Angling to Reach a Destination to Fish—Exploring the Land and Water Travel Dynamics of Recreational Fishers in Port Phillip Bay, Australia

Recreational fishing is a popular pastime and multibillion dollar industry in Australia, playing a key economic role, especially in regional areas. In the State of Victoria, Port Phillip Bay (PPB), bordered by Melbourne and its suburbs, is the largest of the State’s marine recreational fisheries. At present, little is known about the spatial and temporal dimensions of angler travel from origins to destinations, and the applicability of such spatial knowledge in fisheries management. To address this lack of information we assessed spatiotemporal dynamics and patterns in fishing trips, based upon travel distances on land and water, to acquire insight into the spatial ranges over which anglers residing in various locations travel to fishing destinations in the environs of PPB. Data for each angler per fishing trip, from 6,035 boat-based creel surveys, collected at 20 boat ramps in PPB during a 10-year period from 2010 to 2019, were analyzed by applying geospatial modeling. Differences were observed in both land and water travel distance by region and popular target species, with anglers who launched from Bellarine region traveling further on land, and those who targeted snapper traveling further on water. It was also evident that most anglers resided within close proximity of PPB, often less than 50 km, although some anglers traveled long distances across the State to access fishing locations, particularly when targeting snapper. This work further highlights the importance of spatially explicit approaches to inform fisheries management by identifying users across different landscape and seascape scales, and out-of-region or State fishing trips, which may especially impact coastal communities and benefit local businesses.

Monitoring the Performance of Set Longlines Fishing Vessels at Fisheries Management Area 718 Indonesia

Catches reports by set longlines fishing vessels in the 718-fisheries management area (FMA) have been entered into the logbook reporting system since 2012. These vessels targeted reef and demersal fish. Set longlines is considered to be very efficient and productive for catching reef fish. This study aims to see the performance of set longlines vessels. The indicators used are CPUE and fuel efficiency. The results of the study show that the performance of set longlines vessels in the area is getting better and more efficient. Keywords: set longlines; reef fish; CPUE; fuel; efficient Abstrak Laporan hasil tangkapan oleh kapal penangkap rawai dasar di pengelolaan perikanan (WPP) 718 telah dimasukkan ke dalam sistem pelaporan logbook sejak 2012. Kapal-kapal rawai tesebut menargetkan ikan karang dan ikan demersal. Rawai dasar dianggap sebagai alat tangkap yang sangat efisien dan produktif untuk menangkap ikan karang. Penelitian ini bertujuan untuk melihat kinerja kapal rawai dasar. Indikator yang digunakan adalah CPUE dan efisiensi bahan bakar. Hasil penelitian menunjukkan bahwa kinerja kapal longline set di daerah tersebut semakin baik dan efisien. Kata kunci: rawai dasar; ikan karang; CPUE; bahan bakar; efisien

Trawl impacts on the relative status of biotic communities of seabed sedimentary habitats in 24 regions worldwide

Bottom trawling is widespread globally and impacts seabed habitats. However, risks from trawling remain unquantified at large scales in most regions. We address these issues by synthesizing evidence on the impacts of different trawl-gear types, seabed recovery rates, and spatial distributions of trawling intensity in a quantitative indicator of biotic status (relative amount of pretrawling biota) for sedimentary habitats, where most bottom-trawling occurs, in 24 regions worldwide. Regional average status relative to an untrawled state (=1) was high (>0.9) in 15 regions, but <0.7 in three (European) regions and only 0.25 in the Adriatic Sea. Across all regions, 66% of seabed area was not trawled (status = 1), 1.5% was depleted (status = 0), and 93% had status > 0.8. These assessments are first order, based on parameters estimated with uncertainty from meta-analyses; we recommend regional analyses to refine parameters for local specificity. Nevertheless, our results are sufficiently robust to highlight regions needing more effective management to reduce exploitation and improve stock sustainability and seabed environmental status—while also showing seabed status was high (>0.95) in regions where catches of trawled fish stocks meet accepted benchmarks for sustainable exploitation, demonstrating that environmental benefits accrue from effective fisheries management. Furthermore, regional seabed status was related to the proportional area swept by trawling, enabling preliminary predictions of regional status when only the total amount of trawling is known. This research advances seascape-scale understanding of trawl impacts in regions around the world, enables quantitative assessment of sustainability risks, and facilitates implementation of an ecosystem approach to trawl fisheries management globally.

Productivity and Management of Renewable Resources: Why More Efficient Fishing Fleets Should Fish Less

This article analyses the effect of productivity improvements on optimal fisheries management. It is shown that when harvest costs are independent of resource stock and the stock is below its steady state level, then for any given stock it is optimal to reduce harvest levels in response to a productivity increase unless optimal harvest rate is already zero. If harvest costs are stock dependent this result is modified; for stock dependent harvest costs there exists an interval of stock sizes below the steady state where it is optimal to reduce the harvest rate for any given stock size whereas if the harvest rate is close to an economically optimal steady state it is optimal to increase the harvest rate.

Effectiveness of Adaptive Real-Time Closures for Managing Migratory Species in Data-Limited Multispecies Fisheries

Fixed closure (FC) is a standard fisheries management tool for protecting sensitive species or species requiring conservation. However, an FC might not effectively manage migratory species because of the large uncertainties of their migration. Adaptive real-time closure (ARTC) is a tool that updates closure areas according to the latest information. This study aimed to evaluate the effectiveness of ARTC to conserve sensitive species for data-limited fisheries by a series of simulations using migration models with hotspots. In the single species simulation, the conservation ratio for the sensitive species in FC varies widely at greater migration uncertainty. In ARTC, a longer duration of a hotspot resulted in a higher conservation ratio. When the mean duration of hotspots was medium or long, the conservation ratio for the sensitive species was more than 50 % in more than 99 % of the simulation trials. In multispecies fisheries, a clear trade-off was observed between the conservation ratio of sensitive species and other species. ARTC was more effective than whole closure when the proportion of sensitive species was high or without closure when the proportion was low. Conditions in which ARTC was most appropriate were described for hotspot duration, increased numbers of individuals in a hotspot, and the relative value of conservation, representing the ratio of the value of conserving sensitive species to one of catching other species.

Genotyping-in-Thousands by sequencing panel development and application to inform kokanee salmon (Oncorhynchus nerka) fisheries management at multiple scales

The ability to differentiate life history variants is vital for estimating fisheries management parameters, yet traditional survey methods can be inaccurate in mixed-stock fisheries. Such is the case for kokanee, the freshwater resident form of sockeye salmon (Oncorhynchus nerka), which exhibits various reproductive ecotypes (stream-, shore-, deep-spawning) that co-occur with each other and/or anadromous O. nerka in some systems across their pan-Pacific distribution. Here, we developed a multi-purpose Genotyping-in-Thousands by sequencing (GT-seq) panel of 288 targeted single nucleotide polymorphisms (SNPs) to enable accurate kokanee stock identification by geographic basin, migratory form, and reproductive ecotype across British Columbia, Canada. The GT-seq panel exhibited high self-assignment accuracy (93.3%) and perfect assignment of individuals not included in the baseline to their geographic basin, migratory form, and reproductive ecotype of origin. The GT-seq panel was subsequently applied to Wood Lake, a valuable mixed-stock fishery, revealing high concordance (>98%) with previous assignments to ecotype using microsatellites and TaqMan® SNP genotyping assays, while improving resolution, extending a long-term time-series, and demonstrating the scalability of this approach for this system and others.

Examining the Role of Marine Mammals and Seabirds in Southeast Alaska’s Marine Ecosystem Dynamics

Primary producers are the foundation of marine food webs and require reliable nutrient sources to maintain their important role with ecosystems. While marine mammals and seabirds can play critical roles in marine nutrient cycling, their contributions are often overlooked. Southeast Alaska’s marine environment supports abundant marine mammal and seabird populations in addition to valuable fisheries. Nonetheless, there is still relatively little known about nutrient sources and fluxes in this region which is a critical component of fisheries management. The goal of our study was to advance knowledge of the role of mammals and seabirds in marine nutrient cycling and to understand how changing marine mammal and seabird populations may alter ecosystem dynamics. We utilized qualitative network models (QNMs) to examine how a simulated Southeast Alaska ecosystem would respond to an increase in marine mammals, seabirds, and nutrients. Researchers are increasingly utilizing QNMs as a first step in the development of ecosystem-based fisheries management plans as their adaptable nature is well suited to address rapidly changing climatic conditions. Our results indicate that marine mammals and seabirds make important contributions to marine nutrient concentrations in the region and that these valuable ecosystem services should not be overlooked.