[Seavox] Additional Vertical Co-ordinate coverage terms

[Lowry, Roy K.]

Dear All,

It has been pointed out to me that the 'SeaVoX Vertical Co-ordinate Coverages' (L13) vocabulary (entity definition: Terms used to describe data coverage over the vertical (z) co-ordinate.) is somewhat biased towards the atmosphere and the water column, with just one keyword (sediment) available to benthic ecolologists.  Consequently, it has been proposed that the seven keywords given below with definitions provided by CEFAS be added to the controlled vocabulary.

An initial review within BODC has already pointed out that the definition of littoral doesn't specify the upper boundary, so maybe a better definition (courtesy of Wikipedia) of littoral would be 'that part of the shore between the high water mark and the low water mark sometimes referred to as the intertidal zone'.

Are there any other comments, objections, definition revisions?  If so, please let me have your comments by the end of the month.  I plan to include the additions on February 5th.

Cheers, Roy.

Littoral        that part of the shore above the low water mark (i.e. anywhere that is exposed at low tide).

Infralittoral   the algal dominated zone below the low water mark. It extends to a depth where 1% of the surface illumination reaches the seabed. This varies according to turbidity, but can be as little as a few metres or as much as 70 metres.

Circalittoral   the animal dominated zone. On open coastline this is from the bottom of the infralittoral zone to the wave-base, i.e. the depth to which storms and waves still influence the seabed, typically 50 to 80 metres depth for offshore waters.

Deep Circalittoral      below the wave-base to the shelf break at ~200 metres depth. (Sometimes called offshore circalittoral).

Upper slope     the upper part of the continental slope, from the edge of the shelf break at ~ 200m (also the depth of the seasonal thermocline) down to ~ 750 metres (the depth of the permanent thermocline).

Bathybenthic    below the permanent thermocline (~750m) usually incorporating the rest of the shelf slope and the ocean floor to ~2700 metres. Crosses the 4oC permanent thermocline. Includes several faunal discontinuities.

Abyssobenthic   below ~ 2700 metres where the bathyal fauna are replaced by more primitive abyssal fauna.








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