Boets, P.

Goethals, P.L.M.

Lock, K.

Open Marine Archive

 - 14 -
INFLUENCE OF ALIEN MACRO-CRUSTACEA (MALACOSTRACA) ON 
MACROINVERTEBRATE ASSEMBLAGES IN BELGIAN COASTAL 
HARBOURS 
Boets Pieter, Koen Lock and Peter L.M. Goethals 
Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, 
B-9000 Ghent, Belgium 
E-mail: pieter.boets@ugent.be  
Harbours, which are often situated in estuaries and are characterised by intensive international ship 
traffic, tend to be very susceptible to aquatic invasions (Wolff, 1999; Nehring, 2006). Since alien 
macrocrustaceans are known to be very successful across many European waters (Bernauer and 
Jansen, 2006), a study was performed on their distribution and impact in the four Belgian coastal 
harbours (Nieuwpoort, Ostend, Blankenberge and Zeebrugge). Biological and physical-chemical data 
were gathered at 43 sampling sites distributed along a salinity gradient in the four harbours. One 
third of all crustacean species recorded were alien and these represented on average 30% of the 
macrocrustacean abundance and 65% of the macrocrustacean biomass. The large share of alien 
crustaceans in the biomass was mainly due to several large alien crab species. Most alien species 
were found in the oligohaline zone, whereas the number of indigenous species slightly increased 
with increasing salinity. The low number of indigenous species observed at low salinities was 
probably not only caused by salinity, but also by the lower water quality in this salinity range. The 
site-specific biocontamination index (SBCI) was used to assess the impact of alien species. The 
harbour of Nieuwpoort and Ostend scored best and were classified as good, indicating a limited 
abundance and a low species-richness of alien macrocrustaceans. Zeebrugge and Blankenberge 
were characterised by a severe biocontamination, which is for the harbour of Zeebrugge probably 
related to the intensive international ship traffic. Due to its nearby location, it is likely that alien 
species dispersing from Zeebrugge colonised the harbour of Blankenberge rapidly. Sampling 
locations situated more inland generally had a higher SBCI, mostly due to the dominance of one or 
two alien species, reaching high abundances. Consistent monitoring of estuarine regions and 
harbours, which are seen as hotspots for introductions, could help in understanding and predicting 
the impact of alien species on native biota. 
 
References 
Bernauer D. and W. Jansen. 2006. Recent invasions of alien macroinvertebrates and loss of native 
species in the upper Rhine River, Germany. Journal of Aquatic Invasions 1:55-71. 
Nehring S. 2006. Four arguments why so many alien species settle into estuaries, with special 
reference to the German River Elbe. Helgoland Marine Research 60:127-134. 
Wolff W.J. 1999. Exotic invaders of the meso-oligohaline zone of estuaries in the Netherlands: why 
are there so many? Helgolander Meeresuntersuchungen 52:393-400. 


Influence of alien macro-Crustacea (Malacostraca) on macroinvertebrate assemblages in Belgian coastal harbours

Abstract

Similar works

Full text

Available Versions

Open Marine Archive