A characterisation and catch per unit effort (CPUE) analysis were carried out for the South Island commercial freshwater eel fishery for fishing years 1990–91 to 2018–19. Analyses were carried out for shortfin (Anguilla australis) and longfin (A. dieffenbachii) eels individually for all nine South Island Eel Statistical Areas (ESAs AN–AX).
The present study provides an investigation of the relationship between cockles Austrovenus stutchburyi and sediment grain size across northern North Island sites. Using data from five years of monitoring for principal component analysis and the modelling of cockle population abundances as a function of grain size fractions revealed relatively small changes in sediment properties across sites over time. None of the changes were sufficient to notably affect cockle abundance at the study sites.
In 2019–2020, 458 study burrows were monitored within the Great Barrier Island/Aotea study area with 63.1% occupied by breeding pairs and fledging success was 76.5%. Pre-laying foraging trips by 10 adults were 30 days long on average and highly variable. Birds ranged far to the east, west, and north of Aotea and breeding birds made significantly longer trips than non-breeding birds. Distance sampling estimated there were 3130 breeding black petrels within core medium-grade habitat above 300 m.
A simulation testing framework was developed to evaluate and compare the performance of harvest control rules (HCRs) for 4 scampi stocks SCI 1, SCI 2, SCI 3, and SCI 6A. The harvest control rule evaluation (HCRE) framework uses CASAL stock assessment models as operating models and projects the simulated populations forward by applying an HCR each year to determine total annual catch. The framework is generalised and can be used with any CASAL model that has at least one CPUE index to project.
This report describes bycatch of non-protected invertebrates from commercial fisheries and research trawls. Over 660 distinct taxa were identified which contribute to the ongoing discovery and taxonomic description of the New Zealand biodiversity. Specimen records and distribution points inform fisheries interactions with non-target benthic invertebrate bycatch and contribute to research on spatial planning and development of ecological risk assessments of fishing impacts on benthic habitats.