190 research outputs found
Assessment of the Cod Stock in NAFO Division 3M
An assessment of the cod stock in NAFO Division 3M was conducted using a Bayesian SCAA (statistical catch-at-age) model. The STACFIS catch estimates and the Flemish Cap survey indices were used to fit the model. Blim, defined as the SSB of 2007, was estimated at 15 037 t (median). Results indicate a general increase in SSB since 2005 to the highest value in 2017, decreasing since then. SSB has been above Blim since 2008. Between 2013 and 2018 recruitment was at very low levels; the 2016 and 2018 values were among the lowest of the series; as a consequence, 3-year projections indicate that total biomass will decrease during the projected years, while the SSB could increase under some scenarios in the final projected year. The probability of SSB being below Blim is low high (<10%) in all the scenarios. An increase in recruitment occurred since 2019, reaching in 2021 the 2014 level.Versión del editor
Biomass and length distribution for roughhead grenadier, thorny skate, white hake, squid and capelin from the surveys conducted by Spain in NAFO 3NO
Data for roughhead grenadier (Macrourus berglax), thorny skate (Amblyraja radiata) and white hake
(Urophycis tenuis) from the Spanish Spring survey are presented. Abundance and biomass were estimated for
roughhead grenadier and thorny skate for the period 1997-2019 and for white hake for the period 2001-2019.
The length distribution is presented as numbers per haul stratified mean catches for the last five years (2015-
2019). The roughhead grenadier indices showed no discernible trend during the whole series, reaching a
maximum in 2004 and a minimum in 2019. In 2017 and 2018, a quite good presence of small and medium
lengths (1.5-19.5 cm) can be seen. Thorny skate indices follow a large oscillating trend, dropping in 2007 and
has been since then more or less stables at a low level, reaching the minimum of the series by far in 2019. In
2017 there is a discrete presence of length between 12 and 18 cm. White hake indices were highest in 2001
and then showed an overall decreasing trend until 2008 with low values, generally increasing since then with
some fluctuations. The 2019 biomass is the second lowest of the period studied. Small recruitment events were
detected in 2004, 2012 and 2013, with individuals between 16-26 cm. In 2017 the highest numbers are at small
lengths, between 20 and 24 cm, being around 34 cm in 2018. In 2019, the mode is around 8 cm. The estimated
biomass of squid is inconstant and very low in general. There were no catches of squid during the 2002 and
2013-2015 surveys. In 2018 and 2019, a step increase in biomass was observed during the survey, being 5.5
and 7 times, respectively, the third value of the series in 2011. Length samples were taken in 2011, 2017 and
2019. The lengths range between 3.5 and 19 cm. Capelin biomass reached a maximum in 2012, decreasing
sharply since then until 2017. In 2018 the index increased to a level similar to that in the early 2000s,
decreasing slightly in 201
Effect in survey indices of removing stations in the NAFO closed Areas in the design of the EU surveys including the 2021 closed areas
In 2009, the Fisheries Commission established several coral and sponges protection closures areas to bottom fisheries within the NAFO Regulatory Area that started to be applied in 2010. Three random bottom trawl surveys are performed by the EU yearly in the NAFO Regulatory Area: Spanish Div. 3NO (Spring), Spanish and Portuguese in Div. 3M (Summer) and Spanish Div. 3L (Summer). The surveys are currently carried out by the R/V Vizconde de Eza and covers the closed areas. A study of the survey indices of the species assessed in NAFO (except shrimp) have been performed to know the impact of removing the hauls in the closed areas from the survey.
The results of the analysis show that there are two species, Greenland halibut and roughhead grenadier, in which their biomass and/or age/length indices are affected in all the surveys analyzed. This is due to the fact that these two species are distributed at greater depths and that the closed areas are mainly found in deep areas, so the suppression of survey hauls in closed areas has a greater impact on the indices of these two species. The best way to know the impact in the assessment results of these changes in the Greenland halibut and roughhead grenadier indices would be to run the assessment with both indices, the base case ones and the new case ones, and compare the results.
There are other species in which their global biomass indices do not change very much, but their age or length indices change appreciably when hauls from closed areas are removed from the calculations. In one case, the results of the assessment are compromised and it would be better to rerun the assessment with the new case indices to see the differences. In other cases, although the length distribution is not directly used in the assessment models, some recruitment and spawning stock biomass indices are derived from them, so changes in the perception of the stock could be encountered. These changes in the age/length indices should be
considered in future assessments of these stocks if the prohibition of the surveys trawls in closed areas is approved.
If more close areas are added in the future to the existing ones, this study should be redone, which implies a big amount of work. It is not worth to rerun this study each time the closed areas change.Versión del editor
Yellowtail flounder, redfish (Sebastes spp.) and witch flounder indices from the Spanish Survey conducted in Divisions 3NO of the NAFO Regulatory Area
Since 1995, Spain carries out a spring stratified random bottom trawl survey in Div. 3NO of the NAFO
Regulatory Area. Total mean catches, biomass and mean numbers for yellowtail flounder (Limanda ferruginea)
are presented for the period 1995-8 for redfish (Sebastes spp.) for the period 1997-2018 and for witch flounder
(Glyptocephalus cynoglossus) for the period 2002-2018. Detailed indices are presented from 2013.
Yellowtail flounder indices do not show a clear trend. Biomass increased from 1997 to 1999 has maintained
almost constant values until 2013 and then decreased in 2014-2018. Redfish indices oscillate greatly over time,
probably because the gear does not sample adequately aggregating pelagic species. There was a sharp increase
in 2009 and since then until 2015, biomass fluctuated maintaining higher values than before 2009. In 2016
biomass dropped and increase again in 2017-2018 to the 2012 level. The 3N division comprises around the
90% of the total biomass in the last years. Good year classes have not been registered recently. Length
distribution in thousands (abundance) by Division and year since 2002 is presented. Following the trend of the
biomass, most of the abundance corresponds to Division 3N. Witch flounder is very scarce and its indices
fluctuated throughout the series reaching the minimum value in 2014 and 2018, with an increasing trend in
the middle time. Recruitment was quite good at the beginning of the series but poor in recent years
Yellowtail flounder, redfish (Sebastes spp.) and witch flounder indices from the Spanish Survey conducted in Divisions 3NO of the NAFO Regulatory Area
Since 1995, Spain carries out a spring stratified random bottom trawl survey in Div. 3NO of the NAFO
Regulatory Area. Total mean catches, biomass and mean numbers for yellowtail flounder (Limanda ferruginea)
are presented for the period 1995-2019, for redfish (Sebastes spp.) for the period 1997-2019 and for witch
flounder (Glyptocephalus cynoglossus) for the period 2002-2019. Detailed indices are presented from 2015.
Yellowtail flounder indices do not show a clear trend between 1999 and 2016. The 2017-2019 values were
lower than the 1998 one. There has not been good recruitment in recent years. Redfish indices oscillate greatly
over time, probably because the gear does not sample adequately aggregating pelagic species. There was a
sharp increase in 2009 and since then until 2015, biomass fluctuated maintaining higher values than before
2009. In 2016 biomass dropped and increase again in 2017-2019 to or below the 2012 level. The 3N division
comprises around the 90% of the total biomass in the last years. Good year classes have not been registered
recently. Abundance by Division shows since 2002 shows the same trend of the biomass; most of the abundance
corresponds to Division 3N. Witch flounder is very scarce and its indices fluctuated throughout the series
reaching a low level in 2014 and 2018, with an increasing trend in the middle time. The 2019 value is the lowest
of the series, being less than 50% of 2014 value. Recruitment was quite good at the beginning of the series but
poor in recent years
Analysis of the NAFO VMS and logbook data
within the National Program of collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy.The objective of the ecosystem approach is to protect the structures, processes and interactions of the ecosystem through a sustainable use of the natural resources. A key step when studying the environmental impact of the fishing activity is to assess the fishing footprint.
There are two methodologies to study the fishing effort and footprint in the NAFO Regulatory Area (NRA). The first one uses a simple speed filter to select the Vessel Monitoring System (VMS) pings most likely to be associated with fishing effort. The second one filters the VMS pings that correspond with the haul interval registered by the skipper in the logbook.
The purpose of this study is to analyse the quality and coverage of the VMS and logbook data used in these two methods. Data collected by the IEO Scientific Observer Program on board fishing vessels were also used to measure the coverage.
The results show that the current speed range (0.5-5 knots) used in the speed filter method may be adequate to study effort in trawl fisheries but is not representative for longline fisheries. It was also observed that both databases, VMS and logbook, contain errors and the effects of the misreporting are enhanced when both data sets are merged. Data from scientific observers allowed to measure these errors and, as a result, only around 60-70% of the total pings were taken into account with the merging approach.
Despite the merging approach is widely considered an improvement in relation to the former method (i.e. simple speed filter) and a powerful tool for describing the spatial distribution of fishing activity, this improvement relies on the coverage and quality of the available information.
The quality of information, both in the VMS system and in the logbooks, should be of concern to NAFO. The improvement of the quality of these data is crucial for better studying the effort distribution and the tasks related to this effort (SAI, fisheries footprint, fishing overlap with VME, assessments, etc).European Union through the European Maritime and Fisheries Fund (EMFF)Versión del edito
Information to support decisions on authorizing scientific surveys with bottom-contacting gears in NAFO closed areas
There are presently no existing frameworks or approaches in NAFO to assist in determining under what conditions scientific surveys employing bottom-contacting gear can be permitted in protected areas. Fisheries and Oceans Canada (DFO) has produced a Canadian National Framework to guide the evaluation of scientific surveys within protected areas inside the Canadian waters. The objective of this document is to apply to the scientific surveys that are carried out in the NRA the framework developed by the DFO for the collection of information that can help managers in the decision of whether the actual scientific surveys can sample or not in the closed areas to bottom fishing activities
Consumer perception of entire male pork coated with spiced edible films as a new product to mask boar taint
Pork production has undergone a shift towards the rearing of entire male pigs, however, its meat might carry with the presence of boar taint and it would be considered “unfit for human consumption”. To offer a new alternative to the pork sector tailored to the needs of consumers, a viable option would be the use of edible spiced gelatin films to help minimize boar taint and improve its marketability. The responses of 120 regular meat consumers to entire pork with high levels of boar taint and castrated pork free of boar taint, both coated with spiced gelatin films were evaluated. They showed a similar response between entire and castrated male pork coated with spiced films, regardless of whether consumers usually detected unpleasant odours (as farm/animal) when consuming pork or not. Therefore, the new spiced films offer a new range of products to consumers as they contribute to the improvement of the sensory quality of entire male pork, especially among consumers who tend to buy new products.info:eu-repo/semantics/publishedVersio
Analysis of the by-catch of the moratorium stocks in the NRA
In 2017 the Commission approved the Action Plan for the Management and Minimization of by-catch and discards. The Action Plan cited the NAFO Secretariat to conduct the annual mapping of by-catch in NAFO from 2016 onwards using HbH data. The Secretariat presented the results of by-catch analysis of the haul by haul reports of 2016-2019. This analysis was carried out based on the interactions of directed fisheries (non-moratorium stocks) – by-catch stock (moratorium stock). The present document presents an analysis based on the moratoria species/stocks. For each of the species/stocks in moratorium, the main fisheries that catch it as by-catch are identified and analyzed to observe if there are temporal/spatial patterns of the by-catch of stocks in moratorium. These two analyses: moratorium species/fishery, together with the analysis carried out by the Secretariat, fishery/moratorium species, are complementary and will allow a better response to the Action Plan task 3.2: "Areas where there is a risk of causing serious harm to by-catch species. Identify areas, times and fisheries where bycatch and discards, notably of moratoria species, that have a higher rate of occurrence”.
One of the objectives of this document is to search, for the different stocks in moratorium, spatio-temporal patterns of the by-catches carried out by the different fisheries. The seasonal/space catch analysis based on the HbH data will be restricted to: American plaice Div. 3M, American plaice Div. 3LNO and cod Div. 3NO, since they are the stocks in moratorium that have some level of catches and are not mainly distributed within national waters. The conclusions on the last two stocks are partial since the data analyzed only cover part of their distribution (NRA).
The general conclusion of this analysis is that there are no remarkable spatial differences between the hauls with and without by-catch of the moratoria stocks of the different directed fisheries. It can be observed that the directed fisheries that have a higher frequency of by-catch of these species/stocks in moratorium are those that are carried out less than 200 meters deep: yellowtail flounder Div. 3LNO, skates Div. 3LNO and cod Div. 3M in the shallowest part of the Flemish Cap. In some fisheries, it is possible to observe variations in the frequencies of sets with moratoria species by-catch by quarter, this temporal pattern is related to the displacement of the directed fishery to different areas.Versión del edito
Analysis of 3M cod catch in all the fisheries across the Flemish Cap
Analyses of the haul by haul data from 2016 to 2020, as well as samples from observers on board, from the directed and no-directed fishery catching 3M cod, were conducted in order to consider whether measures, such as depth restrictions, spatial and mesh changes, could reduce the catch of juvenile and immature cod across all fisheries in 3M. The recent bycatch of 3M cod in other fisheries is considered low when compared to the directed cod fishery. Therefore, at this time, the implementation of measures to avoid juvenile cod bycatch would be premature, given that the burden of implementing and enforcing these measures on multiple fisheries may outweigh its potential benefits. With respect to the directed 3M cod fishery, and considering that new measures have been just implemented, it is prudent to analyze the effectiveness of these measures to protect juveniles before considering which additional and/or different technical measures may be required to further reduce juvenile cod catches, if needed.Versión del edito
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