11 Marine Species on the Brink

Due to factors such as human encroachment and overfishing, numerous forms of life in the sea are endangered, and sadly, some are even on the brink of extinction. Here are 11 of these species. 

1. MEDITERRANEAN MONK SEAL

Monachus monachus, with a population of just 350–450, are the most endangered pinnipeds in the world. Once hunted for skins, and despite being able to dive up to 100 metres, depleted food sources are just one of many threats they face today.

2. KEMP’S RIDLEY TURTLE

One of the smallest and most endangered of all the turtles (which is really saying something), Lepidochelys kempii populations are slowly recovering from an estimated low of just 1,000 nesting females in the mid-1980s.

 3. BELUGA STURGEON

Critically endangered due to demand for their “roe”, which is eaten as caviar, the Huso huso is also the largest European freshwater fish – the largest one ever caught measured over seven metres long, unsurprising when you consider they can live for more than 100 years.

4. BLUEFIN TUNA

Commercial fishing has driven tuna populations to the brink of collapse, with Thunnus maccoyii, southern bluefin, listed as critically endangered. These fish grow to an average of two metres long, and reach speeds of up to 70km/hour.

5. SAWFISH

The nocturnal Pristidae family comprises seven species of ray, some of which are recorded to grow up to seven metres long. They are adapted to live in rivers, estuaries and the ocean: Their eyesight is relatively poor but their “saw” is highly sensitive.

6. AMSTERDAM ALBATROSS

Nesting only on the tiny Amsterdam Island in the southern Indian Ocean, Diomedea amsterdamensis has a wingspan of almost 3.5 metres. Pairs mate for life but only produce one chick per season. There are likely fewer than 100 left.

7. CHINESE PADDLEFISH

There is a chance that the huge (up to seven-metre) Psephurus gladius is already extinct. As a result of the Gezhouba Dam and overfishing, none of these filter-feeding “elephant fish” have been seen in the Yangzte River since 2003.

8. GIANT SEA BASS

Jewfish or black bass, Stereolepsis gigas, are now critically endangered due to overfishing, vulnerable due to their massive spawning aggregations that make them an easy target. It is thought they might be able to change their patterns or spots at will.

9. ORNATE SLEEPER RAY

All we know about these electric rays, Electrolux addisoni, comes from just a handful of sightings and specimens. They are endemic to a 300km-long strip of South African coast and their conspicuous colours advertise their “shocking” defence mechanism.

10. RIVER SHARK

River sharks of the genus Glyphis are possibly the most critically endangered of all shark species, with their habitats directly and regularly affected by human activity. Most have barely been studied before they are disappearing.

11. VAQUITA

With fewer than 100 left, these tiny porpoises, Phocoena sinus, are some of the world’s most endangered cetaceans. Found exclusively in the Gulf of California, they were only described by science in 1958.

To find out more intriguing facts about marine life and read up about various diving sites and tales, get your copy of Scuba Diver Issue 6 / 2015 here.

For more insightful articles like this one, subscribe to Scuba Diver here.