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(º£½ÇÔÚÏßÃâ·Ñ) - A census to determine the general status of the Seychelles endemic terrapins is being discussed by the Biodiversity and Conservation Unit in the environment ministry.

Ashley Pothin, a conservation officer from the unit,  said that 16 years have passed since the last one was done and the current state of the population is unknown.

"I will not say that the population is really low and that it is alarming but we consider it as a concern because over the years we didn't have an appropriate census to give an exact picture of the terrapin population. In our daily duties we are constantly seeing terrapins around, so we know that they are present in certain areas and we record them in our biodiversity surveys, but this doesn't give us an idea of its status in general for population," he said.

Terrapins are small species of turtles that spend their time both on land and in fresh or brackish water. They have a shell length of up to 30 centimetres.

Seychelles, an archipelago in the western Indian Ocean, is home to three types of terrapin known locally as "torti soupap" -- the Seychelles black mud terrapin, the Seychelles yellow-bellied mud terrapin and the Seychelles terrapin.

The IUCN Red List currently classifies the Seychelles terrapin as extinct, though one or a few specimens could conceivably still exist. It was identified from only three specimens collected on Mahe, the main island, at the end of the 19th century.

The other two species are considered as critically endangered. 

Terrapins are protected under the law of Wild Animals (Seychelles Pond Turtle) Protection Regulations of 1966 and it is forbidden to keep them in captivity and to sell them.

A population estimate of the terrapins was done in 2008 by the Island Conservation Society (ICS) with the Ministry of Environment and others when there was a relocation exercise on North Island.

The areas covered were La Digue, North East Point, Beau Vallon, Anse Intendance, Anse La Mouche, Anse Forbans Sud, Fregate Island, Ile Au Cerf, and Anse Kerlan on Praslin.

The baited fish traps laid throughout the marshes of L’Union Estate were used for a temporary relocation of terrapins on La Digue to ensure their protection. (º£½ÇÔÚÏßÃâ·Ñ) Photo License: CC-BY

"Places like Cousin Island and Ste Anne were not covered because of limited time," said Andre Dufresne, one of the rangers at ICS at that time.

The data collected in 2008 indicated around 800 terrapins existed but since some places were not covered in the research, there is reason to believe that the population was over 1,000.

A recent report about sewage water pollution in the wetland of Intendance area in the south of Mahe highlighted the need to know more about the status of this species in Seychelles.

 "We would like to put in place a research programme as well and to identify new areas where terrapins may have colonised since that they not only live in wetlands but can be found in small streams where the water flows slowly," said Pothin.

Developments near wetlands present a threat to the species that live in there including the terrapins.

"Human development in areas around the wetlands poses a threat to the terrapins and the biodiversity in general. The intensity of the impact will depend on the way the activity is regulated or done. But once humans start cutting trees, and building roads in a pristine area, generally there will be an impact. Imposing a setback from the wetland can minimise the effect but there will still be an impact of carbon emission and sewerage leaking," he added.   

Pothin explained that whenever the environment department receives a request to reclaim the wetland, they object to or recommend that the developer setback the development from the wetland. This is because the protection of the buffer around the wetland will ensure that the terrapins can continue to reproduce, since terrapins lay their eggs on the bank of the marsh or wetland.

He said that terrapins tend to migrate away from areas where there is a lot of disturbance. The Conservation and Biodiversity Unit has evidence of this because on many occasions it received reports from the public who have seen terrapins on the roads.

"I presume that in areas where the impact of pollution happened fast and the terrapins did not get a chance to walk away, then these terrapins would have died in the polluted area. Only when the wetland has dried up can the evidence of carcasses be seen," added Pothin.

The Marine Conservation Society Seychelles (MCSS) has been quite active in the translocating exercise of the terrapins over the years in areas such as the Story Seychelles Beach and Resort at Bel Ombre, where it is currently doing weekly monitoring.

Rebbeca Filipin, a project assistant at MCSS, says that while they were doing trapping work between 2016 to 2019 in areas such as Anse Intendance, at the Ex-Bayan Tree Hotel, and at Anse Forbans and in the North East Point, the populations were quite healthy with 4 to 6 terrapins in one trap.

Grand Police Bay, which still has an untouched wetland with little human activity in the area, is believed to have a larger population of terrapins.

Proposal for hotel development in an area rich in biodiversity such as Grand Police met much opposition from the public and the Ministry of Environment in 2017 because of fear that the impact would be destructive to the wetland the marine and terrestrial habitat, and the development was not allowed to go ahead.

Christophe Mason-Parker, the chief executive of MCSS, said, "It is important that the existing wetland is protected, do not try to reduce the number and size of wetlands that we have on Mahe and another main granitic island. We also have to keep the wetlands clean and reduce the pollution in order not to affect the terrapins, the wildlife and the ecosystem as a whole."