Abstract:
U ncertainty of offshore aquaculture resilience to physical conditions is a barrier to mapping location s and assessing the economic potential of offshore aquaculture. Quantifying oceanographic conditions requires long time-series of high resolution data, yet coarse ocean models and simplified variables are used to map offshore aquaculture potential in a variety of methods. Here, we hypothesise uncertainties within oceanographic data is greater than uncertainty of resilience thresholds (e.g. sites of waves < 4 m and currents < 1 m/s) ; and we apply a sensitivity test to explore the impact on mapping sea-space and location. Using data from a range of ocean models , the impact of spatial and temporal resolution to mapping based on extreme event intensity is determined: 1km to 10km spatial resolution ROMS and AMM15 tidal models; and wave data from ERA5, at hourly to daily mean values, resolving annual and inter-annual variability. Furthermore, the persistence of an extreme event is also calculated (number of hours above resilience threshold), and spatial differences in the maps compared. Differences in the mapping (km^2) of potential offshore aquaculture sites, based on data not physical condition thresholds, was found to be larger than differences in sea-space when changing resilience thresholds by 50% - consistent with spatial variability at such location (e.g. <2m or <6m in Hs, versus <0.5m/s to <1.5m/s). We therefore find a need for a common framework for physical ocean condition assessment, which could then be used to inform future generations of resilience offshore aquaculture – as is done in other marine industries (such as oil and gas).