Some background to the UCT Cape Otter Project:
River and wetland ecosystems are amongst the most threatened, yet most valuable systems worldwide. Habitat degradation through increasing urbanisation and water pollution are two of the largest threats to these systems, and to the animals dependent on them for survival. Of particular concern in urban areas is sewage, and the dumping or run off of waste into water ways. Sewage effluent contains industrial waste, municipal wastes, domestic waste, animal remains and faecal matter, all containing a variety of harmful substances including viral and bacterial pathogens, toxic chemicals such as organo-chlorines, poly-chlorinated biphenyls (PCB’s) and heavy metals. Toxic chemicals are known to enter the food chain and accumulate in the tissues of top predators, contributing to infertility, poor health and vulnerability to disease. Throughout the world, otters and other aquatic top predators have suffered population declines and even local extinctions due to exposure and subsequent bioaccumulation of toxic pollutants.
The Cape Clawless Otter (Aonyx capensis) occupies the role of top predator in the Western Cape’s aquatic systems and is a potentially important umbrella species for freshwater ecosystems. Listed as ‘Least Concern’ on IUCN’s Red List, it may also serve as an important flagship species and bio-indicator of water pollution throughout the Western Cape and South Africa. Within the Western Cape, the Cape Peninsula provides a microcosm of the current threats to otter survival with both urban and agricultural land transformation altering their natural habitat and both chronic and acute pollution events threatening their health. Presently there are no data on the biology, distribution and conservation status of otters in the Cape Peninsula and thus there are no baseline data upon which to assess the combined effects of habitat loss and pollution of aquatic ecosystems on the distribution, abundance and health of otters.
It is for this reason that UCT began a PhD project to study the otters in the Cape Peninsula. Their reliance on fresh water in an urban environment like the South Peninsula does put them at risk to exposure to pollutants and the loss of suitable habitat. In addition, the fact that they’re most active at dawn and dusk makes them difficult to monitor, and so any change in population size might not be noted until it is too late. Still in its early stages, the project aims to understand the spatial ecology of otters living in the Peninsula: how they use the urban space as opposed to the more natural, pristine areas; and most importantly to gain insight into how they are coping with the pollution loads in the urban rivers. Ultimately, by understanding the needs of an aquatic top predator, the project hopes to provide management recommendations for the conservation and sustainable use of the Peninsula’s rivers and wetlands, which in turn will benefit all species dependent on these systems for their survival.
As part of the data collection, we are asking for all sightings of otters to be reported to the Peninsula Otter Watch. The Peninsula Otter Watch coordinates otter sightings to monitor the presence of otters in the Cape. Please contact Nicola Okes with details of any otter sightings, injuries or deaths. If possible, please indicate: location, time, unusual behaviour or markings/injuries, what the otter was doing, and any other information you may have. Photographs and GPS positions of sightings are most welcome. Further information can be found and sightings can be submitted online at www.nicolaokes.co.za.
For the Full Circle article, please click here.
This project is supported by the following organisations: South African National Parks (SANParks), Cape Nature and the City of Cape Town. We thank them for their support, permission and assistance in the project as without them, the project would not be feasible.
A big thank you to the funders of the project: National Research Foundation (NRF) and the University of Cape Town;
And collaborating and interested parties: National Zoological Gardens