This blue marble

– and yet it spins

Trying to make sense of marine mammals

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bottlenoseSo much of the lives of dolphins and whales remains as a mystery. We only see what happens on or near the surface. Most of our study data is biased to surface activities, and when we submerge hydrophones and other tools we are still mostly blindfolded: either we drop in something that only records behavior when animals are nearby, of we tag them but cannot really see what they are doing, and thus miss the big picture.

And so many whale species are rarely spotted alive here; they only make themselves known when stranded, and often either dying or dead.

To a random observer it might look like we are collecting bits and bobs of data just for the sake of details. But for example weather is used to predict the probability of a sighting, and the probability is for example going into a model of distribution of animals in the area, if this is the research question asked. If the weather is poor and we see some animals, it is possible to model their actual existence in a certain area based on how easily they really were to spot vs. what amount we probably missed due to poor conditions. There is some heavy, predictive data modeling going on in the background.

In essence, population ecology and much of cetacean (marine mammal) research is post-hoc analysis, meaning that the minds of scientist work different from those with my own background and working in controlled test-environments of laboratories. We would pose a question, a hypothesis; and then design and conduct an experiment to test this hypothesis. In cetacean research one collects lots and lots of data systematically, and interrogates the data afterwards to answer several research questions. Many times there is no hypothesis when one goes out to collect data, but the research questions can be asked by going backwards in time to look at years and years worth of data, to find a pattern.whaleIn Kenya we collected much information on fishing activities: locations of harpoonists, fishing dhows, and nets. Combined with dolphin sightings one could map out a picture of how fishing activities change the routes the dolphins prefer to take in the area.

In the Amazon, much of the data collection was analysis of social groups of branded animals: who interacts with whom, which animals are seen together year after year who has calves and where do the calves go when they grow up.

And yes, from time to time we see whales, too. We capture data in an opportunistic fashion. This whale was enjoying life and barrel-rolling, flipping its fins, for twenty minutes. Dolphins like to bow-ride boats, but today was the first time I saw tiny Heaviside’s dolphins bowride a humpback whale. Double joy.
whaleandheviside(Walvis Bay, Namibia; July 2017)

(Photos courtesy of Sea Search)

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