Scientists studying migration patterns of sea turtles in Sabah

Borneo Post 2 Mar 11;

KOTA KINABALU: The Marine Research Foundation (MRF), a non-profit conservation agency based in Sabah, recently deployed satellite transmitters on five juvenile turtles from Mantanani island to identify the migration routes and nearshore habitats favoured by the turtles, which can then drive management and conservation activities.

This work is funded in part by the Shell Malaysia Sustainable Development Grants programme, the Forestry Bureau of Taiwan and the Mohammed bin Zayed Species Conservation Fund.

Marine turtles in South East Asia are threatened through habitat loss and indirect capture in fisheries, and are in dire need of conservation action.

With long maturation periods and low survival, they have extremely slow replenishment rates, and a population which has been depleted can take several centuries to recover. Understanding the needs of the turtles depends heavily on an understanding of the extent of habitat use and distribution, which can only be determined through complex research projects involving sea population dynamics, genetics, and satellite tracking.

By tracking marine turtles through the South East Asian region, MRF aims to raise the collective awareness of their plight and to provide the concrete linkages at an international level on which Malaysia may develop conservation agendas linked with other neighboring countries to which turtles migrate, including Indonesia, the Philippines, Taiwan and Vietnam.

Juvenile green turtles were captured during two recent research trips to Mantanani, and Sirtrack PT102 Satellite transmitters were affixed using a silicone base, and secured with fiberglass matting and resin following capture, measurements, laparoscopic examination and genetic sampling. “The measurements allow us to determine growth rates, while the laparoscopic examination allows us to determine whether the turtle is male or female, along with reproductive development stage. The genetic sampling allows us to identify which nesting grounds these turtles came from in the first place,” said Dr Nicolas Pilcher, Executive Director of MRF.

The transmitters will now send signals to an orbiting satellite each time the turtle surfaces for air, and the satellite will re-transmit the data to a receiving station on earth, which can then be accessed through computer and modem. Dr Pilcher also noted that “turtles rarely remain on the surface for very long, so their surfacing must coincide with the satellite passing overhead, and because of this it is uncommon to receive a location from a turtle everyday”.

The tracking data will be uploaded to a database daily and tracking software will output graphic positioning data for management and education activities. Daily progress can be checked at http://www.seaturtle.org/tracking/?project_id=593

Recent findings as part of MRF’s work determined Mantanani was home to sizeable and immensely important foraging population of green turtles.

“Through genetics we know that many of these originate from the Turtle Islands complex in the Sulu sea, but they also share genetic stock origins with turtles from Vietnam and Taiwan,” said Dr Pilcher.

These foraging turtles only spend six to seven years of their lives at Mantanani, and it is unknown where they spend the rest of their developmental years.

“It is critical that we know this so that we can develop networks of protected areas which are based on the true biology of the species,” he said.

Without a clear understanding of the migration paths taken by sea turtles, and the habitats they require, conservation efforts will not be able to protect needed developmental and foraging habitats.

More importantly however, is the need to determine if the current protected area schemes in place in varying South East Asian countries are sufficient to protect all life stages of marine turtles.

Understanding the migration routes taken by juvenile turtles can enable the authorities to establish protected areas, and develop fishing and shipping zones to increase turtles’ overall chances of survival.