DNA research provides clues to dolphin deaths

PUBLISHED : Monday, 06 February, 2012, 12:00am
UPDATED : Monday, 06 February, 2012, 12:00am


Young conservation volunteers have helped to build the largest DNA bank for Chinese white dolphins.

The team, working for the Ocean Park Conservation Foundation (OPCF), have collected more than 120 samples of teeth, skin and internal organs from dolphin bodies that have washed ashore.

The samples are being donated to a genetic research project funded by OPCF and the Sun Yat-sen University in Guangzhou.

The database is expected to shed light on the genetic diversity of the dolphins in the Pearl River estuary. The species is believed to have low biodiversity, making it more susceptible to diseases caused by environmental pollution.

One volunteer, Denise Sze Ching-yee, a final-year environmental science student at City University, is enjoying the rare opportunity to work for a large-scale dolphin conservation project.

In the past 10 months, she has participated in several sample-collecting assignments.

'Dolphins are confronted by many threats,' Sze says. 'If we can find out the cause of death of those that wash ashore, and discover how their living environment looked, we can pinpoint the problems and take proper conservation actions.'

The process of collecting samples begins with the Agriculture, Fisheries and Conservation Department. It receives reports of locations of dead dolphins from its 1823 telephone hotlines. OPCF then sends a three-man team to the site.

The assistants - typically studying biology or ecology - are trained to perform simple dissections. They are equipped with tools, protective clothing, a corpse bag and an ice box.

The project was the first in China to adopt international standards to collect and handle samples, such as strict temperature controls.

The locations where dolphins wash up are often far from populated areas and difficult to reach. Sze and her team needed to take a boat ride and then hike for an hour to reach one site.

Their job can also be physically demanding, especially when they need to carry the bodies back to Ocean Park's labs. Dolphins that have not been dead for long have high scientific value.

Once Sze and two teammates had to remove and inspect a 135kg adult trapped between rocks in Chek Lap Kok. Marine police were called to help free the body. 'It was quite a commotion,' Sze says.

Seeing dead dolphins is sad, even when the deaths are natural, says Sze, who hopes to work in dolphin conservation after her graduation.