their large size, but may be preyed on by large sharks, seals, and killer whales. Nesting females are attacked by flesh flies, feral dogs, and humans. Salt marsh mosquitos can also pester nesting females. In Australia, the introduction of the red fox (Vulpes vulpes) by British settlers in the 19th century led to significant reductions in loggerhead sea turtle populations. In one coastal section in eastern Australia during the 1970s, predation of turtle eggs destroyed up to 95% of all clutches laid. Aggressive efforts to destroy foxes in the 1980s and 1990s has reduced this impact; however, it is estimated that it will be the year 2020 before populations will experience complete recovery from such dramatic losses. Along the southeastern coast of the United States, the raccoon (Procyon lotor) is the most destructive predator of nesting sites. Mortality rates of nearly 100% of all clutches laid in a season have been recorded on some Florida beaches. This is attributed to an increase in raccoon populations, which have flourished in urban environments. Aggressive efforts to protect nesting sites by covering them with wire mesh has significantly reduced the impact of raccoon predation on loggerhead sea turtle eggs. Up to 40% of nesting females around the world have wounds believed to come from shark attacks. Disease and parasites Infectious bacteria such as Pseudomonas and Salmonella attack loggerhead hatchlings and eggs. Fungi such as Penicillium infect loggerhead sea turtle nests and cloacae. Fibropapillomatosis disease caused by a form of the herpes-type virus threatens loggerheads with internal and external tumors. These tumors disrupt essential behaviors and, if on the eyes, cause permanent blindness. Trematodes of the family Spirorchiidae inhabit tissues throughout the body of the loggerhead, including vital organs, such as the heart and the brain. Trematode infection can be highly debilitating. For example, inflammatory trematode lesions can cause endocarditis and neurological disease. A nematode, Angiostoma carettae, also infects loggerheads, causing histologic lesions in the respiratory tract. More than 100 species of animals from 13 phyla, as well as 37 kinds of algae, live on loggerheads' backs. These parasitic organisms, which increase drag, offer no known benefit to the turtle, although the dulling effect of organisms on shell color may improve camouflage. In 2018, researchers from Florida State University examined 24 individual turtle carapaces and found an average of 33,000 meiofauna with one turtle having 150,000 organisms living on the shell. A collection of