Furcellaria lumbricalis (Hudson J.V. Lamouroux 1813) (Rhodophyta)

Compiled by: Georg Martin, Estonia

1. Description of the habitat/autecology of the species

Furcellaria lumbricalis typically grows on rock and stones in the shallow subtidal to a depth of 20 m on sheltered or moderately exposed coasts. It also occurs in rockpools in the eulittoral and down to 30 m or more in clear water. The holdfast is often covered by coarse, sandy deposits. Species is of true marine origin but tolerates low salinity down to 3-4 psu.

2. Distribution (past and present)

In the Baltic Sea, F. lumbricalis is generally wide-spread and present in the areas with suitable salinity regime and substrate conditions. In most of the Baltic Sea, it is belt-forming just below the bladderwrack belt competing with blue mussel for substrate.   

3. Importance (sub-regional, Baltic-wide, global)

In the Baltic Sea area, the species is one of the most important habitat-forming key species after Fucus vesiculosus.

Dense communities are used as shelter by a number of benthic invertebrates and as spawning substrate by many fish species. As the only commercially exploited macroalgae in the Baltic Sea, it has importance as resource for agar production industry.  

4. Status of threat/decline

Species is widely distributed but decline is recorded from several basins in the southern Baltic Sea, the Kattegat, the Eastern Gotland basin and the Gulf of Riga. 

5. Threat/decline factors

Main known factors of threat are eutrophication, habitat destruction by dredging, dumping and trawling activities as well as commercial exploitation. Species is reported to be sensitive to oil pollution. 

6. Options for improvement

Combatting of sources of eutrophication as well as regulation of seabed use and commercial exploitation may prevent species from further decline. 

7. References

Larsen A. & Sand-Jensen K. 2005: Salt tolerance and distribution of estuarine benthic macroalgae in the Kattegat-Baltic Sea area. Phycologia 45: 13-23.

Martin G., Paalme T., Torn, K. 2006: Growth and production rates of loose-lying and attached forms of the red algae Furcellaria lumbricalis and Coccotylus truncatus in Kassari Bay, the West Estonian Archipelago Sea. Hydrobiologia. 554:107–115.

Nielsen R., Kristiansen A., Mathiesen L. & Mathiesen H. 1995: Distributional index of the benthic marine macroalgae of the Baltic Sea area. Acta Botanica Fennica 155: 1-70.