Suspended
planktonic hydroids on Georges Bank: distribution, abundance, and
impacts of a rapacious predator
J. J. Pierson, E. G.
Durbin, and B. K. Sullivan
Hydroids are marine hydrozoans in the Phylum Cnidaria. They have a
two-stage life cycle in which generations of sessile benthic
colonies, called polyps, alternate with generations of pelagic
medusa. The polyp stage is usually found attached to seaweed,
rocks, and other structures on the seafloor, but dynamic processes
can detach and fragment the colonies, suspending the polyps in the
water. Madin et al. (1996) found that although hydroids had
previously been reported suspended in the water on Georges Bank,
they have not been considered important organisms in the pelagic
community.
In this study, we attempt to quantify the distribution and abundance
of hydroid polyps on the crest of Georges Bank throughout the winter
and spring of 1995, 1996, 1997, and 1998. In addition we are going
to examine how these patterns of distribution and abundance could
affect the zooplankton population.