| Title | Benthic‑bycatch dataset from Prince Edward and Marion Islands longline fisheries (2009‑2023) |
|---|---|
| Authors |
Filander, Zoleka Somhlaba, Sobahle Makhado, Azwianewi |
| Publisher | Department of Forestry, Fisheries and the Environment (2025) |
| Contributors |
Contact Person: Filander, Zoleka |
| Abstract | This dataset presents a time series of benthic invertebrate bycatch records collected during pelagic longline fishing operations targeting Patagonian toothfish (Dissostichus eleginoides) in the Prince Edward Islands region of the sub-Antarctic Southern Ocean from 2009 to 2023. The data were obtained from independent scientific observers aboard commercial vessels in accordance with Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) Conservation Measure 22-06, which mandates the reporting of taxa associated with Vulnerable Marine Ecosystems (VMEs). Each record includes an entry number, observer segment unique identifier, vessel unique identifier, observer logbook number, year the record was collected, line segment number, taxonomic code as given in 2009 CCAMLR VME guide, associated taxonomic name, bycatch weight at random segments per fishing line/set, gear type used, number of fishing hooks used at the specific segment, and anonymous vessel number. The dataset comprises 1,817 records spanning 32 benthic morphotypes. The raw dataset has not been validated and therefore dubious records exist. Nonetheless, Filander et al (2025) curated it for reusability and it's intended to support ecosystem-based fisheries management as reflected in CCAMLR Conservation Measure 22-06 and 22-07 notwithstanding the exemptions given to the area by CCAMLR, trait-based vulnerability assessments, and refinement of benthic threshold detection protocols under CCAMLR frameworks. |
| Methods | The sampling approach used by observers involves monitoring a designated section of each longline, which is required to be divided into segments of either 1,200 meters or 1,000 hooks, as outlined in Conservation Measure 22-07. Prior to hauling, the observer randomly selects 50% of these segments for identification, weighing, and counting the taxa. Thus, approximately 50% of the benthic bycatch from these random segments forms the basis of each observer’s report. The data presented here are derived from such treated observational records, which were collected by fisheries observers between 2009 and 2023 aboard longline vessels targeting Patagonian toothfish in the waters surrounding the Prince Edward and Marion Islands. See Filander et al. (2025) for quality check and validation steps taken. |
| Data | |
| Temporal extent | 01 Jan 2009 – 31 Dec 2023 |
| Geographic extent |
Marion and Prince Edward Islands
North: -45.8 |
| Keywords | benthic invertebrates , by-catch , EBV: Species Populations > Species abundances , EBV: Species traits > Morphology , EOV: Biology and Ecosystems > Invertebrate abundance and distribution (emerging) , monitoring , Pantagonian toothfish , SOUTHERN OCEAN |
| Related resources |
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