Scientists have found that the metabolic changes that allowed whales and dolphins to adapt to their aquatic lifestyle have implications on how we should assess the impact of human activities on their conservation.
Human activities such as shipping, tourism, offshore construction, and naval exercises have an impact on the foraging opportunities of sea mammals, which in turn can impact their ability to reproduce. When dolphins and whales are disturbed too often, they are not able to eat enough to keep their calves alive. That is at least what we think based on our understanding of the way terrestrial mammals handle ‘deficits’ in their energy.
New research published in Conservation Physiology from the University of Aberdeen and the Technical University of Denmark (DTU) shows that the way energy is handled by sea mammals has radically changed compared to their terrestrial counterparts. They live in an environment where they have to keep thick layers of fat to avoid hypothermia and where they rely on protein and fat rich, but sugar poor, prey. Their energy metabolism has changed so drastically that we cannot assume it will work the same way as in terrestrial mammals, particularly in the way they might compound foraging disruptions on their energy budget.
Professor David Lusseau from DTU Aqua said: “This research using new approaches of studying dolphins and whales, helps us to gain some fundamental insights about the way energy metabolism works in them. It turns out it has implications for the way we assess the potential conservation impacts of disturbances caused by human activities at sea for example, measuring their fat layer to see how healthy they are. There are a number of marine mammal species that we now know are threatened by human disturbances and so this fundamental physiological work is going to help us better assess how we can mitigate it and estimate what might be safe levels of exposure. "