121 results on '"Lordan, Colm"'
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2. Burrow emergence rhythms of Nephrops norvegicus by UWTV and surveying biases
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Aguzzi, Jacopo, Bahamon, Nixon, Doyle, Jennifer, Lordan, Colm, Tuck, Ian D., Chiarini, Matteo, Martinelli, Michela, and Company, Joan B.
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- 2021
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3. Stochastic modelling and synthesis of dynamic fish recruitment productivity in the Celtic Seas ecoregion
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Silvar-Viladomiu, Paula, primary, Minto, Cóilín, additional, Lordan, Colm, additional, Brophy, Deirdre, additional, Bell, Rich, additional, Collie, Jeremy, additional, and Reid, David, additional
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- 2023
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4. Established and Emerging Research Trends in Norway Lobster, Nephrops norvegicus
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Aguzzi, Jacopo, primary, Violino, Simona, additional, Costa, Corrado, additional, Bahamon, Nixon, additional, Navarro, Joan, additional, Chatzievangelou, Damianos, additional, Robinson, Nathan J., additional, Doyle, Jennifer, additional, Martinelli, Michela, additional, Lordan, Colm, additional, and Company, Joan B., additional
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- 2023
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5. An empirical review of ICES reference points
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Silvar-Viladomiu, Paula, primary, Batts, Luke, additional, Minto, Cóilín, additional, Miller, David, additional, and Lordan, Colm, additional
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- 2022
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6. Metapopulation connectivity via larval transport of the Norway lobster Nephrops norvegicus in waters around Ireland : a modelled approach
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O’Sullivan, David, Lordan, Colm, Doyle, Jennifer, Berry, Alan, and Lyons, Kieran
- Published
- 2015
7. Advancing fishery-independent stock assessments for the Norway lobster (Nephrops norvegicus) with new monitoring technologies
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Aguzzi, Jacopo, primary, Chatzievangelou, Damianos, additional, Robinson, Nathan J., additional, Bahamon, Nixon, additional, Berry, Alan, additional, Carreras, Marc, additional, Company, Joan Batista, additional, Costa, Corrado, additional, del Rio Fernandez, Joaquin, additional, Falahzadeh, Ahmad, additional, Fifas, Spyros, additional, Flögel, Sascha, additional, Grinyó, Jordi, additional, Jónasson, Jonas Pall, additional, Jonsson, Patrik, additional, Lordan, Colm, additional, Lundy, Mathieu, additional, Marini, Simone, additional, Martinelli, Michela, additional, Masmitja, Ivan, additional, Mirimin, Luca, additional, Naseer, Atif, additional, Navarro, Joan, additional, Palomeras, Narcis, additional, Picardi, Giacomo, additional, Silva, Cristina, additional, Stefanni, Sergio, additional, Vigo, Maria, additional, Vila, Yolanda, additional, Weetman, Adrian, additional, and Doyle, Jennifer, additional
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- 2022
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8. INVESTIGATING THE FEASIBILITY OF USING GROWTH INCREMENTS FOR AGE DETERMINATION OF NORWAY LOBSTER (NEPHROPS NORVEGICUS) AND BROWN CRAB (CANCER PAGURUS)
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Sheridan, Michael, Officer, Rick, O'Connor, Ian, and Lordan, Colm
- Published
- 2015
9. Long‐term interannual variability in larval dispersal and connectivity of the Norway lobster (Nephrops norvegicus) around Ireland: When supply‐side matters
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McGeady, Ryan, primary, Lordan, Colm, additional, and Power, Anne Marie, additional
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- 2022
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10. Workshop on ICES Reference Points (WKREF1)
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Albertsen, Christoffer Moesgaard, Bartolino, Valerio, Nord, Mikaela Bergenius, Cerviño, Santiago, van Deurs, Mikael, Dingsør, Gjert Endre, Duplisea, Daniel, Fall, Johanna, Garcia, Dorleta, Gillijam, David, Goñji, NIcolas, Gras, Michaël, Gröhsler, Tomas, Hommik, Kristiina, Horbowy, Jan, Howell, Daniel, Ibaibarriaga, Leire, Jounela, Pekka, Kell, Laurence, Kvamme, Cecilie, Lambert, Debra, Lecomte, Jean-Baptiste, Lordan, Colm, Lövgren, Johan, Lynch, Patrick, Masnadi, Francesco, Methot, Richard D., Miethe, Tanja, Miller, David, Minto, Cóilín, Mosqueira, Iago, Nimmegeers, Sofie, De Oliveira, José, Orio, Alessandro, Pastoors, Martin, Reid, David, Sharma, Rishi, Silva, Andreia, Simmonds, John, Sparholt, Henrik, Stoetera, Sven, Taylor, Marc, Trijoulet, Vanessa, Uriarte, Andres, Vansteenbrugge, Lies, Vatnehol, Sindre, Villanueva, Ching, and Wise, Laura
- Abstract
The ICES Workshop on ICES reference points (WKREF1) was tasked to provide a thorough review of the ICES reference points system as a basis to re-evaluate the process for estimating, updating and communicating reference points in the context of the ICES advice. As part of the preparation leading to WKREF1 a large database of the most recent assessment outputs for 78 Category 1 stocks were collated in the form `FLStock` objects, which formed the basis for several components of the presented analyses.The first part of the meeting involved a detailed overview of the history and basis of the ICES references points system, which was aligned with the results of an empirical review of the procedures and choices made to derive ICES reference points for category 1 stocks. The ICES procedures were then contrasted with those used in the USA, Canada, New Zealand and across tuna Regional Fishery Management Organizations. A limitation in terms of transparency of the ICES procedures is a lack of complete documentation of the settings used for deriving reference points using, e.g., the EQSIM software. In comparison to other international standards, the main differences identified include the absence of a target biomass reference point and inconsistent estimates of the limit biomass reference point Blim, which is estimated to be below 10% of the unfished biomass (B0) for a high proportion of analysed stocks (around 50%). In addition, an important difference is that direct estimates of FMSY are used in ICES (which can be unreliable), whereas elsewhere FMSY is often replaced by more conservative biological proxies, such as Fspr% and FB%.The second part focused on the robustness evaluation of the current ICES reference point system. Work presented included examples that demonstrate differences in reference point estimates between standard ICES procedures (EQSIM) and full Management Strategy Evaluation (MSE) simulations, and a study that highlighted the considerable uncertainty in estimating Blim, with guidance on how to quantify uncertainty depending on length and contrast in the time-series. A large simulation experiment was conducted by applying a short-cut MSE approach to 68 Category 1 stocks, which revealed that the ICES MSY advice rule is the least robust of all tested generic approaches if assumptions about the typically highly uncertain stock recruitment relationship are violated. This led to poor performance of the ICES MSY advice rule associated with the lowest long-term yields, highest risks to fall below limit reference points and lowest probabilities of attaining biomass levels at MSY. Contributing factors to the poor performance were combinations of comparably high FMSY estimates and low Blim (trigger (lim > 10% B0), performance improved notably. Results from a backtest using hindcasting with forecasts of 1-5 years reinforced the need to re-estimate reference points regularly at benchmark assessments, and that short-term forecasts should not exceed a three-year time span to account for time-varying biological traits. Finally, presented work highlighted the advantages (in terms of high consistency and accuracy) of estimating the stock-recruitment relationship or reference points internally in the assessment model, which was illustrated for Stock Synthesis and SAM, and supported by a comprehensive simulation study.The key recommendations of WKREF1 were to: i) revise and simplify how Blim is derived. An absolute Blim should only be specified empirically in cases where there is sufficient contrast in the stock-recruit data to estimate a well-defined break-point. Alternatively, it is suggested that Blim should be determined as a plausible ratio of B0 based on biological principles and the life history of the stock (e.g. 10-25% B0 depending on the stocks characteristic; Section 7). ; ii) FP.05 should be calculated without Btrigger; iii) to use biological proxies (Fbrp) for deriving FMSY, and the resultant FMSY proxy must not exceed FP.05; iv) to report biomass target (Btrg) that corresponds to the FMSY proxy; and v) to set Btrigger as either a fraction of Btrg or multiplier of Blim. Specifications of setting reference points (e.g. Fbrp) or Btrigger should be informed through further simulation testing to be presented at WKREF2.
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- 2022
11. Workshop on ICES reference points (WKREF2)
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Lordan, Colm, Orio, Alessandro, Kempf, Alexander, Pierucci, Andrea, Kuparinen, Anna, Rindorf, Anna, Peyronnet, Arnaud, Wilson, Ashley, Albertsen, Christoffer Moesgaard, Konrad, Christoph, Sparrevohn, Claus Reedtz, Minto, Cóilín, Howell, Daniel, Gilljam, David, Miller, David, Garcia, Dorleta, Armelloni, Enrico, Abad, Esther, Masnadi, Francesco, Scarcella, Giuseppe, Dingsør, Gjert Endre, Winker, Henning, Sparholt, Henrik, Farias, Inês, Horbowy, Jan, Lecomte, Jean-Baptiste, Hutchings, Jeffrey A., Fall, Johanna, Lövgren, Johan, Simmonds, John, Shrives, Jonathan, De Oliveira, José, Hommik, Kristiina, Kell, Laurence, Vansteenbrugge, Lies, Borges, Lisa, Batts, Luke, Taylor, Marc, Pastoors, Martin, Scanu, Martina, Cardinale, Massimiliano, Gras, Michaël, van Deurs, Mikael, Goñi, Nicolas, Graham, Norman, Silvar Viladomiu, Paula, Sampedro, Paz, Hilborn, Ray, Sharma, Rishi, Millar, Sarah, Nimmegeers, Sofie, Miethe, Tanja, Perälä, Tommi, and Bartolino, Valerio
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kalakannat ,vesiekosysteemit ,viitearvot ,sääntely ,tehokalastus ,saaliit ,meret ,populaatiodynamiikka - Abstract
The ICES Workshop on ICES reference points (WKREF2) was tasked review the WKREF1 report and based on the outcome develop updated guidelines for the ICES reference points system and recommendations for ACOM consideration. The WKREF1 report has suggested 5 key recommendations to simplify and harmonise the ICES reference points framework representing a major change to the current guidelines. At WKREF2, we detailed discussions and four key concerns were raised about the proposed approach. The first related to the simplification of rules to define Blim. Around two thirds of category 1 stocks would end up as WKREF1 “Blim Type 2” where Blim would be set as a fraction of B0. The Allee effect or “depensation” maybe more important than previously thought and should be furthered explored for ICES stocks since it has important consequences for Blim. A number of challenges and issues around defining Blim using the current guidelines were documented. Some suggestions on improvement criteria were discussed including using classifiers to define spasmodic stocks and using change point algorithms to address non-stationary productivity regimes. However, further work is need to make these approaches operational and there was no consensus that the WKREF1 Blim types should replace the current guidelines. WKREF1 recommended that the FMSY proxy should be based on a biological proxies and should be less than the deterministic FMSY. It was pointed out that the stochastic FMSY estimated in EqSim for example, is lower than the deterministic FMSY and that the current guidelines ensure that the FMSY should not pose a more than 5% risk to Blim. A large amount of work described in WD 1 was carried out to develop an MSE framework to consistency and robustness test a candidate reference point system for North East Atlantic stocks. However, WKREF2 recommended that further work needs to be carried out to condition and test the simulation framework before the conclusions could be adopted by ICES and incorporated into the guidelines. A number of considerations for defining MSY related reference points were discussed including using model validation and prediction skill to ensure that ICES provide robust and credible advice. There is evidence that density dependence (DD) is important in the majority of ICES stocks (68% in recruitment and 54% in growth). The correct prediction of the shape and strength of density-dependence in productivity is key to predicting future stock development and providing the best possible long-term fisheries management advice. A suggested approach to use surplus production models (SPMs) to account for DD in FMSY was suggested and discussed but there was no consensus on whether that approach was appropriate. There was consensus that the FECO approach as a means of adapting target fishing mortality to medium-term changes in productivity should be included in the guidelines subject to a benchmark and ACOM approval. While WKREF1 and 2 focused mainly on Category 1 stocks ToR c) called for a “simplified and harmonised set of guidelines for estimating MSY and precautionary reference points applicable in the advice framework across various ICES stock categories.” Ideally the ICES assessment categories should provide equivalent risk across all stocks. This issue was discussed but no recommendations emerged. There was no consensus a revised reference point framework was proposed at WKREF2. However, it was agreed that it should be presented here for further discussion at ACOM and other fora. The key feature of the suggested approach is that the stock status evaluation is treated independent of the Advice Rule (AR). The main feature of the system is that the biomass trigger is not linked to a stock status evaluation, it is linked to the expected biomass when fishing at the target fishing mortality, in contrast to the current ICES approach. It also entailed that FMSY would also become an upper limit of fishing mortality and that the advised fishing mortality would be set at or lower than that level. WKREF2 did not discuss what to do in situations where SSB< Blim or alternative forms of HCR for the advice rule. Building community understanding and consensus around simplified and harmonised guidelines has yet to be achieved. A further workshop WKREF3 will be required to achieve that aim. The report includes 6 recommendations for ACOM consideration. nonPeerReviewed
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- 2022
12. empirical review of ICES reference points.
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Silvar-Viladomiu, Paula, Batts, Luke, Minto, Cóilín, Miller, David, and Lordan, Colm
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FIX-point estimation ,PRECAUTIONARY principle ,FISHERY management ,FISHERIES - Abstract
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. [ABSTRACT FROM AUTHOR]
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- 2022
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13. Microsatellites obtained using high throughput sequencing and a novel microsatellite genotyping method reveals population genetic structure in Norway Lobster, Nephrops norvegicus
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Gallagher, Jeanne, primary, Lordan, Colm, additional, Hughes, Graham M., additional, Jonasson, Jónas P., additional, and Carlsson, Jens, additional
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- 2022
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14. Moving reference point goalposts and implications for fisheries sustainability
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Silvar‐Viladomiu, Paula, primary, Minto, Cóilín, additional, Halouani, Ghassen, additional, Batts, Luke, additional, Brophy, Deirdre, additional, Lordan, Colm, additional, and Reid, David G., additional
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- 2021
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15. Modelling fuel consumption of fishing vessels for predictive use
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Davie, Sarah, Minto, Cóilín, Officer, Rick, Lordan, Colm, and Jackson, Emmet
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- 2015
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16. Burrow emergence rhythms of Nephrops norvegicus: UWTV, surveying biases and novel technological scenarios
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Aguzzi, Jacopo, Bahamon, Nixon, O'Malley, C., Berry, Alan, Gaughan, Paul, Doyle, Jennifer, Lordan, Colm, Tuck, Ian, Chiarini, Matteo, Martinelli, Michela, Marini, Simone, Thomsen, L., Flögel, Sascha, Albiez, Jan, Torkelsen, Terje, Pfannkuche, Olaf, Rune, Godoe Olav, Wehde, Henning, López-Vázquez, Vanesa, Zuazo, Ander, Rodriguez, Erik, Valencia, Javier, Calisti, Marcello, Stefanni, Sergio, Mirimin, Luca, Río, Joaquín del, Francescangeli, Marco, Fahalazed, A., Navarro, Joan, Vigo Fernandez, María, Masmitja, I., García, José A., Chumbinho, Rogerio, and Company, Joan B.
- Abstract
3 pages, The occupancy assumption “one burrow system, one animal” (Sardà and Aguzzi, 2012) raises a number of generic research questions concerning the true occupation of burrows in many Nephrops stocks. The burrow system acts as the centre of a strong territorial rhythmic behaviour (Rice and Chapman, 1971; Farmer, 1975) leading the adults’ lobsters to evict subordinates from burrows in a dominance hierarchy framework (Sbragaglia et al., 2017); indeed, two wild adult lobsters are rarely found in the same shelter (Cobb and Wang, 1985). Other studies showed evi-dence that no spatial segregation occurs between juveniles and adults (Maynou and Sardà, 1997) achieving the establishment of adult-juvenile complexes (at least 1 adult and 1 juvenile per bur-row), which become separated as juveniles grow (Tuck et al., 1994). Moreover, Nehprops bur-rows systems could also be inhabited by other benthic crustacean species (e.g. Munida sp.) or may remain empty and intact for an unknown period of time after animals’ death (Sardà and Aguzzi, 2012). These factors still create uncertainties about the true numbers of animals occupy-ing burrow systems, representing an important issue when providing a relative or absolute index for determination of Nephrops’ stock status (i.e. Harvest Rate; Sardà and Aguzzi, 2012). [...]
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- 2021
17. ICES Survey Protocols – Manual for Nephrops Underwater TV Surveys, coordinated under ICES Working Group on Nephrops Surveys (WGNEPS)
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Dobby, Helen, Doyle, Jennifer, Jónasson, Jónas, Jonsson, Patrik, Leocádio, Ana, Lordan, Colm, Weetman, Adrian, and Wieland, Kai
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- 2021
18. Theoretical size at the onset of maturity and its density-dependent variability as an option in crustacean fisheries management
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da Silva Santana, Cesar Augusto, primary, Lordan, Colm, additional, and Power, Anne Marie, additional
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- 2021
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19. Workshop on guidelines and methods for the evaluation of rebuilding plans (WKREBUILD)
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Kempf, Alexander, Benson, Ashleen, Beauchamp, Brittany, Pinto, Cecilia, Sparrevohn, Claus Reedtz, Lordan, Colm, Miller, David, van Helmond, Edwin, Mosegaard, Henrik, Benoít, Hugues, Coull, Kenny, Wise, Laura, Payne, Mark, Pastoors, Martin, Gras, Michael, Wall Andersen, Michael, Campbell, Neil, MacDonald, Paul, Levontin, Polina, Döring, Ralf, Methot, Richard D., Millar, Sarah, Mackinson, Steven, Gröhsler, Tomas, Bartolino, Valerio, Trijoulet, Vanessa, and Ye, Yimin
- Abstract
The Workshop on guidelines and methods for the evaluation of rebuilding plans (WKREBUILD) chaired by Vanessa Trijoulet (Denmark) and Martin Pastoors (Netherlands) met from 24 to 28 February 2020. The workshop attracted 27 participants from the US, Canada, Europe and FAO. When stocks are estimated to be below Blim1 and there is no perceived possibility of rebuilding above Blim within the time-frame of a short-term forecast, ICES has regularly recommended zero catch in combination with the development of a rebuilding plan. A review was carried out on the international experience on the development, evaluation and implementation of rebuilding plans for fisheries management in the Northeast Atlantic and in other fora around the world. In the Northeast Atlantic, rebuilding plans have been implemented in the past (e.g. the cod recovery plans of the early 2000s) but ICES has played a limited role in evaluating the performance of such recovery plans and does not have the tools or criteria to evaluate such plans. Recently, when a rebuilding plan for herring in 6.a 7.bc was submitted to ICES for evaluation, ICES refrained from providing such an evaluation. In the US and Canadian approaches, the legal framework determines the triggering and required elements of rebuilding plans. Such a legal imperative does not exist in the Northeast Atlantic. Nevertheless, the US and Canadian experiences provided useful elements that could be included in establishing ICES approach to rebuilding plans. Several case studies were presented on potential tools for the evaluation of rebuilding plans. Particular attention was given to evaluating options for harvest control rule options of such a plan. The tools focused mostly on short to medium term explorations of the probability of achieving a rebuilding of stocks. Because rebuilding plan evaluations need to be ready and available at short-notice when required, it was concluded that relatively standardized tools (i.e. packages or compiled code) to carry out such evaluations would be preferable over custommade evaluation tools. In addition, certain modelling considerations were highlighted as important such as realistic assumptions of productivity, uncertainty, bias in assessments and implementation error and the possibility of estimating the probability of achieving a rebuilding of stocks.Criteria for the acceptability of rebuilding plans will require an agreed Limit Reference Point (LRP) for initiating a rebuilding plan, definition of targets for fishing mortality or stock biomass, time-frames and the acceptable probabilities whether the rebuilding targets have been achieved. All of these should take into account realistic levels of uncertainty and being consistent with international best (scientific) practices. Although it was recognized that Blim would be the most likely candidate LRP triggering a rebuilding plan, the current approach in ICES for the determination of Blim was questioned during the workshop because it requires a more or less subjective classification of the stock-recruitment pairs into different types. In other regions, the LRP is often set as a certain proportion of the SSB at maximum sustainable yield (BMSY), e.g. 40% BMSY. If changes in productivity have been experienced in recent years at these are taken into account when estimating MSY reference points, the proportion of BMSY approach would likely lead to greater changes in the estimated value of LRP than the current ICES procedures used to estimate Blim, which rely on stock-recruitment pairs or definition of the lowest observed biomass (Bloss). This could have a large impact on the rebuilding target for stocks that experience changes in productivity regimes. Some concerns were raised regarding the often small distance between Blim and MSY Btrigger2 reference points for ICES stocks in comparison to the distance between trigger and limit in other jurisdictions. MSY Btrigger could therefore represent a late trigger to start decreasing fishing mortality when SSB is decreasing. The workshop recommended a future workshop on the revision of the procedure to estimate reference points within the ICES framework.An estimate of the minimum time (TMIN) by which rebuilding may be expected to be achieved, could be calculated by assuming zero catch and should be used as baseline for comparison with other rebuilding scenarios. The maximum time for rebuilding in the US and New Zealand is set to TMAX = 2 * TMIN or to TMIN plus one generation time1 (average length of time between when an individual is born and the birth of its offspring NRC (2014)). While the workshop did not arrive at an overall agreement on a default value for TMAX, it was suggested that TMAX = 2 * TMIN could be explored as a potential bounding on the rebuilding period, even though this should be subject to scientific analysis of potential effects on the stock in question. The workshop generated a guidance table summarizing the best practices for evaluation of rebuilding plans against the potential criteria of acceptability. The guidance table includes elements such as estimation of reference points, time-frames for rebuilding, rebuilding targets, handling uncertainties and bias, probability of achieving rebuilding targets and visualizing results. The workshop recommended that a follow-up workshop (WKREBUILD2) be organized for testing the guidelines with actual test cases, with the aim of defining more specific criteria and guidelines, i.e. learning by doing. Some of the elements that were discussed in the workshop but that have not (yet) entered the guidelines for evaluation of rebuilding plans are socio-economic trade-offs (e.g. between fast and slow rebuilding), mixed fisheries aspects (e.g. unavoidable bycatch due to mixed fisheries) and elements in rebuilding plans other than the HCR part (e.g. monitoring to improve the knowledge base). Most of the discussion at WKREBUILD was centred on stocks with analytical assessments (Category 1+2). Identifying when a data limited stock is in need of rebuilding (or has rebuilt) and how to evaluate rebuilding plan options for such stocks would likely require a separate process.
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- 2020
20. Habitat and Ecology of Nephrops norvegicus
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Johnson, Mark P., primary, Lordan, Colm, additional, and Power, Anne Marie, additional
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- 2013
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21. Shift in the larval phenology of a marine ectotherm due to ocean warming with consequences for larval transport
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McGeady, Ryan, primary, Lordan, Colm, additional, and Power, Anne Marie, additional
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- 2020
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22. How much of the seabed is impacted by mobile fishing gear? Absolute estimates from Vessel Monitoring System (VMS) point data
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Gerritsen, Hans D., Minto, Cóilín, and Lordan, Colm
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- 2013
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23. Integrating vessel monitoring systems (VMS) data with daily catch data from logbooks to explore the spatial distribution of catch and effort at high resolution
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Gerritsen, Hans and Lordan, Colm
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- 2011
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24. Defining métier for the Celtic Sea mixed fisheries: A multiannual international study of typology
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Moore, Claire, primary, Davie, Sarah, additional, Robert, Marianne, additional, Pawlowski, Lionel, additional, Dolder, Paul, additional, and Lordan, Colm, additional
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- 2019
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25. Theoretical size at the onset of maturity and its density-dependent variability as an option in crustacean fisheries management.
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Santana, Cesar Augusto da Silva, Lordan, Colm, and Power, Anne Marie
- Subjects
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SHELLFISH fisheries , *DISTRIBUTION (Probability theory) , *CAPABILITY maturity model , *POPULATION density , *FISHERY management , *SIZE - Abstract
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 (R 2 = 0.60) with population density and a significant positive linear relationship with average size in females (R 2 = 0.84). The size class at which 50% of the females are sexually mature (L 50) was linked to the new TSOM metric by a significant positive linear relationship (R 2 = 0.40). This set of linear relationships ultimately allowed TSOM and L 50 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, L 50, and smallest berried female represent sequential maturity events: (i) onset of maturity, (ii) 50% mature (from gonad staging), and (iii) berried females. [ABSTRACT FROM AUTHOR]
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- 2021
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26. New monitoring technologies assisting deep-water and deep-sea crustacean decapods stock assessment
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Aguzzi, Jacopo, Company, Joan B., Navarro, Joan, Bahamon, Nixon, Rotllant, Guiomar, García, José A., Río, Joaquín del, Gomáriz, Spartacus, Masmitja, Ivan, Marini, Simone, Fanelli, Emanuela, Lordan, Colm, Doyle, Jennifer, Chumbinho, Rogerio, Tuck, Ian, Martinelli, Michela, Chiarini, Matteo, Ministerio de Ciencia, Innovación y Universidades (España), and European Commission
- Abstract
The Crustacean Society Mid-Year Meeting (TSC 2019), 26-30 May 2019, Hong Kong.-- 1 page, The stock assessment of Norway lobster (Nephrops norvegicus) is made by fishery-dependent (i.e. trawl catches) or fishery-independent (i.e. burrow counts) methods. In both cases, important methodological assumptions affect the validity of derived population demographic estimates. Here, we provide a description of cabled underwater sensor networks in relation to the production of ancillary data for stock assessment of deep-sea highly commercially exploited decapods, whose fishery is in decline in the Mediterranean Sea. Specifically, two 20 m depth cabled video-observatories belonging to the European Multidisciplinary Seafloor and water column Observations (EMSO) network (SmartBay, in Ireland and OBSEA in Spain) are being used for in situ high-frequency time-lapse video and oceanographic monitoring of the burrow emergence of individuals. This monitoring will be used to quantify inter-individual variability in frequency and duration of emergence as a product of ecological and environmental forcing, and inform population level estimates of emergence (and hence availability to trawling) and burrow occupancy. Obtained data will serve as cross validation for acoustic tagging trials (i.e. animals bearing frequency-specific emitters, operating in tandem with listening hydrophone stations). Emissions and silences will be proxy of emergence timing and duration. A shallow water trial performed at OBSEA will serve as test-bed for acoustic mooring placement at 350-400 m depth, in the no take zone off Blanes Canyon (Spain), The present work was supported by RESBIO (TEC2017-87861-R) and RESNEP (CTM201782991-C2-1-R) as well as TNAs: ADVANCE (H2020-INFRAIA-2014-2015 under the Grant Agreement no. 654410, JERICO-NEXT) and SmartLobster (EMSO-LINK).
- Published
- 2019
27. WORKSHOP ON GUIDELINES FOR MANAGEMENT STRATEGY EVALUATIONS (WKGMSE2)
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Bertignac, Michel, Bjornsson, Hoskuldur, Brooks, Mollie Elisabeth, Brunel, Thomas, Butterworth, Doug, Campbell, Andrew, Cerviño, Santiago, Deroba, Jonathan, Elvarsson, Bjarki Thor, Fischer, Simon, Garcia, Dorleta, Goto, Daisuke, Gras, Michael, Hintzen, Niels T., Holmgren, Noél, Howell, Daniel, Huynh, Quang, Jardim, Ernesto, Kell, Laurence T., Konrad, Christoph, Kraak, Sarah B. M., Kronlund, Allen, Levontin, Polina, Lordan, Colm, Mendes, Hugo, Miethe, Tanja, Mosqueira, Iago, De Oliveira, José A.A., Pastoors, Martin, Pinto, Cecilia, Sparrevohn, Claus Reedtz, Taylor, Marc, and Fernández, Carmen
- Abstract
The purpose of the meeting was to bring up to date the methodologies and technical specifications that should be incorporated in Management Strategy Evaluation (MSE) work in ICES. The workshop was tasked with reviewing recent methodological and practical MSE work conducted in ICES and around the world, as well as the guidelines provided by the 2013 ICES Workshop on Guidelines for Management Strategy Evaluations (WKGMSE). The Terms of Reference indicated that the revision should include all aspects involved in MSE, while paying specific attention to several issues that had been identified through ICES practice. The Terms of Reference also requested WKGMSE 2 to consider how best to disseminate the guidelines to experts within the ICES community and the need for training courses. The workshop addressed all its Terms of Reference. The main results of the workshop are the revised MSE guidelines, as well as recommendations in relation to the ICES criterion for defining a management strategy as precautionary and in relation to the evaluation and advice on rebuilding strategies.
- Published
- 2019
28. New monitoring technologies to produce ancillary data on Nephrops stock assessment
- Author
-
Aguzzi, Jacopo, Company, Joan B., Navarro, Joan, Bahamon, Nixon, Rotllant, Guiomar, García, José A., Río, Joaquín del, Gomáriz, Spartacus, Masmitja, Ivan, Fanelli, Emanuela, Marini, Simone, Lordan, Colm, Doyle, Jennifer, and Chumbinho, Rogerio
- Abstract
Working Group on Nephrops Surveys (WGNEPS), 6-8 November 2018, Lorient, France.-- 2 pages, 2 figures, Current stock assessment based on UWTV surveys counts of Nephrops burrows (and thus inhabiting individuals) based on the peculiar morphological traits of these structures within the substrate. Three major uncertainties have been identified in this methodology: i. burrow occupancy which is currently assumed to be of one individual >17mm carapace length per identifiable burrow system; ii. burrow system size and the “edge effect” which could bias the estimates of effective area surveyed; iii. Burrow identification because other sympatric fish and decapod species construct tunnels with morphology similar to those of Nephrops. It is therefore of relevance to produce data on burrow emergence to validate or improve the assumptions made in the UWTV assessment methodology. New in situ technological applications should be used to monitor burrowing behavior producing data on the following key aspects: i. Burrow persistence related to the death and opportunistic occupation by other species; ii. Burrow emergence rhythms at different time-scales which oblige to perform surveys in specific time windows (tidal, day and seasons); iii. Emergence duration that varies according to the hunger state (predation-scavenging), predator presence (visual contact, odor plumes, noise) and intraspecific interactions (territoriality); and finally, iv. emergence range, identifying how many holes belong to a single animal
- Published
- 2019
29. Shift in the larval phenology of a marine ectotherm due to ocean warming with consequences for larval transport.
- Author
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McGeady, Ryan, Lordan, Colm, and Power, Anne Marie
- Subjects
- *
PHENOLOGY , *FISHERY management , *OCEAN , *CHRONOBIOLOGY , *INFORMATION resources management , *ADVECTION - Abstract
Because environmental temperature has an important influence on developmental rate and physiology, marine ectotherms are vulnerable to phenology changes due to ocean warming. Identifying changes to phenology, the timing of biological events, and understanding their effect on recruitment and abundance is of critical importance to establish potential population effects. We examined the larval phenology of the commercially important Norway lobster (Nephrops norvegicus) and used a larval transport model to examine its effect on simulated transport patterns. Using a model to estimate annual larval release dates based on temperature‐dependent embryo incubation, an earlier shift of 17.2 d occurred between 1982–1995 and 2000–2010 in the Irish Sea, similar to an observed empirical shift in phenology of 19.1 d using historical zooplankton data sets. Despite this earlier phenology, temperature‐dependent pelagic larval durations were unchanged because the water column to which larvae were released earlier had also warmed. Larval transport simulations in the western Irish Sea indicated that the phenology shift had minimal effects on larval retention and advection distance overall, because major variations were observed only at very early or late stages of the larval season, that is, times when lower proportions of larvae were present. As the western Irish Sea grounds exports small but consistent quantities of larvae to nearby populations, especially off Scotland, it may act as an important source of larvae, especially when retention of native larvae is low. Overall, larval transport tools may indicate grounds that are periodically vulnerable to recruitment failures and offer potentially valuable information in fishery management. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Using underwater television surveys to assess and advise on Nephrops stocks
- Author
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Bell, Ewen, Clements, Annika, Dobby, Helen, Doyle, Jennifer, Feekings, Jordan P., Leocádio, Ana, Lordan, Colm, Weetman, Adrian, Wieland, Kai, Leocádio, Ana, Weetman, Adrian, and Wieland, Kai
- Published
- 2018
31. A Low-Complexity Mosaicing Algorithm for Stock Assessment of Seabed-Burrowing Species
- Author
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Corrigan, David, primary, Sooknanan, Ken, additional, Doyle, Jennifer, additional, Lordan, Colm, additional, and Kokaram, Anil, additional
- Published
- 2019
- Full Text
- View/download PDF
32. Report of the Workshop to consider FMSY ranges for stocks in ICES categories 1 and 2 in Western Waters (WKMSYREF4)
- Author
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Abad, Esther, Bertignac, Michel, Boje, Jesper, Cerviño, Santiago, Dobby, Helen, Drogou, M., Fernández-Llana, Carmen, García, D., Khlivnoy, V., Lorance, Pascal, Lordan, Colm, Lundy, Mathieu, Sampedro-Pastor, Paz, Simmonds, J., Lissardy, Muriel, Walker, N., Alpoim, Ricardo, and Robert, M.
- Subjects
sustainable fisheries ,fisheries ,Harvest Control Rule ,methodology ,Pesquerías ,Centro Oceanográfico de A Coruña ,MSY - Published
- 2016
33. Guidelines for the definition of operational management units
- Author
-
Uriarte, Andres, Zarauz, Lucia, Aranda, Martin, Santurtun, Marina, Iriondo, Ane, Berthou, Patrick, Castro, Jose, Delayat, Stephanie, Falcon, Jesus, Garcia, Javier, Gaspar, Miguel, Gonzalez, J. F., Jimenez, Sebastian, Lordan, Colm, Gilles Morandeau, Florence Sanchez, Santamaria, Maria Theresa, and Villegas, Noemi
- Subjects
ComputingMethodologies_SIMULATIONANDMODELING ,Unidad de gestión ,Flota ,Pesquerías Mixtas ,Centro Oceanográfico de Canarias ,Pesquerías ,Stock ,GeneralLiterature_MISCELLANEOUS ,ComputingMethodologies_COMPUTERGRAPHICS ,Pesquerías Artesanales - Abstract
The objective of fisheries management is the sustainable exploitation of the fish resources over the extent of their spatial distribution. Along with the Common Fisheries Policy (CFP) objectives, the socio-economic viability of the fisheries exploiting the resource is also to be achieved. To reach these aims, managers need to define the management units they are going to work with. For the purpose of GEPETO project, we define a management unit (MU) as the set of fishing fleets exploiting a common pool of fish resources with strong spatial overlapping and sharing of habitats, which make them being typically fished together. In other words, a MU is the set of fishing fleets exploiting a common fish community over their spatial distribution. MUs have to be defined by the fish community, by the spatial range of distribution of the fish community, and by the set of fishing fleets sharing the exploitation of the fish community, L'objectif de gestion de la pêche est l'exploitation durable des ressources halieutiques sur l'étendue de leur répartition spatiale. Avec la nouvelle Politique Commune de la pêche (PCP) l' objectif de la viabilité socio-économique des pêcheries exploitant la ressource doit également être réalisé. Pour l'atteindre, les gestionnaires doivent définir des unités de gestion. Les partenaires du projet GEPETO, définissent une unité de gestion (MU) comme l'ensemble des flottes de pêche exploitant un pool commun de ressources halieutiques disponibles dans des habitats communs, ce qui les rend très imbriquées. En d'autres termes, un MU est l'ensemble des flottes de pêche exploitant une communauté de poissons ordinaires sur leur répartition spatiale. La MU peu être définie par la communauté de poissons, par la gamme spatiale de la distribution de la communauté de poissons, et par l'ensemble des flottes de pêche qui partagent l'exploitation de la communauté de poissons.
- Published
- 2014
34. Atlas of Commercial Fisheries around Ireland
- Author
-
Gerritsen, H. D. and Lordan, Colm
- Subjects
Total Allowable Catch ,Commercial Fisheries ,Fishing Atlas ,Irish commercial fishing ,TAC ,Celtic sea ,Irish Sea ,Fish Stocks - Abstract
The Atlas of Commercial Fisheries around Ireland is the second of its kind published by the Marine Institute. It shows the distribution of fishing activities in Irish waters by gear and country. Fishing grounds as well as the distribution of landings for all the main commercial species is also shown at high resolution., This “Atlas of Commercial Fisheries Around Ireland” uses informatics, the science of processing data into information, to give useful new insights into fishing activities and fisheries resources. Fishing is one of the most significant ocean uses in the waters around Ireland with around 1000 vessels active on a daily basis. More than 8 million hours of fishing effort spent annually are mapped by gear and country. Landings statistics are summarised by port. Fishing activities and landings values and volumes within the Irish Exclusive Economic Zone are estimated for 2012. Landings of the key commercial species are mapped individually and by gear. This information is put into context by maps of effort and landings at a broader European scale and by the historical time series of landings that are provided for each species., European Union ERDF - INTEREG Atlantic Area Programme
- Published
- 2014
35. Sediment characteristics and local hydrodynamics and their influence on the population of Nephrops around Ireland
- Author
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O Sullivan, David, Lordan, Colm, Doyle, Jennifer, Berry, Alan, and Lyons, Kieran
- Subjects
Nephrops norvegicus ,fungi ,hydrodynamics ,larval drift modelling ,fishing grounds - Abstract
The Norway lobster, Nephrops norvegicus, is the second most valuable commercial spe-cies landed from Irish waters. The species is dependent on muddy seabed sediment in which burrows are constructed. Larvae are hatched from the seabed into the water column. The distribution of Nephrops depends in part to the presence of suitable sediment and also from larval supply modulated by existing local hydrodynamic regimes. The pelagic stage of the life-cycle is governed by both physical and biological factors including temperature, water speed and larval maturation rate. This study encompasses three aims, 1: to synthesise available sediment data and examine the spatial extent of potential Nephrops habitat in waters around Ireland, 2: investigate local hydrodynamic conditions on Nephrops fishing grounds which are likely to be encountered by planktonic larvae following hatching and 3: to employ a particle tracking model to study the potential dispersal fields of Nephrops larvae from individual fishing grounds and assess stock connectivity. The study finds that larval distribution between fishing grounds is dependent on variable seasonal conditions, the geographical size of an area and its proximity to other grounds. Fishing grounds in the Irish Sea and Porcupine Bank are isolated from other areas, whereas grounds in the Celtic Sea exhibit a high degree of connectivity and should be considered as a meta-population. Successful annual recruitment to the adult population of this species is largely dependent on favourable environmental conditions which enable the re-seeding of the same or adjacent grounds., Marine Institute & INFOMAR.
- Published
- 2014
36. The 'Smalls' Nephrops Grounds (FU22) 2012 UWTV Survey Report and catch options for 2013
- Author
-
Doyle, Jennifer, Lordan, Colm, Hehir, Imelda, Fee, Dermot, O Connor, Sean, Browne, Patricia, and Casserly, Joanne
- Subjects
Nephrops norvegicus ,underwater television (UWTV) ,benthos ,geostatistics ,stock assessment - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This report provides the main results and findings of the seventh annual underwater television on the ‘Smalls grounds’ ICES assessment area; Functional Unit 22. The survey was multi-disciplinary in nature collecting UWTV, fishing, CTD and other ecosystem data. An analysis of the precision, accuracy and sampling intensity trade-offs showed that sampling intensity could be reduced without compromising the utility of the survey. Consequently, sampling intensity was reduced this year from around 100 stations in the past to 47 stations this year. The krigged burrow abundance estimate for Smalls ground has increased by 17% relative to 2011and was the second highest in the 7 year history of the survey. Abundance estimates have been fairly stable over the time series. The 2012 randomised isometric grid design result in a CV (or relative standard error) of 8%. Well below the upper limit of 20% recommended by SGNEPS 2012. Nephrops accounted for 22% of the catch weight from 6 beam trawl tows. Length-weight, maturity and by-catch data are all reported.
- Published
- 2012
37. Porcupine Bank Nephrops Grounds (FU16) 2012 UWTV Survey Report and catch options for 2013
- Author
-
Lordan, Colm, Doyle, Jennifer, Dobby, Helen, Hehir, Imelda, Fee, Dermot, Allsop, Chris, and O Neill, Ross
- Subjects
Nephrops norvegicus ,Porcupine Bank ,underwater television (UWTV) ,benthos ,geostatistics ,stock assessment - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This report provides the results of the first underwater television on the ‘Porcupine Bank Nephrops grounds’ ICES assessment area; Functional Unit 16. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. The UWTV results and a scientific basis for survey based catch advice in 2013 are presented. In total 47 UWTV stations were successfully completed. The mean burrow density was 0.19 burrows/m² (empirical 95% confidence intervals are from 0.17-0.21). The final krigged abundance estimate was 992 million burrows with a relative standard error of 5% and an estimated stock area of 7,100km2. This abundance estimate can be considered as a conservative estimate given that the spatial coverage of the southern part of the ground was not complete. A correction factor of 1.26 is proposed based on expert judgments of burrow size and potential detection and identification biases. A yield and spawner per recruit analysis was used to estimate a harvest rate of 5.0% for the combined sex F0.1 and other F reference points. This harvest rate is low compared to other FUs and can be considered very conservative. Applying this harvest rate to the abundance observed in the survey and using a mean weight in the landings of 45.0g implies landings in 2013 of 1,770 t. The results here could form the basis of the catch advice for 2013.
- Published
- 2012
38. Aran, Galway Bay and Slyne Head Nephrops Grounds (FU17) 2012 UWTV Survey Report and catch options for 2013
- Author
-
Lordan, Colm, Doyle, Jennifer, Hehir, Imelda, Fee, Dermot, Allsop, Chris, and O Neill, Ross
- Subjects
Nephrops norvegicus ,benthos ,geostatistics ,nderwater television (UWTV) ,stock assessment - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This report provides the main results and findings of the eleventh annual underwater television on the Aran, Galway Bay and Slyne head Nephrops grounds, ICES assessment area; Functional Unit 17. The survey was multi-disciplinary in nature collecting UWTV, fishing, CTD and other ecosystem data. The sampling intensity was reduced this year from around 75 stations in the past to 31 on the Aran grounds. A randomised isometric grid design was employed with UWTV stations at 3.5nmi or 6.5km intervals. Previously a 2.25 nmi square grid was used. The kigged burrow abundance estimate declined by 34% relative to 2011 with a CV (or relative standard error) of 5 %. Abundance estimates have fluctuated considerably over the time series but the 2012 abundance is the lowest in the 11 year history of the survey. Four UWTV stations were carried out on the Galway Bay and 3 on the Slyne Head Nephrops grounds. Raised abundance estimates for Galway Bay and Slyne Head are provided based on improved knowledge of the boundaries of those areas. Nephrops accounted for 85% of the benthic catch by weight from 4 beam trawl tows. The observed length frequency and maturity of female Nephops caught was similar to previous years. Various further investigations needed before the next ICES benchmark are discussed.
- Published
- 2012
39. Aran, Galway Bay and Slyne Head Nephrops Grounds 2011 UWTV Survey Report
- Author
-
Lordan, Colm, Doyle, Jennifer, Bunn, Robert, Fee, Dermot, and Allsop, Chris
- Subjects
Nephrops norvegicus ,Benthos ,Stock assessment ,Geostatistics ,Underwater television (UWTV) - Abstract
This report provides the main results and findings of the tenth annual underwater television on the ‘Aran grounds’ ICES assessment area; Functional Unit 17. The survey was multi-disciplinary in nature collecting UWTV, fishing, CTD and other ecosystem data. In total 76, 10 and 7 UWTV stations were successfully completed on the Aran, Galway Bay and Slyne Head Nephrops Grounds. The observed abundance estimate for the main Aran ground has declined by 23% relative to 2010. Abundance estimates have fluctuated over the time series. The 2011 abundance is the third lowest in the 10 year history of the survey. This is not a cause for immediate concern about the stocks sustainability. Raised abundance estimates for Galway Bay and Slyne Head are provided for the first time based on improved knowledge of the boundaries of those areas. Nephrops accounted for 26% of the catch weight from 10 beam trawl tows. The observed length frequency and maturity of female Nephops caught was similar to previous years. Various further investigations needed before the next ICES benchmark are discussed.
- Published
- 2011
40. Western Irish Sea Nephrops (FU15) 2010 UWTV Survey Report
- Author
-
Lordan, Colm, Doyle, Jennifer, and Briggs, Richard
- Subjects
UWTV - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., Since 2003 a joint UWTV survey has been carried out by the Marine Institute(Ireland) and AFBI (Northern Ireland). For the first time in 2009 this survey was used to develop catch options for the stock using a bias corrected survey estimate as an absolute measure of stock size and recent discard rates and mean weight to forecast catch (ICES, 2009a). This report details the results of the 2010 survey for the western Irish Sea Nephrops stock. We also update the catch option table using the most recent survey estimate.
- Published
- 2011
41. Celtic Sea Nephrops Grounds 2010 UWTV Survey Report
- Author
-
Lordan, Colm and Doyle, Jennifer
- Subjects
UWTV - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This is the fifth in a time series of UWTV surveys on the ‘Smalls grounds’. The 2006 survey covered the distinct mud patches of the Smalls Grounds and also indicator stations on the Labadie Bank, Nymphe Bank and Seven Heads, whereas the 2007 to 2010 survey covered the Smalls grounds only due to poor weather and time contraints. This report details the results of the 2010 survey for the Smalls ground Nephrops stock.
- Published
- 2011
42. FU19 Nephrops Grounds 2011 UWTV Survey Report
- Author
-
Lordan, Colm, Doyle, Jennifer, and Fitzgerald, Ross
- Subjects
Nephrops norvegicus ,Benthos ,Stock assessment ,Geostatistics ,Underwater television (UWTV) - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This report provides the main results and findings of the second underwater television survey of the various Nephrops grounds in Functional Unit 19. The survey was multi-disciplinary in nature collecting UWTV, CTD and other ecosystem data. In total 35 UWTV stations were successfully completed on the following Nephrops grounds: Bantry Bay, Galley, Cork Channels and Helvick. Raised abundance estimates for these grounds are provided for the first time based on improved knowledge of the boundaries of those areas.
- Published
- 2011
43. Western Irish Sea Nephrops Grounds (FU15) 2011 UWTV Survey Report
- Author
-
Lordan, Colm, Service, Matthew, Doyle, Jennifer, and Fitzgerald, Ross
- Subjects
UWTV - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This is the ninth in a time series of UWTV surveys in the western Irish Sea carried out jointly by the Marine Institute, Ireland and the Agri-Food and Biosciences Institute (AFBI), Northern Ireland. The 2011 survey was multi disciplinary in nature and this report details the final UWTV results of the 2011 survey and also documents other data collected during the survey.
- Published
- 2011
44. Celtic Sea Nephrops Grounds 2011 UWTV Survey Report
- Author
-
Doyle, Jennifer, Lordan, Colm, Fitzgerald, Ross, O’Connor, Sean, Fee, Dermot, Nolan, Cormac, and Hayes, Joan
- Subjects
UWTV - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., The prawn (Nephrops norvegicus) are common in the Celtic Sea occurring in geographically distinct sandy/muddy areas were the sediment is suitable for them to construct their burrows. The Celtic Sea area (Functional Units 19-22) supports a large multi-national targeted Nephrops fishery mainly using otter trawls and yielding landings in the region of ~6,000 t annually over the last decade (ICES, 2011). Nephrops spend a great deal of time in their burrows and their emergence behaviour is influenced many factors; time of year, light intensity and tidal strength. Underwater television surveys and assessment methodologies have been developed to provide a fishery independent estimate of stock size, exploitation status and catch advice (ICES, 2009 & 2011).This is the sixth in a time series of UWTV surveys in the Celtic Sea carried out by the Marine Institute, Ireland. The 2011 survey was multi disciplinary in nature and this report details the final UWTV results of the 2011 survey and also documents other data collected during the survey.
- Published
- 2011
45. Defining value per unit effort in mixed métier fisheries
- Author
-
Davie, Sarah, primary, Minto, Cóilín, additional, Officer, Rick, additional, and Lordan, Colm, additional
- Published
- 2015
- Full Text
- View/download PDF
46. Spatial Transferability of Habitat Suitability Models of Nephrops norvegicus among Fished Areas in the Northeast Atlantic: Sufficiently Stable for Marine Resource Conservation?
- Author
-
Lauria, Valentina, primary, Power, Anne Marie, additional, Lordan, Colm, additional, Weetman, Adrian, additional, and Johnson, Mark P., additional
- Published
- 2015
- Full Text
- View/download PDF
47. Marine strategy framework directive task group 3 Report commercially exploited fish and shellfish
- Author
-
PIET Gerjan, ALBELLA Alvaro J., ARO Eero, FARRUGIO Henri, LLEONART Jordi, LORDAN Colm, MESNIL Benoit, PETRAKIS George, PUSCH Christian, RADU George, RAETZ Hans-Joachim, DOERNER Hendrik, and SCOTT ROBERT
- Subjects
Vis ,Life Science - Abstract
The Marine Strategy Framework Directive (2008/56/EC) (MSFD) requires that the European Commission (by 15 July 2010) should lay down criteria and methodological standards to allow consistency in approach in evaluating the extent to which Good Environmental Status (GES) is being achieved. ICES and JRC were contracted to provide scientific support for the Commission in meeting this obligation. A total of 10 reports have been prepared relating to the descriptors of GES listed in Annex I of the Directive. Eight reports have been prepared by groups of independent experts coordinated by JRC and ICES in response to this contract. In addition, reports for two descriptors (Contaminants in fish and other seafood and Marine Litter) were written by expert groups coordinated by DG SANCO and IFREMER respectively. A Task Group was established for each of the qualitative Descriptors. Each Task Group consisted of selected experts providing experience related to the four marine regions (the Baltic Sea, the Northeast Atlantic, the Mediterranean Sea and the Black Sea) and an appropriate scope of relevant scientific expertise. Observers from the Regional Seas Conventions were also invited to each Task Group to help ensure the inclusion of relevant work by those Conventions. This is the report of Task Group 3 Commercially exploited fish and shellfish., JRC.DG.G.4-Maritime affairs
- Published
- 2010
48. Mosaics for Nephrops detection in underwater survey videos
- Author
-
Sooknanan, Ken, primary, Doyle, Jennifer, additional, Lordan, Colm, additional, Wilson, James, additional, Kokaram, Anil, additional, and Corrigan, David, additional
- Published
- 2014
- Full Text
- View/download PDF
49. Aran, Galway Bay and Slyne Head Nephrops Grounds 2008 UWTV Survey Report
- Author
-
Lordan, Colm and Doyle, Jennifer
- Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., In 2008 the seventh in a series of annual UWTV survey was complete and the results of that survey together with a synthesis and analysis of the results is presented. A geostatistical analysis indicates that burrow densities and abundances have fluctuated considerably in space and time. The highest densities occurred in 2004 and the lowest densities in 2008.The 2008 survey shows a decrease in burrow density to the lowest observed. Using the survey directly for assessment and management has been discussed at WKNEPHTV (2007) and at SGNEP (2009).This stock was a focus at the benchmark workshop on Nephrops assessment held in Aberdeen WKNEPH, (2009). There appears to a negative relationship between abundance and landings in the autumn and a positive relationship between observed densities and landings the following spring. There is some concern about the stock given the most recent survey abundance observed to date. The time series is short and to date survey estimates have fluctuated across a large dynamic range.
- Published
- 2009
50. Celtic Sea Nephrops Grounds 2008 UWTV Survey Report
- Author
-
Lordan, Colm and Doyle, Jennifer
- Subjects
UWTV - Abstract
Use the URI link below to search the Marine Institute Data Discovery Catalogue for datasets relevant to this report., This is the third in a time series of UWTV surveys on the ‘Smalls grounds’. The 2006 survey covered the distinct mud patches of the Smalls Grounds and also indicator stations on the Labadie Bank, Nymphe Bank and Seven Heads, whereas the 2007 and 2008 survey covered the Smalls Grounds only due to poor weather and time contraints. This report details the results of the surveys on the Smalls Grounds only to date.
- Published
- 2009
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