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Papers by Paul Winger

Journal of Marine Science and Engineering, 2022

The hydrodynamic performance of one full-scale T0 (mesh size 90 mm) and three T90 (mesh size 90, ... more The hydrodynamic performance of one full-scale T0 (mesh size 90 mm) and three T90 (mesh size 90, 100, and 110 mm) codends was investigated and compared using flume tank testing, with and without a small-mesh cover. We evaluated how flow velocity, mesh circularity, and drag changed in each codend at five different towing speeds (0.5–0.9 m/s). The results demonstrated that flow velocity decreased along the length of a codend, and this effect was pronounced in the T0 codend. Increasing the mesh size of T90 codends from 90 to 110 mm did not significantly affect flow velocity. A novel parameter, termed mesh circularity, was developed and introduced to describe mesh opening. Mesh circularity in the T0 codend decreased along the length of the codend, which contrasted with the T90 codends. Results showed that the T90 codends maintained relatively open meshes (circularity ranged from ~0.8 to 1.0 along the length of the codend) compared to the T0 (circularity ranged from ~0.6 to 0.4). Each T9...

Marine Pollution Bulletin, 2022

To prevent the spread of the COVID-19 contagion, some regions of Brazil implemented a prohibition... more To prevent the spread of the COVID-19 contagion, some regions of Brazil implemented a prohibition of beach use, which contributed to a reduction of artisanal fishing activity. This study aimed to evaluate the influence of these beach closures on the incidence of abandoned, lost, or discarded fishing gear (ALDFG) along four beaches located on the northern coast of Pernambuco, Brazil. The absolute and relative frequency of occurrence and the number of observations per unit of effort (OPUE) between the periods before and after the prohibition period were analyzed. A total of 1935 fishing gear residues were found (63% before and 37% after prohibition). There was also a significant reduction in OPUE and in absolute frequency (p < 0.05) between these two periods. Although beach closures appear to have contributed to a reduction in the amount of ALDFG in the region, it does not indicate a complete pause in fishing activities.

This file contains data associated with a study of active buoyancy adjustment (ABA) in holothuroi... more This file contains data associated with a study of active buoyancy adjustment (ABA) in holothuroid echinoderm

Aquaculture and Fisheries, 2021

This study evaluated the hydrodynamic forces produced by whole panels of handmade (geometrically ... more This study evaluated the hydrodynamic forces produced by whole panels of handmade (geometrically different) rope meshes typically found in midwater trawls. Experimental treatments included both knotted and knotless meshes constructed of helix composite ropes, conventional braided nylon (PA) ropes, and twisted polyethylene (PE) ropes. Direct measurement of lift (L) and drag (D) forces were conducted using controlled flume tank experiments on panels oriented at 21°relative to the flow. For knotted netting, our results showed that the hydrodynamic forces (L and D) were statistically higher for helix ropes compared to conventional ropes of the same diameter. For knotless netting constructed of helix ropes, our primary finding is that the arrangement of helix ropes (S and Z lay) in individual meshes significantly affects the resulting D and C d of whole netting panels. Arranging the mesh bars in the S-Z-S-Z lay pattern exhibited 29% and 32% lower drag (D) compared to S-S-S-S and S-S-Z-Z lay meshes, respectively. We also use computational fluid dynamics (CFD) to characterize the finescale flow-field around helix and conventional ropes. The resulting streamlines and pressure contours provide a functional explanation for the empirical measurements collected in the flume tank. These results can be useful in informing the design of midwater trawls.

An international technical workshop to discuss the capture of gadoids (cods, haddock, and saithe/... more An international technical workshop to discuss the capture of gadoids (cods, haddock, and saithe/pollock) in baited traps, or pots, was held in Gloucester, Massachusetts, USA on 4 November 2006. Attendance at the workshop included 50 scientists and fishermen actively studying pot capture of gadoids, technical staff and others interested in pots in general from 16 nations and five continents. The workshop determined basic principles for potting gadoid species by examining the current state of research on gadoid capture in pots and assessing the direction of future research for improving catch rates. Conclusions suggested that research into pots was still at an early stage, and that much vital work needed to be done; however, pot volume and orientation of the bait plume and entrances were identified as important factors. Future studies using a combination of laboratory and field techniques to identify critical design details and behavioral factors such as reaction and behavioral thres...

High incidental catches of Greenland shark (Somniosus microcephalus) in Greenland halibut (Reinha... more High incidental catches of Greenland shark (Somniosus microcephalus) in Greenland halibut (Reinhardtius hippoglossoides) longline fisheries has led to studies on the feasibility of capturing halibut with baited pots. In this study I compare catch data among six experimental pots and examine video of halibut interacting with pots. Catch rates of halibut did not differ among treatments and pots did not produced substantial amounts of bycatch. Video observations revealed that halibut become entangled by their teeth significantly more often in entrance funnels constructed with 50 mm than with 19 mm netting, resulting in 45% higher entry rates in the latter. Most (80%) halibut approached pots against the current following the scent of the bait. I recommend that future studies consider a four-entrance pot to ensure an entrance is aligned with bottom currents. To reduce likelihood of entanglement, I recommend 19 mm netting for entrance funnels, 100 mm polyethylene for exterior panels, and ...

Fisheries Research, 2020

Luminescent netting increases the catch rate of snow crabs (Chionoecetes opilio) over short soak ... more Luminescent netting increases the catch rate of snow crabs (Chionoecetes opilio) over short soak times (1 d), however the commercial fishery often requires longer soak periods, up to1 week. Building on previous research, this study investigated the catch efficiency and size selectivity of pots with luminescent netting over long soak times (144-336 h) in the inshore snow crab fishery of Newfoundland, Canada. A total allowable catch and individual quota allocation management system for snow crab is regulated in Canada and using luminescent netting to increase catch rates would reduce the carbon footprint of the fishery by reducing days fished. Our results showed that luminescent pots had a 21.6 % and 18.3 % higher catch-per-unit-effort (CPUE; number of crabs per pot) of legal-sized crab and sub-legal sized crab, respectively, than control pots; with no difference for soft-shelled crab. Additionally, no significant differences were shown for size selectivity over the range of carapace widths observed between luminescent and control pots. Little other bycatch (female snow crab and unwanted species) were caught in either pot treatments. This study shows that luminescent netting increases the efficiency of the snow crab fishery, which provides economic and environmental benefits.

Aquaculture and Fisheries, 2020

The size selectivity and usability of three codends were quantified and compared for the first ti... more The size selectivity and usability of three codends were quantified and compared for the first time in the inshore Northern shrimp (Pandalus borealis) trawl fishery of Iceland using the covered codend method: a conventional diamond-mesh codend (T0), conventional square-mesh codend (T45), and a 90 • turned mesh codend (T90) constructed of four panels and with shortened lastridge ropes. Fishers, wanting to increase the average-individual size of captured shrimp, had requested the T90 codend to be compared with conventional codends for consideration in the fishery. Results showed that, on average, the T45 and T90 codends had better size selectivity than the T0 codend in terms of releasing individuals smaller than 13 mm carapace length (Minimum References Size; MRS). The T90 codend retained significantly less Northern shrimps between 9 and 19 mm than the T0 codend and between 15 and 19 mm than the T45 codend. No significant difference of size selectivity between T45 and T0 codends was observed. All three codends presented high retention ratios of Northern shrimps above MRS (>63%) for the population encountered. However, the T0 codend was not effective at sorting out small Northern shrimps; at least 86% of Northern shrimps smaller than 13 mm were retained in the T0 codend if encountered. Catches from T45 and T90 codends had a lower proportion of shrimp below MRS. Since discarding of undersized Northern shrimps is prohibited in Iceland and fishers wanted to catch on average larger shrimp, using the novel T90 codend would enable fishers to use their quotas more efficiently.

PeerJ, 2019

Commercial harvesting of snow crab (Chionoecetes opilio) in the Barents Sea started in 2012 by No... more Commercial harvesting of snow crab (Chionoecetes opilio) in the Barents Sea started in 2012 by Norwegian fishing vessels. This new fishery has significant bait requirements, representing an emerging conservation challenge. In this study, we evaluate the performance of five alternative (natural) baits manufactured from the waste stream of existing and sustainably managed harp seal (Pagophilus groenlandicus) and minke whale (Balaenoptera acutorostrata) capture. Five different types of new bait were evaluated, including seal fat (SF), seal fat with skin (SFS), seal meat with bone (SMB), whale fat with skin (WFS), and whale meat with fat (WMF). A comparative fishing experiment was conducted onboard a commercial snow crab fishing vessel in the Barents Sea (May–June, 2016) to evaluate the performance of traditional bait (squid, Illexs spp.) and alternative baits at catching snow crabs. Performance of the different baits were compared on the basis of the number of commercial crab caught pe...

Fisheries Research, 2019

The size selectivity and usability of two diamond mesh codends, a traditional two-panel codend ve... more The size selectivity and usability of two diamond mesh codends, a traditional two-panel codend versus an experimental four-panel ultra-cross knotless mesh codend, were compared using the covered codend method in the Iceland redfish (Sebastes norvegicus and S. viviparous) fishery. Results showed that there was no significant difference in size selectivity between the codends at lengths greater than 29 cm for S. norvegicus and 19 cm for S. viviparous. At smaller lengths, size selectivity was undetermined due to small catches at those sizes. For S. norvegicus, both codends demonstrated a high retention ratio (93.4 and 92.9%, respectively) above the minimum reference length (MRL; 33 cm), but also had a high retention below MRL (90.9 and 83.4%, respectively). However, the actual proportion of catch below MRL was low due to few small fish on fishing grounds. Since these fish are difficult to tell apart and have similar morphologies, we investigated the size selectivity of the two codends for both species combined, resulting in similar results of no difference in size selectivity, but a large increase in actual catches below MRL, which were primarily S. viviparous. This study concludes that the experimental codend does not improve the size selectivity or usability in the Iceland redfish fishery and both codends will retain large proportions of undersized fish if present on fishing grounds; however, few undersized fish were present in the study area.

ICES Journal of Marine Science, 2019

Snow crab (Chionoecetes opilio) has become an important species for the Norwegian seafood industr... more Snow crab (Chionoecetes opilio) has become an important species for the Norwegian seafood industry since its first commercial harvest in 2012. However, periodically catch rates can be low, causing a financial strain on the fishery. Thus, improving the catch rate of existing pot designs has the potential to significantly improve the profitability of fishing enterprises. In this study, we investigated whether the addition of low-powered purple and white light-emitting diode (LED) fishing lights inside the pots could improve catch rates of snow crab in the Barents Sea. Results showed that pots with purple lights harvested a 12.8% higher catch per unit effort (CPUE; number of crab per pot) of legal-sized crab, which was significantly more than the control pots (p = 0.035); pots with white lights did not catch significantly more crab (p > 0.05). Pots equipped with only light (no bait) caught very few crabs and were not considered a viable alternative. Although purple LEDs increased sn...

Journal of Animal Ecology, 2019

Canadian Journal of Fisheries and Aquatic Sciences, 2017

We developed and evaluated an innovative trawl technology that reduces seabed contact while targe... more We developed and evaluated an innovative trawl technology that reduces seabed contact while targeting northern shrimp (Pandalus borealis) off the east coast of Canada. The innovative footgear, referred to as the “aligned footgear”, was evaluated in a flume tank to estimate contact area with the seabed and then tested at sea for engineering performance and catchability. Results demonstrated that the aligned footgear trawl produced a substantial reduction (i.e., 61%) in the predicted contact area with the seabed compared with the identical trawl equipped with traditional rockhopper footgear. A total of 20 paired tows (n = 40 tows) were subsequently conducted at sea to evaluate fishing performance. The aligned footgear trawl caught significantly more northern shrimp (+23%), capelin (Mallotus villosus) (+71%), and Greenland halibut (Reinhardtius hippoglossoides) (+99%) compared with the traditional rockhopper bottom trawl.

Fish and Fisheries, 2015

Management and technical approaches that achieve a sustainable level of fish production while at ... more Management and technical approaches that achieve a sustainable level of fish production while at the same time minimising or limiting the wider ecological effects caused through fishing gear contact with the seabed might be considered to be 'best practice'. To identify future knowledge-needs that would help to support a transition towards the adoption of best practices for trawling a prioritisation exercise was undertaken with a group of 39 practitioners from the seafood industry and management, and 13 research scientists who have an active research interest in bottom-trawl and dredge fisheries. A list of 108 knowledge-needs related to trawl and dredge fisheries was developed in conjunction with an 'expert task force'. The long list was further refined through a three stage process of voting and scoring, including discussions of each knowledge-need. The top 25 knowledge-needs are presented, as scored separately by practitioners and scientists. There was considerable consistency in the priorities identified by these two groups. The top priority knowledge-need to improve current understanding on the distribution and extent of different habitat types also reinforced the concomitant need for the provision and access to data on the spatial and temporal distribution of all forms of towed bottom-fishing activities. Many of the other top 25 knowledge-needs concerned the evaluation of different management approaches or implementation of different fishing practices, particularly those that explore trade-offs between effects of bottom-trawling on biodiversity and ecosystem services and the benefits of fish production as food.

2013 Oceans San Diego, Sep 1, 2013

Although the problem of terrestrial camera calibration has been studied extensively, this knowled... more Although the problem of terrestrial camera calibration has been studied extensively, this knowledge does not necessarily transfer to the underwater environment directly. Because of the significant differences between the optical properties of the two transfer media, it is necessary to address the task of underwater camera calibration as a unique problem. Correspondingly, this paper studies the differences between terrestrial and underwater camera calibration and shows that the calibrated camera models are significantly different in these two environments. Thus, the necessity for in-situ calibration for an underwater environment is quantitatively ascertained. In addition, an underwater stereoscopic vision system is calibrated employing two calibration algorithms; namely, the Rahman-Krouglicof and the Heikkila algorithm. Since the mathematical formulations of the calibration problem in both environments are identical, a general calibration algorithm can be adopted for an underwater application provided that it is robust enough to overcome the suboptimal imaging conditions of an underwater environment. In order to identify a suitable calibration algorithm for aquatic environments, this paper assesses the stereoscopic performance of the two calibration algorithms in terms of reconstruction error. The experimental data confirms that the Rahman-Krouglicof algorithm is well-equipped to address the peculiarities of underwater 3D reconstruction.

Aquatic Telemetry, 2002

... Paul D. Winger1,∗ , Barry R. McCallum2, Stephen J. Walsh2 &amp; Joseph A. Brown3 1Bio... more ... Paul D. Winger1,∗ , Barry R. McCallum2, Stephen J. Walsh2 &amp; Joseph A. Brown3 1Biopsychology Program, Departments of Biology and ... Transmitters deployed in the morning were consumed faster (mean soak time = 3.3 h) than transmitters deployed in the afternoon (mean ...

DESCRIPTION This study compared the effectiveness of a reduced seabed impact footgear versus a tr... more DESCRIPTION This study compared the effectiveness of a reduced seabed impact footgear versus a traditional rockhopper footgear on identical bottom trawls targeting northern shrimp (Pandalus borealis) in Newfoundland and Labrador, Canada. The experimental trawl used in this study was designed to be low seabed impact through the reduction of contact area of the footgear by replacing traditional heavy rockhopper footgear with only a few drop chains lightly in contact with the seabed (i.e., drop chain footgear). Two variants of the experimental drop chain footgear (9-drop chain and 5-drop chain) were designed, evaluated in a flume tank to estimate contact area with the seabed, and then briefly tested at sea for engineering performance and catchability. Results from the flume tank tests were encouraging, demonstrating that the traditional and experimental trawls were similar in performance, but with the experimental drop chain footgears producing substantial reductions in the predicted c...

Fisheries Research, 2015

Fillet discolouration, commonly known as bruising, is an unintended and undesirable consequence i... more Fillet discolouration, commonly known as bruising, is an unintended and undesirable consequence in many commercial fishing operations. The purpose of this study was to develop a method to objectively measure and characterize the size and location of discolouration patterns that are currently observed in the fillets of commercially harvested yellowtail flounder (Limanda ferruginea) on the east coast of Canada. To accomplish this, an image processing program was developed to analyse fillet discolouration patterns. Total discoloured area and percent fillet coverage were measured and compared to total bruise weight and percent bruise weight attained from manual assessment. Results revealed that bruising was evident in 86.5% of the fish sampled. Of all the parameters measured, fish weight was the only parameter correlated with bruise weight. Bruise area ranged from 0 to 124.5 cm 2 , with a mean of 12.1 cm 2 (s.d. = 21.4), and accounted for an average of 4.3% of fillet area. Bruises were not uniformly distributed on any of the fillet sides. Results revealed a strong tendency for bruising to occur at the anterior dorsal region of the fillet, commonly known as the "nape". Functional explanations for this finding are provided, including recommendations for future research.