title for learn-about section of A SNAIL'S ODYSSEY
  Life in the intertidal zone
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Translocation studies

  Topics dealing with life in the intertidal zone include translocation studies considered here, and TEMPERATURE EFFECTS, HEAT-SHOCK PROTEINS, GAS EXCHANGE, WAVE EFFECTS, SALINITY EFFECTS, and WATER-CHEMISTRY EFFECTS, considered in other sections.
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Research study 1

map showing sites used in translocation study on growth and survival of mussels Mytilus trossulusgraphs comparing survival and growth of mussels Mytilus trossulus after being translocated to a new areaWith so many variable environmental factors affecting the health of mussels at any given location on the shore, how well do mussels do when moved1 from one site to another?  This is tested on the east coast of Vancouver Island, British Columbia using mussels Mytilus trossulus2  collected at Chemainus and Quadra Island (150km apart), then rearing both sets in cages3 at the Quadra-Island site for 384d (see map).

Results show, as expected, that survival is significantly better for the Quadra mussels (59%) in comparison with Chemainus ones (39%), and growth is somewhat better for the Quadra mussels, as well (see graphs on Right). Salinities are similar at the 2 sites, fluctuating around 25‰ during the year, but temperatures are up to 10oC warmer at the Chemainus site during summer. Overall results show that the local mussels perform better than the translocated ones, perhaps indicating an acclimatisation effect and/or different gene expression in different localities. Yanick et al. 2003 Aquacult Res 34: 869.

NOTE1   the original idea relates to aquaculture and, as such, should be outside of the stated aims of the ODYSSEY.  However, as the experiment has broader environmental considerations, it is included here for interest’s sake

NOTE2   at the end of the experiment, the researchers check the species identity of the mussels using established tests for genetic markers.  All but 2 mussels are confirmed as being native M. trossulus, and these 2 are excluded from the data set

NOTE3   there are only 2 cages, one for each set of mussels.  This immediately suggests that there will be only a single datum from each cage to be used for statistical comparisons.  The cages, however, are constructed with 144 small compartments, each housing a single mussel, so perhaps the researchers are justified in treating each sample as having a potential ‘n’ value of 144

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