The Past and Present Impact of Oil Pollution on Seabird Mortality World-wide.

Abstract

The impact of oil pollution on seabirds has been widely reported in the ornithological literature. We reviewed the worldwide mortality of seabirds resulting from oil spills occurring from the 1960s to the present. Oil spills were classified as either 1) accidental, or 2) chronic. Among accidental oil spills from ships, oil terminals or pipelines, oil spills from ships were the commonest, with 43 events. Following the increasing use of supertankers for oil delivery, the spill volume from recent accidental spills sometimes outweighs the total annual spill volumes recorded during the 1970s. The spill volume of an event is only weakly correlated with the degree of impact on seabirds, as has previously been reported, because depending on the time of the year and the location, even a small amount of oil can have a great impact on seabirds, as was the case along the Norwegian coast in 1979. A few studies have estimated the total numbers of seabirds dying by taking into account the proportion of carcasses that sink, and the persistence rate of carcasses along coasts. Many studies have claimed that determining the impact of oil spills on seabird populations is fraught with difficulties, unless information on pre-spill status is available for targeted populations. Sources of chronic oil pollution include the discharge or dumping of oil polluted water or waste oils from ships, oil tanks or pipelines. Although chronic oil pollution has

Assessing Seabird Mortality From Chronic Oil Discharges at Sea

“…The absence of a strong relationship between spill volume and seabird mortality points to the necessity of thoroughly investigating impacts of smaller spills . Concerns have been raised that chronic small spills may kill as many seabirds as do more widely publicized large spills, and chronic spills may be equally, or more, detrimental to long-term population stability (Hunt 1987, Camphuysen 1989, Burger and Fry 1993, Oka et al 1999. Our results confirm this concern.…”

Status of Seabirds Breeding in Hokkaido.

“…Recently, oil spills of ships have become occasional serious factor to local population of seabirds (Burger & Fry 1993, Oka et al 1999. In 1996, the Nakhodka (Russian tanker) oil spill in Japan Sea killed 2,800-3,500 Rhinoceros Auklets at sea (Nippon Foundation 1998, Japan Alcids Group 1998), although serious effect to its breeding population on Teuri Island was not reported.…”