| dc.description.abstract | We examined the distribution and abundance of the hyperbenthos in tidepools on a rocky shore,
near Halifax, Nova Scotia, Canada, at approximately monthly intervals between March and November
1991, and between April and June 1992. We sampled 4 pools at each of 3 intertidal heights: mid and
high intertidal and splash zones. Additional samples were taken at the sea surface for comparison.
Calanoid and harpacticoid copepods, cladocerans, foraminiferans, nematodes and rotifers were the
most abundant groups within our samples. Significant differences in the abundance of these groups
among zones were detected on only 5 out of 12 sampling dates. Total hyperbenthos, as well as
calanoid and harpacticoid copepods, nematodes and rotifers, generally were more abundant in the high
and/or the splash pools. The abundance of total hyperbenthos varied significantly among pools within
zones from May to October 1991 and in June 1992. Significant differences in abundance among pools
within zones were also detected for harpacticoid copepods and nematodes on 3 sampling dates, for
calanoid copepods and rotifers on 5 sampling dates, and for cladocerans and foraminiferans on 2
sampling dates. In most cases, the significant variability in abundance among pools arose within the
high intertidal or the splash zones. Over the entire sampling period, the diversity of faunal groups
was lower in the splash pools, possibly as a result of harsh conditions in these pools. The few
groups that survived in these high pools, such as rotifers and the calanoid copepod Eurytemora
affinis, reached densities of up to 106 ind. m-3. Dominant populations may be established in
particular pools by founder effects and persist due to low flushing rates. Thus, variability among
pools in the high intertidal and splash zones may exceed that observed among pools in lower
intertidal zones. | en_US |
