Habitat types key navigation

You can use the 'key navigation' function to identify a specific habitat by answering a set of questions. Starting from first question to next questions you select one of the possible answers. Here are samples of possible answers:

• No ( 002 ) - Leading to question named '002'
• Yes [ G ] - Leading to another questions subset of level G
• No [ E6 ] - Links directly to factsheet for E6

Additionally the diagram may be used for reference.


Category : (A4 )Circalittoral rock and other hard substrata
Diagram :

Question a21 :   Developed at seeps?

Habitats in hard substrata in the circalittoral zone characterised by the presence of seeping or bubbling gases, oils or water are distinguished (path = Yes).

Answers: Yes [ A4.7 ] No ( a22 )

Question a22 :   Recently colonised artificial substrata?

Recently colonised artificial hard substrata in the circalittoral zone are distinguished (path = Yes).

Answers: Yes [ A4.7 ] No ( a23 )

Question a23 :   Cave or overhang?

Habitats developed in rock caves or underneath overhangs in the circalittoral zone are separated (path = Yes).

Answers: Yes [ A4.7 ] No ( a24 )

Question a24 :   Baltic?

Circalittoral habitats in the Baltic Sea (as defined by the Helsinki Convention, from and including the Kattegat eastward to the Bothnian Bay, Gulf of Finland and Gulf of Riga) are separated (path = Yes) from other geographical sea areas. The Baltic Sea is effectively a vast estuary with sills, characterised by a stable reduced salinity gradient, lack of tides and reduced fetch energy.

Answers: Yes ( a25 ) No ( a26 )

Question a25 :   Exposure

The criterion separates out habitats in the Baltic circalittoral zone which are exposed to wave action or currents from those only moderately exposed or sheltered. The exposure status is that impacting on the area concerned at the relevant scale. Thus there may be enclaves of different exposure status caused by localised variation in relief (e.g. steeper rock in more moderately exposed or even sheltered areas). Note that ‘exposed’ has an effective fetch of greater than 25 km; ‘moderately exposed’ has an effective fetch of 5 – 25 km; and ‘sheltered’ has an effective fetch less than 5 km.

Answers: exposed [ A4.4 ] moderately exposed [ A4.5 ] sheltered [ A4.6 ]

Question a26 :   Energy level

The criterion separates out habitats in the circalittoral which have high energy status caused by wave action, currents or tidal streams from those with moderate energy or low to negligible energy. The energy status is that impacting on the area concerned at the relevant scale. Thus there may be enclaves of different energy status caused by localised variation in relief (e.g. steeper rock in more moderately exposed or even sheltered areas). Note that ‘high energy’ includes wave exposure classes extremely exposed, very exposed or exposed OR tidal streams/currents classes very strong or strong; ‘moderate energy’ includes wave exposure class moderately exposed OR tidal streams/currents class moderately strong; and ‘low to negligible energy‘ includes wave exposure classes sheltered, very sheltered, extremely sheltered or ultra sheltered OR tidal streams/currents classes weak or very weak or without any tidal stream or current. (See glossary.)

Answers: high energy [ A4.1 ] moderate energy [ A4.2 ] low to negligible energy [ A4.3 ]