Living in the Baltic Sea

Habitat
Barnacles will attach their heads to a hard, smooth surface with glue like secrete produced by their glands. They might get attached to rocks, other animals like whales, crustaceans, shells and mussels as well as man made objects like boats, wind-turbines etc. Usually close to other adult individuals.
Food
As young plankton they feed on algae and bacteria. Adults filter millimeter size jump crustacean, microscopic size germs and plankton from the water. If the water around the Barnacle is in movement, they simply need to keep their legs up to filter the passing stream and catch food that passes by.
Reproduction
In the Baltic Sea they usually only spawn once a year. Barnacles are hermaphrodite – both males and females at the same time and utilize internal fertilization. The sperm is inserted in to a close by individua. After spawning the penis will fall off and a new one will re-develop after about a year. The small larvae – Aupliuslarvae are plankton and live close to the mother until the spring when there is lots of plankton and then take on a pelagic life and can travel far distance. When they have found the ultimate place for attachment, they will rid themselves of the larvae shell and start develop a new shell. Each shell is separated with a living membrane, so that they can keep growing along the edges. To continue growing they need to change body parts that are not hard shell. This can take place up to 15 times during one year. It is not unusual to come across large quantities of Balanidae skin floating around in the water.

Human impact and Status
Barnacles that attach themselves to boats are a problem, since this cause an increase the weight, add to a larger friction and cause increases fuel usage and might accelerate the rusting process. This will all lead to negative impact on the environment. It is quite easy to wash them off within 2 weeks, with a high-pressure sprayer, might be the easiest and for the environment, least harmful way. If they stay longer, they become very difficult to remove. It is not unusual for bathers to get cut by Barnacles on rocks, while swimming or playing in the water. CLOSE