Hailuoto is by far the largest island in the Bothnian Bay, and it’s the third largest island in the sea areas of Finland. The island started to rise from the sea by post glacial land uplift about two thousand years ago, but the first inhabitants didn’t find Hailuoto before around 1100. If the land uplift would proceed with the current speed, Hailuoto would be connected with the mainland in a few hundred years. The island is separated from the continent by a shallow water area of about 7 km wide.
There are about one thousand year round inhabitants in Hailuoto island, but many more tourists and summer vacationers come flocking during the summer months. There’s still a ferry connection with the mainland but that is about to change in the near future, when a causeway and two bridges will be built between the mainland and the island. This is a concern for nature conservation people who fear, for example, that the possible reduction of ice erosion on the flat and sandy or muddy areas will affect the competition between the different vascular plant species and that the most endangered ones will suffer. Some of these species are Primula nutans and Puccinellia phryganodes. There are also many new findings of a directive species Macroplea pubipennis aquatic beetle from the eastern shores of Hailuoto island, where the new road will be built. At least the road will bring many more visitors to the island since the ferry has limited the number of cars and busses arriving to the island.
The nature on the shores and at the shallow waters around the Hailuoto island is very unique. Since the shores are very shallow and slope very gently to deeper water, there are large areas where endangered aquatic (or semiaquatic, if you don’t consider 5-70 cm as really aquatic) macrophytes can be found. Alisma wahlenbergii and Hippuris tetraphylla form large meadows at the water’s edge. There are vast mudflats with short lush vegetation where migrating birds stop for resting and feeding. On the north side of the island, there are long succession series of lagoons – from fladas to glo-lakes. These represent some of the best examples of land uplift lagoon series in the world and have been vastly studied.
For a marine biologist, Hailuoto represents a challenge when it comes to underwater inventories. Deeper areas are mainly sandy with some occasional rocks and very scarce vegetation or fauna while the extremely shallow shore areas are densely vegetated with many different species. The trouble is getting there. The shores are so shallow that approaching from the sea with even a small boat is nearly impossible, and trying to get to the area from land takes a lot of effort and walking.
The island’s name, Hailuoto, is literally translated “A Shark skerry” but of course, Finland doesn’t have any sharks in her waters. The word “hai” is a short version of “haili”, which has previously meant a fresh Baltic herring. The island was first inhabited by fishermen who fished for Baltic herrings and thus the name.
If you want to know more about the Natura 2000 areas of Hailuoto, you can visit HELCOM marine protected areas database. The North Shore natura area is located within the SEAmBOTH project borders but the two others lie on the southern side of the island and thus outside the project boundaries. If you want to visit the island, better do it before the bridge turns it into a peninsula from the mainland.
Hailuoto North shore: http://mpas.helcom.fi/apex/f?p=103:12:::NO::P12_ID:147
Written by Essi Keskinen, Metsähallitus