A study of bottlenose dolphins living off the coast of Zanzibar has found that the many tourist boats operating in the area are harassing the animals, preventing them from resting, feeding and nurturing their young. Tourists who also swim with the dolphins, trying to touch them are being urged to keep their distance in a bid to protect both the animals and the local communities whose livelihoods depend on them.

One of the researchers Dr Berggren, said that the current situation in Zanzibar is unsustainable and is concerned that unless the activity is regulated the dolphins may leave. Part of the study found that whenever the tourist boats were present the dolphins were very unsettled and spent less time feeding, socialising or resting which, long term, could have a devastating effect on the population. Watching the dolphins over a period of 40 days, the research team found that in the presence of the tourist boats, the time the dolphins spent resting dropped from 38 per cent of the time to 10 per cent, while the time they spent foraging and socialising dropped from 19 and 10 per cent to just 10 and 4 per cent respectively. Meanwhile, travelling behaviour more than doubled in proportion, from 33 to 77 per cent, becoming by far the most dominant activity state during interactions with tourist boats which means they are using more energy than they are taking in because they aren't resting or feeding as much but are spending more time swimming as they try to avoid the tourist boats. The latest findings were published in the journal Endangered Species Research.

Marine Connection director Margaux Dodds comments; "Everyone loves watching dolphins in their natural environment but boat operators must act responsibly by keeping their distance and putting the dolphins welfare first. Not all wild dolphins want to interact with humans, therefore its vital that operators do not automatically allow their passengers to enter the water. 20 years ago it wasn't as popular for people to want to swim with these animals but now its an activity that most people want to do. There is also the issue of noise disturbance from the vessels themselves. Fast-moving vessels often cause disruption of behaviour and social life to dolphins and control of vessel speed should also be implemented. However there are many responsible operators out there".

Dolphin watching was introduced off the South coast of Zanzibar in 1992 and is one of the few places in the world where tourism has completely replaced the traditional dolphin hunt - an activity which once threatened the local population of around 150 bottlenose dolphins. Sightings of dolphins usually peak between July and October and there is also the opportunity of seeing humpback whales.