Zanzibar swimming crabs deaths being investigated

It is not definitively clear what is causing the crab deaths, but climate change is being blamed

Zanzibar's government is investigating why thousands of dead swimming crabs have washed up on the beaches of the Tanzanian islands.

Since 28 September, there have been reports of the dead crabs washing ashore at Mtoni, Mizingani and Forodhani public beaches.

The government is urging people not to worry it might be caused by pollution.

Reports indicate climate change leading to an abrupt change in the temperature of the sea might be to blame.

"Some living things like the swimming crabs cannot resist sudden changes in the sea, and they die and wash ashore," Dr Salum Soud, a marine biologist and Zanzibar's director of development and fisheries, told the BBC.

"Ocean waters have layers of temperatures and so the waves force water underneath to go up, thus may cause low oxygen hence the crabs are likely to face death," he added.

The mass deaths of the crabs is not an isolated incident, according to Sheha Mjaja Juma, Director General of the Zanzibar Environment Management Authority (Zema), who told Tanzania's The Citizen paper it had also happened in Seychelles.