Touristic marine mammal watching is increasingly popular worldwide. It develops an important local economy (income and jobs) in coastal regions. Responsible whale watching allows to raise public awareness and contributes to scientific research when commercial vessels participate in data gathering.
However, when not done properly, these watching trips have adverse consequences for the animals.
They cause changes in swimming sequences (longer, more frequent and deeper dives) and rapid changes of direction to avoid boats that they may consider as potential predators. These disturbances can interrupt natural behaviour such as feeding, socialising, resting or breeding, and generate significant additional energy expenditure. The consequences can be serious and lead to a displacement of populations, a decline in breeding success and even increased mortality.
Take the example of the Humpback Whales that come to breed and give birth in warm waters. Repeated disturbances during this period can be harmful and sometimes fatal for the mothers and their calves. Did you know that they stop feeding when they are in our tropical waters to raise their calves? Disturbances generate energy-intensive avoidance and flight behaviours for this animal that lives on its reserves at this time.
What will happen when it has to re-migrate to colder waters to start feeding again but does not have enough energy to support this long migration on an empty stomach? What will happen to the calf that may never reach the feeding ground?
Sustainable observation of marine mammals can have economic and educational benefits, but it must imperatively be supervised to limit the impact of these disturbances on the animals.
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