The impact of electronic monitoring on fleet wide discarding of small cod in Scottish demersal fisheries

Acknowledgments The authors of this paper would like to acknowledge the fishers, fisheries inspectors, and video reviewers who participated in or supported the Scottish cod catch quota management scheme. Additionally, we thank two anonymous reviewers for their encouraging and insightful comments and suggestions.Peer reviewedPublisher PD

Deep neural networks for analysis of fisheries surveillance video and automated monitoring of fish discards

We report on the development of a computer vision system that analyses video from CCTV systems installed on fishing trawlers for the purpose of monitoring and quantifying discarded fish catch. Our system is designed to operate in spite of the challenging computer vision problem posed by conditions on-board fishing trawlers. We describe the approaches developed for isolating and segmenting individual fish and for species classification. We present an analysis of the variability of manual species identification performed by expert human observers and contrast the performance of our species classifier against this benchmark. We also quantify the effect of the domain gap on the performance of modern deep neural network-based computer vision systems

Motion stereo at sea: Dense 3D reconstruction from image sequences monitoring conveyor systems on board fishing vessels

A system that reconstructs 3D models from a single camera monitoring fish transported on a conveyor system is investigated. Models are subsequently used for training a species classifier and for improving estimates of discarded biomass. It is demonstrated that a monocular camera, combined with a conveyor's linear motion produces a constrained form of multiview structure from motion, that allows the 3D scene to be reconstructed using a conventional stereo pipeline analogous to that of a binocular camera. Although motion stereo was proposed several decades ago, the present work is the first to compare the accuracy and precision of monocular and binocular stereo cameras monitoring conveyors and operationally deploy a system. The system exploits Convolutional Neural Networks (CNNs) for foreground segmentation and stereo matching. Results from a laboratory model show that when the camera is mounted 750 mm above the conveyor, a median accuracy of <5 mm can be achieved with an equivalent baseline of 62 mm. The precision is largely limited by error in determining the equivalent baseline (i.e. distance travelled by the conveyor belt). When ArUco markers are placed on the belt, the inter quartile range (IQR) of error in z (depth) near the optical centre was found to be ±4 mm

A policy-based framework for the determination of management options to protect vulnerable marine ecosystems under the EU deep-sea access regulations

Vulnerable marine ecosystems (VMEs) are particularly susceptible to bottom-fishing activity as they are easily disturbed and slow to recover. A data-driven approach was developed to provide management options for the protection of VMEs under the European Union “deep-sea access regulations.” A total of two options within two scenarios were developed. The first scenario defined VME closure areas without consideration of fishing activity. Option 1 proposed closures for the protection of VME habitats and likely habitat, while Option 2 also included areas where four types of VME geophysical elements were present. The second scenario additionally considered fishing. This scenario used VME biomass—fishing intensity relationships to identify a threshold where effort of mobile bottom-contact gears was low and unlikely to have caused significant adverse impacts. Achieving a high level of VME protection requires the creation of many closures (> 100), made up of many small (∼50 km2) and fewer larger closures (> 1000 km2). The greatest protection of VMEs will affect approximately 9% of the mobile fleet fishing effort, while closure scenarios that avoid highly fished areas reduce this to around 4–6%. The framework allows managers to choose the level of risk-aversion they wish to apply in protecting VMEs by comparing alternative strategies.En prensa2,27

A policy-based framework for the determination of management options to protect vulnerable marine ecosystems under the EU deep-sea access regulations

Vulnerable marine ecosystems (VMEs) are particularly susceptible to bottom-fishing activity as they are easily disturbed and slow to recover. A data-driven approach was developed to provide management options for the protection of VMEs under the European Union “deep-sea access regulations.” A total of two options within two scenarios were developed. The first scenario defined VME closure areas without consideration of fishing activity. Option 1 proposed closures for the protection of VME habitats and likely habitat, while Option 2 also included areas where four types of VME geophysical elements were present. The second scenario additionally considered fishing. This scenario used VME biomass—fishing intensity relationships to identify a threshold where effort of mobile bottom-contact gears was low and unlikely to have caused significant adverse impacts. Achieving a high level of VME protection requires the creation of many closures (> 100), made up of many small (∼50 km2) and fewer larger closures (> 1000 km2). The greatest protection of VMEs will affect approximately 9% of the mobile fleet fishing effort, while closure scenarios that avoid highly fished areas reduce this to around 4–6%. The framework allows managers to choose the level of risk-aversion they wish to apply in protecting VMEs by comparing alternative strategies

ICES Scientific Reports. 2:114. 237 pp.

Under regulation (EU) 2016/2336, the EU fleet will be banned from bottom fishing in all waters between 400 and 800m in depth, apart from within the existing fishing footprint. Within the fishing footprint, EU vessels will be prohibited from bottom fishing in any closed areas that might be introduced to protect VMEs. To meet these regulatory requirements, ICES was requested by the European Commission to provide “advice on the list of areas where VMEs are known to occur or are likely to occur and on the existing deep-sea fishing areas (ref. (EU)2016/2336)”. The ICES workshop WKEUVME was tasked to produce the technical evidence base for producing a set of regulatory area options, building on 2019 work (Technical Service and WKREG workshop), as well as previous ICES advice (ICES 2018a) and technical services (ICES 2018b). The work drew upon the most recent fishing activity and vulnerable marine ecosystem (VME) distribution data at ICES, which has been quality assured following the respective annual ICES data calls for VMS/logbook (link) and VMEs (link). The assessment procedure herein is fully documented, with the respective scripts to run the assessment available on an open source platform (WKEUVME GitHub site). Two “assessment sheets” with respective regulatory area options for two larger ecoregions (Bay of Biscay and Iberian Coast, and the Celtic Seas) were produced. These assessment sheets served as the basis for dissemination documents for managers – stakeholders meeting of WKEUVME in September 2020, and could be incorporated into their respective annual ICES Ecosystem and Fisheries Overviews in future. There are also strong links to shallower water assessment procedures developed by WGFBIT (Working Group on Fisheries Benthic Impact and Trade-offs) that have been developed for the ICES Ecosystem Overview advice in the context of Descriptor 6 seafloor integrity of the EC’s marine strategy framework directive (MSFD). WKEUVME used a data-driven approach to provide management options for this request. Two broad scenarios were provided, each with two options. For each option a set of rules was defined for producing the outcomes. The first scenario defined VME closure polygons without any modification by known fishing activity. The first option under this scenario focused on VME habitats and areas with a High or Medium VME Index score (a multi-criteria assessment method developed by WGDEC). The second option included areas identified in option 1 and added in areas where four types of VME elements were present (areas where VMEs are likely to occur: seamounts, banks, coral mounds, and mud volcanoes); allowing managers to choose the level of precaution they wish to apply in protecting VMEs. The second scenario identified areas where the fishing footprint overlapped with VMEs and then used VME biomass/fishing intensity relationships to identify a threshold (swept-area ratio (SAR) < 0.43) for areas where effort was low and unlikely to have caused Significant Adverse Impacts to the VMEs (at C-square resolution). Two options for closing areas under this scenario were presented: the first where VME habitats and areas with a High or Medium VME Index score (irrespective of fishing effort) and only Low VME Index score with low fishing effort were closed; the other where all areas of VME presence (habitats and Low, Medium and High VME Index values) were closed, but only in areas of low fishing effort, on the basis that any VME habitat in heavily fished C-squares would be degraded