Forwarded by Jane Clark DECREASED WATER QUALITY MAY POSE THREAT TO MIGRATING WATERFOWL-SCIENTISTS WILL TRACK IOWA DUCKS FROM OUTER SPACE By Lowell Washburn, Iowa Department of Natural Resources Migratory waterfowl are currently winging their way toward ancestral nesting grounds. And although millions of migrating birds will fly across Iowa during the next several weeks, scientists will be keeping an especially watchful eye on the daily activities of seventeen lesser scaup ducks. Following their arrival on Mississippi River Pool 19 last week, the two-pound birds [also known as bluebills] were captured, anesthetized, and then surgically implanted with state-of-the-art satellite transmitters. Following a two-hour recovery, the ducks [all females] were released to rejoin the northward migration. According to Louisiana State University Professor and project coordinator, Alan Afton, this high-tech endeavor will allow scientists to chart the scaups' migration paths, habitat use, and ultimate survival. Although previous land based telemetry studies have been conducted in the state, this is the first time Iowa waterfowl have been monitored from space. Afton, who has been studying scaup for more than thirty years, hopes the experiment will shed light into factors affecting the species' overall survival. Scaup populations have waned by as much as 50 percent during recent years --- down from 7 million breeding birds inventoried during the 1970s to around 3.5 million today. "While most other duck species are holding their own or even showing an increase, scaup numbers continue to decline," says Afton. "Although there are theories, no one can say for certain why the decline is occurring. What we do know is that migrating scaup are in really good [physical] condition when they arrive at Keokuk each spring. But by the time those birds arrive in northwestern Minnesota, they are in poor body condition." Ongoing water quality studies have revealed that 97 percent of surveyed wetlands in north central and northwestern Iowa contain measurable levels of herbicides, pesticides, or other chemical contaminants. Additional pollutants include widely-ranging levels of phosphorus and nitrogen. Many researchers suspect the pollution is disrupting aquatic food chains. Biologists note that spring migration is a time when female scaup stoke up on the natural aquatic foods needed to build nutrient reserves essential to egg production. Failure to acquire those reserves could result in lowered nesting success and significant decreases in the annual recruitment of young. Tiny crustaceans known as amphipods represent the scaup's most important food source as ducks migrate across Iowa's interior. "For lesser scaup to maintain the healthy body condition needed for egg production, they must have amphipods," says DNR waterfowl biologist, Guy Zenner. "Historically, it was no problem for scaup and other water birds to find that nutritional source in Iowa. Today, wetland water quality has been compromised to the point that amphipods no longer exist in most of our marshlands. Scaup end up surviving on alternate food sources which are insufficient to increase or even maintain critical body weights." "It's a water quality issue and everyone living in Iowa should be very dismayed by these findings," added Zenner. During the next several days those seventeen radio implanted females are expected to leave the Mississippi River and disperse northwest across Iowa. As hens continue toward the boreal forest breeding grounds of northwestern Canada, space stationed satellites will track and report the ducks' whereabouts on a daily basis. In most instances, the information will be "location specific" where biologists can pinpoint the exact wetlands northbound scaup are utilizing. Ducks Unlimited personnel are currently constructing a website that will allow the public to view the project's outer space observations. Beginning mid-April, the radioed scaups' progress can also be viewed on the Iowa DNR's web site. Transmitters are expected to provide data through the 2008 migration. "Once we pinpoint the actual wetlands scaup are using, we can go in and sample those locations for food," says Afton. "Once we determine what types of wetlands the birds are using along the course of their migration, we can go in and look at the landscape features affecting those habitats." "If we can identify a fairly narrow corridor that scaup are utilizing, then we can focus on improving the condition of those particular wetlands," said Afton. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - To unsubscribe from the IOWA-TOPICS list, send any message to: [log in to unmask] Check out our Listserv Lists support site for more information: http://www.sierraclub.org/lists/faq.asp Sign up to receive Sierra Club Insider, the flagship e-newsletter. Sent out twice a month, it features the Club's latest news and activities. Subscribe and view recent editions at http://www.sierraclub.org/insider/