University of Basel’s marine biology excursion to the Strait of Gibraltar
by Course participant
Text: Catherine Cornaz; Photos: Luise Wormbs, Catherine Cornaz, Leonie Kneipp, Sylvie Flämig, Anne Kistner
The rumour is out... The Levante will finally be calming down Wednesday night! The excitement in our group rises. Does the weather forecast hold what it promises?
The Levante is a strong easterly wind which is channeled through the strait of Gibraltar and can reach up to 8 Beaufort in the area. Whale watching is not possible under these conditions. We use the time on land for interesting lectures held by Professor Patricia Holm and Dr. Karl-Hermann Kock about marine organisms, soft sediment communities, intertidal rocky shores, fishes, plankton, fisheries, the International Whaling Convention and the conservation of the seas and their inhabitants. The student seminars which cover topics from fishing methods over marine food chains to captive breeding programs of endangered sea horse species are just as informative and captivating. Katharina Heyer’s presentation about firmm and about local hydrology and biology gives us a taste of what is awaiting us on the whale watch trips. But we do not spend the whole time in class rooms. Tarifa is a well-suited location for marine studies due to its location between the Atlantic and the Mediterranean. The western coast consists of sandy beaches while the east side is characterized by rocky shores. We examine both habitats in the field as well as under microscopes and binoculars and discover interesting organisms, which have perfectly adapted to these harsh living conditions.
Our visit to the local fish market gives us the chance to prove what we had learned and we identify anchovies, European pilchards, tuna, cod, John Dory, sword fish and many other species.
And as predicted, the wind calms down on Wednesday evening and there is nothing stopping us anymore from going out to sea and observe whales. The bottlenose and the striped dolphins accompany our vessel and surf in the bow wave. They surprise us with acrobatic leaps and we can observe several behaviours such as tail slapping, spy hopping, leaping, floating and of course a lot of socializing: the animals interact with one another; they communicate, chase each other and swim in perfect synchrony. The strong family bonds are obvious.
The pilot whales exhibit a much calmer behaviour. We often watch them lie quietly at the water surface. They need these breaks to recover from their long dives into great depths where they hunt for cephalopods. But even the pilot whales manage to take our breaths away a few times. They approach us directly and come so close that we can hear their whistles underwater. Some air bubbles rise to the surface which is another indication of vocalization. After having examined us they dive past under the boat and rise again on the other side. They spy, hop and perform a few leaps which is rather unusual for these large animals. Seeing them spy hop makes us wonder who is really studying whom.
Another highlight consists of plankton sampling during one of the whale watch trips in order to examine the plankton under the microscope. Studying the smallest and largest organisms of the seas is breathtaking. To see and understand how these different life forms are all connected and even depend upon each other is a strong motivation to protect the seas and their inhabitants.