Independent Report
This report summarises the findings of the “Principles of Ecosourcing” project, conducted with funding from Te Uru Rākau – New Zealand Forest Service under Statement of Work C0036181. Project activities reported on here include:
• Review of existing ecosourcing literature, including consideration of the effects of climate change
• Interviews focussing on perceptions and drivers of ecosourcing and assisted migration
• Wānanga feedback sessions evaluating the representative nature of the information collected from the literature and interviews
This report presents the results of the updated trawl footprint in New Zealand waters within the Exclusive Economic Zone in waters open to trawling to a maximum depth of 1600 metres (fishable area).
Results are presented for the 1989–90 to 2021–22 fishing years for deepwater fisheries, and for the 2007–08 to 2021–22 fishing years for inshore fisheries, and combined inshore and deepwater (‘All stocks’) fisheries.
Statistics are presented on the measures of seabed contact for these groupings and include the area in square kilometres of the overall trawl footprints and aggregate (cumulative footprint) areas by year and all years combined. Other measures of contact also presented include the number of tows, the number of cells contacted (a 5 × 5 kilometre grid overlaid on the fishable area), and the number of ‘new’ cells contacted each year that had previously not been contacted.
This study also considered the above measures of contact when including midwater trawl used within five metres of the seabed and within ten metres of the sea bed. Methods were also developed to refine the placement of bottom-contacting trawl effort on underwater topographic features.
Results show that overall measures of contact have decreased in recent years for deepwater, inshore, and All stocks fisheries. Measures of contact increase little when including midwater trawl used within five metres and ten metres of the seabed. The development of methods to refine mapping of trawl effort to underwater topographic features shows promise but would benefit from external validation, perhaps through comparison with data held by the fishing industry.