Monday, 25. October 2010
2010 is the International Year of Biodiversity – the 10th UN Convention on Biological Diversity is currently meeting in Nagoya, Japan. But are we human beings really prepared to make room for nature once again? After all, we will have to cut back. The re-introduction of beavers into the Eifel region over 20 years ago was accompanied by protests. And the uproar can flare up again and again if one of these large rodents goes looking for a new brook for its living space. To say nothing of run-ins with bears (oh, yes, good old Bruno).
We are no longer accustomed to living together with wild animals. And if a farmer employs sturdy livestock guard dogs to protect his herds from invading wolves, he will run into trouble with joggers, bicyclists and strollers. But difficulties with acceptance are not only a European phenomenon, it also exists on the west coast of Canada, where people still live side-by-side with many wild animals. Bears live here, pumas, wolves and, and, and... They were always here and are like neighbours. But now, sea otters are returning, after fur hunters had nearly wiped them out at the start of the 20th century. And all of a sudden, there are problems.
The otters were reintroduced from the Aleutian Islands in the1970’s. A few starts were necessary, but now these equally intelligent and cute predators are thriving: they are taking over one bay after another. “Sea otters belong to the key species of an ecosystem,” explains Kai Chan of the Institute for Resources, Environment and Sustainability of the University of British Columbia in Vancouver: “Wherever they turn up, they alter the structure of their environment.”
The reason: with a body weight of up to 40 kilogrammes, they devour more than ten kilos of mussels, sea urchin, crabs and whatever else they can catch: daily. They adjust their ecosystem by means of their feeding behaviour. And this pleases species protection activists because, thanks to the otters, the kelp forests - the undersea version of rainforests - are growing back. And where seaweed is beginning to proliferate, an immensely diverse biosphere arises, that in turn spreads and makes neighbouring sea regions more fertile.
Unpopular protectors of the kelp forests
Sea otters protect kelp forests and promote their growth. Their concept for success as “gardeners” lies in the fact that they devour masses of sea urchin that destroy kelp forests and prevent the seaweed from recovering due to their feeding pressure. Great, one might think. But it is precisely here that the problem of acceptance comes into play: sea urchin are not only a delicacy for sea otters. And sea otters love mussels at least as much as people do. Kai Chan: “That the otter populations are thriving is great for species conservation, but not so great for the human population, which is no longer accustomed to sharing mussels and sea snails and sea urchin with somebody else – somebody with a huge appetite, to boot.”
No wonder the sea otter is struck by the same curse as the cormorant: among fishermen, anglers, mussel breeders and also the indigenous population of the Canadian west coast, the sea otter is often not all that popular. “In many people’s eyes, otters generate costs because they feed on animals that have a market value,“ explains Kai Chan. One of the results: although only members of the First Nations have special rights, and killing otters is prohibited to everyone else, one or the other otter is killed surreptitiously. Some people would like to be rid of the otters again altogether – or would at least like to have their numbers sharply reduced.
The world with and without otters
Sea otters intervene deeply in an ecosystem. Chan: “Where sea otters settle in, the behaviour of their prey animals changes, such as that of sea urchin or abalones. They become rare and are also hard to find because they conceal themselves in cracks in the cliffs and rocks.” And mussels stay much smaller in their presence than in otter-free ecosystems. But fish, crabs and many other organisms of the kelp forests thrive. The transition from a “world” without otters to one with them and with kelp forests goes very fast: the new regime is firmly established after five years.
The Aquatic Management Board was created to enable everyone in spite of everything to one day live with the changes to the ecosystem – not just those caused by the otters. The population, as well as environmental groups, government representatives, administrators, fishers and anglers all participate in this agency. Scientists like Kai Chan are also involved. He and his colleagues are seeking to develop solutions by researching the ecosystems and to offer assistance in decision-making. For instance, when otter-management plans being worked on by some of the tribes are on the table.
In spring, Kai Chan and his colleagues visited the Kyuquot-Checleseht. People who live in this remote part of Vancouver Island depend on the sea as a source of food. Therefore, several meetings were held here to better understand people’s wishes: “they told us very urgently how much they miss sea urchin, which had made up a large portion of their traditional diet and are also considered a delicacy. In the past they were abundant and easy to obtain, today it is practically impossible to find them.” In the discussions, the Kyuquot-Checleseht returned time and again to the fact that: a meal of sea urchin was and is an important part of their culture, perhaps comparable to beer for Bavarians. And the sea otters have “taken it away from them.”
In search of solutions
Archaeological data convey an impression of how things were when the First Nations and otters still habitually lived with each other. Kitchen refuse is very revealing here, and the rubbish tips of the twentieth century will one day serve as treasure troves for future generations of researchers. But back to our theme. Historic data show that, through the millennia, there was always a back-and-forth in the ecosystem between sea otters and sea urchin. And that human beings at the time managed to seed mussel beds and to harvest them themselves – not the clever little predators. Whatever might have been the trick at the time to keep a couple of bays free of otters: it would be ideal today if one could once again develop suitable measures for doing so. Kai Chan explains: “Sea otters are terribly intelligent, and wherever there is a closed area where there is a lot of easily available food, they will find a way to get in. We are therefore considering how one might create a system of deterrents like noise or pain, so that they keep out of individual bays.” People could raise what they need there, without having to share it with the competition – and the sea would belong to the otters, in part, anyway, if the mussel fishers allow them.
Tip: Dagmar Röhrlich on Deutsche Welle
Translation: Ani Jinpa Lhamo
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