Bangladesh is a country deeply connected to water, dominated by extensive floodplains, a dynamic system of estuaries and islands, and a coastal sea. Marine ecosystems are considered as the habitats that complete the largest system from the shores to the dark seafloor. The marine ecosystem includes marshes, tidal zones, estuaries, the mangrove forest, lagoons, seagrass beds, the sea floor, and the coral reefs.
The marine ecosystems are foremost to the world without them, the marine life would not have any protection from predators, which could eventually make the marine life go extinct. Marine water covers more than 70% of the surface of the Earth and accounts for more than 97% of Earth’s water supply and 90% of habitable space on Earth.
Adaptation is a feature of an organism that enables it to live in a particular habitat. The organism becomes more fitted on surviving and multiplying itself on the environment where it lives. For an organism, the adaptation of aquatic life is very difficult on the ocean.
In Addition, adaptation is an evolutionary process whereby a living thing becomes increasingly well suited to living in a particular abode. Unfortunately, it’s not an expeditious process. Now, the most remarkable adaptation process is physiological adaptation. It’s related to how the organism’s metabolism works. These adaptations enable the organism to regulate their bodily functions.
For a living organism, adaptation to aquatic life involves changes that affect not only its shape but also its internal physiology to solve the physical and chemical problems affecting this particular environment, although this proves to be a little more stable than the air environment.
Each marine species adapts to the various habitats to reach an equilibrium, trying to solve problems that may compromise its survival such as the regulation of temperature, salinity, pressure, and the provision of oxygen for respiration, food, locomotion, how to defend oneself and how to perpetuate the population.
The high salt content found in the ocean can support the large bodies of giant squids and whales, which has allowed them to evolve without the use of strong limbs for support. Nevertheless, salt water exerts enormous pressure on the air spaces of marine animals at depth.
Some marine mammals, such as whales, migrate over large distances and may spend time in a combination of the arctic, tropical and temperate waters. To cope with these temperature changes, they are endothermic or warm-blooded. It means that they can maintain a constant body temperature that is not dependent on the surrounding water.
According to the IPCC (2019), since 1950 many marine species across various groups have undergone shifts in geographical range and seasonal activities in response to ocean warming, sea ice change and biogeochemical changes, such as oxygen loss, to their habitats. It has been estimated that only 13% of the ocean area remains as wilderness, mostly in open ocean areas rather than along the coast.
Most organisms do not tolerate large variations in salinity (they are called stenohaline) and only a few can survive when it changes (euryhaline) – as can happen in coastal lagoons. Very few are the species able to switch from fresh to salt water or vice versa during their life. Salmon and eel are the most famous examples.
Some marine organisms that carry out their lives in the absence of light. In response to this, they have developed various types of adaptation, among these, the main one is the production of light through bioluminescence.
Marine ecosystems are an essential part of the world because the marine ecosystems give marine life such as tiny plankton, fish, crustaceans, invertebrates, reptiles, marine mammals, sharks, and rays a place to live and survive. It also gives those marine animals a place to hunt.
Much marine life has a vital role in the world such as the tiny plankton because without them the world would build up with carbon dioxide, the plankton absorbs the carbon dioxide in the air and releases oxygen back into the air. Without marine ecosystems to protect the tiny plankton, more species would become extinct.
But marine biota adaptation is facing various challenges such as lacking proper management and not enough protection strategy. Particularly sensitive areas at risk from shipping activities and pollution, over extraction of marine living resources as the main barrier of adaptation.
Marine adaptations include reproductive strategies, symbiosis, defensive behavior, contact and communication, camouflage, and adaptations to environmental conditions like temperature, light and salinity. The high salt content found in the ocean can support the large bodies of mammals. But Marine life has developed many adaptations to the variations in temperature.
Coral reefs are valuable for marine life because it provides a shelter for various species. Coral reefs also are the most diverse ecosystem in the whole aquatic system. Without all the marine ecosystems, the marine food web and the entire ocean would be in danger of continuing in its current state.
The most important marine ecosystems for marine life are estuaries and coral reefs. These two marine ecosystems are predominant because the estuaries are breeding territories for many marine animals. After all, it is easy for young-lungs to survive here since there are no known predators that live in that region.
Finally, we need to take the initiative to protect the marine ecosystem and resources. For a while, only marine can provide a great contribution to economic development. Day by day our marine are being destroyed by pollution and other ways. So we need to make sure that marine biota can live in this condition.
Author is an Associate Editor at The Environment Review