When monitoring marine recreational fishers at sub-bio-regional scales—for example those who are accessing a Marine Park—on-site sampling is often required. This poses various logistical challenges, such as the efficient timing of intercept interviews. Here, we examine these challenges, combining trail cameras, closed-circuit television (CCTV), weather stations, and interviews at boat ramps that bracket an offshore Marine Park. Trail camera results were similar to those from a CCTV system co-located at one of the boat ramps. Fishers’ boat launches peaked early, but return times varied considerably by ramp and weather. Both the numbers of launches and trip durations were strongly responsive to good weather, particularly at ramps used for offshore fishing. Weather was a more important factor to predict the likelihood of intercept interview opportunities than holiday period, which may reflect changing dynamics in work culture and improvements in weather prediction. Interviewed fishers reported preferences to individual ramps over the fishing season and nearly all trips to the Marine Park were reported by fishers accessing just one ramp. The strong relationships between fishing, weather, and ramp, observed by the trail camera and correlated with the weather station data, may allow for the efficient targeting of intercept interviews and potentially the modelling of fishing effort.

The ‘Huon’ and ‘Tasman Fracture’ areas off southern Tasmania contain seamounts that support unique deep-sea coral reefs, which are part the Australian Marine Park network. This report presents findings of the RV Investigator voyage V06. The surveys aimed to determine the extent of deep-sea coral communities in and adjacent to the Huon and Tasman Fracture parks, and quantify changes in the communities on these seamounts since 1997 and 2007. The survey also sampled the St. Helens Seamount in north-east Tasmania which was previously surveyed in 2008. The study found that coral reefs extend from seamounts onto adjacent rocky areas, and also occur on small areas on the continental shelf edge, expanding their previously known distribution. The results will provide important data on recovery and resilience to bottom trawling on deep sea coral communities and improve our understanding of the dynamics of deep-sea communities.

The Marine Biodiversity Hub provided scientific leadership and communication support for this voyage.

Link to Investigator Post Voyage Report => INV 2018_06 Voyage Summary

Link to Voyage Blogs => Blogging the Seamounts 23 Nov - 19 Dec 2018

Marine fisheries in coastal ecosystems in many areas of the world have historically removed large-bodied individuals, potentially impairing ecosystem functioning and the long-term sustainability of fish populations. Reporting on size-based indicators that link to foodweb structure can contribute to ecosystem-based management, but the application of these indicators over large (cross-ecosystem) geographical scales has been limited to either fisheries-dependent catch data or diver-based methods restricted to shallow waters (<20 m) that can misrepresent the abundance of large-bodied fished species. We obtained data on the body-size structure of 82 recreationally or commercially targeted marine demersal teleosts from 2904 deployments of baited remote underwater stereo-video (stereo-BRUV). Sampling was at up to 50 m depth and covered approximately 10,000 km of the continental shelf of Australia. Seascape relief, water depth, and human gravity (i.e., a proxy of human impacts) were the strongest predictors of the probability of occurrence of large fishes and the abundance of fishes above the minimum legal size of capture. No-take marine reserves had a positive effect on the abundance of fishes above legal size, although the effect varied across species groups. In contrast, sublegal fishes were best predicted by gradients in sea surface temperature (mean and variance). In areas of low human impact, large fishes were about three times more likely to be encountered and fishes of legal size were approximately five times more abundant. For conspicuous species groups with contrasting habitat, environmental, and biogeographic affinities, abundance of legal-size fishes typically declined as human impact increased. Our large-scale quantitative analyses highlight the combined importance of seascape complexity, regions with low human footprint, and no-take marine reserves in protecting large-bodied fishes across a broad range of species and ecosystem configurations.

We present a national social and economic benchmark for the Australian Marine Parks (AMPs), focussing on four key groups: the general public, recreational fishers, non-extractive recreational users, and charter operators. Establishing this benchmark involved conducting four integrated surveys nationally reaching approximately 4,000 respondents. The AMP benchmarks established here are amongst the most comprehensive globally in terms of the spatial extent and stakeholder groups considered. Overall, the surveys highlight the substantial values associated with the AMPs, and generally positive perceptions and attitudes towards the parks. The surveys also highlight potential areas for survey improvement, and data was collected to help address these (e.g. preferred modes of contact). The information is intended to inform management of the AMPs in ways that align with the preferences of stakeholders and the broader community.