Dear Daniel and other annelid list subscribers, in response to Daniel's
question on the recent introduction to PPB of Sabella spallanzanii ...
Although there is currently work being done in Port Phillip Bay on Sabella
spallanzanii by a PhD student at Melbourne University (Mike Holloway) and
by people at the MAFRI government research laboratories at Queenscliff, I
do not know of any verified effects (published or otherwise) due to
S.spallanzanii. But I did miss a recent seminar by Mike Holloway, so
there may be recent results or unpublished reports that I am unaware of.
However, it seems inconceivable that the advent of a large suspension
feeder with few local predators would have no effects on the community.
Although the worm does clog scallop dredges as Geoff Read said, this will
be a temporary problem for the simple reason that the government has now
banned scallop dredging in the bay for envirnomental reasons! (even though
a recent MAFRI study did not reveal significant long term effects on
benthic communities from dredging). But Sabella would appear to compete
directly with scallops and other suspension feeders for food and maybe
space, and probably has impacts on recruitment to the benthos of other
species. Greg Parry at MAFRI discovered also that Sabella spallanzanii
is distasteful to most common PPB fish species, so the incorporation of
so much benthic biomass into a species that will eventually be an energy
source for microbial decomposition (rather than supporting fish
communities) is bound to have widespread consequences. It will be
worrying if "fixing" some PPB environmental problems by banning scallop
dredging means that government environmetal monitoring agencies find it
difficult to get resources to monitor these and other environmental
problems in the Bay.
But most of the above (except for the fish feeding bit) is unsupported by
evidence, so far as I am aware. The field seems wide open for futher
research, and a major environmental "experiment" is already well
underway.
Hope this is of some interest. If anyone needs further information they
will have to go directly to the people at MAFRI and Melb Uni doing the
work now.
bye
Robin
Robin Wilson
Museum of Victoria
71 Victoria Crescent
Abbotsford
AUSTRALIA 3067
rwilson at mov.vic.gov.au; telephone 61 3 9284 0216; fax 61 3 9416 0475
polychaetes of Australia: http://www.mov.vic.gov.au/poly
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