In the Southern Ocean, the at‐sea distributions of most predators of Antarctic krill are poorly known, primarily because tracking studies have only been undertaken on a restricted set of species, and then only at a limited number of sites. For chinstrap penguins, one of the most abundant krill predators breeding across the Antarctic Peninsula, we show that habitat models developed utilizing the distance from the colony and the bearing to the shelf‐edge, adjusting for the at‐sea density of Pygoscelis penguins from other colonies, can be used to predict, with a high level of confidence, the at‐sea distribution of chinstrap penguins from untracked colonies during the breeding season. Comparison of predicted penguin distributions with outputs from a high‐resolution oceanographic model shows that chinstrap penguins prefer nearshore habitats, over shallow bathymetry, with slow‐flowing waters, but that they sometimes also travel to areas beyond the edge of the continental shelf where the faster‐flowing waters of the Coastal Current or the fronts of the Antarctic Circumpolar Current occur. In the slow‐moving shelf waters, large penguin colonies may lead to krill depletion during incubation and chick‐rearing periods when penguins are acting as central place foragers. The habitats used by chinstrap penguins are also locations preferentially used by the commercial krill fishery, one of the last under‐developed marine capture fisheries anywhere on the planet. As it develops, this fishery has the potential to compete with chinstrap penguins and other natural krill predators. Scaling our habitat models by chinstrap penguin population data demonstrates where overlap with the fishery is likely to be most important. Our results suggest that a better understanding of krill retention and krill depletion in areas used by natural predators and by the krill fishery are needed, and that risk management strategies for the fishery should include assessment of how krill movement can satisfy the demands of both natural predators and the fishery across a range of spatial and temporal scales. Such information will help regional management authorities better understand how plausible ecosystem‐based management frameworks could be developed to ensure sustainable co‐existence of the fishery and competing natural predators.
Fisheries and Fisheries Management
This study synthesizes results from observations, laboratory experiments and models to showcase how the integration of scientific methods and indigenous knowledge can improve our understanding of (a) past and projected changes in environmental conditions and marine species; (b) their effects on social and ecological systems in the respective communities; and (c) support management and planning tools for climate change adaptation and mitigation. The study links climate-ecosystem-economic (CEE) models and discusses uncertainties within those tools. The example focuses on the key forage species in the Inuvialuit Settlement Region (Western Canadian Arctic), i.e., Arctic cod (Boreogadus saida). Arctic cod can be trophically linked to sea-ice algae and pelagic primary producers and are key vectors for energy transfers from plankton to higher trophic levels (e.g., ringed seals, beluga), which are harvested by Inuit peoples. Fundamental changes in ice and ocean conditions in the region affect the marine ecosystem and fish habitat. Model simulations suggest increasing trends in oceanic phytoplankton and sea-ice algae with high interannual variability. The latter might be linked to interannual variations in Arctic cod abundance and mask trends in observations. CEE simulations incorporating physiological temperature limits data for the distribution of Arctic cod, result in an estimated 17% decrease in Arctic cod populations by the end of the century (high emission scenario), but suggest increases in abundance for other Arctic and sub-Arctic species. The Arctic cod decrease is largely caused by increased temperatures and constraints in northward migration, and could directly impact key subsistence species. Responses to acidification are still highly uncertain, but sensitivity simulations suggests an additional 1% decrease in Arctic cod populations due to pH impacts on growth and survival. Uncertainties remain with respect to detailed future changes, but general results are likely correct and in line with results from other approaches. To reduce uncertainties, higher resolution models with improved parameterizations and better understanding of the species' physiological limits are required. Arctic communities should be directly involved, receive tools and training to conduct local, unified research and food chain monitoring while decisions regarding commercial fisheries will need to be precautionary and adaptive in light of the existing uncertainties.
The dangerous effects of Abandoned, Lost or Discarded Fishing Gears (ALDFG) is documented in the literature. However, there exists an overall lack of understanding in quantifying the pollution loads of fishing gears (FG) in territorial waters or on the beaches. The lack of data on FG life cycle results in mismanagement of one of the troublesome resources across the globe. In the remote and data-less situations, local stakeholders’ knowledge remains the only source of information. Therefore, in this article, we propose:
A methodology to extract fishers’ knowledge (FK) for generating evidence on FG handling and management practices in Norway.
The stepwise approach includes mapping of relevant stakeholders, drafting and finalizing a structured questionnaire using the Delphi method among experts to build the consensus and finally, statistically analyzing the recorded responses from the fishers.
The questions are designed to extract both qualitative and quantitative information on purchase, repair, gear loss and disposal rates of commercial FGs.
The responses from 114 Norwegian fishers are recorded, analyzed and presented as a part of method validation.
The evidence from the survey is then used as an input to coin the regional FG handling and management strategies in Norway. The presented method is proven a robust strategy to retrieve scientific information from the local stakeholders’ and can easily be replicated elsewhere to build global evidence around the ALDFG problematic.
The rationale applied for monitoring and managing fisheries is based on the implicit assumption that yield and stocks status is essentially determined by fisheries. Moreover, the fisheries yield is quantified and analyzed in terms of landings with respect to official management area of registration of vessels. In this way, the real area of activity of each fleet is not considered and this prevent an effective spatial analysis of the factors affecting fisheries yield and stocks status. This paper firstly presents a VMS-based reconstruction of the fishing effort and of the area of activity of the Italian trawlers in the Mediterranean Sea. The fishing area of each fleet is then used as a spatial reference to estimate primary productivity rate and gross primary production and to investigate, by using General Additive Models, the effects of trawling effort, primary production and time on fisheries yield, fisheries productivity and overexploitation rate for some key demersal species. The results evidence that the usage of satellite-based information of fishing activities and of primary production, when combined at the real spatial scale of fishing activities, could effectively improve our ability to analyze the response of the ecosystems to these driving forces and allow capturing the main trends of yield, productivity and overexploitation rate of demersal stocks.
This article recognizes that the impacts and effects of fishing are key to marine ecosystem management and explores the relationship between fisheries exploitation and sustainable harvests, and the collapse and depletion of stocks. A survey of 21 fisheries from around the world assessed key biological, environmental, social, economic, industry, governance, and management variables and associated criteria that potentially affect stock abundance. We developed 51 criteria as potential contributing factors underpinning three main fishery management outcomes: a sustainable fishery, a depleted fishery, or a collapsed fishery. The criteria that scored highest for the 15 sustainable fisheries in the analysis were associated with the broad groupings of biology (characteristics of the species and stock), management (legal and policy frameworks, tools and decision systems), and industry (economic performance and value). This analysis showed that while a fishery might have a high score for management, sustainability is likely to be difficult to achieve without a medium or high score for biological knowledge.
Full no-take marine reserves (MRs) act as tools for biodiversity protection that reduce or remove human-induced disturbances and support the recovery of harvested species. Even if not designed specifically for fisheries management, MRs have the potential to enhance locally and distantly fished populations. This study quantified contemporary catch per unit effort (CPUE) of rock lobsters (RLs) with respect to weight and abundance inside and outside two central New Zealand MRs (Kapiti MR established in 1992, Taputeranga MR established in 2008) using commercial fishing methods (pots), and compared it to historical CPUE data. On average, mean CPUE and mean RL size were significantly greater inside than outside at both MRs. Contemporary CPUE at both MRs was approximately twice that of historical CPUE prior to the reserves being established. At Taputeranga, but not at Kapiti MR, we observed a gradient in CPUE with distance from the centre of the reserve. MRs had higher CPUE at reefs that were fully protected (entire reef in the MR) than at partially protected reefs (reef spans the MR boundary), which in turn had higher CPUE than unprotected reefs (entire reef outside the MR). Our results indicate that RL populations are responding positively to protection, but that factors such as the amount of reef area protected and proximity to reserve boundary contribute differently to RL responses. Our findings contribute to the design of MRs with respect to the habitat they protect and to a better understanding of the interactions between MRs and local fisheries.
Scientific understanding of coupled social-ecological systems has grown considerably in recent years, especially for fisheries and ocean management. However, few studies test the utility of approaches that capture multiple interactions between people and ecosystems within a real-world planning process. We developed a set of quantitative models that estimate catch and revenue from the Caribbean spiny lobster (Panulirus argus) fishery as a function of coastal habitat extent and quality. We applied the models iteratively, with input from stakeholders, to assess fisheries outcomes of alternative scenarios for integrated coastal zone management in Belize and sustainable development planning in The Bahamas. We found that integrated management reduces risk to nursery habitats from multiple coastal and marine activities and increases lobster catch and revenue by large margins. In Belize, siting activities such as marine transportation and tourism development to explicitly reduce risk to nursery and adult habitats enhanced returns from the lobster fishery. In The Bahamas, strategic investments in economic development that focused on updating existing infrastructure, such as roads, rather than expanding the footprint of development, increased the catch of lobster by approximately half again as much relative to a business as usual scenario. Our findings show how models that link spatial information about coastal habitats and the dynamics of a key fishery can inform expected change in catch and revenue as a result of coastal management. In addition to strengthening stakeholder understanding of social-ecological relationships and highlighting national-scale outcomes of regional development decisions, modeled results allowed us to transparently and effectively improve coastal plans to achieve the goals of the citizens and governments of Belize and The Bahamas. These cases illustrate how models that account for relationships between development, nursery habitats, and fishing catch and revenue can elevate the importance of fisheries management in national development decisions.
In the United States, implementation of strong legislative mandates and investments in scientific programmes have supported sustainable fisheries management for seafood production, marine ecosystems, and maritime communities and economies. Changing climate and ocean conditions present new and growing challenges that affect the ability to manage fisheries. To better prepare for and respond to these challenges, the U.S. National Marine Fisheries Service has called for increasing the production, delivery, and use of climate and environmental information to fulfil its living marine resource stewardship mandates. Addressing these challenges and more formally including climate-informed decision-making in the fisheries management process requires strengthening and adapting the current fisheries management framework. We focus on two impacts of a changing climate, shifting species distributions and changing productivity, which can have significant implications for effective fisheries management. We identify six key steps of a climate-informed science-to-management system: detecting changes, understanding mechanisms of changes, evaluating risks and priorities, conducting assessments, communicating advice, and making management decisions. For each step, we identify challenges and provide recommendations to address those challenges and increase the capacity to develop and apply climate-related science to support sustainable fisheries management in a changing world.
Timing of reproduction may be of crucial importance for fitness, particularly in environments that vary seasonally in food availability or predation risk. However, for animals with spatially separated feeding and breeding habitats, optimal reproductive timing may differ between parents and their offspring, leading to parent-offspring conflict. We assume that offspring have highest survival and fitness if they are spawned around a fixed date, and use state-dependent life-history theory to explore whether variation in conditions affecting only parents (food availability and survival) may influence optimal timing of reproduction. We apply the model to Pacific herring (Clupea palasii) in Puget Sound, USA, where 20 subpopulations spawn at different times of the year. Our model suggests that relatively small differences in adult food availability can lead to altered prioritization in the trade-off between maternal fecundity and what from the offspring’s perspective is the best time to be spawned. Our model also shows that observed among-population variability in reproductive timing may result from adults using different feeding grounds with divergent food dynamics, or from individual variation in condition caused by stochasticity at a single feeding ground. Identifying drivers of reproductive timing may improve predictions of recruitment, population dynamics, and responses to environmental change.
We describe an investigation into the challenges faced by fishing gear technologists inspiring the voluntary uptake of proven fishing gear by fishers, defined as fishing gear that has satisfied research objectives following field trials between fishers and fishing gear technologists. We applied a multifaceted approach to understand how the uptake rate of this fishing gear can be achieved based on the results of a 3-year ICES-FAO Working Group on Fishing Technology and Fish Behaviour (WGFTFB) topic group on change management in fisheries. This was supported by an online survey and interview of WGFTFB members, comprising mainly of fishing gear technologists and researchers from Europe and North America, and a review of projects in the US Northwest Atlantic to evaluate the performance of fishing gear in close collaboration with fishers. We found that widespread voluntary uptake of proven fishing gear by fishers is rare, and usually takes place over many years if at all. The uptake of this gear was more likely occur in the face of perceived financial benefit or impending regulation, although financial benefit was not always sufficient inducement for fishers change their gear. The effectiveness of outreach programmes to inspire the uptake of this gear was also found to be questionable, and the efficacy of incentives was limited and inconsistent, even if the informational deficit of fishers was low. Few WGFTFB members were found to use change management models such as that by Kotter, and they relied mainly on informal, ad hoc approaches to inspire the uptake of proven fishing gear. Based on our findings we posit a need to (i) examine our assumptions about the behaviour of fishers, (ii) augment communication of the results of fishing gear research, (iii) focus on emotions to overcome motivational deficits, and (iv) consider how the application of change management models can improve the ability of fishing gear technologists to inspire the uptake of proven fishing gear by fishers.