A Comparison of Drop Camera and Diver Survey Methods to Monitor Atlantic Sea Scallops (Placopecten magellanicus) in a Small Fishery Closure

Bethoney, N. David; Cleaver, Caitlin; Asci, Samuel C.; Bayer, Skylar; Wahle, Richard A.; Stokesbury, Kevin D. E.

doi:10.2983/035.038.0104

Cited by 7 publications

(2 citation statements)

References 29 publications

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“…The limitations of diving (effort, maximum diving depth, safety issues) together with recent technological advances have motivated the incorporation of remote observations to collect abundance data, especially using video cameras (e.g., towed cameras, drop cameras, remotely operated vehicles, autonomous underwater vehicles) (Batter et al ., 2021, Fields et al ., 2019, Stokesbury and Bethoney, 2020, Singh et al ., 2014, Flannery and Przeslawski, 2015; Goshima and Fujiwara, 1994). Such technologies have demonstrated efficiency for collecting georeferenced data in a wider depth range than diving, making it possible to cover larger areas with less effort and greater security (Bethoney et al ., 2019; Conan and Maynard, 1987).…”

Section: Introductionmentioning

confidence: 99%

"Toki", a light low-cost video system for seabed research: performance and precision of Tehuelche scallop (Aequipecten tehuelchus) survey estimates in San José Gulf, Argentina

Trobbiani,

Getino Mamet,

Irigoyen

et al. 2024

Preprint

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Studies of benthic abundance and biodiversity are essential for fisheries management and environmental impact assessments. In the case of commercial species, such as Tehuelche scallop (Aequipecten tehuelchus), accurate information on the stocks and their densities is crucial. The standard survey method used to estimate abundance of Tehuelche scallops in San José Gulf, Argentina Patagonia, based on visual counts obtained by divers is labor-intensive and limited to diving depths. This study introduces a light low-cost video remote system, named "Toki", for monitoring scallop beds from small boats. Toki consists of a steel pyramidal structure that houses two cameras, capable of capturing georeferenced high-definition images. The performance of Toki for estimating the density and size composition of scallops was evaluated. The results demonstrate that Toki provides efficient and accurate density estimates, with variations that can be attributed to observer experience and environmental factors such as bottom algal cover. The size frequency distributions obtained from Toki aligned well with those from hand collection, which allows such measurement for beds beyond diveable depths. Toki offers advantages in terms of spatial coverage and permanent data records. While there are some limitations, such as processing time for image analysis, future developments based on artificial intelligence can overcome these challenges. Toki has the potential to improve the monitoring of scallop beds and data collection.

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Section: Introductionmentioning

confidence: 99%

"Toki", a light low-cost video system for seabed research: performance and precision of Tehuelche scallop (Aequipecten tehuelchus) survey estimates in San José Gulf, Argentina

Trobbiani,

Getino Mamet,

Irigoyen

et al. 2024

Preprint

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“…These types of reserves have a long history of use and have been seen to successfully rehabilitate stocks (Camp et al, 2015; Gnanalingam & Hepburn, 2015). For example, seasonal closures have been shown to be an effective conservation strategy in increasing biomass the Atlantic sea scallop ( Placopecten magellanicus ) fishery in the United States (Bethoney & Cleaver, 2019), restored natural trophic interactions in coral reef fisheries in Kenya (McClanahan, 2008), and successfully restored the striped marlin ( Kajikia audax ) stocks in Baja California (Jensen et al, 2010). This method is flexible, logistically simple for fishers and managers to understand, and mitigates the financial loss from the fishery that can be seen with permanent closures (Nowlis, 2000; Humber et al, 2006; Cohen & Foale, 2013; Camp et al, 2015; Gnanalingam & Hepburn, 2015; Oliver et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Assessing the need for temporary fishing closures to support sustainability for a small-scale octopus fishery

Wulfing

Kadba

Baker-Médard

et al. 2023

Preprint

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Mechanistic models are particularly useful for understanding and predicting population dynamics in data deficient species. Data deficiency is a relevant issue in small scale fisheries as they are generally under studied and underrepresented in global fishing datasets. As overfishing remains a global issue, especially in small-scale fisheries, one commonly utilized conservation method is temporary closures. The blue octopus (Octopus cyanea) fishery off the southwest coast of Madagascar is one such system that uses temporary closures, yet lacks sufficient data collection to assess the viability of the population. This fishery is a key economic resource for the local community as blue octopus catch is sold by local fishers to international and local export markets and is a major component of fisher income. To assess the sustainability of blue octopus, we parameterize a Levkovitch population matrix model using existing catch data. In this study, we show that this population was in a decline of 1.8% per month at the time of data collection. To sustain the existing population of blue octopus, our model indicates that the fishery would need to close for at least three months annually. Increasing the length of closure is predicted to significantly increase the octopus population at these sites. We show that if implemented correctly, temporary closures could be used to restore this population. The local communities of Madagascar have implemented various fishing restrictions to ensure sustainable fishing, indicating a need for further research into the effectiveness of these fishing closures. Therefore, our study provides insight into the underlying population dynamics of this fishery and provides survivability estimates of this species.

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Assessing the need for temporary fishing closures to support sustainability for a small-scale octopus fishery

Wulfing,

Kadba,

Baker-Médard

et al. 2024

Fisheries Research

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A Comparison of Drop Camera and Diver Survey Methods to Monitor Atlantic Sea Scallops (Placopecten magellanicus) in a Small Fishery Closure

Cited by 7 publications

References 29 publications

"Toki", a light low-cost video system for seabed research: performance and precision of Tehuelche scallop (Aequipecten tehuelchus) survey estimates in San José Gulf, Argentina

"Toki", a light low-cost video system for seabed research: performance and precision of Tehuelche scallop (Aequipecten tehuelchus) survey estimates in San José Gulf, Argentina

Assessing the need for temporary fishing closures to support sustainability for a small-scale octopus fishery

Assessing the need for temporary fishing closures to support sustainability for a small-scale octopus fishery

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