– I think it’s quite frightening, actually. That’s what researcher at the Institute of Marine Research, Vivian Husa, says about the increasing occurrence of the alien species of harbor sparrow (also known as Japanese sea urchin). – In Haugesund harbour, all the quay fronts are completely covered with it. It grows over kelp and everything. There are almost no rock walls left there, because it is covered in harbor spew, she says. RESEARCHER: Marine scientist Husa and her research team will in the future check several harbors in Western Norway. Photo: Helene V. Lervik / news The invasive species is now constantly being discovered in new places. Last week it was discovered for the first time in Bergen and north of the Sognefjord. This is part of a larger survey that has now been carried out along the coast from the Swedish border all the way to the Trondheimsfjord. The entire coast from the Swedish border to the Trondheimsfjord will now be surveyed for occurrences of harbor sparrow So far, 41 finds of harbor sparrow have been detected along the Norwegian coast, mainly in Western Norway, according to the Artsdata Bank. Marine researcher Vivian Husa is alarmed by how quickly harbor sparrow has established itself in Haugesund, where the animal laid down on all quay fronts. The species was discovered for the first time in Norway outside Stavanger in 2020. The harbors are coming together However, the pest species is here to stay, even though it has been declared undesirable in Norway. And it is incredibly difficult to remove. The way it spreads is via ship traffic. Bergen and Oslo harbors have recently introduced their own guidelines to limit the spread of harbor vomit. MEASURES: Here in Bergen harbor, you can no longer wash the hull as was done previously. Photo: Helge Løvfall/Luftoptakt.no – No ship is allowed to wash its hull in Bergen harbour. Before, it was common for the ships to be scrubbed, and then everything fell to the bottom. That is a guaranteed recipe for spread, says environmental manager at Bergen Harbor Even Husby. And the same applies to Oslo. Hull washing can only be carried out in ports if the washing system ensures full collection of the waste. INVESTIGATOR: Here is researcher Vivian Husa and environmental manager at the port of Bergen looking for harbor spew in Bergen. Photo: Helene V. Lervik / news Husby now wants national guidelines to limit the spread of harbor spume. – We have a great focus on this type of problem here in the port of Bergen, but it is not necessarily the case in all ports, he says. Husby therefore points out that a common approach for all ports would be a much better starting point for the work to combat harbor spewing. – It is possible to limit the spread by keeping the boat clean and oiled, says researcher Husa. EXTRAORDINARY SPECIES: Here you can see that Havnespy which grows on kelp and suffocates the organisms that normally grow on the kelp stalk. Here from the harbor in Haugesund. Photo: Institute of Marine Research – Working with a national regulatory framework The Norwegian Maritime Directorate says that they are now working with a national regulatory framework for handling fouling on ships. – Today there are only international guidelines for this, but we hope that a national, binding set of regulations can be ready during the current year, says communications adviser in the directorate, Marit Nilsen. JOB: Communications adviser in the Norwegian Maritime Directorate, Marit Nilsen, says that rules to limit harbor spewing are something that is worked on nationally and internationally. Photo: Norwegian Maritime Directorate She also points out that they already have a guide which they encourage commercial vessels and owners of leisure boats to follow. – We think it is good that the port of Bergen chooses to focus on the problem of harbor vomit, and it is important that measures are taken so that it does not spread further, she says. Measures to reduce the spread of harbor spew: To prevent harbor spew from sticking, staying for more than 24 hours in areas with harbor spew should be avoided if possible. For ships that have been in an area with harbor spit for a longer period, it is encouraged to carry out an inspection of the hull. For ships where harbor sputum is identified on the hull or where harbor sputum is suspected on the hull, it is encouraged to carry out cleaning with a technology that collects the waste, before the ship can be moved to other areas. Anchoring in areas where harbor spit occurs should be avoided. Moorings and gear used in areas with harbor spew are cleaned when they are picked up, and should not be used in other areas until it is certain that possible harbor spew remains have been removed. Be especially careful with fishing gear that has been in contact with the seabed. It is very important that harbor sewage is not released back into the sea. The waste from cleaning hulls, moorings and fishing gear must be delivered to an approved reception facility. Contact the State Administrator or the Norwegian Environment Agency for more information. Avoid taking in ballast water without an approved ballast water treatment system in areas with harbor spits. Source: The Norwegian Maritime Directorate – We would also like to remind you that the duty of care means that you are responsible for activities in areas with harbor pollution, and that you have a duty to limit the risk of spreading, says Nilsen. How to limit harbor spewing and fouling is being discussed this week by flag states in the International Maritime Organization’s subcommittee. The committee looks at how pollution can be avoided. – This is on the international agenda, she says. To survey the whole of Bergen Bergen municipality will now survey the whole of Bergen for harbor spew during the summer. Husa and her research team will in the future check several ports in Western Norway. – Among the Eldøyane on Stord, in Florø and Måløy, she says. But why is the species so dangerous? Harbor spews form colonies that kill all life on the seabed below them, displacing all other species. It multiplies incredibly quickly, and can 11-fold colonies within two weeks. The Norwegian Environment Agency states that the spread of species can have major consequences for the ecology and natural diversity in Norwegian sea areas. Research is now being done into several possible ways to get rid of the species. Facts about harbor sparrow Photo: Erling Svensen Scientific name: Didemnum vexillum Popular name: Japanese sea urchin, also called harbor sparrow Species group: Cape mollusks Habitat: Marine, from 0-80 meters depth and -2 to 24℃ Recruitment: Sexual reproduction – larval production at 14-20℃ , the larvae hatch within 6-24 hours. Asexual reproduction – one animal becomes two (the colony can 11-fold its size in 14 days), in addition, small pieces of the colony can be laced off and form new colonies. Origin: The species is spread over large parts of the world, but probably originally comes from Japan. Risk assessment: In 2018, the Species Data Bank assessed D. vexillum as a doorstep species. This means that the species did not reproduce in Norwegian waters, but it was expected that this would happen within 50 years. The species has now been found in several places off the coast of Norway and can no longer be described as a doorstep species for Norway. The species data bank has assessed D. vexillum as very high risk (SE). Source: Statsforvalteren.no
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– Quite frightening, says researcher – news Vestland
