The results of the third annual survey of entanglement of Antarctic fur seals at Signy Island, South Orkney Islands are reported for the 1998/99 summer season. There were ten sightings of seals wearing neck collars of man-made debris, although one individual was observed twice and another observed on three separate occasions. Two additional sightings were of animals that had been previously entangled but had lost their collars by the time of observation. All of the animals involved were juvenile males, the main component of the population at this time of year. The number of sightings increased by 66% since the previous season but was 17% lower than 1996/97. Data are compared with results from a parallel study undertaken at Bird Island, South Georgia in 1998/99. These indicated that the number of entangled fur seals had also increased (by 84%) since 1997/98 and decreased (by 8%) since 1996/97. Packaging bands and synthetic line were the main entangling materials at both sites although a greater proportion of fur seals was entangled in packaging bands at Signy Island (67%) than at Bird Island (38%). Entanglements in packaging bands at Signy Island were 47% higher than the previous season. There were no reports of entanglements in fishing net. 'Severe' and 'very severe ' injury was being caused to 70% of animals at Signy Island (25% at Bird Island). This suggests that the majority of fur seals had been entangled for some time before arriving at Signy Island and had most likely been entangled in other areas, such as South Georgia, where fishing activity is higher. The continued presence of packaging bands despite the CCAMLR restrictions imposed since 1995/96 may be due to their persistence in the environment or to illegal un-monitored fishing activity. The prevalence of synthetic line is also a cause for concern. CCAMLR needs to continue monitoring the incidence of entanglement and enhance its campaign against the disposal of debris at sea.
Abstract:
Results of the survey of entanglements of Antarctic fur seals at Bird Island, South Georgia for the ninth consecutive winter (1998) and eleventh consecutive summer (1998/99) are reported here. The number of seals observed entangled in the winter (13) represented an 86 % increase on the 1997 winter total and an 87 % decrease on the highest previous total (1992). The proportion of animals showing severe injuries was 39 %, up threefold on the 1997 winter and the third highest total since records started. Two animals (15 % ) were entangled in polypropylene straps, down by 50 % on the 1997 winter and the second lowest level (with 1995) since records started. The number of seals observed entangled in the summer (24) was the fourth lowest total recorded, being 84 % more than the 1997/8 summer but 88 % less than the highest previous total (1988/89). The proportion of adult animals affected (8 %) was down by half on the previous summer and represents the lowest adult total recorded. The proportion of animals showing severe injuries (30 %) was a contrast to 1997/98 when none was noted. Entanglements in polypropylene straps was the third lowest recorded, up 29% on 1997/98 but 93% less than the highest total of 1988/89. Overall occurrence of entanglement in summer and winter is still down by 80-90 % in comparison to the early 1990's, with summer adult and net fragment incidences at their lowest since recording began. Polypropylene strap incidences have decreased slightly (35 %) since CCAMLR prohibition on their use (1994) but severity of entanglement was increased. Synthetic string incidence is at its highest level since recording began. This highlights the need for sustained monitoring and continuing publicity aimed at preventing the disposal of debris at sea.
