By Ania Lichtarowicz BBC World Service health reporter

Malaria is spread by mosquitoes

Scientists writing in the Proceedings of the Royal Society say the algae are an important food source for larvae.

Removing them can substantially reduce adult mosquito numbers, they say.

Combined with other measures, like spraying homes with insecticides, they believe it could have a big impact on the spread of the malaria parasite.

Breaking the mosquito life-cycle is an extremely efficient way of reducing the numbers of malaria-carrying insects - and consequently, the number of people contracting the disease.

But some methods - like draining stagnant ponds - can also cause major environmental damage.

This research, though, looked at a much simpler and safer way of removing algae from breeding pools along the River Coatan in the Chiapas region of Mexico.

Algae are an important food source for developing larvae and also offer protection from predators and give adult mosquitoes a safe place to lay their eggs.

During two dry seasons, algae were removed. At these sites, the number of adult mosquitoes was half that of control areas where the algae were untouched.

The scientists believe this method could be used by local communities to reduce malaria transmission during the dry season.