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Sharing the Space with Many Others

I remember the day when professor David Senn from the University of Basel visited our study area for the first time. Within the first hour of the outing he encountered five cetacean species; tiny harbour porpoises and giant blue whales, agile minke whales, several finback groups, and last but not least beluga whales with their calves. I believe we even added the humpback whale at the end and above all, grey seals were constantly present as well. David, who has seen marine mammals in all oceans from the Arctic to the Antarctic couldn’t believe what he encountered within such a short time period. And even more all encounters weren’t just a short glimpse; each and any one was a clear and long sighting.


Unique in many respects

Compared to other areas of the world, the pure number of cetacean species seen in the Estuary might not be exceptionally high. What makes this area special is the unique mix of species, which share a rather confined area daily, repetitive sightings in high numbers, the whales’ proximity to the shore, and their regular activities above the water.

This makes this area to be one of the best places worldwide to watch and study cetaceans.

Here we present short portraits on the biology of the following marine mammal species found either regularly or rarely during the summer months in the study area:

Toothed whales

Harbour porpoise (common)
Atlantic white-sided dolphins (rare)
White-beaked dolphins (rare)
Beluga whale (common)
Orca (rare)
Sperm whale (rare)

Baleen whales

Minke whale (common)
Humpback whale (common)
Finback whale (common)
Blue whale (rare)


Grey seal (common)
Common seal (rare)
Harp seal (rare)