GSNZ Taranaki branch meeting
Celebrating Collaboration: Multibeam mapping an extensive mosaic of South Taranaki’s Sub-Tidal Rocky Reefs through Community and Scientific Outreach
presented by Karen Pratt
Without collaboration, mapping offshore reefs can be like “searching for needles in a haystack”. This presentation introduces the nationally recognised community science initiative, ‘Project Reef South Taranaki’ and how they came to be involved in a 250 km seafloor survey conducted by NIWA in 2020. We will also look at why the informally named ‘Project Reef’ (11km offshore of Pātea, 23m depth) was included in the multibeam survey.
The topographies of rocky reefs encountered during the 2020 multibeam survey will be shared - including long narrow rock ridges, some extending for kilometres, smaller scattered patch reefs and knolls and a larger raised reef complex. Fault-lines were evident for several of the reefs.
Footage from a 2021 ‘ground-truthing’ of a small subset of those reefs will be shown, revealing a series of complex seafloor geo- morphologies, often with many changes over short spatial differences.
Finally there will be consideration of how multibeam sonar data providing landscape variables such as seafloor slope, aspect, and roughness, at fine scales (tens of metres) can be matched to video segments, and how combined, these ecological and geophysical data-sets could be analysed to answer a range of fundamental questions about South Taranaki’s subtidal reefs.
The presentation will include findings from NIWA CLIENT REPORT ‘Offshore subtidal rocky reef habitats on Pātea Bank, South Taranaki, prepared for the Taranaki Regional Council, September 2022 of which ‘Project Reef South Taranaki’ is a contributor.