Realm: Marine
Climate: Temperate
Biome: Temperate shelf and seas ecoregions
Central latitude: 51.439215
Central longitude: 2.682711
Duration: 19 years, from 1976 to 2001

15901 records

344 distinct species

Across the time series Nephtys cirrosa is the most frequently occurring species

Methods

All samples were taken with a Van Veen Grab (+/- 50 kg) with a sampling surface of 0.1026 m?. or in some cases 0.12 m?. This grab enables fast sampling. The variability within replicates corresponds to about 13 %. what gives a difference in depth of 0.7 to 1.2 cm (Lie & Pamatmat. 1965). __Processing samples: Every sample (already stained with a Bengal Rose or eosin solution) is decanted (10 times) on a 1000 ?m sieve in order to separate the present fauna from the sediment. With this technique the residue of coarse sediment and fauna is pored into a measuring cup (5 l) and is brought into suspension with a strong jet of water. During this process the smaller and lighter organisms will go into suspension. whereas the heavier sediment and organisms remain on the bottom. The water containing the organisms is there after pored over a 1000 ?m sieve. All retained fauna is stored in a 4-8 % neutral formalin solution and stained with Bengal-Rose of eosin (if not done earlier). Both solutions colour all organic material. This enables easier sorting of the animals. After decantation the residue is checked for bigger and heavier organisms (e.g. Mollusca. Actinaria). Decantation must not be applied to fine sediment samples (< 1000 ?m) as all sediment is directly rinsed through the 1 mm sieve and what remains on the sieve can directly be fixated. Identification: All organisms are counted and identified. if possible to species level. For some animal groups however this is not the case:Nematoda. Nemertinea. Sipunculida. Turbellaria. Actinaria. Oligochaeta and Copepoda are never identified to a higher level because they are not representative for the macrobenthos community. The sampling technique is not suited to quantify these groups neither.The identification of some taxa is still under discussion. Whether they should be identified up to species level or grouped into complexes is still not clear due to uncertain taxonomy (e.g. Phyllodoce maculata of P. mucosa; Harmotho? spp.; Bathyporeia spp.; Cirratulidae; Capitellidae). Sediment analysis: Two standard methods were applied: using sieves with different mesh sizesDuring the period 1976-1986 all sediment analyses were done using at least 7 sieves with different mesh size (see table 1). Approximately 25 g of homogenized substrate was used for grain size analysis of the sand fraction according to Buchanan & Kain (1971). The wet-sieved fraction smaller than 63 ?m was used as a measure for mud content.using a Coulter LS 100From 1994 on all sediment samples were analysed using a Coulter counter. Within the measuring range of 2 ?m to 850 ?m the grain sizes are measured. The fraction larger than 850 ?m is separated and expressed as weighed percentage. The subdivision in sediment fractions follows the Wentworth scale (Buchanan. 1984). Density: All densities are shown as the number of individuals per square meter (ind/m?). Only the anterior parts of the organisms are counted. Unit of abundance = IndCountInt, Unit of biomass = NA

Citation(s)

Degraer, S., Wittoeck, J., Appeltans, W., Cooreman, K., Deprez, T., Hillewaert, H., Hostens, K., Mees, J., Vanden Berghe, E. & Vincx, M. (2006) “Macrobel: Long term trends in the macrobenthos of the Belgian Continental Shelf.” Oostende, Belgium. Available at: http://www.emodnet-biology.eu/data-catalog?module=dataset&dasid=145, accessed 2013.