PREGNANT women have been advised to eat fish no more than once a week by scientists heading a project to investigate elevated levels of mercury in Bermuda's environment.

High mercury levels in mothers have been proven to cause brain damage to their children.

The results of a survey carried out by Canadian scientists in 2003 found the island had double the level of the poisonous trace metal considered safe by the World Health Organisation.

Dangerous levels of mercury were found in 50 Bermuda mothers and the scientists working with the Atlantis Mobile Laboratory found that 90 per cent of that mercury had come from eating fish.

Scientists and officials from the Departments of Health and Environment met at the Bermuda Biological Station For Research (BBSR) this week and held a workshop to plan a programme to study the problem further.

"Mercury and its compounds are potentially toxic, especially to the nervous system in the early development of the foetus," said Dr. Andrew Peters, an associate research scientist at BBSR and one of the workshop's co-ordinators.

"We must stress that fish is still an excellent source of nutrition and levels of mercury in fish should only be of concern to pregnant women and women who expect to become pregnant in the near future.

"In accordance with the advice provided by the US Food and Drug Administration, we recommend that people in these groups limit their consumption of fish to one meal per week."

The study, which will begin later this year, will put an emphasis on gaining a better understanding of the sources and environmental fate of mercury.

Scientists will also examine levels of mercury in local fish species. Initially, measurements will be made of mercury in air and rainwater and will be based at BBSR's Air Quality Programme field laboratory at Prospect.

The research will then expand to include soil, sediment and key fish species, including those consumed locally.