Stunning video of a leatherback turtle captured off the South Hams coast

Two fisherman have filmed a leatherback turtle off the coast of the South Hams, shared by BBC Radio Devon.  

The video, which you can view here https://fb.watch/v/f7B_dsChy/, a leatherback turtle is spotted by fishermen Gordon and Paul between Dartmouth and Start Point. 

According to NOAA Fisheries, the leatherback sea turtle is "the largest turtle in the world".

Their website says: "They are the only species of sea turtle that lack scales and a hard shell. They are named for their tough rubbery skin and have existed in their current form since the age of the dinosaurs. Leatherbacks are highly migratory, some swimming over 10,000 miles a year between nesting and foraging grounds. They are also accomplished divers with the deepest recorded dive reaching nearly 4,000 feet—deeper than most marine mammals.

"The leatherback sea turtle is listed as endangered under the Endangered Species Act. It is estimated that the global population has declined 40 percent over the past three generations. Leatherback nesting in Malaysia has essentially disappeared, declining from about 10,000 nests in 1953 to only one or two nests per year since 2003.

Threats (https://www.fisheries.noaa.gov/species/leatherback-turtle)

Bycatch in Fishing Gear
The primary threat to sea turtles is their unintended capture in fishing gear which can result in drowning or cause injuries that lead to death or debilitation (for example, swallowing hooks or flipper entanglement). The term for this unintended capture is bycatch. Sea turtle bycatch is a worldwide problem. The primary types of gear that result in leatherback turtle bycatch include gillnets, trawls, longlines, and vertical lines attached to pot/traps.

Direct Harvest of Turtles and Eggs
Historically, sea turtles including leatherbacks were killed for their meat and their eggs were collected for consumption. Presently, leatherback turtles are protected in many countries, but in some places, the killing of leatherbacks and collection of eggs continue.

Loss and Degradation of Nesting Habitat
Coastal development and rising seas from climate change are leading to the loss of nesting beach habitat for leatherback turtles. Human-related changes associated with coastal development include beachfront lighting, shoreline armoring, and beach driving. Shoreline hardening or armoring (e.g., sea walls) can result in the complete loss of dry sand suitable for successful nesting. Artificial lighting on and near nesting beaches can deter nesting females from coming ashore to nest and can disorient hatchlings trying to find the sea after emerging from their nests.

Vessel Strikes
Various types of watercraft can strike leatherback turtles when they are at or near the surface, resulting in injury or death. Vessel strikes are a major threat near ports and waterways, and adjacent to highly developed coastlines. Vessel strikes are a significant cause of leatherback strandings in the eastern United States.

Ocean Pollution/Marine Debris
Increasing pollution of nearshore and offshore marine habitats threatens all sea turtles and degrades their habitats. The Deepwater Horizon oil spill was the largest offshore oil spill in U.S. history and affected nesting (including nesting females, eggs, and hatchlings), small juvenile, large juvenile, and adult sea turtles throughout the Gulf of Mexico. Ingestion of marine debris is another threat to all species of sea turtles. Leatherback turtles may ingest fishing line, balloons, plastic bags, floating tar or oil, and other materials discarded by humans which they can mistake for food. They may also become entangled in marine debris, including lost or discarded fishing gear, and can be killed or seriously injured.

Climate Change
For all sea turtles, a warming climate is likely to result in changes in beach morphology and higher sand temperatures which can be lethal to eggs, or alter the ratio of male and female hatchlings produced. Rising seas and storm events cause beach erosion which may flood nests or wash them away. Changes in the temperature of the marine environment are likely to alter the abundance and distribution of food resources, leading to a shift in the migratory and foraging range and nesting season of leatherbacks.