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24 hours, 775 species

^{Töölönlahti bay with Linnanmäki amusement park on the background. Photos: Elisa Lautala.}

Töölönlahti bay is a combination of tended and untended park area. 50 zoologists and botanists spent 24 hours at the bay, trying to identify as many species as they could. The result was quite astonishing, altogether 775 species have already been identified, and more will probably be indentified during the coming weeks. This results to 2% of the species found in Finland. Leif Schulman from the Finnish Museum of Natural History helps to put these figures into context.

“It has been estimated that there are 2–200 million different species in the world. The most frequent estimate is 15 million. Only 1,7 million of these species have been identified. There are estimated 45 000 species in Finland, if 2% of them can be found at Töölönlahti in 24 hours, it is a very good result.”

The cities and towns in Finland are not very densely built; therefore the urban ecology is quite rich in Finland. Especially, untended park areas are very important to biodiversity.

This year is UN’s International Year of Biodiversity. Global goals to tackle the threats to biodiversity will be agreed upon in autumn. Already, at EU-level, it has been decided that the member countries aim at halting the loss of biodiversity and ecosystem services in the EU by 2020.

^{Two male Mallards having an afternoon nap at Töölönlahti on 26 May.}

Introduced species, and few surprises

Marine biologist Essi Keskinen discovered the first species that was not known to thrive at Töölönlahti. In Finland, the Conrad’s false mussel has only been found in the condensation waters from Loviisa and Olkiluoto nuclear reactors before. Even though the scientists were surprised that the mussel was living in the cold waters of Töölönlahti, the discovery was not particularly pleasant; the Conrad’s false mussel is an introduced species that has no value to the ecosystem. The mussel has undoubtedbly travelled to Töölönlahti with vessels.

Other introduced species found at Töölönlahti Bay were: North-American Polychaete, and The North American Gammaridean Amphipod, Gammarus Tigrinus. Also one indroduced mammal was found. European rabbit has become a common pest in the parks of Helsinki during the recent years. The rabbit population descend from dometic rabbits that have run away or been let loose by their owners.

Other mammals that were spotted by the scientists were: Yellow-necked Mouse, Harvest Mouse, and Northern Bat. Surprisingly, Eurasian Red Squirrel, that is a common sight in the parks and cemeteries of Helsinki, was not seen at all. That is because there are hardly any conifers by the bay.

Other surprise was the small amount of butterflies. Only two species were seen. Schulman says that this can explained by the point in time; the hibernated butterflies do not fly anymore, and the next generation of larvae have not yet metamorphosed into adult butterflies.

The water of Töölönlahti Bay is quite muddy, but the quality of it has improved. This is because of the Helsinki Environment Centre’s project, which includes pumping of water from the Humallahti bay to the Töölönlahti bay. The scientists identified nine different fish species, including large Zanders.

Projects to preserve the urban ecosystems are important to biodiversity. Recently, a national urban park was established in Porvoo, 40 kilometres from Helsinki.

“The best way to protect the species is to protect the environment. Urban ecology should not be taken for granted, instead it should be preserved. According to researches, biologically diverse and clean urban environment has positive effects on the wellbeing and health of the city dwellers,” Schulman says.

^{The Black-headed Gull watching over the water flowing from Humallahti bay.}

Examples of what was found

• 119 different species of flies, one of them may be new to Finland.
• The overall amount of fish and the number of different species was a surprise to the scientists. 9 different species were found.
• 120 species of lichen and bryophyte.
• 11 species of bumblebees, 2 species of wasps, 5 species of bees, 5 species of ants.
• Considering the season, the number of different fungi was quite high. Also edible St. George’s mushroom, which is considered a delicacy.
• 4 species of mammals (humans and pets not included).
• 47 species of birds.

Link: Biodiversity Action Day internationally

Elisa Lautala works as web editor for University of Helsinki's Faculty of Science. Elisa likes all kinds of cultural events, good books, warm weather, and aqua-jogging.