Critical aspects of the Falkland Islands pelagic ecosystem: distribution, spawning and migration of pelagic animals in relation to oil exploration

1. The oceanography and topography of the southern Patagonian shelf, with the strong Falkland current deriving from the Antarctic Circumpolar current moving northwards both west and east of the Falkland Islands, creates an area of very high zooplankton productivity immediately to the north of the islands. 2. Information on the distribution, spawning times and larval distribution of the most important fish and squid species is reviewed in this paper. High densities of macroplanktonic euphausid and hyperiid amphipods, especially in the summer, attract and sustain squid stocks (the pelagic Illex argentinus and bentho‐pelagic Loligo gahi) and pelagic fish (Micromesistius australis and Sprattus fuegensis). 3. There is an important spawning ground for three fish species having pelagic eggs and larvae (Micromesistius australis, Salilota australis and Sprattus fuegensis) on the shelf break immediately to the south and southwest of the Islands. The shelf surrounding the islands, and west and south towards the Argentine coast, forms a nursery area for the larvae of these and a number of other fish and squid species. 4. Pollution emanating from the oil exploration tranches to the north of the islands or oil‐based activities on the north shores of the Islands, although coincident with the area of high plankton productivity, would be unlikely to affect, in any major way the pelagic ecosystem around the Falkland Islands unless it became entrained in the area of slack water to the north of East Falkland. However, water flows from the Special Co‐operation Area over critical spawning areas for a number of fished species (red cod, southern blue whiting and L. gahi) and has the potential to affect not only these but the Falkland shelf waters which act as a nursery area for many marine species. Copyright © 2002 John Wiley & Sons, Ltd.