SANCCOB: a sound investment for saving seabirds
Marine oil pollution is a threat faced by many of the world's seabirds. Oil spills have become an all too frequent event around our coastline. Accidents, such as the sinking of the "Apollo Sea", a bulk ore carrier, off Dassen Island in 1994, tend to grab the headlines, but there are many incidents of oil discharge where the source of the pollution is never ascertained. This "chronic oiling" may account for as many oiled birds over time as the major accidents do.
Prevention of oil pollution is by far the best cure for the problem, but when oil spills do occur, it is good to know that southern Africa has a world leader in the successful rehabilitation of oiled seabirds to call on. The Southern African Foundation for Conservation of Coastal Birds, known to most of us simply as SANCCOB, has over 30 years of experience and an unrivalled record in successful rehabilitation of seabirds, and their restoration back into the wild. African Penguins Spheniscus demersus comprise the majority of the birds which have been treated, but SANCCOB can claim equal success with their rehabilitation of Cape Gannets Morus capensis.
In the Northern Hemisphere, the amount of money, time and effort that has been put into cleaning oiled birds has been in question. The results are not very encouraging. In North America, the median survival of Guillemots Uria aalge after cleaning and release was just 6-8 days (Sharp, B.E. 1996. Post-release survival of oiled, cleaned seabirds in North America. Ibis. 138:222-228)! This means that half of the released birds had died within this period. The situation in Europe is no better. In Britain and Ireland, median survival of the same species was found to be just seven days (Wernham, C.V., Peach, W.J. & Browne, S.J. 1997. Survival rates of rehabilitated Guillemots. BTO Research Report No. 186). Dispersal of released birds was also severely affected. The median distance moved by a cleaned Guillemot after release in Britain and Ireland was just 8 km, compared to a median distance of 496 km for a fully-grown non-oiled Guillemot (Wernham et al. 1997).
In contrast, SANCCOB have enjoyed a great deal of success in the de-oiling and restoration of African Penguins in particular. The short term success of SANCCOB's efforts can be seen by the proportion of released birds that return to the breeding colonies. An incident in July 1979 led to 150 African Penguins being sent to SANCCOB from St Croix Island, Algoa Bay. By February 1980, 87% of those released had returned to the island, some back with their mates and at nests (Randall, R.M., Randall, B.M. & Bevan, J. 1980. Oil pollution and penguins - is cleaning justified? Marine Pollution Bulletin. 11:234-237). The feat is even more remarkable given that the penguins were released from Robben Island, c. 900 km from St Croix Island.
The sinking of the "Apollo Sea" in June 1994 caused the oiling of c. 10 000 African Penguins. This one incident exceeded the total number of penguins received by SANCCOB during the years 1970-1991 combined! It is a great tribute to the staff and volunteers at SANCCOB that they were able to successfully clean and release about 50% of those birds. Since the release of the birds over five years ago, the Avian Demography Unit, Cape Nature Conservation and Marine and Coastal Management have followed the fortunes of the 4000+ penguins that were flipper-banded before release. Five years after the spill, 2961 (73%) of the released birds had been seen alive back at breeding colonies in southern Africa, and the number continues to grow. Fieldwork around Saldanha Bay in February 2000, revealed another four of these birds which had not been seen prior to their release in 1994. The 67 birds found dead (2% of those released) is in-keeping with the number of expected mortalities from a similar number of non-oiled penguins over the course of five years. Some of the survivors have undergone some interesting movements. S20711 was released in August 1994 and was present on Dassen Island in February 1996 and February 1997, before being seen 760 km to the north at Possession Island, Namibia, in November 1998. Another of the survivors S23236 was released at Robben Island as a juvenile on the same day as S20711. It was present on Mercury Island, Namibia in November 1995 before turning up at Stony Point, Betty's Bay in April 1999, a distance of 1100 km.
The long term survival of rehabilitated African Penguins was investigated in 1996. An analysis of flipper-banded penguins which had died within ten years of banding, showed that the median survival of rehabilitated African Penguins was 23 months (compared to 6-8 days for a Guillemot in the Northern Hemisphere) (Whittington, P.A. 1999. The contribution made by cleaning oiled African Penguins Spheniscus demersus to population dynamics and conservation of the species. Marine Ornithology. 27:177-180). Equally important was the finding that the long term survival of rehabilitated penguins was not significantly different from that of penguins which had not been treated at SANCCOB. This again differs markedly from Northern Hemisphere findings, where median survival of non-oiled seabirds could be anything from 30 to 50 times greater than that of cleaned oil spill victims (Sharp 1996). Re-sightings of flipper banded African Penguins show that 121 de-oiled penguins have survived for ten years or more following their release. The oldest of these was 24 years old when last seen at Dyer Island in October 1995. It is one of five rehabilitated African Penguins known to have attained an age of over 20 years old (Whittington, P.A., Dyer, B.M. & Klages, N.T.W. In press. Maximum longevities of African Penguins Spheniscus demersus based on banding records. Marine Ornithology).
Long term survival of rehabilitated penguins is very encouraging, but equally important is the question of whether they can be restored to the breeding population. Five years after the release of the "Apollo Sea" survivors, 1587 (39%) of the birds were known to have bred or attempted breeding. Cape Nature Conservation has been monitoring the breeding success of those survivors, along with other penguins which have not been oiled, on Dassen Island during the course of the past five years. During the two years following the oil spill, the de-oiled birds had a lower breeding success than the other penguins at times when feeding conditions were assumed to be poor. But in the past three years, there has been no difference in breeding success between the oil spill victims and non-oiled birds (Anton Wolfaardt & Deon Nel pers. comm.).
The above research on flipper-banded African Penguins has shown that the hard work of SANCCOB's staff and volunteers is making an important contribution towards the conservation of this endemic species, now listed as "vulnerable" under the IUCN red data criteria. SANCCOB can be justifiably proud of its achievements and deserves our full and continued support.