Do Seals have a Problem with Alternative Energy?

Scientists in Denmark are researching the effect of a wind park
on the native seal population

Seals are shrewd animals. They can swim against the strongest currents, sleep while floating in the water, and plunge out from the water to get air without even waking up. These elegant swimmers manage to find food in obscured waters by using their whiskers to locate plaice. The question is, will their habits be negatively effected by an offshore wind farm?

A Danish power company, SEAS, is building a large offshore wind farm south of Lolland, by Rødsand. Around 250 million euros have already been invested in the project. A total of 72 69-metre-high turbines with 80-metre-long rotors will provide up to 120,000 households with this alternative wind energy.

However, around 200 seals live in the area of the planned wind mill farm. Perhaps many more live in the surrounding area. The increased volume of traffic and noise resulting from the wind mill farm could negatively impact the sensitive seals way of life in their native environment.

In order to determine the impact, an extensive research project is being undertaken. Scientists are trying to determine how far the animals swim to search for food, how much food they eat in the area of the wind farm, and how much time they spend onshore. Researchers from the Danish environmental research institute have been working together with SEAS for over two years already.

Experts know that seals are very mobile - they can cover a distance of 650 kilometres in just ten days. On the other hand, harbour seals, verifying their namesake, tend more to the shore. Up to now, such studies have used airplanes in order to count and monitor the animals. As one would expect, this method is expensive and not so effective, given that mammals spend much of their time underwater. As a consequence, the results of such studies have been scattered and unsatisfying.

Since that time, Danish animal researchers have furthered their research considerably by placing a small monitoring device (ENAiKOON locate) on the head of the seals, to be worn for a certain amount of time. Once the seal emerges from underwater, its current geographic position is received via GPS and saved in the module. Once a day, the module switches on and sends out the newest location and movement data to the researchers. This takes place while the seals sun themselves on shore.

The high-capacity battery lasts, using this method, for about 10 months. GPS satellite tracking and mobile network connections keep the researchers up-to-date. They know the animals' migrations paths, if the animals are currently eating, or if they are on the beach enjoying a nap. This is a long-term study. This summer, additional devices will be implemented on even more seals. Until the middle of 2007, the researchers plan to continue monitoring the animals' behaviours to help them understand potential damaging effects of the wind farm.