<P> Møller and Tim Mousseau have published the results of the largest census of animal life in the Chernobyl Exclusion Zone. (2) It said, contrary to the Chernobyl Forum's 2005 report, (3) that the biodiversity of insects, birds and mammals is declining . Møller and Mousseau have been criticized strongly by Sergey Gaschak, a Ukrainian biologist who did field work for the pair beginning in 2003 . He regards their conclusions to be the result of a biased and unscientific anti-nuclear political agenda, unsupported by the data he collected for them . "I know Chernobyl Zone," he says . "I worked here many years . I can't believe their results ." (4) </P> <P> Some researchers have said that by halting the destruction of habitat, the Chernobyl disaster helped wildlife flourish . Biologist Robert J. Baker of Texas Tech University was one of the first to report that Chernobyl had become a wildlife haven and that many rodents he has studied at Chernobyl since the early 1990s have shown remarkable tolerance for elevated radiation levels . </P> <P> Møller et al. (2005) suggested that the reproductive success and annual survival rates of barn swallows are much lower in the Exclusion Zone; 28% of barn swallows inhabiting Chernobyl return each year, while at a control area at Kanev, 250 km to the southeast, the return rate is around 40% . A later study by Møller et al. (2007) furthermore claimed an elevated frequency of eleven categories of subtle physical abnormalities in barn swallows, such as bent tail feathers, deformed air sacs, deformed beaks, and isolated albinistic feathers . </P> <P> Smith et al. (2007) have disputed Møller's findings and instead proposed that a lack of human influence in the Exclusion Zone locally reduced the swallows' insect prey and that radiation levels across the vast majority of the exclusion zone are now too low to have an observable negative effect . But the criticisms raised were responded to in Møller et al. (2008). It is possible that barn swallows are particularly vulnerable to elevated levels of ionizing radiation because they are migratory; they arrive in the exclusion area exhausted and with depleted reserves of radio - protective antioxidants after their journey . </P>

Which of the following was an environmental consequence of the nuclear meltdown at chernobyl