Category Archives: UC News

Secret lives of killer whales explored

A series of recording devices will be deployed in Antarctica this summer to explore the secret lives of killer whales in an unprecedented monitoring programme.

University of Canterbury PhD student Alexa Hasselman is preparing for her first Antarctic field season with Gateway Antarctica this summer. In an expansion of Gateway Antarctica’s ongoing Antarctic top predator programme in the Ross Sea  the recording devices  will monitor the species for four-weeks,  24 hours a day.

As top predators, killer whales are sentinels for the Ross Sea ecosystem. More specifically, tracking their interactions with one commercially important prey species in particular, the toothfish, is critical to supporting the recently announced Ross Sea region Marine Protected Area (MPA) established under the auspices of CCAMLR.

Gateway Antarctica’s work is leading the effort to meet New Zealand’s commitment to study top predators such as killer whales under that agreement. Alexa’s work adds a key capability  says  field team leader Dr Regina Eisert,  who is Alexa’s supervisor at Gateway Antarctica.

“Establishing a passive acoustic monitoring network is a critical step in getting the data we need to effectively protect the Ross Sea.” 

The research team includes two acoustics experts, Dr Andrew Wright, also of Gateway Antarctica, and UC’s College of Engineering Associate Professor Dr Michael Hayes.

Alexa says the New Zealand-made devices will be recording the sounds made by killer whales, and other marine mammals, for several weeks at multiple locations.

“The recorded sounds give us the ability to study animals all day and night, even at times when we cannot be in the field. This will provide a comprehensive record of the various patterns of the whales’ movements, and explore whether Antarctic killer whales have a regular daily schedule.”

In addition to supporting the MPA, this information will direct other work by Gateway Antarctica, specifically the deployment of non-invasive satellite transmitters onto the whales.

The wider initiative, funded through United Nations Environment Programme and a Pew Marine Conservation Fellowship to Dr Eisert, aims to provide further information about the ecology of Antarctic killer whales and other top marine predators, and the connectivity between the Ross Sea and New Zealand.

Whales, dolphins and porpoises – sleeping with half a brain

Every wondered how and where whales, dolphins and porpoises sleep?

New work by Gateway Antarctica’s Andrew Wright released this week reveals, for the first time, sleeping during diving in harbour porpoises. Part of his PhD work in Denmark before coming to the University of Canterbury, Andrew attached behavioural loggers to porpoises and found a new type of dive in the data obtained. The dives are slow, low energy and low in echolocation clicks – the biosonar that porpoises use to find food.

Cetaceans (whales, dolphins and porpoises), sleep with only half their brain at a time because they spend their lives underwater and must return to the surface to breathe. This unusual behaviour is also seen in many migrating birds that sleep on the wing. Yet life underwater means that we know little about sleeping in wild cetaceans. Applying behavioural criteria for sleep developed in terrestrial mammals to behavioural data from tags, Andrew identified a roughly semi-circular dive form that measured up. Stereotypical in not only dive shape, but also the swimming movements throughout the dive, the dives are typically quiet. This discovery means raises the possibility that animals sleeping at depth might be more susceptible to becoming entangled in fishing nets set at those depths because they are not echolocating.

The work raises some interesting possibilities for resolving the conflict between fishermen and cetaceans around the world, including New Zealand’s own Maui dolphin. For example, it may be possible to reduce entanglement rates if fishermen can avoid setting nets at the depths that the porpoises and dolphins sleep at.

“Although the dives make up less than 10% of all the activities for each animal, even small reductions in fisheries bycatch can make a big difference to the long-term survival of many endangered cetacean species,” notes Andrew.

However, the finding also has implications for scientists themselves. The use of passive acoustic monitoring technologies are becoming commonplace. Detecting marine mammal sounds as the whales and dolphins swim past, such devices were thought to be able to detect all porpoises as they were believed to produce clicks at all times. However, the existence of quiet dives means than not all animals will necessarily be detected. This means the finding also has implications for industries relying upon passive acoustic monitoring to protect marine mammals from harmful effects, such as the oil and gas industry.

Sustainability Awards winners

Chloe from the UC Sustainability Office has followed up with some of the winners from the 2017 Sustainability Awards! Held as part of Sustainapalooza, the Sustainability Awards celebrates all things sustainable within our university community. These awards recognise student and staff efforts to improve the world around us, and make UC a part of that journey. Enjoy the student and staff videos, and learn about the work that is being done here at UC, and further afield!

Student awards:

  • Fair Trade Diamond Award: Selva Ganapathy and Joyce Chen – Fog Water Harvesting Project
  • Silver Student Award: Jackson White – The Solar Project
  • Gold Student Award: Robbie Murray and Ben Murton – representing the Shell Eco Marathon Team

Staff awards:

  • Supreme Award: Glynne Mackey – Sustainability and social justice in Early Childhood  / Teacher Education.
  • Gold Academic Staff Award: Catherine Febria representing The CAREX team.
  • Silver General Staff Award: Mark Homewood, RRSIC Stormwaters Treatment.