Queen triggerfish Balistes vetula: Validation of otolith-based age, growth, and longevity estimates via application of bomb radiocarbon

Ensuring the accuracy of age estimation in fisheries science through validation is an essential step in managing species for long-term sustainable harvest. The current study used Δ14 C in direct validation of age estimation for queen triggerfish Balistes vetula and conclusively documented that triggerfish sagittal otoliths provide more accurate and precise age estimates relative to dorsal spines. Caribbean fish samples (n = 2045) ranged in size from 67–473 mm fork length (FL); 23 fish from waters of the southeastern U.S. (SEUS) Atlantic coast ranged in size from 355–525 mm FL. Otolith-based age estimates from Caribbean fish range from 0–23 y, dorsal spine-based age estimates ranged from 1–14 y. Otolith-based age estimates for fish from the SEUS ranged from 8–40 y. Growth function estimates from otoliths in the current study (L∞ = 444, K = 0.13, t0 = -1.12) differed from spined-derived estimates in the literature. Our work indicates that previously reported maximum ages for Balistes species based on spine-derived age estimates may underestimate longevity of these species since queen triggerfish otolith-based ageing extended maximum known age for the species by nearly three-fold (14 y from spines versus 40 y from otoliths). Future research seeking to document age and growth population parameters of Balistes species should strongly consider incorporating otolith-based ageing in the research design.

The Overfishing Problem: Natural and Social Categories in Early Twentieth-Century Fisheries Science

This article looks at how fisheries biologists of the early twentieth century conceptualized and measured overfishing and attempted to make it a scientific object. Considering both theorizing and physical practices, the essay shows that categories and understandings of both the fishing industry and fisheries science were deeply and, at times, inextricably interwoven. Fish were both scientific and economic objects. The various models fisheries science used to understand the world reflected amalgamations of biological, physical, economic, and political factors. As a result, scientists had great difficulty stabilizing the concept of overfishing and many influential scholars into the 1930s even doubted the coherence of the concept. In light of recent literature in history of fisheries and environmental social sciences that critiques the infiltration of political and economic imperatives into fisheries and environmental sciences more generally, this essay highlights both how early fisheries scientists understood their field of study as the entire combination of interactions between political, economic, biological and physical factors and the work that was necessary to separate them.

Fishing in the Dark: Science, Values and Deep Water Fisheries Research

<p>This research sought to assesss the safeguards protecting scientific objectivity in New Zealand deep-water fisheries science decision-making fora. Managing depleted, slow-growing and poorly-understood stocks demands particularly accurate, objective scientific information. New Zealand's Ministry of Fisheries undertakes deep-water fisheries management in an nformation-poor, high-stakes context. This context means neither of the two strictly separate policy and scientific advice processes is able, in isolation, to provide advice confidently. Preliminary investigations suggested that to enable the Ministry to meet the ongoing need for management of deep-water fishing, science fora are effectively taking on a quasi-policy role. This research investigated whether deep-water fisheries science processes have sufficient safeguards to protect the objectivity of scientific decision-making in this difficult climate, thereby ensuring maximum accuracy in their advice. Twentytwo personal interviews were conducted with key informants, and analysed using grounded theory. Themes thus revealed were analysed in light of concepts from economics, philosophy of science and institutional analysis literature. Research suggested that the scientific process is ill-suited for handling non-scientific judgements, and the spread of non-scientific considerations into scientific fora is risking the objectivity of scientific analysis which is critical for fisheries management. Imbalanced stakeholder representation in scientific fora further imperils objectivity in these fora, with potentially significant implications for sustainable fisheries management.</p>

Fishing in the Dark: Science, Values and Deep Water Fisheries Research

<p>This research sought to assesss the safeguards protecting scientific objectivity in New Zealand deep-water fisheries science decision-making fora. Managing depleted, slow-growing and poorly-understood stocks demands particularly accurate, objective scientific information. New Zealand's Ministry of Fisheries undertakes deep-water fisheries management in an nformation-poor, high-stakes context. This context means neither of the two strictly separate policy and scientific advice processes is able, in isolation, to provide advice confidently. Preliminary investigations suggested that to enable the Ministry to meet the ongoing need for management of deep-water fishing, science fora are effectively taking on a quasi-policy role. This research investigated whether deep-water fisheries science processes have sufficient safeguards to protect the objectivity of scientific decision-making in this difficult climate, thereby ensuring maximum accuracy in their advice. Twentytwo personal interviews were conducted with key informants, and analysed using grounded theory. Themes thus revealed were analysed in light of concepts from economics, philosophy of science and institutional analysis literature. Research suggested that the scientific process is ill-suited for handling non-scientific judgements, and the spread of non-scientific considerations into scientific fora is risking the objectivity of scientific analysis which is critical for fisheries management. Imbalanced stakeholder representation in scientific fora further imperils objectivity in these fora, with potentially significant implications for sustainable fisheries management.</p>

Unveiling the recovery dynamics of Walleye after the invisible collapse

Walleye (Sander vitreus) populations in Alberta, Canada collapsed by the mid-1990s and were a case study in the paper Canada’s Recreational Fisheries: The Invisible Collapse? Here we fit age-structured population dynamics models to data from a landscape-scale monitoring program to assess Walleye population status and reconstruct recruitment dynamics following the invisible collapse. Assessments indicated that populations featured low F_msy values of approximately 0.2-0.3 under conservative assumptions for the stock-recruitment relationship but that many populations were lightly exploited during 2000-2018. Recruitment reconstructions showed that recovery from collapse in 33/55 lakes was driven in part by large positive recruitment anomalies that occurred during 1998-2002. Additionally, 15/55 lakes demonstrated cyclic recruitment dynamics. Both the recruitment anomalies and cyclic fluctuations could be due to environmental effect(s) and(or) cannibalism, and experimentation may be necessary to resolve this uncertainty. These findings contribute new information on the recovery dynamics of Walleye following the invisible collapse, and demonstrate the effectiveness of coupling traditional fisheries science models with broad-scale monitoring data to improve understanding of population dynamics and sustainability across landscapes.