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Iceland Mag

Animals

Reykjavík's downtown Lake Tjörnin (The Pond) is teeming with life

By Staff

  • The Downtown Lake Recent studies show the downtown lake is coming back to life. For the past 30 years the lake was devoid of life due to pollution. Photo/Stefán Karlsson.

A recent study by the Natural History Museum of Kópavogur for City of Reykjavík of the downtown Lake, shows that it is teeming with life.

Two surveys were made of plant and animal life in the lake one in June and the second one last week. Further studies will be performed next summer. The study has charted the distribution of three-spined sticklebacks, the dominant fish of the lake, plant life and various crustaceans and algae. According to the study the lake is teeming with life, which came as a pleasant surprise to the biologists, as only a few years ago the lake had been virtually devoid of life due to pollution.

The downtown lake Tjörnin
The lake, called Tjörnin or Reykjavíkurtjörn, is composed of four distinct parts, the main lake, cut across by Skothúsvegur street, a smaller pond north of the Miklabrautin highway and the wetlands and pond between Miklabrautin and the Nordic House. The lake is connected to the sea by a small river which runs in a sewer beneath Lækjargata street.

For the past thirty years the part of the lake north of Miklabrautin was entirely devoid of plant life. The reason, according to Þóra Hrafnsdóttir, biologist, was primarily pollution. Þóra told the Icelandic National Broadcasting Service that when pollution in the lake was measured in 2007 it showed very high levels of various pollutants. Following this measurement the City launched an extensive program to clean up the lake which seem to have begun to bear fruit.

Read more: Record number of Arctic Terns by the downtown lake provide protection for ducklings

A second reason for the improving conditions in the lake are efforts to restore the wetlands south of Miklabrautin highway. The area has been fenced off as a bird sanctuary and wetlands which had been destroyed over decades of development restored. As the wetlands and the southernmost tip of the lake were restored life spread throughout the lake.

Growing plant life encourages birdlife
The study showed that alpine pondweed and small pondweed is found throughout the pond, while the bottom of the southern end of the lake is covered with fineleaf pondweed and mare’s tail. The plants provide cover and habitat for the three-spined sticklebacks who are now again common throughout the lake.

The growing number of three spined spindlebacks in the lake are believed to have contributed to the growing success of tern nesting by the lake.

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