Sea turtles
Introduction
Although turtles breed in the tropics and subtropics, there are five species of turtle that are seen in New Zealand waters. Green and Leatherback turtles are the most common.Leatherback turtle
Report injured or stranded turtles to the DOC emergency hotline 0800 DOC HOT (0800 362 468).
Leatherback turtles (Dermochelys coriacea) are widely spread around New Zealand and have been recorded as far south as Fiordland. Satellite tracking studies indicate that the waters around North Cape and the eastern coast of Northland are favoured foraging grounds.
They prefer oceanic waters and can tolerate much colder temperatures than other turtle species (they have even been recorded in the Arctic).
Leatherbacks only come ashore to breed; those occurring in the Southwest Pacific breed in northern Australia, Papua New Guinea, Vanuatu and the Solomon Islands. They appear to return swiftly to feeding grounds in cooler waters, such as those around New Zealand.
There is uncertainty about the life expectancy of leatherback turtles. They're currently estimated to live for 45 to 50 years, maybe more. There is also uncertainty about the age that they reach sexual maturity. Estimates range from 9 to 20 years.
Leatherback turtles are listed as critically endangered by International Union for Conservation of Nature (IUCN).
Estimates suggest a 70% reduction in the global population of females within the last generation. Much of this is due to development and degradation of their nesting beaches.
In New Zealand and elsewhere, leatherback turtles are bycatch in the pelagic longline fisheries.
Green turtle
Green turtles (Chelonia mydas) are the only herbivorous turtle, feeding mostly on seagrasses, algae and mangroves. They also eat fish and their eggs, jellyfish, sponges and various shellfish.
In turn they are preyed upon by many animals throughout their life cycle, including humans. They are called green turtles because of the colour of their meat when made into soup.
Some green turtles spend a part of their life cycle around the northern North Island and are regularly seen at Rangaunu Harbour (Far North) and Poor Knights Islands.
These turtles mainly come from the Indo/Western Pacific population, although some from the Eastern Pacific population have been found here. Eastern Pacific green turtles can be recognised by their distinctive tent-shaped carapace (particularly the females).
The IUCN lists green turtles as Endangered (population decreasing). Coastal development and overharvesting by humans are thought to be the main causes of their decline. Some also die by ingesting plastic bags, as rubbish collects easily in the shallow harbours where they feed.
Loggerhead turtle
Records of loggerhead turtles (Caretta caretta) in New Zealand are concentrated around the upper North Island, though they have washed up on beaches as far south as Stewart Island.
They appear to be only occasional visitors to mainland New Zealand, however they can live in relatively cold waters (10◦c) and some may even hibernate in waters below 15◦c. They do this by resting on the seafloor and surfacing as little as every 10 hours to breathe.
It's estimated that they live for 47 to 67 years.
Hawksbill turtle
Because they are the most tropical species, hawksbill turtles (Eretmochelys imbricata) are relatively rare visitors to mainland New Zealand.
They are mostly seen in the upper North Island though they have been recorded as far south as Cook Strait.
They generally live in the clear, shallow waters of continental and island shelves and are distributed widely through the tropical band of the central Atlantic and Indo-Pacific regions.
Olive ridley turtle
The olive ridley turtle (Lepidochelys olivacea) is one of the rarest species found in New Zealand waters. Strandings of this species are relatively uncommon and may represent stragglers – possibly sick or injured individuals that have drifted here on ocean currents.
The turtle is not named after a person called Olive Ridley. Rather the 'olive' refers to its colour, and the 'ridley' may refer to the fact that 19th Century fishermen around Florida and the Bahamas (where it is common) often confused it with loggerhead or green turtles. It was therefore considered to be 'riddly' (a riddle).
Turtles in the Kermadecs
The Kermadec Islands are a string of volcanic islands and islets in the subtropical zone between New Zealand and Tonga. Hawksbill, green, and leatherback turtles have been found in the Kermadecs, which are New Zealand territory.
Green turtles are commonly seen in the Kermadecs, but records are sparse because the region is so remote. The first records (made by W.B. Oliver in 1911) note that turtles were seen in the summer months, and that they did not breed in the Kermadecs but went north to the tropics.
Green and hawksbill turtles were spotted inshore. All of this is consistent with our current understanding of the habitat and behaviour of these turtles.
Most records of leatherback turtles from the Kermadec region are of individuals accidentally caught on pelagic longlines. Again this is consistent with our understanding of leatherback turtles, who prefer a deeper, offshore environment.
DOC's work with turtles
DOC staff attend beached or entangled sea turtles.
Those that are alive when found may be sent to a specialist facility such as an aquarium for rehabilitation. Dead specimens may be given to museums and scientists for research and educational purposes.
Data from beached turtles and live sightings are recorded in the New Zealand Amphibian and Reptile Distribution Scheme.
DOC monitors the bycatch of turtles and other protected species in commercial fisheries through our Conservation Services Programme.
All reptiles, including sea turtles, are protected under the Wildlife Act 1953. This means it is illegal to kill or harass any species of sea turtle within New Zealand's Territorial Sea or Exclusive Economic Zone.
It is also illegal to possess a sea turtle, or any part of a sea turtle, without a permit issued under the Wildlife Act, or evidence that it was legally imported into New Zealand or was in your possession prior to commencement of the Wildlife Act (1 April 1954).
Convention on International Trade in Endangered Species
DOC is also involved in monitoring and regulating international trade in endangered species under the Convention on International Trade in Endangered Species (CITES).
CITES officers work closely with officers from other government agencies, particularly Customs and the Ministry for Primary Industries biosecurity team, to detect illegal trade in endangered species.
All species of sea turtle are listed on Appendix 1 of CITES. This prohibits all international trade in specimens and products derived from sea turtles, except for exceptional non-commercial purposes such as scientific research.
CITES export permits
No sea turtle products can be carried or shipped out of New Zealand without a CITES export permit – this includes personal items such as specimens and curios that may have been in your possession prior to protection under the Wildlife Act (1 April 1954).
It also applies to items shipped through New Zealand. Without a CITES export or re-export permit issued by DOC, these items are likely to be confiscated by customs officers upon arrival in any country that is a party to CITES.
Similarly, any sea turtle material imported into New Zealand without an export permit from the country of origin is likely to be confiscated at the border.
