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E-M:/ FW: INFOTERRA: NOAA & UMICH discover tumors in freshwater plankton
- Subject: E-M:/ FW: INFOTERRA: NOAA & UMICH discover tumors in freshwater plankton
- From: "Harris, Craig" <Craig.Harris@ssc.msu.edu>
- Date: Tue, 25 May 1999 10:13:38 -0400
- List-Name: Enviro-Mich
- Reply-To: "Harris, Craig" <Craig.Harris@ssc.msu.edu>
Enviro-Mich message from "Harris, Craig" <Craig.Harris@ssc.msu.edu>
some information on lake michigan, presumably indicative of water quality
> NOAA 99-R511
> FOR IMMEDIATE RELEASE
> Contact: Jana Goldman
> NOAA AND UNIVERSITY OF MICHIGAN SCIENTISTS DISCOVER TUMORS IN
> Zooplankton, near the bottom of marine and freshwater food chains, can
> develop tumors like those of higher life forms, according to scientists
> the Commerce Department 's National Oceanic and Atmospheric
> Great Lakes Environmental Research Laboratory and the University of
> Center for Great Lakes and Aquatic Sciences in Ann Arbor, Michigan.
> The evidence, including photographs, will be presented on May 27 during
> annual meeting of the International Association for Great Lakes
> which begins on May 24 in Cleveland, Ohio. Although tumors in
> were reported in 1994 from an area of the Baltic Sea, this is the first
> 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
> that are usually less than an eighth of an inch in size.
> Tumors, or neoplasms, have been found in a variety of invertebrates such
> molluscs, insects, and flatworms, but reports of tumors on crustaceans
> Earlier research speculated that tumors might form in zooplankton, but
> 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
> Preliminary analyses suggest that tumors are more common nearshore than
> The work is the effort of a team of five scientists: Drs. H.A.
> of NOAA's Great Lakes Environmental Research Laboratory ( GLERL ); G. L.
> Fahnenstiel of GLERL's Lake Michigan Field Station ; M. Omair and D.J.
> 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
> 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
> in a contract to identify and count zooplankton in preserved samples
> 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
> 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
> is a recent phenomenon in the Great Lakes in general and in Lake
> Michigan in
> It is also possible that previous monitoring efforts, restricted to a
> spring and late summer collections, would have missed the tumors because
> their limited seasonal coverage and focus on offshore surface waters.
> research team plans to examine archived collections and make new
> at many nearshore and offshore sites to find hot spots that might be
> associated with some environmental factor. Careful microscopic analyses
> the tumors also may give some insight into their cause.
> NOAA's mission is to describe and predict changes in the Earth's
> and manage wisely the nation's coastal and marine resources.
> Editor's Note: Images of the zooplankton showing the growths discussed
> 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
> 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
> 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)
> view of Diaphanosoma sp. (Body length = 0.9 mm); (Upper right)
> pediculus (body length =0.7 mm); and (Bottom) Daphnia galeata mendotae
> length -1.1 mm) with abnormalities on the helmet near compound eye,
> abdominal claw, and body carapace.
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