Australian population of fur seal pups decreases

A census of annual pup production in Australian fur seal populations has revealed the first reduction since the implementation of species-wide protection in 1975, according to a study published on September 5 in the US. open access journal. PLOS ONE by Rebecca McIntosh of Phillip Island Nature Parks in Victoria, Australia, and her colleagues. The study also shows that the Australian Fur Seal's long-term surveillance program has tracked population trends over time.

In the marine environment, monitoring the abundance and trends of populations of a top predator can provide measurements of ecosystem health and management success. Fur seals, Arctocephalus pusillus doriferusare important predators of the upper trophic level which, in Australia, are protected marine species facing specific problems related to the management of fisheries and aquaculture, ecotourism, potential impacts on birds For these reasons, it is important to obtain accurate information on their abundance and population changes. An ad hoc monitoring program coordinated by several stakeholders conducted a range-wide census of live young in the southern summers of 2002, 2007 and 2013. In the new study, McIntosh and his colleagues sought to determine whether the seal monitoring program is achieving its objectives of determining the abundance of small and estimating demographic trends.

The results reveal that surveillance of the Australian fur seal between the years 1970 and 2013 has indeed recorded population changes. The census successfully followed the signs of recovery of the population until 2007. In addition, the 2013 census identified the first decline in the small population, estimated at 4.2% per year since 2007, since the establishment of a protection at the scale of the species. According to the authors, the study underscores the importance of regularly evaluating long-term monitoring programs and provides valuable information on how to design and effectively improve these programs.

Roland Pick, of Phillip Island Nature Parks, notes: "As wildlife managers, it is important for us to regularly review our monitoring programs to review the reliability of the information collected and to identify improvements that can help to better understand any demographic change detected. We are currently using drone technology and citizen science programs at Phillip Island Nature Parks to enhance our monitoring of Seal Rocks as the largest breeding colony in the species. "

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More information:
McIntosh RR, Kirkman SP, Thalmann S, Sutherland DR, Mitchell A, Arnould JPY, et al. (2018) Understand trends in meta-populations of fur seal in Australia, with indications for adaptive surveillance. PLoS ONE 13 (9): e0200253. doi.org/10.1371/journal.pone.0200253