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Summary
Protected coral species frequently occur as bycatch in commercial fisheries around New Zealand. Accurate knowledge of the species diversity of coral bycatch is essential to facilitate their management and conservation and help to further understand how vulnerable they are to anthropogenic impacts. The Conservation Services Programme (CSP) of the Department of Conservation (DOC) recognise that Government Fisheries Observers on commercial fishing vessels are not always able to identify bycatch at sea with high precision (especially to species level), with the confirmation of species requiring identification from a coral taxonomist in many cases.
This project facilitates, through the examination of returned coral specimens and specimen digital images by experts, confirmation of the taxon and the provenance of corals bycaught in New Zealand fisheries. This report, covering the third and final year of a three-year contract, summarises the sample and image identifications of all observed coral bycatch that was returned during the period 1 July 2024 to 30 June 2025. A total of 25 physical specimens (in 25 samples) were collected by Observers and returned for identification during the reporting period. Twenty subsamples from live-caught specimens with sufficient live tissue were taken for future genetic studies. Additionally, there were 19 historical physical specimens (from 18 samples) collected by Observers prior to 1 July 2024 for which revised higher-level identifications were made during the reporting period. Identifications for a further six research trawl-collected specimens in six samples are also reported here.
There were 6162 specimens identified from 125 digital images and one digital video file that were processed during the reporting period; 6145 were identified by experts as protected coralvtaxa. The remaining 17 specimens from images were of other, non-protected coral, taxa. The location of capture of all specimens from images was able to be determined (i.e. all files were able to be georeferenced) and 6158 specimens were confirmed to be from within the New Zealand Exclusive Economic Zone (EEZ) (four specimens were from the Lord Howe Rise, beyond the EEZ).
Corrected identifications (where the Observer identification is revised by an expert) have been made where necessary in the COD database, with both the original and amended identifications retained. All raw data are provided in the Appendices of this report and as a separate Excel file.
Data summaries of protected coral bycatch occurring in New Zealand region fisheries are presented by Fisheries Management Areas (FMAs), fishing method, and target fishery. The greatest number of protected coral specimen counts from images came from SEC South-East Coast (FMA 3) and SOE South-East (Chatham Rise) (FMA 4) followed by CEE Central East (FMA 2) regions. Most were taken by bottom trawl operations targeting hoki, smooth oreo and orange roughy, although there were also few captures from bottom trawling, longlining and potting targeting ling, and bottom trawling alfonsino & long-finned beryx, scampi and several other fisheries. Similarly, most protected corals identified from physical specimens came from SEC South East Coast (FMA 3) management area (OEO 3A) bottom trawling for smooth oreo. The remainder were captured from SOE South East (Chatham Rise) (FMA 4) targeting smooth oreo, scampi and orange roughy, and CEE Central East (FMA 2) targeting alfonsino & long-finned beryx.
While no formal analyses of accuracy have been carried out during this reporting period, comparing Observer and Earth Sciences New Zealand expert identifications, brief nonstatistical summaries of accuracy are provided to help inform Observers.
As part of this project, Earth Sciences New Zealand hosted an in-person Observer refresher training workshop on New Zealand Aotearoa’s protected coral species in Wellington on 7 November 2025. Observers were shown examples of protected coral species using specimens from the Earth Sciences New Zealand National Invertebrate Collection (NIC) and following the descriptions and instructions in the updated Coral Identification Guide, shown how to characterise them and tell them apart from easily confused non-coral taxa.
Following prioritisation discussions with CSP, genetic analysis for this year of the project focused on identification and characterisation of the diversity of bycaught specimens of bubblegum corals (Paragorgia spp.). A review of all NIC holdings identified 69 Observer collected specimens of these species plus 12 reference specimens obtained through other means (research expeditions and fisheries research trawls) from SOE South East (Chatham Rise) (FMA 4) and SUB Subantarctic incl. Bounty Is and Pukaki Rise (FMA 6), which were targeted for genomic characterisation. Genome skimming was successfully conducted on 72 specimens (60 bycatch + 12 non-bycatch and reference specimens), including the holotypes of eight species. After assembly and matching to known UCE (Ultra-Conserved Elements) loci, 65 specimens retained sufficient data for diversity analyses. A phylogenetic analysis of these specimens indicated the majority of specimens were correctly identified as P. arborea and P. alisonae. However, significant genetic variation within these two species warrants fine-scale examination using population-genomic approaches, to determine if cryptic species are present. The remaining specimens represented occurrences of other rare species plus a potentially new or undocumented species but a lack of sufficient sample size made assessments of distribution patterns and taxonomic validity premature. Further genetic or genomic assessment of bubblegum corals are required but currently there is evidence for a minimum of six (possibly seven) species being represented among Observer-collected fisheries bycatch samples, four of which are represented in the focal areas FMA 4 and FMA 6.
Publication information
Macpherson, D., Bilewitch, J., Brooks, A., Connell, A., Mills, S., Smith, L., Wood, C. R. (2026) INT2022-03 Identification, storage and genetics of cold-water coral bycatch specimens. Milestone 9. Final Annual Report. Prepared for Conservation Services Programme, Department of Conservation. Earth Sciences New Zealand Client Report 2026101WN. 93p