Do crabs get cancer? That may seem a tautologous question to horoscope readers. But the government says other crustaceans--tiny ones living in Lake Michigan--appear to be afflicted with malignant tumors for reasons unknown.
Scientists at the National Oceanic and Atmospheric Administration's (NOAA's) Great Lakes Environmental Research Laboratory in Ann Arbor, Michigan, reported at a meeting last week of the International Association for Great Lakes Research in Cleveland that tumors have shown up in several species of copepods and Cladocera, or water fleas. Only a small number have been analyzed so far, from the southern basin of Lake Michigan. Cancers are rare in crustaceans, and tumors have been reported in zooplankton only once before--in the Baltic Sea in 1994--says Henry Vanderploeg, a research ecologist at the NOAA lab. But he says this is the first time such growths have been documented scientifically. So far, scientists have "not the slightest idea" as to the cause, Vanderploeg says.
Copepod (1.7 mm long) with tumors.
CREDIT: UNIV. OF MICHIGAN/NOAA GREAT LAKES ENVIRONMENTAL RESEARCH LABORATORY
But NOAA scientists say there's a great deal more going into Lake Michigan than what's on the list of 139 toxic substances that must be monitored by law. Most of these are persistent toxicants, says NOAA toxicologist Peter Landrum: "We've not really paid attention to things that are present in high quantities but not necessarily as persistent." Prime suspects these days, he says, are endocrine disrupters, a huge source of which are nonophenols from laundry detergents, which have been implicated in estrogenlike activity.
But more research is needed. Vanderploeg says, "We're going to start looking at archived samples going back to the early '80s and nail down the hot spots" in hopes of getting to the bottom of what's messing up life in the lake.
