Re-use of shallow sediment patches by Pacific sand lance (Ammodytes hexapterus) in Barkley Sound, British Columbia, Canada

摘要

We determined whether, during the summers of 2002-2004, young-of-the-year (YOY) Pacific sand lance (Ammodytes hexapterus) re-used patches of sediment in intertidal and shallow subtidal regions of Barkley Sound, British Columbia, Canada. We examined re-use weekly at a single sediment patch in 2003 and 2004 via mark-recapture methods, monthly by re-sampling 15 patches in 2002 and interannually by re-sampling 36 patches in all 3 years (2002-2004). The mark-recapture results showed that, within each summer, batch marked YOY sand lance re-used the same patch up to 8 weeks later. The re-sampling of 15 patches over 4 months in 2002 showed that YOY sand lance consistently occupied patches within a season. We found the greatest variability in sediment patch re-use at the interannual time scale with major fluctuations in occurrence and abundance during 2002-2004. The interannual variability in patch re-use is most likely linked to abundance rather than the local or regional environmental characteristics that we examined.