Besides being the largest, the marine biome also boasts of being the most diverse biome on the Earth. It plays a crucial role in the presence of life on the planet. For instance, if it was not for the large-scale evaporation of water from these oceans, there would have been no rain. Our dependence on oceans for food is also well documented. The study of oceans and their attributes is known as oceanography.
When you hear the term 'marine biome', the first thing that is likely to come to your mind is an ocean. The fact that oceans form a major part of this biome is indisputable, but that doesn't mean the biome is restricted to them. Besides oceans, it also comprises coral reefs and estuaries, both of which are crucial components of the Earth's ecosystem.
The five oceans that form the marine biome include the Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean, and the Southern Ocean. (The Southern Ocean was added to the list of world's oceans only in 2000.)
While the scientific estimates suggest that there are 230,000 marine lifeforms on the Earth, the actual number is expected to be 10 times that figure. Abiotic conditions like the depth of the ocean and the distance from land play a crucial role in determining the presence of lifeforms in the marine biome.
Basically, marine plants are those plants which grow in saline water of oceans and estuaries. They play a crucial role in regulating the carbon dioxide (CO2) concentration in the Earth's atmosphere. As in the case of terrestrial plants, even marine plants absorb carbon dioxide and release oxygen in the process of photosynthesis. If it was not for these plants, we would have faced a serious dearth of oxygen on the planet.
Even though algae is an aquatic eukaryotic organism, which doesn't have true stem, roots, or leaves, it plays a crucial role in regulation of the CO2 in the atmosphere; courtesy, its chlorophyll content. Therefore, we have to take it into consideration when we talk about the benefits of marine plants.
Some of the most popular plant species found in this biome include kelp, phytoplankton, sea weeds, sea grass, etc. There also exist flowering plants, which are grouped into four categories: Cymodoceaceae, Hydrocharitaceae, Posidoniaceae, and Zosteraceae.
Other than all these plants, even mangroves and marsh grasses, which grow in estuaries, are taken into consideration when we talk about marine biome plants.
One gets to see a great deal of diversity when it comes to marine biome animals, which range from microscopic organisms, like bacteria and fungi, to gigantic creatures, like the blue whale, which is way larger than the elephant―the largest animal on land. In between, lie a wide variety of marine species which are categorized into different groups, namely fish, reptiles, mammals, etc.
As many as 31,500 species of fish, ranging from tiny stout infantfish to 12-ft-long whale shark, inhabit various oceans of the world. The blue whale, which happens to be the largest animal on the planet, is not a fish. It is one of the 120 species of mammals inhabiting the oceans. Other marine mammals include the humpback whale, leopard seal, sea otters, sea lions, etc.
Coral snakes, sea turtles, and saltwater crocodiles are the best examples of marine reptiles. Each of these species play a crucial role in smooth functioning of the ocean food chain.
The marine biome is quite diverse and marked by quite a few extremes, which shouldn't come as a surprise if we consider its size. The plants and animals inhabiting this biome are equipped with various adaptations to survive these extremes. Marine plants, for instance, have the ability to live with less sunlight and absorb carbon dioxide dissolved in water. Besides the ability to absorb oxygen dissolved in water, marine animals are equipped with a thick blubber that helps them to survive the cold water of this biome.