FRESHWATER FISHING IN SEABIRDS FROM THE SUB-ANTARCTIC KERGUELEN ISLANDS

• Main Authors: Cook, Timothée R., Davaine, Patrick
• Other Authors: Centre d'Études Biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: Kerguelen Shag; Phalacrocorax verrucosus; Salmonidae; Gentoo Penguin; Pygoscelis papua; Kerguelen Islands; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.ES]Environmental Sciences/Environment and Society; Antarctic; Kerguelen; Antarc*; Gentoo penguin
• Online Access: https://hal.science/hal-00527100

International audience Salmonid fish were introduced into the freshwater ecosystems of the sub-Antarctic Kerguelen Islands between 1955 and 1992. Before that period, those ecosystems were free of freshwater fish. Because of the absence of competition and other factors, the various populations of salmonid fish increased exponentially soon after their first successful introductions. Field workers have been monitoring the populations of salmonids over a period of 40 years. Here, we present a summary of observations by those field workers of seabirds foraging on freshwater fish. Observations show that several seabird species benefit from the fish. However, although the density of fish is extremely high, the numbers of seabirds actually exploiting them remains low. Simple calculations show that seabirds probably do not affect freshwater fish demography significantly. The discrepancy between the numbers of seabirds freshwater fishing and the numbers of fish present could result from difficulty of access for seabirds to this potential resource.