Mr Shawn Gerrity1
1Marine Ecology Research Group, University Of Canterbury, New Zealand, Christchurch, New Zealand, 2Professor David R. Schiel , Christchurch, New Zealand
New Zealand has one of the world’s few remaining wild abalone fisheries, but the long term viability of customary, commercial and recreational harvest faces numerous challenges. Although populations of blackfoot abalone (pāua, Haliotis iris) are robust in many management areas, some regions are experiencing declines in catch due to overharvest, illegal fishing, disturbances and habitat loss, resulting in dwindling quota allocation and closures to harvest. One region was forced to ban all harvest following the devastating 2016 Kaikōura earthquake and coastal uplift event, which left hundreds of thousands of pāua stranded, resulting in widespread mortality. Our work follows the recovery trajectory of this iconic fishery in the wake of the disturbance through 5 years of harvest closure, and through the 2021 reopening of the region to unprecedented fishing pressure. We use a combination of shore-based surveys to assess juvenile population structure and abundance, and dive surveys to quantify adult biomass. Our data depict a phenomenal rebounding of abalone stock during the closure, only to then be dramatically fished down by recreational fishers in 3 months. Surveys before and after the fishing season showed a 74% decline in adult biomass in fished areas, as well as significant demographic changes in the remaining population. This work highlights the importance of proactive management and having effective, enforceable controls on recreational harvest, which are currently inadequate. We discuss the ‘race to the bottom’, and the need for new management that accounts for increasing human pressures on limited resources.
Biography:
Shawn is a PhD student and research assistant with the Marine Ecology Research Group at the University of Canterbury, Otautahi, New Zealand. He specializes in intertidal community ecology, and is working on the recovery and restoration of abalone populations following an earthquake-caused mass mortality event.
