The remains of a leatherback turtle have been discovered near Motiti Island by a Tauranga cruise company.
The turtle was found floating in the water by crew on board the Bay Explorer.
Skipper Brandon Stone says it was found with a large mollymawk, or albatross species, right next to it.
“We assume would have likely been eating around its neck.”
He says upon inspection, the crew has also discovered its underside, fins and flippers had been eaten.
“This would have definitely been done by fish and sharks after it died.
“We suspect this has either died in a commercial net and has been released; it suffered from hunger or disease; or it has ingested plastic.
“It’s unlikely it’s been eaten by local sharks until after its death because naturally they are able to protect themselves from sharks.
“We decided to bring it back in so we could get an autopsy done to find out the cause behind its death.”
Brandon says the discovery highlights a need to increase conservation efforts in the Bay of Plenty.
“We encourage people to follow conservation advice to reduce plastics; not recycle but reduce.
“The environment out there is sustainable for marine wildlife but we would like to see more areas protected from commercial fishing.”
The species put the Bay under a global spotlight last year, when a number of leatherback turtles were discovered to be making a return to the region.
At the time, it was discovered the typically solitary animals are actually former Bay of Plenty residents. “On one occasion during the summer of 2016-2017 we found three leatherback turtles in one position also out by Motiti Island.
Pink spot on head
“We gained international attention for that and ended up with people coming as far as Costa Rica to find out why we found three. Typically they travel as a solo animal and the only time they aggregate is to breed.
“We spoke with many science researchers during this time and the conjecture that came from that is that the turtles were likely decimated in the area by Maori in the early days, and that they possibly lived on Papamoa beach.
“This sensory urge they have to come back to their breeding grounds is innate in them and they are coming back in larger numbers.”
Brandon says a key characteristic of leatherback turtles is a light pink spot on their head, which is located directly above their brain.
“It’s thought this allows light to reach their pineal gland, which may be used for migration. The pineal is an endocrine gland, found in vertebrates which affects weight, sleep patterns and functions of signal.
“Light hits the spot which helps them gather information about time and they use this information to determine the length of days to help them sync with the seasons for mating and food.”
The World Wildlife Fund page on Leatherback turtles says they are the largest sea turtle species and also one of the most migratory, crossing both the Atlantic and Pacific Oceans.
In addition Leatherbacks can dive to more than a kilometre and can remain underwater for four to seven hours.
Hundreds of thousands of sea turtles a year are accidentally caught in shrimp trawl nets, on longline hooks and in fishing gillnets.
Sea turtles need to reach the surface to breathe, and therefore many drown once caught. Known as bycatch, this is a serious threat to leatherback turtles.
As fishing activity expands, this threat is more of a problem.
Sea turtles are dependent on beaches for nesting.
Sea level rise, uncontrolled coastal development, vehicle traffic on beaches, and other human activities have directly destroyed or disturbed sea turtle nesting beaches around the world.
Turtle feeding grounds such as coral reefs and sea grass beds are also damaged and destroyed by activities onshore, such as sedimentation from clearing of land and nutrient run-off from agriculture.