Public Lecture Series
Speaker:
Leif Nøttestad, Ph.D.
Principal scientist, Institute of Marine Research
Bergen, Norway
SEEING BY SOUND AT SEA:
Revealing underwater secrets of dynamic fish schools, diving seabirds and hunting whales and dolphins
Wednesday, April 22nd, 2009
7 pm
DeMeritt Hall - 112, University of New Hampshire
directions to UNH - campus map
Abstract:
Seeing by sound is a solution when vision is useless. Some animals use echolocation for a range of tasks; to see, listen, communicate, move, migrate and hunt in murky waters or at night. Emitting and receiving sound waves at different frequencies, have evolved in nature through natural selection for different purposes by marine animals. Whales and dolphins have sophisticated biological sonars. The principle of underwater echolocation is rather simple, similar as bats use their sonar at night in open air to navigate and catch insects. Echolocating animals translate this sound spectre into information and knowledge like a television picture.
How can we study animal behaviour such as swimming fish schools when we can't see them? One way is to copy the advanced sonar skills of marine mammals, adapt the technology and use it for our own scientific purposes. When echolocation works so well for animals at sea, why should it not work for us? In my presentation fisheries sonar and echosounder are used in combination with oceanographic and visual observations, trawling and zooplankton sampling. We aim to reveal new scientific knowledge on predator-prey interactions, fish schooling dynamics, migration and ecology of pelagic fish and marine mammals. A spectre of examples include killer whales attacking schooling herring and mackerel, fin whales feeding on herring at night, antipredator behaviour of schooling fish, and puffins chasing fish aggregations off breeding colonies in Northern Norway. Such integrated knowledge is useful to better understand marine ecosystems.
I will also present some historical data on Atlantic bluefin tuna fishery and science in Norway . The epic bluefin tuna used to be abundant in Norwegian waters and sustained a large fishery. The question we are asking now is: where have all the tuna gone and why?
Pictures, movies and acoustic recordings will illustrate the science in my presentation, which should be of general interest to a wide audience with a curiosity and fascination for marine animals.
