Ecological role of cetaceans
Ecological role of cetaceans
Cetaceans (Cetacea Brisson, 1762) are an infraorder of eutherian mammals, completely adapted to aquatic life.
Cetaceans have a fusiform body, similar to that of fish, which ensures greater hydrodynamics. The forelimbs are modified into flippers; the hind limbs as such are absent; only a few small vestigial bones remain, hidden inside the body, and not connected to the spine due to the absence of the pelvis. The caudal fin is arranged horizontally and divided into two lobes. They are generally hairless and are thermally insulated by a thick layer of fat.
Within the Cetacea infraorder there are approximately 85 species, which are almost all marine except for 5 species of freshwater dolphins.
Cetaceans are widespread in all the seas and oceans of the world and some species inhabit lakes and rivers in North America, South America and Asia. Some species, such as killer whales (Orcinus orca) are cosmopolitan, others are widespread in large geographical areas but are not present in all the world’s waters and still others live in more restricted areas. This is the case, for example, of Phocoena sinus, endemic to the northern part of the Gulf of California.
Some cetaceans live near the coasts, in what is called the neretic province, others live in the open sea, in the oceanic province and some species, such as Tursiops truncatus, have different populations that live in one province or the other. Furthermore, some cetaceans live near river estuaries and others swim in fresh water.
Ecology –
Cetaceans play an important role in the ecological balance of marine ecosystems, because they occupy the top of the food chain and therefore contribute, together with other large pelagics such as sharks, tunas and sea turtles, to maintaining the populations of the fauna of which they are in numerical balance. they feed themselves.
In fact, they are high-level predators in the marine food chain. They take prey such as fish, squid and other marine organisms, helping to maintain the balance of prey populations and preventing the proliferation of inferior species.
Seasonal cetacean migrations can contribute to the transport of nutrients across the oceans. When they migrate, they release nutrient-rich feces that can help fertilize waters, promoting the growth of marine organisms.
The movement of whales and dolphins can influence the distribution and density of phytoplankton. These microscopic organisms are essential for photosynthesis and oxygen production, thus contributing to the health of the entire marine ecosystem.
Predation by cetaceans can influence the dynamics of prey populations, favoring the survival of the fittest individuals and contributing to genetic diversity.
The presence of cetaceans attracts tourism, contributing to the local economy through whale watching. This activity can be managed sustainably, promoting environmental awareness and the conservation of marine species.
Cetaceans use natural sonar to communicate, orient themselves and hunt. This acoustic ability is critical for survival and can impact the distribution and behavior of other marine species.
Cetacean populations can give an indication of the health of the oceans. Changes in their populations may reflect environmental impacts such as pollution, climate change and decreasing food resources.
Preserving and protecting cetacean populations is therefore crucial to maintaining the balance of marine ecosystems and ensuring the sustainability of the marine environment.