TY - JOUR
T1 - Improvements to a passive trap for quantifying barnacle larval supply to semi-exposed rocky shores
AU - Todd, Christopher D.
AU - Phelan, Patrick J.C.
AU - Weinmann, Birgit E.
AU - Gude, Adrian R.
AU - Andrews, Christopher
AU - Paterson, David M.
AU - Lonergan, Michael E.
AU - Miron, Gilles
PY - 2006/5/16
Y1 - 2006/5/16
N2 - Planktonic cyprid larvae of the intertidal barnacle, Semibalanus balanoides (L.) and the infralittoral/sublittoral Balanus crenatus Brug., are readily captured in small, chambered, passive traps deployed on rocky shores. Several structural developments of a previous trap design improved urea (killing solution) retention and capture of cyprids of both species. The design adopted for assessment of the larval supply/settlement relationship of the focal species, S. balanoides, included additional internal baffles and the replacement of the cylindrical trap opening with a coned aperture. Three sizes of cone aperture area were compared, with the intermediate size (1 cm2) being optimal for measuring larval supply over the full range of wave action on local shores. Most daily catches included larvae that were recognizable as having been dead before they were trapped, and had recently passed through the guts of grazing limpets (Patella vulgata L.). One site showed that ∼32% of trapped S. balanoides were so-called 'faecal' cyprids. An inability to distinguish these in trap samples would lead to a significant over-estimation of larval supply. Preliminary data indicated that S. balanoides larval supply to the intertidal is enhanced by onshore winds (or perhaps increased wave turbulence), whereas B. crenatus supply was positively correlated with offshore winds (or decreased turbulence). A clear 'supply/settlement' relationship for S. balanoides at six sites along ∼40 km of coastline was derived from 1 cm2 coned trap catches and daily counts of settlement on ceramic tiles. There were no instances of disproportionately high settlement in relation to larval supply, but at five sites there were days when settlement apparently failed. The identification and explanation of settlement success and failure is fundamental to understanding the importance of larval supply in structuring marine benthic populations and communities.
AB - Planktonic cyprid larvae of the intertidal barnacle, Semibalanus balanoides (L.) and the infralittoral/sublittoral Balanus crenatus Brug., are readily captured in small, chambered, passive traps deployed on rocky shores. Several structural developments of a previous trap design improved urea (killing solution) retention and capture of cyprids of both species. The design adopted for assessment of the larval supply/settlement relationship of the focal species, S. balanoides, included additional internal baffles and the replacement of the cylindrical trap opening with a coned aperture. Three sizes of cone aperture area were compared, with the intermediate size (1 cm2) being optimal for measuring larval supply over the full range of wave action on local shores. Most daily catches included larvae that were recognizable as having been dead before they were trapped, and had recently passed through the guts of grazing limpets (Patella vulgata L.). One site showed that ∼32% of trapped S. balanoides were so-called 'faecal' cyprids. An inability to distinguish these in trap samples would lead to a significant over-estimation of larval supply. Preliminary data indicated that S. balanoides larval supply to the intertidal is enhanced by onshore winds (or perhaps increased wave turbulence), whereas B. crenatus supply was positively correlated with offshore winds (or decreased turbulence). A clear 'supply/settlement' relationship for S. balanoides at six sites along ∼40 km of coastline was derived from 1 cm2 coned trap catches and daily counts of settlement on ceramic tiles. There were no instances of disproportionately high settlement in relation to larval supply, but at five sites there were days when settlement apparently failed. The identification and explanation of settlement success and failure is fundamental to understanding the importance of larval supply in structuring marine benthic populations and communities.
KW - Balanus crenatus
KW - Cyprid
KW - Larval supply
KW - Panel
KW - Semibalanus balanoides
KW - Settlement
KW - Tile
KW - Trap
UR - http://www.scopus.com/inward/record.url?scp=33646141876&partnerID=8YFLogxK
U2 - 10.1016/j.jembe.2005.11.013
DO - 10.1016/j.jembe.2005.11.013
M3 - Article
AN - SCOPUS:33646141876
VL - 332
SP - 135
EP - 150
JO - Journal of Experimental Marine Biology and Ecology
JF - Journal of Experimental Marine Biology and Ecology
SN - 0022-0981
IS - 2
ER -