Yáñez Chávez and Ana Carolina Ruiz Fernández, from the Mazatlán Academic Unit; José Gilberto Cardoso Mohedano, from El Carmen Station; Carlos Alberto Herrera Becerril, from the Postgraduate in Marine Sciences and Limnology, and León Felipe Álvarez Sánchez, from the Marine Computing Unit, all from ICML.
“Although the world’s oceans are warming on average at a rate of almost two-tenths of a degree per decade, a figure similar to that of atmospheric warming, we see in our analysis a number greater than half a degree per decade, that is, that every 20 years the temperature has increased by one degree. It may not seem like much, because between winter and summer or day and night there are many oscillations, but it causes a significant impact on coastal ecosystems,” said Joan Albert Sánchez Cabeza, from the ICML Mazatlán Unit.
This increase is related to “human-induced global warming, which is increasing seawater surface temperatures around the world.”
The more rapid rise in the coastal area of Mazatlan could be due to a variety of factors, including shallow water effects, an increasing influence of warmer tropical surface water carried by the Mexican Coastal Current, and the transport of warmer water from the Western Pacific during El Niño events.
However, Sánchez Cabeza commented, “we don’t have a clear explanation; we know that marine systems around the planet are not homogeneous. One place does not heat up the same as another: in one place there may be colder currents than in another, or there is vertical mixing that brings cold water, and in other places, it does not. None of these processes is identical everywhere.
He explained that, in collaboration with François Colas, from the French Research Institute for Development (IRD, for its acronym in French), “we are developing a numerical model, and we hope that it will give us a more concrete answer as to the reason for this warming.” . The fact is that it is happening. It is a field observation with hard data that leads us to draw this conclusion.”
If the current trend persists, the study points out, the water in the Bay of Mazatlán would increase its temperature by seven degrees Celsius by 2100. Sánchez Cabeza specified that this scenario would be the most catastrophic, since “it is hard to believe that it will continue until the end of the century because the increase is spectacular. If sustained, an increase of seven degrees is really very big, especially for ecosystems, ”he assured.
The expert in global warming and climate change pointed out that it is necessary to “think of the organisms of the region” such as fish. Although everyone has “some degree of tolerance to changes in temperature,” he added, “many can’t live below or above a certain temperature level, causing those that can move to migrate. This has already been happening for decades; some North Atlantic species have moved further north seeking cooler waters,” he commented.
He added that with this trend we are going to have species that are going to progressively disappear due to this migration to colder waters; the ecosystem will be transformed. “We cannot generalize, because it depends on each species; but, in general, these ecosystems will be transformed, as is happening in other parts of the world”.
He explained that this is the local/regional impact, but other things that are currently happening will be added to the warming: our waters have more and more organic matter, which causes oxygen to drop; global warming, which is not going at this fast rate, causes the sea level to rise. All this affects the most sensitive areas, which are the coastal ones.
The increase in temperature of the coastal areas in the Bay of Mazatlán goes beyond the fact that “the waters will be warmer for tourists. It is much more complicated than that because they are going to be more polluted and oxygen-poor waters, generating problems for the fishing communities of Mazatlan. These changes are slow and it is difficult to see them, perceive them, and have a feeling of what is happening, but things are happening. The temperatures will be more and more extreme,” said Sánchez Cabeza.
This could be due to a variety of factors, including shallow water effects, an increasing influence of warmer tropical surface water carried by the Mexican Coastal Current, and the transport of warmer water from the Western Pacific during El Niño events.
Even though a seven degree Celsius rise in water temperature by 2100 is the most catastrophic scenario, a smaller rise would still permanently transform the ecosystem of the Bay of Mazatlan, so action needs to be taken sooner than later possible to alleviate its effects.
“That scenario is a calculation on paper; We are not saying that it will happen, but it is possible and it would be the most catastrophic. For example, we have all heard of coral bleaching: when there are events that raise the maximum temperature of the Caribbean waters by two or three degrees, a large part of the coral’s bleach, and not all of them recover from these events caused by the warm-up”, considered Joan Albert Sánchez Cabeza.
He said that the planet is warming mainly because we are consuming fossil fuels, which produce carbon dioxide and cause what we know as the greenhouse effect. The most important source of carbon dioxide is us and our vehicles. That’s still hard data.”
He considered that it is a multifactorial problem. “Governments must decide how they generate their energy and whether to prioritize clean energy or fossil fuels. Governments have the very important role of modulating what the population does in one direction or another”.
For the scientist, the main message is that the responsibility lies with each one of us, what we do because there are many of us and we exert enormous pressure on the planet. The change that must take place is a cultural one in each one of us; we have to be aware that everything we do or consume, or what vehicle we take to transport us, contributes to this increase. We must think before every action we take, he said.
“This is seen on a local and global scale: we have pollution, rising sea levels, destruction of the coastal zone… The damage we are doing to the planet is impressive. We have to start learning to live with them, because if not, life will be very difficult for us, ”she warned in conclusion.