The main objectives of the SCANS-II
1. To determine the absolute abundance of small cetacean populations
2. To develop and test methods to monitor cetacean populations
3. To develop a framework for management
To determine the absolute abundance of small cetacean populations, particularly of harbour porpoise (Phocoena phocoena), bottlenose dolphin (Tursiops truncatus) and common dolphin (Delphinus delphis) inhabiting shelf waters of the Atlantic margin, the North Sea and adjacent waters.
In addition to the area surveyed during SCANS, this project will also cover continental shelf waters to the west of Britain, Ireland, France, Spain and Portugal. The northern boundary will be approximately 62° N and the southern limit will be the boundary of the region covered by the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic Area (ACCOBAMS). The map shows the extended survey area of SCANS-II compared to SCANS area; species likely to be encountered are shown here.
To estimate absolute abundance, a combination of shipboard and aerial surveys will be carried out in July 2005. Both visual and acoustic survey methods will be used to detect cetaceans on the shipboard surveys The visual data collection and analytical methods developed for SCANS (Borchers et al. 1998; Hiby and Lovell, 1998) will form the basis for this project to maintain consistency and comparability but methods will be revised to incorporate recent developments for shipboard (e.g. Palka and Hammond 2001) and aerial surveys (Hiby, 1999).
Technical advances in the construction and deployment of passive acoustic arrays in recent years mean that, with some further development, this methodology could provide a reliable means of monitoring harbour porpoises and other species, and aid in absolute abundance estimation. Visual and acoustic methods will be standardised and shipboard protocols tested during an experimental survey in spring 2005, which will also be used for training and testing equipment and methodologies.
2.To develop and test methods to monitor cetacean populations
An essential part of long-term management of cetacean populations is a robust and cost-effective means of monitoring relative abundance between major decadal SCANS-type surveys. SCANS-II will develop and test potential methods, which may include the use of passive acoustics and vessels of opportunity, and recommend a suite of monitoring protocols tailored by species and area.
3.To develop a framework for management of bycatch
The information on abundance is essential to assess the impact of bycatch and other anthropogenic threats to cetacean populations. SCANS-II will develop a management framework based on abundance estimates and other available information to enable conservation objectives to be met in the short and long-term.