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United States Department of Agriculture

Agricultural Research Service

Title: Seabirds and Their Helminth Parasites

Author
item Hoberg, Eric

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: October 12, 2004
Publication Date: January 30, 2005
Citation: Hoberg, E.P. 2005. Seabirds and their helminth parasites, Chapter 10, Economic, environmental and medical importance. In: K. Rohde ed. CSIRO, Sydney, Australia. pp. 414-421.

Interpretive Summary: Seabirds are highly visible and significant members of marine ecosystems. They are widespread geographically and in an ecological context are generally second and third-level predators in marine environments. Due to their ecological associations, food habits and migratory paths, such birds can tell us important information about the state of oceanic systems. At the same time, parasites of these birds serve as elegant indictors of ecology. The highly intricate life history patterns for parasites are predictable. We can use this predictability to recognize changes in marine environments based on both natural and anthropogenic events. Host and geographic ranges for parasites are historically constrained by genealogical and ecological associations, and these determinants interact resulting in characteristic and predictable community structure and biogeography. Understanding or predicting the range of possible effects that parasites may exert on seabirds, across the continuum linking individuals, populations, species and complex communities, requires a biodiversity context.

Technical Abstract: Seabirds are significant and conspicuous components of marine ecosystems occurring on estuarine, neritic and pelagic habitats encompassing latitudinal extremes from the Southern Ocean to the north polar seas. Collectively in excess of 300 species are represented among 6 orders including the Podicipediformes, Gaviiformes, Sphenisciformes, Procellariiformes, Charadriiformes and the paraphyletic 'Pelecaniformes;' Anseriformes is excluded here. Obligate seabirds, those that only return to land for reproduction and forage exclusively at sea, characterize 4 orders consisting of penguins, the albatrosses, shearwaters and petrels, the auks and some larids, and the assemblage of shags, tropicbirds, frigatebirds, gannets and boobies. In contrast, facultative seabirds such as pelicans and cormorants, many larids, the grebes, and the loons may breed adjacent to inland freshwater systems while dispersing into coastal marine zones over the winter. Marine birds are typically highly vagile, secondary and tertiary predators that occupy specific geographic ranges and habitats, show site fidelity for reproduction, and often follow predictable migratory paths linking breeding and wintering grounds. As a consequence seabirds are excellent indicators of the state of marine ecosystems on short and long time scales. Parasitic helminths are elegant markers of contemporary ecology and the stability of trophic linkages for marine birds. Dependence on an array of intermediate, paratenic, and definitive hosts indicates that each parasite species represents an assemblage of organisms within a community and tracks broadly and predictably across trophic levels. Host and geographic ranges for parasites are historically constrained by genealogical and ecological associations, and these determinants interact resulting in characteristic and predictable community structure and biogeography. Understanding or predicting the range of possible effects that parasites may exert on seabirds, across the continuum linking individuals, populations, species and complex communities, requires a biodiversity context.

Last Modified: 9/20/2014
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