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E-M:/ FW: INFOTERRA: NOAA & UMICH discover tumors in freshwater plankton

Enviro-Mich message from "Harris, Craig" <Craig.Harris@ssc.msu.edu>

some information on lake michigan, presumably indicative of water quality

>  http://www.publicaffairs.noaa.gov/releases99/may99/noaa99r511.html
>   NOAA 99-R511
>   Contact: Jana Goldman
>   5/24/99
>                                   ZOOPLANKTON
>   Zooplankton, near the bottom of marine and freshwater food chains, can
>   develop tumors like those of higher life forms, according to scientists
> at
>   the Commerce Department 's National Oceanic and Atmospheric
> Administration's
>   Great Lakes Environmental Research Laboratory and the University of
> Michigan
>   Center for Great Lakes and Aquatic Sciences in Ann Arbor, Michigan.
>   The evidence, including photographs, will be presented on May 27 during
> the
>   annual meeting of the International Association for Great Lakes
> Research,
>   which begins on May 24 in Cleveland, Ohio. Although tumors in
> zooplankton
>   were reported in 1994 from an area of the Baltic Sea, this is the first
> time
>   photographs have been taken of the abnormalities and that preliminary
>   evidence has been presented that the tumors are cancerous. The affected
>   zooplankton are copepods and Cladocera (water fleas), which are
> crustaceans
>   that are usually less than an eighth of an inch in size.
>   Tumors, or neoplasms, have been found in a variety of invertebrates such
> as
>   molluscs, insects, and flatworms, but reports of tumors on crustaceans
> are
>   rare.
>   Earlier research speculated that tumors might form in zooplankton, but
> the
>   organisms would die at molting before tumors would be obvious. The team
>   found large tumors on juveniles and on young, recently molted adult
>   zooplankton in Lake Michigan.
>   Researchers found tumors in several species of copepods and Cladocera.
>   Predatory species were more likely to have tumors than herbivorous
> species.
>   Preliminary analyses suggest that tumors are more common nearshore than
>   offshore.
>   The work is the effort of a team of five scientists: Drs. H.A.
> Vanderploeg
>   of NOAA's Great Lakes Environmental Research Laboratory ( GLERL ); G. L.
>   Fahnenstiel of GLERL's Lake Michigan Field Station ; M. Omair and D.J.
> Jude
>   of the Center for Great Lakes and Aquatic Sciences; and T.M. Rizki,
>   Department of Biology, University of Michigan. All but Fahnenstiel, who
>   works in Muskegon, Mich., are based in Ann Arbor, Mich.
>   Zooplankton showing the tumors were collected during 1995 and 1998 as
> part
>   of GLERL's food web and water-quality monitoring program and as part of
>   Michigan Sea Grant-supported research by D. Jude on larval fish and
>   zooplankton interactions in the nearshore zone. Analysis of the tumors
> by T.
>   Rizki showed a high frequency of dividing cells, which is suggestive of
>   cancerous growths. M. Omair was the first one to observe the
> abnormalities
>   in a contract to identify and count zooplankton in preserved samples
> from
>   GLERL's monitoring study. Only a few samples have been analyzed so far.
>   "We can only speculate as to when the tumors first occurred in Lake
> Michigan
>   zooplankton," said Dr. Vanderploeg. "Because such tumors have never been
>   seen until now, despite the many programs on the Great Lakes that have
>   monitored or collected zooplankton, we suspect the occurrence of the
> tumors
>   is a recent phenomenon in the Great Lakes in general and in Lake
> Michigan in
>   particular."
>   It is also possible that previous monitoring efforts, restricted to a
> few
>   spring and late summer collections, would have missed the tumors because
> of
>   their limited seasonal coverage and focus on offshore surface waters.
> The
>   research team plans to examine archived collections and make new
> collections
>   at many nearshore and offshore sites to find hot spots that might be
>   associated with some environmental factor. Careful microscopic analyses
> of
>   the tumors also may give some insight into their cause.
>   NOAA's mission is to describe and predict changes in the Earth's
> environment
>   and manage wisely the nation's coastal and marine resources.
>   Editor's Note: Images of the zooplankton showing the growths discussed
> above
>   are available at: ftp://ftp.glerl.noaa.gov/publications/
>   All images must be credited to: University of Michigan and NOAA / Great
>   Lakes Environmental Research Laboratory.
>   Captions for the images follow.
>   Figure 1: Appearance of neoplasms or growths on a predatory copepod
>   Limnocalanus macrurus: (Upper left) An individual with a large
> multi-lobed
>   tumor on the ventral surface of the prosome (anterior body) between the
>   swimming feet and mouthparts. (Upper right) Dorsal view of an individual
>   with a large nearly spherical tumor (large arrow) attached by stalk-like
>   structure (small arrow) to right side of prosome. (Bottom) Individual
> with
>   tumors (arrows) on the ventral prosome and first segment of urosome
>   (posterior body). Prosome length is approximately 1.7 mm in all cases.
>   Figure 2: Another predatory copepod with tumors: lateral view of three
>   Epischura lacustris copepodids with neoplasms (at arrows). Prosome
> length of
>   these individuals is 1.0 mm.
>   Figure 3: Appearance of tumors on ventral prosome of Diaptomus sp., an
>   ominivorous copepod. (Prosome length is ~ 0.7 mm in both cases)
>   Figure 4: Appearance of tumors (at arrows) in Cladocera: (Upper left)
> Dorsal
>   view of Diaphanosoma sp. (Body length = 0.9 mm); (Upper right)
> Polyphemus
>   pediculus (body length =0.7 mm); and (Bottom) Daphnia galeata mendotae
> (body
>   length -1.1 mm) with abnormalities on the helmet near compound eye,
>   abdominal claw, and body carapace.
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