Marine Biodiversity Data Portal - NI
Ordnance Factory, Belfast Lough.
Survey number: 555 Event number: 19861002/21 Date: 1986-10-02 GPS: 54.63900,-5.85100. Depth: 3.5 to 0.2 m. [ View map ]
Site Description: The transect site is composed of an extensive low tide flat of muddy sand and a man-made upper shore of large boulders and rubble piled on top of one another next to the sea wall. A mussel bed covers the upper part of the sand flats. The sand is very flat - the rise between low water and the edge of the mussel bed ( a distance of 160m) is only 0.4 m. The intertidal vertical distance (measured to the top of the algal band on the boulders) was 2.7 m. Therefore it was impossible to dig at the normal heights, up to the bottom 2/3 of the intertidal. Three levels were chosen on the lower flats, and 4 quadrats dug at each level, at low water, at a point roughly midway up the sand flat and at the edge of the mussel bed. Samples were also taken from the mussel bed and from the mound of boulders and rubble which formed the upper shore. The boulders were covered by green algae (mainly Ulva sp. (originally recorded as Enteromorpha sp.), with some Ulva and Ulothrix), Porphyra umbilicalis and patchy Fucus spiralis. Between the boulders and the mussel bed stretched a narrow 'beach' of cast up cockle shells. The mussels themselves were encrusted with barnacles, and supported a population of Littorina littorea. The low tide flat was made up of muddy fine and medium sand, with a black layer (smelling strongly of hydrogen sulphide) near the surface. There were no Arenicola casts, but several patches of cockles and isolated Ulva (originally recorded as Enteromorpha) filaments growing attached to pebbles on the surface. A patchy clay layer lay under the sand. Diatoms were visible as brown patches in ripple marks on the surface. Wet areas on the surface.
No images for site.
Species list (31 species recorded)
| Previous site | Next site |