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- Professor Lena Kautsky gets ready to go into the water and collect some seaweed. Photo:Roine Karlsson
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- The apical (top) shoots reach up for the sun, some even breaking the surface.
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- Bladderwrack (Fucus vesiculosus) forms air bladders in early spring and then begin to grow. The growth for this season is about 10 cm, so far. Photo is taken in early June.
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- Summertime in the Baltic Sea can be very green indeed. A high level of nutrients in the water stimulates the growth of billions and billions of microalgae. Finding the seaweed can sometimes be difficult, but it is very pretty all the same.
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- The seaweed is home to many.
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- The snail Theodoxus fluviatilis is one of the most common fauna associated with Fucus seaweed in the Baltic Sea, at least along the Swedish coastline. It grazes mainly on the biofilm of the Fucus, eating small microscopic algae wich contains lots of silica.
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- The stickleback (Gasterosteus aculeatus) likes to live in the seaweed.
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- In early summer, it is not unusual to find the seaweed covered in the brown filamentous algae Pilayella littoralis. This annual algae is favoured by high level of nutrients and can quickly cover seaweed growing in sheltered sites.
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- The bladderwrack Fucus vesiculosus is so named because of its gas filled bladders (vesiculosus is latin for “small bladder”) that helps it stay upright in the water column.
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- In sheltered sites, where there is not much pull from strong waves, the bladderwrack grows high with many bladders. This specimen is about 70 cm, but they can easily grow to over 1m.
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- Evidence of ongoing photosynthesis in the bladderwrack can be seen as air bubbles, here caught in the brown filamentous algae Dictyosiphon foeniculaceus that grows epiphytically on Fucus.
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- The older parts of seaweed are browner, since they do not have as much photosynthetic activity as the new tips up in the top.
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- The top metre below the surface is often scraped clean from algae by the ice during winter. This clean space rapidly fills up with annual filamentous alga such as the green algale Cladophora glomerata and the brown algae Ectocarpus siliquosus.
This page has the following sub pages.
Baltic Sea Weed Blog 