2013 Antarctic Blue Whale Voyage to the Southern OCean

Brief description

This metadata record is a parent for all data collected during the 2013 Antarctic Blue Whale Voyage. Description of specific data sets can be found in the Voyage Science Plan and within child datasets.

Lineage

Progress Code: completed

Statement: Not applicable

Notes

Purpose
The Australian Government sponsored the 2013 Antarctic Blue Whale Voyage to develop methods and initiate research that will lead to a new estimate of abundance for blue whales (Balaenoptera musculus intermedia) in the Southern Ocean. Commercial whaling decimated this species, and the state of its recovery is currently unknown. The 65-m FV Amaltal Explorer was chartered for a 47-day voyage leaving from and returning to Nelson, New Zealand and conducting studies in Antarctic waters between 135 degrees E and 170 degrees W. This voyage was conducted as part of the Antarctic Blue Whale Project (ABWP) of the Southern Ocean Research Partnership (SORP). SORP is a consortium of ten countries working together on six collaborative research programs under the auspices of the International Whaling Commission (IWC). The 2013 voyage was conducted by Australia in the expectation that it would be the first in a series of such voyages by SORP partners that would, collectively, produce a new estimate of abundance for Antarctic blue whales. The main purpose of the 2013 Antarctic Blue Whale Voyage was to evaluate methods that can be used to estimate blue whale abundance and to initiate the collection of necessary data. Prior research shows that mark-recapture methods using photographic and genetic identification may be the most cost-effective method to estimate Antarctic blue whale abundance (Kelly et al. 2012). However these methods depend on the collection of sufficient identification photographs (photo-IDs) and biopsy samples. Blue whales make extremely loud, low frequency sounds that travel for hundreds of kilometres, and can be used to find areas where blue whales are concentrated. The 2013 Voyage was designed to test whether acoustic detection and localisation of blue whales can facilitate the collection of an adequate sample of photo-IDs and biopsies to serve as a foundation for a new estimate of Antarctic blue whale abundance. A list of eight prioritised objectives was developed for the 2013 voyage: Objective 1. To assess and refine passive acoustic methods for locating Antarctic blue whales Objective 2. To collect photographic data and biopsies for individual identification of blue whales Objective 3. Linking blue whale calls to their behaviour and environment Objective 4. Collect distance sampling data for regional abundance estimate of cetacean species Objective 5. Deploy satellite tags to describe the movement and behaviour of blue whales Objective 6. Collect Antarctic krill (Euphausia superba) for krill ecological genomics study Objective 7. Testing of kite-antenna for improved sonobuoy radio reception Objective 8. Evaluate the body condition of humpback whales from biopsy samples All eight objectives were met. Most importantly, disposable directional hydrophones (DIFAR sonobuoys) were able to detect concentrated areas of blue whale abundance at distances of hundreds of kilometres. Following acoustic bearing angles, these concentrations of Antarctic blue whales were located and sampled. Photographs of 57 individuals and biopsy samples from 23 individuals were obtained from the Amaltal Explorer and an outboard-powered launch. Approximately thirty hours of detailed behavioral data were collected to help link acoustic behavior to a broader context of Antarctic blue whale behavior. Rigorous sighting surveys detected 39 sightings of 84 individual Antarctic blue whales in 10 595 km of searching in the survey area (530 sightings of 1 313 all species of cetaceans, including Antarctic blue whales). Two satellite tags were deployed on Antarctic blue whales, the first in history. Over 100 Antarctic krill were collected for a study of krill population genetics being conducted at the Australian Antarctic Division. A kite-antenna was tested, and sufficient information was obtained to suggest design changes to the system which would enable the improvement of sonobuoy radio reception. Finally, eight biopsy samples were obtained for a study of humpback whale nutritional condition at Griffith University.