Marine World
What is the Marine World?
The term ‘Marine' is dervived from the latin marinus meaning ‘of the sea’.
Through many millennia the complexity and diversity of marine life has expanded to form millions of species, some examples can be seen below.
Marine ecosystems are the largest of Earth's aquatic ecosystems and are distinguished by waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Marine ecosystems include nearshore systems, such as the salt marshes, mudflats, sea grass meadows, mangroves, rocky intertidal systems and coral reefs. They also extend outwards from the coast to include offshore systems, such as the surface ocean, pelagic ocean waters, the deep sea, oceanic hydrothermal vents, and the sea floor. Marine ecosystems are characterised by the biological community of organisms that they are associated with and their physical environment.
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Our Planet Earth
Our planet is can be split into two ecosystems, terrestrial and aquatic. The terrestrial ecosystems includes all land mass, covering a total surface area of 148.9 million km2. The rest of Earth is classified as an aquatic ecosystem . Ecosystems within the aquatic environments fall under two categories - Freshwater and Marine.
We differentiate the two aquatic ecosystems through their sodium chloride content.
A Freshwater ecosystem contain little to no dissolved Sodium Chloride (NaCl) content (0 - 0.5 parts per thousand).
In a complete contrast, Marine ecosystems contain anywhere between 31g - 38g of sodium chloride (NaCl) for every Kg of seawater (31- 38 ppt). The vastly differing conditions within these systems has forced life to evolve and diverge from each other.
It seems incorrect to label our planet ‘Earth’, since 71% of the surface is covered by oceans. Ideally, we should be naming it by how it appears from space….Blue.
The marine ecosystems include tropical and temperate coral reefs, mangroves, salt marshes, sea grass meadows, pelagic oceans, Kelp forests, Rocky intertidal shores, Sandy beaches, Polar regions, Deep sea and hydro-thermal vents, each posing its own unique set of challenges on the organisms brave enough to call them home.
“Some marine ecosystems are so highly diverse, they exceed tropical rain forests for the sheer number of species! ”
Coral reefs of the world demonstrate this point clearly, occupying approximately 0.1% of the world’s ocean floor but account for 25% of all marine species. A vast array of diversity can be found in not just the coral reefs but in all marine ecosystems across the planet. Exploring the marine world has taken centuries and we are still making new discoveries every day.