The Conservation Services Programme, within the Marine Species and Threats team, Department of Conservation, recognise that Government Fisheries Observers on commercial fishing vessels are not always able to identify protected cold-water corals at sea with high precision (especially down to the species level), with the confirmation of bycaught species requiring identification from a coral taxonomist in the majority of cases.
Building on the description of the protected coral specimens identified and presented in the April and July 2017 Progress Reports, this Final Report summarises the sample identifications for the year ending 31 October 2017, and includes coral identifications made by visiting gorgonian octocoral expert Dr Phil Alderslade (CSIRO). A total of 169 specimens were identified to finest taxonomic level possible and appropriate updates made to the Centralised Observer Database (COD). Sample processing is on going and the number of coral tissue samples held in storage for future genetic studies now numbers 26.
The identification of protected corals from digital images provided by Observers are also described. There were 163 images identified and 112 protected coral images geo-referenced. Efforts were made to use trip number and image properties (date, time), to help populate the data poor images with georeferenced information. The instructions to Government Observers on methods to capture images at-sea will be stressed via the MPI Observer Programme.
Interactions between corals collected and fishing gear are summarised. Several protected coral samples have been returned from both within the New Zealand Exclusive Economic Zone as well as the High Seas Fisheries Management Areas. Of the samples received, and digital images processed,
bottom trawling in all regions has contributed to the highest counts of coral mortality. Coral by-catch samples were also returned from long line tows but in lower numbers.
Recommendations are made in this report to help improve the at-sea image data labelling and to automate the image geo-referencing workflow. Potentially the process of geo-referencing could be made more robust by adding business rules for metadata validation. We also highlight the numbers of protected corals that have been identified from the High Seas regions.
Tracey, D., Mills S., Macpherson, D., Thomas, H. (2017). Identification and storage of cold-water coral bycatchspecimens. Final Report prepared by NIWA for the Conservation Services Programme, Department of Conservation. INT2015-03. NIWA Client Report 2017349WN. 38 p.