Counts of seabirds around commercial fishing vessels within New Zealand waters, 2007–08 to 2018–19

Citation

Richard, Y., Abraham, E. R., & Berkenbusch, K. (2020). Counts of seabirds around commercial fishing vessels within New Zealand waters, 2007–08 to 2018–19. (Unpublished report held by the Department of Conservation, Wellington.). Retrieved from http://files.dragonfly.co.nz/publications/pdf/Richardetal_2020_seabird-counts.pdf

Summary

Many seabird species are experiencing a global decline, with incidental mortalities in commercial fisheries considered one of the main causes. While the high seabird diversity in New Zealand waters has been widely recognised, the distribution of many species remains largely unknown. In addition, current estimates of seabird bycatch within New Zealand's Exclusive Economic Zone lack distribution data for the majority of species, with model estimates based on the assumption that seabird distributions are spatially uniform, at least within large areas. Statistical bycatch models could be greatly improved if observed captures could be related to the number of seabirds present around fishing vessels.

Counts of the number of seabirds present around commercial fishing vessels in New Zealand waters have been carried out by government observers in a relatively consistent framework, and recorded on paper forms. Another type of counts by observers were recorded on Nomad electronic devices under a different protocol. The data from 2007--08 to 2018--19 in both datasets were processed and groomed to correct inconsistencies and mistakes made during the data collection. Here, a summary of seabird abundance and distribution data are presented, including comparisons of observer data with other data sources. Some preliminary exploration of the data is also presented, including its limitations and suggestions to improve the value of data collected in the future. Furthermore, an Internet website was created to make the dataset publicly available, including distribution maps of seabirds by species or species group within New Zealand's Exclusive Economic Zone.