|Changes in marsh nekton communities along the salinity gradient of the river Schelde: preliminary results (poster)|
|Hampel, H.; Cattrijsse, A.; Vincx, M. (2002). Changes in marsh nekton communities along the salinity gradient of the river Schelde: preliminary results (poster), in: Mees, J. et al. (Ed.) (2002). VLIZ Young Scientists' Day, Brugge, Belgium 13 March 2002: book of abstracts. VLIZ Special Publication, 7: pp. 38|
|In: Mees, J.; Seys, J. (Ed.) (2002). VLIZ Young Scientists' Day, Brugge, Belgium 13 March 2002: book of abstracts. VLIZ Special Publication, 7. Vlaams Instituut voor de Zee: Oostende. VI, 57 pp., more|
|In: VLIZ Special Publication. Vlaams Instituut voor de Zee (VLIZ): Oostende. ISSN 1377-0950, more|
Estuarine organisms; Marshes; Marine; Brackish water
In the salt marshes different habitats as well as the environmental parameters influence the composition of the nekton community. Considering both the environmental parameters and the different habitats, our sampling campaign occurred in five marshes along the River Schelde (Grembergen, Saeftinghe, Waarde, Zuidgors and Zwin).
The salinity gradient differed from 0.2 till 29 psu. Sampling campaign occurred from April until October in 2000.
Three different sampling techniques were used adapting to the different habitats. Fyke nets were set in the big creeks. Block net sampled the small creeks by closing the mouth of the creek at the moment of the high water and fish traps were placed into small ponds.
Data analysis is still under progress but already remarkable differences were observed.
The eel, Anguilla anguilla dominate the fish community in the fresh water marsh. This area is characterised by low catch.
Mesohaline and oligohaline marshes are dominated by two fish species, Pleuronectes flesus and Dicentrarchus labrax. High catch of fyke net marks these marshes. In the small creeks, adult Palaemonetes varians and Pleuronectes flesus was captured by block net. Larvae of Pomatoschistus microps and adult Palaemonetes varians appeared in high number in the fish traps.
Polyhaline marsh was characterised by low catch with all the different sampling techniques. Only the shore crab, Carcinus maenas was present in very high abundance in the creeks. But in the autumn high numbers of Pomatochistus microps were caught in the small channel.