The Marine Mammal Programme at the Prince Edward Islands: 38 years of research

Abstract

The Marine Mammal Programme (MMP) conducts research on pinnipeds and killer whales at Marion Island, Prince Edward Islands, under the auspices of the Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria. The early history of the MMP is described, emphasizing the contributions in subsequent years, ending with current research. The setting up of long-term studies such as the mark-resighting of southern elephant seals Mirounga leonina was implemented in 1983. The varying fates of the three seal populations are described, with the Marion Island elephant seal population declining by 87% from 1951 to 2004, followed by a change in growth rate in 1997 and a current increase. Sympatric populations of Subantarctic fur seals Arctocephalus tropicalis and Antarctic fur seals A. gazella breed at Marion Island and the recovery (following cessation of commercial sealing) and subsequent rapid increase of these populations are documented. Insights into many aspects of elephant seal and fur seal biology, including life-history, demography, diet, growth, foraging and ranging behaviour are described.Ancillary work on morphology, genetics, anthropogenic influences and rare events are mentioned, as well as the extent of current research that addresses population dynamics in an ecosystem context, i.e. to relate survival, fecundity and foraging success to environmental conditions. Presently, the response of the populations to increased abundance is gauged and investigations into the foraging ecology, maternal provisioning and diet of both fur seal populations reflect changes in the environment. Opportunistic, land-based photographic identification of killer whales (Orcinus orca) provide baseline population size, seasonal abundance and sociality data for the Marion Island population. Recent dedicated observations are used to quantify observer effort, improve sighting rates and to further our understanding of the 3 potential impact of the killer whale population on resident pinniped populations. The MMP benefits from collaboration with leading national and international researchers. The programme has a long track record of training postgraduate students, as evidenced by the reference list to the manuscript. Their endeavours in the field and completion of postgraduate studies make them ideal candidates to contribute to marine mammal science in South Africa. October 1951-April 1952 published the first scientific papers on the seals of the island (Rand 1955(Rand , 1956(Rand , 1962, followed by Le Grange (1962) (Condy et al. 1978) was elaborated on in an opportunistic fashion (Keith et al. 2001). Throughout, personnel were also alert to seal vagrants (Kerley 1983a) or transients hauling out, sightings of cetaceans (Condy and Burger 1975, Ryan and Bester 2008, fur seal females successfully rearing twin pups Kerley 5 1983, de Bruyn et al. 2010) and extraordinary leucistic individuals (de Bruyn et al. 2007, Reisinger et al. 2009). Terrestrial feeding events by fur seals (Hofmeyr and Bester 1993, ...

First confirmed record of a leucistic Antarctic fur seal pup born outside the Scotia Arc Islands

“…Fur seal populations at Marion Island are closely monitored as part of the Marion Island Pinniped Monitoring Programme (Bester et al 2011). The leucistic individuals described here were all observed at Landfall Beach, MI (Fig.…”

“…(Bonner 1968). The pup weaned successfully in April 2011, but was subsequently never resighted despite extensive field researcher presence through intensive multi-species seal research at MI (de Bruyn et al 2007, Bester et al 2011. A leucistic adult female was recorded during the breeding seasons of 2006/2007, 2007/2008, 2009/2010, 2010/2011 and 2011/2012 at Landfall Beach ( Fig.…”

Multiple occurrences of king penguin (Aptenodytes patagonicus) sexual harassment by Antarctic fur seals (Arctocephalus gazella)

“…Considering the extraordinarily high observer effort of marine mammal field personnel at Marion Island over the past three-and-ahalf decades (Bester et al 2011), the observation reported by de Bruyn et al (2008) Determining the drivers of the unusual behaviour described here is nearly impossible.…”

Trends in tagging of marine mammals: a review of marine mammal biologging studies

“…Of course, technological improvements allow for answering new questions, and therefore require new deployments of suitable instruments, and in some cases ongoing deployments of appropriate devices are pursued in the context of long-term monitoring programmes (e.g. Bester et al 2011). However, there is a substantial amount of marine mammal biologging data among researchers across the world that could support new research.…”