Dear Annelid enthusiasts,
Angel de leon wrote:
> In reply to the discution of the worldwide distribution of some
>polychaete species. I found a article titled "Ecological Roulette: The
>Global Transport of nonindigenous marine organisms" Science, 261:
>78-82(1993). Cartlon and Geller sampled ballast water from 159 cargo
>ships in Coos Bay, Oregon, USA. The ships and their ballast water were
>originated from 25 Japanese Ports. They found a minimum of 367
>different marine taxa, including spionids, polynoids among other
>polychaete families.
> These study may explain the transpacific distribution in the recent
>past. The interesting point is, how many transpacific species Jim
>Blake found in his Atlas?.
The cited paper is one of several authored by Jim Carlton detailing his
interesting work on transport of invertebrates. An early summary,
relevent to California appeared in the 1975 edition of Light's Manual.
The answer to Angel's question, however, is easy if we are considering
introduced or non-indigenous species. None!!
The Atlas I am referring to deals almost exclusively with polychaetes
from the continental shelf and slope, not from estuarine habitats where
the opportunitistic species found in ballast water colonize.
Geologically, the estuaries of California are so young, that there are
relatively few endemic invertebrates. This provides opportunities for
invading species that are transported to these estuaries in ballast
water or through aquaculture transplants. Typically such species are
tolerant to shifts in salinity and temperature. This is not true for
offshore species found in the deeper waters of the shelf and slope.
These species have a narrow range of tolerance and occur there because
of natural transport and colonization.
Jim Blake
ENSR
89 Water Street
Woods Hole, MA 02543
(jablake at ix.netcom.com)
