De grootste kennisbank van het HBO

Inspiratie op jouw vakgebied

Vrij toegankelijk

Terug naar zoekresultatenDeel deze publicatie

The community composition of native and exotic species on the artificial oyster reefs at the Oesterdam in the Eastern Scheldt

Rechten: Alle rechten voorbehouden

The community composition of native and exotic species on the artificial oyster reefs at the Oesterdam in the Eastern Scheldt

Rechten: Alle rechten voorbehouden

Samenvatting

At the Oesterdam four artificial oyster reefs were built to stabilize the sediment of the sand nourishment. These provide a new hard substrate in a previously soft substrate environment, thereby creating a new habitat. This allows species that were previously excluded from the area to now occur there. If the artificial reefs have a positive effect for one or more exotic species, it may cause problems for the native species.
The aim of this research project is to investigate the biodiversity on the artificial oyster reefs to get an indication of the ratio between the native and exotic species on this new habitat. As an indicator for the effect of the oyster reefs on the community composition the two crab species Hemigrapsus takanoi (exotic species) and Carcinus maenas (native species) were studied. Van den Brink et al. (2012) hypothesized that C. maenas was being outnumbered by H. takanoi due to adult H. takanoi out-competing juvenile C. maenas of smaller or similar size to adult H. takanoi for shelter.
To get a better insight on the effect both species have on each other a behavioral experiment was set up to be able to see the competition for food and shelter between juvenile C. maenas and adult H. takanoi.
The ratio of exotic and native species seems to be close to that of the natural reef. The species richness on both artificial reefs is higher compared to the natural reef. This is expected to decrease as the species find a balance by outcompeting each other resulting in a lower species richness and a higher evenness like the natural reef. Some exotic species pose a threat. Maybe these populations can be slowed down to give other species the change to conquer the niche hopefully keeping the invasive species at bay.
It is likely considering the results of this study that juvenile C. maenas are outcompeted for food and shelter by H. takanoi of a similar size. This will in turn cause a problem for the population as a whole since less crabs were able to reach maturity ultimately preventing them to reproduce.
If in the future more reefs will be built it is recommended to look into ways to improve the design in order to help some species like giving the reef a more natural shape and add some open spaces in between to create patches.

Toon meer
OrganisatieHZ University of Applied Sciences
OpleidingWatermanagement/ Aquatische Ecotechnologie
AfdelingDelta Academy
PartnersHZ University of Applied Sciences, Vlissingen
Datum2015-04-20
TypeBachelor
TaalEngels

Op de HBO Kennisbank vind je publicaties van 26 hogescholen

De grootste kennisbank van het HBO

Inspiratie op jouw vakgebied

Vrij toegankelijk