Juan Sebastian Rengifo
Juan Pablo Barrero
The great white shark is one of the top predators in the food chain that regulates the variety and abundance of many species and helps to maintain the health and balance of marine life in the ocean. Sharks are used to certain conditions such as moderate water temperatures between 12 to 25 degrees Celsius. Rising, global temperatures that have been increasing during the last 13 years due to the greenhouse effect are affecting several aspects of these species and consequently endangering marine ecosystems.
There is a direct relationship between the effects on sharks and the melting of poles caused by the high temperatures on the Earth’s surface. First, sharks are cold-blooded animals and an excessive increase of water temperature produced by the amount of reflectivity of the ice caps on Earth may kill them by altering their homeostasis. Second, ice melting of the poles causes a change in the normal characteristics of the ocean regarding the sea level which is increasing by 3 millimeters per year, warming of currents, acidity and salinity which alter the conditions of sharks’ natural environments. In addition, sharks migrate seasonally. During the summer, when water temperatures increase, they tend to migrate to colder temperatures near the poles. As a consequence of global warming, when summer is over water temperatures do not decrease, forcing sharks to permanently abandon their natural ecosystem and to adapt. As global warming drastically affects some aspects concerning sharks, such as food sources and their biology, they may be considered as temperature- and ice-dependent species.