Effect of sediment particle size on recruitment of Owenia fusiformis in the Bay of Blanes (NW Mediterranean Sea): an experimental approach to explainfield distribution

Citation
S. Pinedo et al., Effect of sediment particle size on recruitment of Owenia fusiformis in the Bay of Blanes (NW Mediterranean Sea): an experimental approach to explainfield distribution, MAR ECOL-PR, 203, 2000, pp. 205-213
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Aquatic Sciences
Journal title
MARINE ECOLOGY-PROGRESS SERIES
ISSN journal
0171-8630 → ACNP
Volume
203
Year of publication
2000
Pages
205 - 213
Database
ISI
SICI code
0171-8630(20000918)203:<205:EOSPSO>2.0.ZU;2-G
Abstract
The spatial distribution of the tubicolous polychaete Owenia fusiformis Del le Chiaje in the Bay of Blanes was studied during summer 1996. Populations were located on sandy sediments and a heterogeneous distribution of specime ns was found. Three areas with different densities were observed: the vicin ity of the harbour, the mouth of the Tordera River, and the open bay. Altho ugh adult individuals were present all over the bay at low densities, large numbers were mainly found near the harbour. Differences in mean individual biomass were also observed among stations. The largest individuals were fo und at the mouth of the river, where the fluxes of suspended matter were ma ximal. Juveniles of O. fusiformis also showed a regular pattern of spatial variation along the bay. The highest density of juveniles was found in the area where high densities of adults occurred. The consequences of this spat ial variability were analyzed in relation to the effect of sediment grain s ize on 3 successive processes of recruitment (metamorphosis, juvenile trans formation and tube construction) in running still-water experiments. The in fluence of sediment particle size on the disappearance of larvae in the 3 p rocesses was analyzed. The large grain size of the substratum had a signifi cant negative effect on the construction of O. fusiformis tubes. After sett lement, O. fusiformis needs a high percentage of fine sediment to construct the tube. Our results support the hypothesis that the spatial distribution pattern of the species in the field is influenced by sediment particle siz e. The importance of the presence of O. fusiformis adult tubes and seagrass shoots in stabilizing the sediments, and thus determining the pattern, is also discussed.