Year: 1987
Type: article
Abstract: Did the 19821983 El Niilo-Southern Oscillation affect seabirds in Alaska?-The causes and effects of the oceanographic and atmospheric phenomena known as El Niiio and the Southern Oscillation (ENSO) have been studied intensively in recent years (Cane 1983, Rasmusson and Wallace 1983, Barber and Chavez 1983, Cane and Zebiak 1985).ENSOs occur at semiregular intervals of 3-4 years, and the stronger events have important biological consequences, including reduced breeding success and survival of seabirds in the central and eastern tropical Pacific (Boersma 1978, Barber and Chavez 1983, Schreiber and Schreiber 1984, Duffy 1986).The ENS0 event of 1982-1983 was perhaps the strongest of this century (Cane 1983) and there is evidence that seabird populations as far north as the Oregon coast (42-46ON) were adversely affected (Hodder and Graybill 1985, Bayer 1986).Here I examine evidence for similar effects on seabirds along the Alaskan coast.In 1983 there was widespread breeding failure among some surface-feeding seabirds in the Gulf of Alaska and eastern Bering Sea.The phenomenon seemed to be most pronounced in the Black-legged Kittiwake (R&a triductylu).Essentially, total breeding failure occurred at four kittiwake colonies visited in the Gulf of Alaska (Fig. 1) (Table l), and at two colonies in the Bering Sea (Table 2).A few young were raised at a colony in Norton Sound, however, and production appeared to be about average at Cape Lisbume in the Chukchi Sea.In addition to the observed breeding failure, there was widespread mortality of adult Black-legged Kittiwakes and Short-tailed Shearwaters (Pu@zus tenuirostris) in Alaskan waters during August and September 1983 (D. R. Nysewander and J. L. Trapp, unpubl.data).A. Middleton Island B.
Author: Scott A. Hatch
Language: English
Topic: Avian ecology and behavior
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life below water
Open Access status: green
OpenAlex ID: W2522917747