Volume 6 Pages 1 - 35 (February 1991)

Citation: Madsen, A.B. (1991) Otter News from Denmark. IUCN Otter Spec. Group Bull. 6: 13-14

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Otter News from Denmark

Aksel Bo Madsen

National Forest and Nature Agency, Project Otter, Grenavej 14, Kalo, DK-8410 Ronde, Denmark

Stopgrids or stopnets in all otter areas

To protect otters in Denmark the Ministry of Fisheries has declared that all fisherman in the northern part of Jutland must use Stopgrids or stopnets in fish traps.

The new stopgrid-stopnet law replaces two former proclamations regarding fisheries in the watersheds of the rivers Hvidbjerg and Karup. The area in which their use is now mandatory coincides with known otter distribution. Besides freshwater habitats the law also applies to certain brackish and saltwater areas, particularly in the Limfjord.

The law, made in collaboration with the Ministry of Environment and Forest and Mature Agency, based on work started by Project Otter in 1985, will be enforced from 1 January 1991 until 30 April 1995. There is reason to hope that the small Danish otter population will increase during this five-year period. During this period the otter population will be monitored by both the Forest and Mature Agency and the Ministry of Fisheries.

A brochure written in Danish, and illustrated in colour, outlining the use of stopgrids and stopnets is available from the address given above.

Second Danish otter survey

Otter distribution was surveyed in Denmark during 1984 - 86. During the spring of 1991 the survey will be repeated, completely covering the counties in which otters were recorded during the previous survey viz. Nordjylland, Vibord, Ringkbinq, Arhus, and Vejle. Throughout the rest of the country only watersheds, where the expected occurrence of otters has been reported, will be visited. The extent and duration of the survey is somewhat limited by finances, but I am sure useful comparative information will be collected.

Otters and Motor Traffic

The following is a summary of the recently published paper "Oddere Lutra lutra og trafik", written in Danish (See Recent Publications" for full reference). 

As an introduction, the numbers of otters killed by cars in Denmark and other European countries is presented showing that the problem is considerable.

The investigation is based on the following sources: information of 39 otters killed by cars and delivered to the Natural History Museum, Arhus, observations on marking behaviour at 48 different bridges with possibilities for rnarking, experiences with game mirrors placed at 13 bridges over River Skals, and direct observations of otters crossing the road at the dam of Virksund

Many otters were killed at places without banks under bridges or at dams between two wetlands. Although otters are killed in all months of the year, an increasing trend of collisions is seen in the months July - December.

25 (64 %) male otters, especially adult sexually mature males were killed in the traffic, probably as a result of their greater activity in the home-range than that of females.

In 66 (73 %) of the visits at bridges with banks, the otters preferred to mark with spraints at the bank rather than outside the bridge. Footprints and tracks on banks showed that the otter, in many cases, continued under the bridge.

The effect of game mirrors at bridges to prevent traffic killing otters is evaluated to be smaller than the efforts. Problems with maintenance are extensive in relation to a full non-risk possibility for passage.

Direct observations seem to show that otters are not able to estimate the risk in crossing roads. The consequence of abovementioned investigations is that we must try to prevent the otters crossing the roadway, either by luring them under roadsystems on stones and banks, or by forcing them away from the road by means of fences.

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