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The International Council for the Exploration of the Sea (ICES) has provided scientific stock advice based on reference points to manage fisheries in the North Atlantic Ocean and adjacent seas for decades. ICES advice integrates the precautionary approach with the objective of achieving maximum sustainable yield. Here, we examine ICES reference point evolution over the last 25 yr and provide a comprehensive empirical review of current ICES reference points for data-rich stocks (Category 1; 79 stocks). The consistency of reference point estimation with the ICES guidelines is evaluated. We demonstrate: (1) how the framework has evolved over time in an intergovernmental setting, (2) that multiple precautionary components and sources of stochasticity are included, (3) that the relationship and historical context of stock size and recruitment are crucial for non-proxy reference points, (4) that reference points are reviewed frequently, taking into account fluctuations and multiple sources of variability, (5) that there are occasional inconsistencies with the guidelines, and (6) that more comprehensive and clearer documentation is needed. Simplifying the stock-recruit typology and developing quantitative criteria would assist with this critically important classification. We recommend a well-documented, transparent, and reproducible framework, and periodic syntheses comparing applications across all stocks.

For many environmental indicators, the sustainable status can change because of changes in either the monitored state or the policy goal. Fisheries provide an intensively monitored setting to investigate the relative impacts of such change. Key fisheries sustainability indicators comprise the ratio between fishing pressure or biomass and their respective reference levels. We developed a retrospective database of population status, reference point changes and reported reasons for changes for all data-rich stocks in the ICES region. We derived methods to distinguish the impacts of either source of change (monitored state or policy goal) on sustainable status. We found that reference points changed frequently (64% of populations had reference point changes) with varying magnitudes. Contrary to expectation, reference point changes were often not compensated by changes in the state thus significantly impacting inferred sustainability status and dependent scientific advice. Across a range of life histories and assessments, changes in reference points dominate retrospective revisions in status over the full time series. Overall, status before and after the change of reference point had no significant directional differences that would suggest reference point change effecting movement towards or away from sustainability. Although multiple factors have contributed to reference point changes, our results show that the reference point definition and the technical basis for estimation were the most important reasons for change. Recognizing that reference points are not constant in time but rather form reference series is paramount to quantifying present and historical sustainability. Properly documenting, justifying and quantifying the impacts of such change is an ongoing challenge.

Theoretical size at the onset of maturity (TSOM) for female Norway lobster was estimated by a new methodology based on the probability distributions of mature individuals built on physiological maturity measures. Onset of maturity using TSOM varied from 18.4- to 33.7-mm carapace length for the Irish functional management units (FUs). These estimates showed a significant negative linear relationship (R2 = 0.60) with population density and a significant positive linear relationship with average size in females (R2 = 0.84). The size class at which 50% of the females are sexually mature (L50) was linked to the new TSOM metric by a significant positive linear relationship (R2 = 0.40). This set of linear relationships ultimately allowed TSOM and L50 to be estimated without a requirement for maturity stages to be distinguished. As well as contributing to the stock assessment and management of Nephrops (e.g. in data-limited FUs) and its potential for the calibration of more routinely used estimates, TSOM might be applied in new species and meta-analyses where size of maturity data are scarce. This new metric also better-defines the maturity process since, taken together, TSOM, L50, and smallest berried female represent sequential maturity events: (i) onset of maturity, (ii) 50% mature (from gonad staging), and (iii) berried females.

Genotyping by sequencing along with high throughput sequencing approaches allows for the rapid development and discovery of variable markers such as microsatellites, which can be highly informative for population genetics. These approaches, along with combinatorial barcoding techniques and a novel genotyping protocol, were employed to examine the population structure of commercially valuable fisheries species, Nephrops norvegicus. Results suggest at least four genetically distinct groupings of the species across the sampled distribution and the presence of isolation by distance. No evidence for genetic bottlenecks were found in any population, however the genetic structure observed in this study does not correspond to current fisheries management delineations. This study is the first to apply microsatellite markers distribution-wide for this species, revealing a population structure for Nephrops norvegicus important for informing management of this widely fished species.

There is growing international focus on ecosystem based fisheries management. Within the EU this has manifested in the provision of mixed fisheries advice, using the FCube model. The operational implementation and accuracy of this model relies on accurate identification of the technical interactions between fleets, gears and the resulting composition of species in the retained catch. These interactions are defined using units of fishing activity based on gear type and target species assemblage, but with no consideration for spatiotemporal heterogeneity. We assess the relevance of the fishing units used in relation to the spatial and temporal trends in retained catch within the Celtic Sea. To achieve this multivariate analysis (principal component and hierarchical clustering) were conducted to identify homogenous groupings of fishing activity using 5 years of international Celtic Sea retained catch data. The groupings identified demonstrate that a fairly simplistic structure of fishing activity units (country of provenance, fishing location, gear and target species) can effectively describe the complex mixed fisheries scenarios being executed within the Celtic Sea consistently across multiple years. This international and multiannual analysis improves our understanding of the mixed fisheries scenarios within the Celtic Sea and reveals a multifaceted spatial structure in the species assemblages landed, indicating the presence of several distinct mixed fisheries within the region appropriate for mixed fisheries analyses.

Peer-reviewed This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. Manuscript received January 27, 2017; revised August 17, 2017 and December 27, 2017; accepted February 16, 2018. Published in: IEEE Journal of Oceanic Engineering ( Early Access ) DOI: 10.1109/JOE.2018.2808973, This paper proposes an algorithm for mosaicing videos generated during stock assessment of seabed-burrowing species. In these surveys, video transects of the seabed are captured and the population is estimated by counting the number of burrows in the video. The mosaicing algorithm is designed to process a large amount of video data and summarize the relevant features for the survey in a single image. Hence, the algorithm is designed to be computationally inexpensive while maintaining a high degree of robustness. We adopt a registration algorithm that employs a simple translational motion model and generates a mapping to the mosaic coordinate system using a concatenation of frame-by-frame homographies. A temporal smoothness prior is used in a maximum a posteriori homography estimation algorithm to reduce noise in the motion parameters in images with small amounts of texture detail. A multiband blending scheme renders the mosaic and is optimized for the application requirements. Tests on a large data set show that the algorithm is robust enough to allow the use of mosaics as a medium for burrow counting. This will increase the verifiability of the stock assessments as well as generate a ground truth data set for the learning of an automated burrow counting algorithm., This work was supported by the Science Foundation Ireland under Award SFI-PI 08/IN.1/I2112.

This is the author’s version of a work that was accepted for publication in Fisheries Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Fisheries Research, 165,pps 1-10, doi:10.1016/j.fishres.2014.12.007, Value achieved from time spent at sea is a central driver of fishing decisions and fishing behaviors. Value per unit effort (VPUE) is an important indicator of economic performance in itself and a useful metric within integrated mixed fisheries models. A time series of Irish first sale prices and total per trip landings values (VPT) highlight heterogeneity in fish prices and VPTs achieved by the Irish fleet spatially and temporally, as well as variability with species targeting. This investigation compared models to standardize fishing trip VPUE accounting for species targeting (métier groupings), engine power (a kW proxy for vessel size), seasonal and annual variability, fishing effort, and individual vessels (encompassing variability in vessel characteristics and skipper effects). Linear mixed effects models incorporating random vessel effects and within-group variance between métier groupings performed best at describing the variability in the dataset. All investigated factors were important in explaining variability, and thus important in standardizing VPUE. Models incorporating fishing days (days with reported fishing activity) and engine power as separate variables resulted in improved AIC values. Therefore, fishing days were considered to be the most appropriate effort measure to generate VPUE. The effort unit traditionally applied in measures of per unit effort, fishing hours, performed comparatively poorly in relation to VPT.

Rihan, D., Graham, N., Reid, D. G., and Lordan, C. 2011. The provision of fishery information by ICES–WGFTFB to assessment working groups: use of information and lessons learned. – ICES Journal of Marine Science, 68: 1809–1814. ICES is now asked to provide advice that is more holistic in nature, including information on the influence and effects of human activities on the marine ecosystem. From a fishing-technology perspective, this includes information on how fishers respond and adapt to changes in regulatory frameworks, the impact of technology creep, ecosystem impacts, and changes in fleet dynamics. Recognizing the importance of this, in 2005, the ICES–Food and Agriculture Organization (FAO) Working Group on Fish Technology and Fish Behaviour (WGFTFB) began to collect data and information to support scientific advice on fisheries and ecosystem issues through a questionnaire circulated to its members. The information from the questionnaires was collated by the WGFTFB and submitted in the form of summary documents to various ICES assessment working groups. This paper describes the background to this initiative, the questionnaire structure, the type of information provided, and its utility.

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in ICES Journal of Marine Science following peer review. The definitive publisher-authenticated version “Davie, S., & Lordan, C. (2011). Examining changes in Irish fishing practices in response to the cod long-term plan. ICES Journal of Marine Science, 68(8), 1638–1646” is available online at: http://icesjms.oxfordjournals.org/content/68/8/1638, In 2009, there were marked changes in Irish demersal fishing effort owing to the implementation of a new cod long-term plan (CLTP). This replaced previous top-down cod recovery plans, first implemented in 2002, that set days-at-sea limits for fishing vessels. The new plan specifies a harvest control rule, annual effort ceilings for EU Member States, and rules for adapting fishing effort. It encourages cod avoidance, but leaves Member States to allocate effort between individual vessels. During 2009, effort was allocated through a series of pilot schemes in Ireland. These can be considered as an evolution towards co-management. Industry and state authorities worked closely together to develop strategies for effort management and cod avoidance. The impact of recent effort-management measures on the Irish fleet, fishery, and métiers affected by the CLTP is evaluated. Vessel movements within and between métiers are described and discussed, and unintended impacts resulting from the implementation of management schemes are highlighted. In future, possible fishers' responses to policy initiatives should be considered prior to implementation to minimize potentially adverse consequences.

The sex ratio in the catches of megrim ( Lepidorhombus whiffiagonis , Walbaum) varied systematically with depth on three independent trawl survey series off the west coast of Ireland. Female megrim dominated the shallow catches, while males were more common in catches from deeper waters. The size difference between the sexes alone cannot explain this pattern because it remained evident when fish length was taken into account. Therefore size-specific habitat preferences or size-selective fishing mortality cannot fully explain the observed trend in the sex ratio of megrim. Female megrim grow to a larger size, at a faster rate than males and it is likely that their differences in habitat preferences are related to this. Shallower waters are warmer during the growing season and are likely to provide better conditions for fast growth. An understanding of the mechanisms behind these patterns is an important consideration in the management and conservation of this fish stock, which might be particularly vulnerable because the commercial landings are to a large extent dominated by female megrim.

It has recently been confirmed that some species of decapod crustacean retain their gastric mill and calcified region of the eyestalks throughout their moults. It had previously been assumed that crustacea lost all growth structures that could potentially record age information, such as the bones and otoliths in fish, through moulting. In this study, a novel preparation method was used for observing growth increments within these calcified structures of Nephrops norvegicus and Cancer pagurus (Linnaeus, 1758). This method involved: boiling, drying, resin embedding, sectioning, and polishing the gastric mill and eyestalks. Clear and readable growth increments were observed in longitudinal sections of the mesocardiac ossicle of the gastric mill for N. norvegicus, and longitudinal sections of the zygocardiac ossicle of the gastric mill for C. pagurus. Growth increments were also observed in longitudinal sections of the calcified region of the eyestalk for N. norvegicus. Validation is needed to confirm the periodicity of these growth increments.

This is an author produced pre-print pdf. The article has been accepted for publication in ICES Journal of Marine Science, published by Oxford University Press. Available at: ICES J. Mar. Sci. (January/February 2015) 72(2):708-719. doi:10.1093/icesjms/fsu084. First published online: June 10, 2014, Fuel costs are an important element in models used to analyse and predict fisher behaviour for application within the wider mixed fisheries and ecosystem approaches to management. This investigation explored the predictive capability of linear and generalized additive models (GAMs) in providing daily fuel consumption estimates for fishing vessels given knowledge of their length, engine power, fleet segment (annual dominant gear type), and fuel prices. Models were fitted to half of the Irish fishing vessel economic data collected between 2003 and 2011. The predictive capabilities of the seven best models were validated against the remaining, previously un-modelled, data. The type of gear used by a fleet segment had an important influence on fuel consumption as did the price of fuel. The passive pot gear and Scottish seine gear segments indicated consistently lower consumptions, whereas dredge and pelagic gears showed consistently higher fuel consumptions. Furthermore, increasing fuel price negatively affected fuel consumption, especially for more powerful, larger vessels. Of the formulated models, the best fit to training data were a GAM with a gear main effect and two smooth functions; standardized vessel length and engine power interacting with fuel price. For prediction, overall, this model showed the closest predictions with the least bias, followed by three linear models. However, all seven models compared for predictive capability performed well for the most sampled segments (demersal and pelagic trawlers).

The stomach contents of seven male sperm whales Physeter macrocephalus (Odontoceti: Physeteridae) from the north-east Atlantic were examined. One animal was stranded on 27 November 1997 near Wassenaar (the Netherlands). Four became stranded the following day, 28 November 1997, on the island of Ameland (the Netherlands); three of these had food remains in the stomach. Samples were also examined from a whale stranded in August 1998 at Bettyhill (Scotland) and one live-stranded in March 1996 at Tory Island, Co. Donegal (Ireland). Finally, a sample of the stomach contents from a whale stranded near Terneuzen (Scheldt Estuary, the Netherlands) in February 1937 was also examined.All samples consisted almost entirely of cephalopod beaks. Some fish remains were also found in the stomach of the Wassenaar and one of the Ameland whales. The cephalopod prey were mainly oceanic species: Gonatus sp. (probably Gonatus fabricii, Oegopsida: Gonatidae) was the main prey for all the animals stranded in the Netherlands. The specimen stranded in Ireland had consumed a wider range of prey, mainly Histioteuthis bonnellii (Oegopsida: Histiotetuhidae), but also Architeuthis sp. (Oegopsida: Architeuthidae), Chiroteuthis sp. (Oegopsida: Chiroteuthidae), Teuthowenia megalops (Oegopsida: Cranchiidae) and the octopod Haliphron atlanticus (Incirrata: Alloposidae). The fish remains from the Wassenaar whale were saithe (Pollachius virens, Gadiformes: Gadidae), while remains of monkfish (Lophius sp., Lophiiformes: Lophiidae) and an unidentified fish were recorded from one of the Ameland animals.

Harvesting the commercially significant lobster, Nephrops norvegicus, is a multimillion dollar industry in Europe. Stock assessment is essential for maintaining this activity but it is conducted by manually inspecting hours of underwater surveillance videos. To improve this tedious process, we propose an automated procedure. This procedure uses mosaics for detecting the Nephrops, which improves visibility and reduces the tedious video inspection process to the browsing of a single image. In addition to this novel application approach, key contributions are made for handling the difficult lighting conditions in these kinds of videos. Mosaics are built using 1-10 minutes of footage and candidate Nephrops regions are selected using image segmentation based on local image contrast and colour features. A K-Nearest Neighbour classifier is then used to select the respective Nephrops from these candidate regions. Our final decision accuracy at 87.5% recall and precision shows a corresponding 31.5% and 79.4% improvement compared with previous work [1].

Between November 1993 and May 1997, the stomach contents of trawl-caught Illex coindetii and Todaropsis eblanae from the edge of the continental shelf west and south-west of Ireland were examined. When visually assessed, 82.1% of the I. coindetii stomachs and 73.4% of the T. eblanae stomachs had no food remains present. In both I. coindetii and T. eblanae stomachs with prey, crustaceans, particularly euphausids, are relatively more important as prey in smaller squid. As the squid grow, fish and squid become increasingly important prey. The small mesopelagic fish Maurolicus muelleri is a particularly important prey item of both species, occurring in 48.3% of I. coindetii and 34.7% of T. eblanae stomachs with prey remains. M. muelleri otoliths were also often found in high numbers. In one I. coindetii stomach, 43 pairs of otoliths were found. However, this great abundance may be an over-representation of their importance in the diet as a result of the techniques used to identify prey remains in squid stomachs. Three other pelagic fish, Gadiculus argenteus, Micromesistius poutassou, Argentina sp. and the euphausid Meganyctiphanes norvegica, are also important prey of both species. Data on possible trawlnet-associated feeding are also presented, although the importance of this as a source of error in diet studies is unclear. Using data from research vessel surveys, there seems to be a peak in feeding intensity in the early morning in I. coindetti.

This review summarizes the data on habitat, population ecology and ecosystem roles of Nephrops norvegicus. The species has a broad range in the northeast Atlantic and Mediterranean, although it is possible that small or isolated patches of suitable habitat may not be occupied due to restrictions on larval supply. Nephrops densities are related to the silt-clay content of sediments, with interactions between habitat quality and density indicating competition for resources. An analysis of density-size interactions across fishery functional management units (FUs) suggests that growth is suppressed at high densities due to competition (e.g. in the western Irish Sea), although recruitment dynamics or size-selective mortality may also shape the size structure of populations. Nephrops biomass available across FUs may be similar, reflecting a constant yield due to the inverse relationship between individual size and population density. Gaps in the understanding of Nephrops' ecology reflect uncertain ageing criteria, reliance on fisheries-dependent data and few if any undisturbed habitats in which to examine fisheries-independent interactions.

Peer- reviewed This is a pre-copy-editing, author-produced PDF of an article accepted for publication in ICES Journal of Marine Science following peer review. The definitive publisher-authenticated version is available online at: doi: 10.1093/icesjms/fst017, Demersal trawling impacts extensively on the seabed and the extent and frequency of this impact can be assessed using Vessel Monitoring Systems (VMS) data (positional data of fishing vessels). Existing approaches interpolate fishing tracks from consecutive VMS locations (track interpolation) and/or aggregate VMS point data in a spatial grid (point summation). Track interpolation can be quite inaccurate at the current 2-hour time interval between VMS records, leading to biased estimates. Point summation approaches currently only produce relative estimates of impact and are highly sensitive to the grid size chosen We propose an approach that provides absolute estimates of trawling impact from point data and is not sensitive to an arbitrary choice of grid cell size. The method involves applying a nested grid and estimating the swept area (area covered by fishing gear) for each VMS point. We show that the ratio of the swept area to the surface area of a cell can be related to the proportion of the seabed that was impacted by the gear a given number of times. We validate the accuracy of this swept-area ratio approach using known vessel tracks and apply the method to international VMS data in the Celtic Sea., Funder: Marine Institute

This review summarizes the data on habitat, population ecology and ecosystem roles of Nephrops norvegicus. The species has a broad range in the northeast Atlantic and Mediterranean, although it is possible that small or isolated patches of suitable habitat may not be occupied due to restrictions on larval supply. Nephrops densities are related to the silt–clay content of sediments, with interactions between habitat quality and density indicating competition for resources. An analysis of density–size interactions across fishery functional management units (FUs) suggests that growth is suppressed at high densities due to competition (e.g. in the western Irish Sea), although recruitment dynamics or size-selective mortality may also shape the size structure of populations. Nephrops biomass available across FUs may be similar, reflecting a constant yield due to the inverse relationship between individual size and population density. Gaps in the understanding of Nephrops’ ecology reflect uncertain ageing criteria, reliance on fisheries-dependent data and few if any undisturbed habitats in which to examine fisheries-independent interactions.

High-resolution fisheries data from integrated logbook and Vessel Monitoring Systems (VMS) records have revealed a detailed spatial structure in the species composition of the retained catches of the Irish demersal otter trawl fleets. Hierarchical cluster analysis was used to define 8 clusters with relatively homogenous species compositions. These clusters formed 34 distinct spatial regions in the waters around Ireland. Identification of these regions can be useful for a number applications, including spatial stratification of commercial or survey data, defining and characterising fishing grounds for marine spatial planning, evaluation of closed areas and prediction of how fishing effort might be re-allocated following a closure. A case-study is presented that explores options to reduce cod (Gadus morhua) catches by implementing seasonal closures in two of the 34 regions. Cod are caught by demersal trawlers in a mixed fishery and the catches often exceed the quota, resulting in discarding of marketable fish. Two regions were identified that had relatively low effort and high cod landings. The effects of closing these regions during the first quarter of the year were explored. Cod catches were likely to be reduced by 8–22% while only 3–9% of the annual demersal otter trawl effort would be displaced. Whiting catches were also likely to be reduced, the change in catches of some other species depended on the assumed effort displacement.

Stomach contents of Loligo forbesi obtained from commercial landings and research cruises in Irish waters and the Irish Sea were examined. A total of 62.3% of stomachs were empty. Fish remains occurred in 73.7% of all full or partially full stomachs, with crustaceans and cephalopods occurring in 26.4% and 7.5% respectively, L. forbesi was found to consume a wide range of fish and crustacean prey. Sagittal otoliths were used to identify fish species, and vertebrate to identify families. The most frequent species by per cent occurrence sprat (Sprattus sprattus), poor cod (Trisopterus minutus), Norway pout (T. esmarkii), and transparent goby (Aphia minuta). Crustaceans were the main prey item is squid of less than 100 mm mantle length, together with small clupeids and gobies. the predominant prey of medium-sized squid (100–220 mm) was found to be gadoid and clupeid fish, while gadoids and other cephalopods were the main prey of larger squid (>220 mm). Seasonal differences in the diet were apparent but were shown to be influenced by seasonal changes in squid size.

NOTICE: this is the author’s version of a work that was accepted for publication in Fisheries Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Fisheries Research, [Volume 111, Issue 3, (November 2011)] doi: 10.1016/j.fishres.2011.07.005 http://www.sciencedirect.com/science/article/pii/S0165783611002505, peer-reviewed, The Irish otter trawl fleet operates in a complex multi-species multi-gear fishery, spanning a wide geographic area, and involving around 275 trawlers. Factorial and clustering methods were applied to 2003 fishing trip data to define thirty-three métiers. Definitions were based on six trip characteristics taken from logbooks, namely: fishing gear, mesh size, vessel length, species composition, area, and month. Métiers exploiting demersal species or species groups are characterised by single vessel bottom otter trawls, typically with mesh sizes of 70 mm or more, operating year round. This includes nine Nephrops dominated métiers highlighting the importance of this species to the fleet. Many demersal métiers are characterised by groups of species, such as mixed whitefish or slope species. Métiers exploiting pelagic species are often focussed on single species, and are typically seasonal, mid-water trawling (often paired) with mesh sizes less than 70 mm. Pelagic métiers account for the majority of landings by over an order of magnitude in several cases. Demersal métiers account for the majority of fishing trips and effort, (primarily Nephrops métiers), and vessels (primarily mixed species métiers). The new métier definitions were found to be appropriate remained relevant despite declining fleet landings and effort between 2003 and 2006. Species compositions within these métiers have generally remained similar to the proportions defined in 2003. These robust métier definitions present opportunities to improve fisheries sampling, assessment and management. Although métiers pose complexity challenge for such applications they can be used the building blocks for appropriate management units.

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in ICES Journal of Marine Science following peer review. The definitive publisher-authenticated version “Lordan, C., Ó Cuaig, M., Graham, N., Rihan, D. The ups and downs of working with industry to collect fishery-dependent data: the Irish experience. (2011) ICES Journal of Marine Science, 68 (8), pp. 1670–1678” is available online at: http://icesjms.oxfordjournals.org/content/68/8/1670, peer-reviewed, Working with the fishing industry to collect fishery-dependent data for scientific and advisory purposes is essential in most countries, but despite the many advantages of working with fishers, it is not without challenges. The objectives and the ups and downs of 16 recent projects in Ireland are described, and four case studies are discussed in detail. Some common themes that characterize both successful and unsuccessful experiences are identified. One critical aspect is industry’s sometimes unrealistic time-horizons and expectations when engaging in scientific data collection. Detailed communication of objectives, procedures, results, and relevance not only to industry representatives, but also to vessel owners and crew, is required throughout the life cycle of a project. For some projects, there is a clear need to include incentives in the design, but for others this is less critical. The critical needs for ongoing quality control and assurance, validation of data, and appropriate project design are discussed, along with the link between successful management systems and participatory research. Finally, comment is provided on how the expected reforms of the EU’s Common Fisheries Policy will place new demands on joint research.

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in ICES Journal of Marine Science following peer review. The definitive publisher-authenticated version “Gerritsen H., Lordan C., Integrating vessel monitoring systems (VMS) data with daily catch data from logbooks to explore the spatial distribution of catch and effort at high resolution. (2011) ICES Journal of Marine Science, 68 (1): 245-252” is available online at: http://icesjms.oxfordjournals.org/content/68/1/245, peer-reviewed, Vessel monitoring systems (VMS) automatically collect positional data from fishing vessels. The VMS data can be linked to catch data from logbooks to provide a census of spatially resolved catch-and-effort data. We explore and validate the most appropriate and practical method for integrating Irish VMS and logbook data. A simple speed rule is applied to identify VMS records that correspond to fishing activity. These data are then integrated with the catch data from logbooks using date and vessel identifier. A number of assumptions were investigated, and the resulting distribution maps of catch and effort appear to be unbiased. The method is illustrated with an example of a time-series of spatially explicit catch-per-unit-effort (cpue) estimates. The proposed method is relatively simple and does not require specialist software or computationally intensive methods. It will be possible to generalize this approach to similar datasets that are available within the EU and many other regions. Analysis of integrated VMS and logbook data will allow fisheries data to be analysed on a considerably finer spatial scale than was possible in the past, which opens up a range of potential applications.

Records of the squid (Loligo forbesi) egg masses which were incidentally caught in demersal trawls at three offshore sites are presented. These sites were at water depths of 135, 302 and 507 m. This represents the deepest ever record of spawning in a loliginid squid species. There has been speculation in the literature about offshore spawning in L. forbesi but it has not previously been recorded and may have important implications for the life cycle.

Knowledge of the spatial distribution and habitat associations of species in relation to the environment is essential for their management and conservation. Habitat suitability models are useful in quantifying species- environment relationships and predicting species distribution patterns. Little is known, however, about the stability and performance of habitat suitability models when projected into new areas (spatial transferability) and how this can inform resource management. The aims of this study were to model habitat suitability of Norway lobster (Nephrops norvegicus) in five fished areas of the Northeast Atlantic (Aran ground, Irish Sea, Celtic Sea, Scotland Inshore and Fladen ground), and to test for spatial transferability of habitat models among multiple regions. Nephrops burrow density was modelled using generalised additive models (GAMs) with predictors selected from four environmental variables (depth, slope, sediment and rugosity). Models were evaluated and tested for spatial transferability among areas. The optimum models (lowest AICc) for different areas always included depth and sediment as predictors. Burrow densities were generally greater at depth and in finer sediments, but relationships for individual areas were sometimes more complex. Aside from an inclusion of depth and sediment, the optimum models differed between fished areas. When it came to tests of spatial transferability, however, most of the models were able to predict Nephrops density in other areas. Furthermore, transferability was not dependent on use of the optimum models since competing models were also able to achieve a similar level of transferability to new areas. A degree of decoupling between model 'fitting' performance and spatial transferability supports the use of simpler models when extrapolating habitat suitability maps to different areas. Differences in the form and performance of models from different areas may supply further information on the processes shaping species' distributions. Spatial transferability of habitat models can be used to support fishery management when the information is scarce but caution needs to be applied when making inference and a multi-area transferability analysis is preferable to bilateral comparisons between areas.

Todarodes sagittatus (N=1131) were opportunistically sampled from commercial and research trawling in Irish and Scottish waters between 1993 and 1998. The results suggest that the species is common in deep waters (>200 m) to the west of Ireland and Scotland, particularly in late summer and autumn. The size of squid caught was related to depth, with larger squid caught deeper, and is indicative of an ontogenetic, bathymetric migration. Females were more common (sex ratio 1·00:0·46), and attained a larger maximum size (520 mm mantle length (ML)) than males (426 mm ML). Mature females (360–520 mm ML) were caught in deep water (>500 m), between March and November, with a large catch of mature females taken off the west coast of Ireland in August 1996. Mature males (300–426 mm) were found from August to November. Potential fecundity was estimated to range from 205,000–523,500 eggs female−1. Putative daily increments in statoliths indicated a life cycle of slightly over a year, with rapid growth of approximately 1·8 mm d−1 during subadult and adult life. Fish were the most important prey of T. sagittatus and 17 fish prey taxa were identified, of which pelagic species were the most important.

Records of unusual cephalopods, taken as by-catch in Irish and Scottish waters in the years 1985–1995, are presented. Of most interest are three specimens of giant squid (Architeuthis) that were caught in bottom trawls off the west of Ireland between April and June 1995, all were mature males of mantle length ∼1000 mm. Other records include a large mature female Histioteuthis bonnellii from the west of Ireland and three specimens of the gelatinous incirrate octopus, Haliphron atlanticus.