Distribution of South American fur seals along the Atlantic coast of South America.

TÚNEZ JI.; CAPPOZZO HL.; CASSINI MH.

Brisbane

Congreso; The 10th International Congress of Ecology, INTECOL. Ecology in a Changing Climate. Two hemispheres - One globe; 2009

Breeding colonies of the South American fur seal, Arctocephalus australis are not homogeneously distributed along the coast of the Atlantic Ocean but they show an unusual patchiness, with colonies located only in the northern and southern extremes of the breeding range. We used bibliographic data of censuses carried out about the middle and at the end of the XX century and a Geographic Information System to: (1) compare the pattern of distribution of colonies in these two periods, and (2) identify the anthropogenic and natural factors associated with the present pattern at a regional scale using a Principal Components Analysis. The distribution of colonies did not vary in the period of time analyzed even when population abundance increased tenfold. This distribution was associated with distance to the continental shelf break, availability of island and protected zones. We concluded that A. australis colonies are located in places with a narrow continental shelf, and without human disturbance. We compared the pattern of distribution of A. australis with those of other species of fur seals distributed around the Southern Hemisphere.