Exploitation of deep-sea fishery resources

Watling, Les; Victorero, Lissette; Drazen, Jeffrey C.; Gianni, Matthew

doi:10.1093/oso/9780198841654.003.0004

Cited by 4 publications

(3 citation statements)

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“…With respect to carrying capacity, given the large biomass estimates for the mesopelagic (Irigoien et al, 2014; Kaartvedt et al, 2012) we expect that their carrying capacity in any given area will far exceed that of the epipelagic fish; this is an assumption that we expect to hold at least in oceanic environments with limited certainty however for shelf areas. In addition, we expect that the intrinsic growth rate will be higher for the epipelagic compared to the mesopelagic species since the literature suggests that it is negatively related to depth (Drazen & Yeh, 2012; Watling et al, 2020). This assumption also comes with limitations, given how short‐lived mesopelagic species are (which may indicate a similar or higher intrinsic growth rate), and is likely species‐dependent.…”

Section: Assumptions and Datamentioning

confidence: 99%

Mesopelagic–epipelagic fish nexus in viability and feasibility of commercial‐scale mesopelagic fisheries

Kourantidou

Jin

2022

Natural Resource Modeling

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While considerable scientific uncertainties persist for mesopelagic ecosystems, the fishing industry has developed a great interest in commercial exploitation with improved technologies as part of their search for new sources of feed for fishmeal and fish oil for aquaculture, which will intensify with the planet's growing population. The multiple uncertainties surrounding the ecosystem structure and particularly the size of biomass, hinder a good understanding of the risks associated with large-scale exploitation, which is needed for a management framework for sustainable ocean uses. Despite concerns regarding irreversible losses triggered by commercial fishing, work exploring the vulnerability of mesopelagic fish to harvesting is largely missing. This study investigates the economic feasibility of mesopelagic fishing which is the primary driver for any possible future expansion. Using very limited information currently available, we conduct a high-level assessment focusing on key ecological and economic interactions and develop an initial understanding of the economic feasibility of commercial harvesting for mesopelagic fish in the coming years.

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Section: Assumptions and Datamentioning

confidence: 99%

Mesopelagic–epipelagic fish nexus in viability and feasibility of commercial‐scale mesopelagic fisheries

Kourantidou

Jin

2022

Natural Resource Modeling

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“…These efforts are laudable and necessary and work in complement with each other to demystify the deep ocean and address goals of the UN Ocean Decade (Howell et al, 2020). Understanding the deep ocean is critical as the human population (Kramer, 2019) continues to exploit deep-sea fisheries (Watling et al, 2020), interrupt deep-sea planetary processes in terms of carbon sequestration (Teng and Zhang, 2018) and O 2 production (Gao et al, 2019), and now is on the verge of deep-sea mining and other invasive extraction activities (Amon et al, 2022b;Amon et al, 2022c). Yet, the community of deep-sea scientists is small, with relatively few deep submergence assets (Intergovernmental Oceanographic Commission, 2020;Bell et al, 2022b).…”

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confidence: 99%

COBRA Master Class: Providing deep-sea expedition leadership training to accelerate early career advancement

Rotjan,

Bell,

Huber

et al. 2023

Front. Mar. Sci.

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Leading deep-sea research expeditions requires a breadth of training and experience, and the opportunities for Early Career Researchers (ECRs) to obtain focused mentorship on expedition leadership are scarce. To address the need for leadership training in deep-sea expeditionary science, the Crustal Ocean Biosphere Research Accelerator (COBRA) launched a 14-week virtual Master Class with both synchronous and asynchronous components to empower students with the skills and tools to successfully design, propose, and execute deep-sea oceanographic field research. The Master Class offered customized and distributed training approaches and created an open-access syllabus with resources, including reading material, lectures, and on-line resources freely-available on the Master Class website (cobra.pubpub.org). All students were Early Career Researchers (ECRs, defined here as advanced graduate students, postdoctoral scientists, early career faculty, or individuals with substantial industry, government, or NGO experience) and designated throughout as COBRA Fellows. Fellows engaged in topics related to choosing the appropriate deep-sea research asset for their Capstone “dream cruise” project, learning about funding sources and how to tailor proposals to meet those source requirements, and working through an essential checklist of pre-expedition planning and operations. The Master Class covered leading an expedition at sea, at-sea operations, and ship-board etiquette, and the strengths and challenges of telepresence. It also included post-expedition training on data management strategies and report preparation and outputs. Throughout the Master Class, Fellows also discussed education and outreach, international ocean law and policy, and the importance and challenges of team science. Fellows further learned about how to develop concepts respectfully with regard to geographic and cultural considerations of their intended study sites. An assessment of initial outcomes from the first iteration of the COBRA Master Class reinforces the need for such training and shows great promise with one-quarter of the Fellows having submitted a research proposal to national funding agencies within six months of the end of the class. As deep-sea research continues to accelerate in scope and speed, providing equitable access to expedition training is a top priority to enable the next generation of deep-sea science leadership.

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“…Concerns about the impact of bottom trawling on deep-sea coral communities and seamounts has led them to be identified as indicators of vulnerable marine ecosystems (VMEs), and the United Nations has instructed regional fisheries management organisations (RFMOs) to take urgent action in protecting these communities and habitats (UNGA, 2004(UNGA, , 2006. Consequently, spatial management measures have been established globally in areas beyond national jurisdiction to conserve and/or promote recovery of deep-sea habitats, as well as within areas of national jurisdiction (i.e., Territorial Seas and Exclusive Economic Zones (EEZs)) (Morato et al, 2010;Watling et al, 2020). In the New Zealand EEZ, spatial management of the deep seafloor has primarily been implemented through seamount closure areas (SCAs) and benthic protection areas (BPAs).…”

Section: Introductionmentioning

confidence: 99%

Resilience of Seamount Benthic Communities to Fishing Disturbance

Goode

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Seamounts are important marine habitats that commonly occur in deep waters, with global estimates ranging from tens of thousands to several million. Interactions between seamount topographies and surrounding currents increase local productivity at some features, supporting high abundances and biomasses of both pelagic and benthic fauna. For this reason, many seamounts host fish aggregations, including several commercially-important species. Early observations of seamount fish aggregations led to their initial targeting in the 1960s by bottom trawlers. Since then, this practice has expanded globally. In New Zealand, seamounts were initially targeted by fisheries in the late 1970s, and by the early 1990s a majority of the annual orange roughy (Hoplostethus atlanticus) catch was obtained from several seamounts. Bottom trawling has significant impacts not only on the target fish population, but also on the non-target benthic fauna caught as bycatch, as they can be comprised of fragile, emergent, sessile animals (e.g., deep-sea corals and sponges) that are easily damaged or removed by trawling gear. However, the extent to which these communities can recover from trawling impacts is uncertain, and this information is necessary to design effective spatial management measures, particularly in New Zealand where many seamounts are located within the Exclusive Economic Zone and actively fished. Designing studies to address this knowledge gap and provide management recommendations first requires an assessment of current understanding regarding resilience of seamount benthic communities to fishing. In this thesis, such an assessment was done through a global literature review and meta-analysis of seamount benthos, fisheries, known trawling impacts, and a three-fold evaluation of community resilience (Chapter 1). This review indicated that recovery will likely be initially patchy, and information on community spatial patterns is a necessary starting point to determine recovery potential. In order to provide such baseline spatial context to subsequent studies of previously fished seamounts, the structure and distribution of benthic communities at two unfished seamounts was investigated to characterise fine-scale community structural patterns and identify environmental drivers of these patterns (Chapter 2). Megabenthic (seafloor fauna with body sizes >2 cm) fauna were identified and described from 1,233 total seafloor images collected with camera transects on both seamounts in 2015 to identify communities. The predicted spatial distributions of these communities were mapped and characteristics of the patches they were predicted to occupy were described. Habitat drivers were found to differ between the two features at different spatial scales, and these differences were reflected in the predicted spatial distributions and patch characteristics of communities characterising each seamount. Post-fishing responses of benthic communities were determined by examining fine-scale spatio-temporal changes in their structure and function over 20 years on a seamount that was intensively trawled from the early 1990s until its protection in 2001 (Chapter 3). As part of a long-term research programme, camera surveys were conducted on this seamount (and others) in 2001, 2006, 2009, 2015, and 2020. In total, 2,343 images were analysed across years to obtain megabenthic faunal counts of 148 taxa. Results showed there was a temporal shift in community structure driven by small relative changes in abundances of several taxa, indicative of early recovery. However, community function showed little sign of ongoing recovery. Juvenile colonies of a reef-forming stony coral, Solenosmilia variabilis, were observed, demonstrating that the fisheries closure may have facilitated the early recovery process of this species and its associates. Data obtained from these analyses was used to develop joint-species distribution models to predict changes in benthic faunal occurrence and abundance up to 200 years post-fisheries closure (Chapter 4). Spatial distributions of 36 aggregated megabenthic taxa were predicted for five post-closure time-steps in 2001, 2020, 2040, 2100, and 2200. Nine communities were described from the spatial predictions using cluster analysis and spatial patterns of the patches they occupied were characterised. Results of this study suggested that the fisheries closure may enable the recovery of most, but not all, taxa. Additionally, several communities on the seamount summit may undergo succession towards a reef climax community, but are unlikely to fully reverse fishing impacts even on this long timescale.Key findings from the preceding chapters were synthesised, and their implications for seamount management and future research discussed (Chapter 5). The latter includes the need for studies determining the physiology and life history traits of seamount benthic species to better predict their resilience to fishing impacts. Major contributions of this thesis study to the field of seamount ecology were also presented, including a conceptual model of seamount recovery, hypothesised changes in community patch characteristics after trawling disturbance, and a decision framework for seamount management prioritisation.

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Exploitation of deep-sea fishery resources

Cited by 4 publications

References 0 publications

Mesopelagic–epipelagic fish nexus in viability and feasibility of commercial‐scale mesopelagic fisheries

Mesopelagic–epipelagic fish nexus in viability and feasibility of commercial‐scale mesopelagic fisheries

COBRA Master Class: Providing deep-sea expedition leadership training to accelerate early career advancement

Resilience of Seamount Benthic Communities to Fishing Disturbance

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