The North Amercian spionid _Marenzelleria (Scolecolepides) viridis_
(Verrill, 1873) was first reported in European waters in 1982 (McLusky et
al., 1993). Since then, the polychaete has spread into several estuaries
around the North Sea and also appeard in the Baltic Sea. Essink and Kleef
(1993) formulated a hypothesis regarding the possible mode by which the
spionid polychaete was able to spread.: a second introduction in the Ems
estuary; and the anti-clockwise water circulation pattern from the two sites
of introduction (Forth estuary, Ems estuary). Given the genetic differences
between the North Sea and Baltic populations, the Baltic populations
probably result from a third introduction (Bastrop et al. 1995).
Last week, specimens of this polychaete were found in the south-west of the
Netherlands. The benthic fauna of this area, built op by several estuaries,
was studied intensively by Wolff (1973). Since then the area has been
changed profoundly my major coastal engineering projects. Several estuaries
have been dammed and in the Oosterschelde a storm-surge barrier has been
built. As a result, some of the estuaries were turned into non-tidal lakes
or lagoons filled with brackish or saline water.
We might expect Marenzelleria to start colonizing the whole area. In the
southern Baltic it has become the dominant macrobenthos species (Zettler et
al., 1995), and given the different water bodies in the Delta area, this may
happen here as well. Therefore, I am looking for references on the
distribution of this species in America, and on the ecology of this species.
Thanks in advance,
Johan Craeymeersch
Netherlands Institute of Ecology
Centre for Estuarine and Coastal Ecology
Vierstraat 28
NL-4401 EA Yerseke
the Netherlands
craeymer at nioo.nl
