Census of Marine Life scientists yesterday unveiled a roll call of marine species distribution and diversity in key global ocean areas.
Australian and Japanese waters both contain almost 33,000 documented forms of life, by far the most biodiverse. The oceans off China, the Mediterranean Sea and the Gulf of Mexico round out the biodiversity top five.
The most prevalent marine organisms:
* 19% Crustaceans (which includes crabs, lobsters and barnacles)
* 17% Mollusca (includes squid, octopus, clams, snails and slugs)
* 12% Pisces (fish, including sharks)
* 10% Protozoa (unicellular micro-organisms)
* 10% Algae and other plant-like organisms
* 7% Annelida (segmented worms)
* 5% Cnidaria (includes sea anemones, corals and jellyfish)
* 3% Platyhelminthes (includes flatworms)
* 3% Echinodermata (includes starfish, sea urchins and sea cucumbers)
* 3% Porifera (includes sponges)
* 2% Bryozoa (mat or ‘moss animals’)
* 1% Tunicata (includes sea squirts)
The rest are other invertebrates (5%) and other vertebrates (2%) which includes whales, sea lions, seals, sea birds, turtles and walruses.
The Mediterranean had the most alien species among the 25 regions, with over 600 (4% of the all species inventoried), most of
which arrived from the Red Sea via the Suez Canal; a man-made waterway opened in 1869.
The main threats to marine life up until recent times have been overfishing, lost habitat, invasive species and pollution. Emerging threats include rising sea temperature and acidification through carbon dioxide saturation, and the enlargement of areas characterized by low oxygen content (called hypoxia) of seawater – also known as dead zones.
In October, the Census will release its latest estimate of all marine species known to science, which is likely to exceed 230,000. It’s an incredible number, but those involved in the Census acknowledge it will still be nowhere near the true count.