• Boarfish Acoustic Survey Cruise Report 10 July – 31 July, 2015

      O'Donnell, C.; Nolan, C. (Marine Institute, 2015)
      From the early 1970s the abundance of boarfish (Capros aper) was seen to increase exponentially and distribution spread increasingly northwards along the western seaboard and Bay of Biscay (Blanchard and Vandermeirsch, 2005).This survey represents the fifth dedicated research survey for boarfish in the time series. The commercial fishing vessel MFV Felucca was employed for the survey and the vessels hull mounted transducer was calibrated for scientific output. Data from this survey will be presented to the ICES assessment Working Group for Widely Distributed Stocks (WGWIDE) meeting in August 2015 and as part of the ICES Planning Group meeting for International Pelagic Surveys (WGIPS) meeting in January 2016 (WGIPS).
    • Boarfish Acoustic Survey Report 07 July – 28 July, 2011

      O'Donnell, Ciaran; Farrell, Edward; Saunders, Ryan; Campbell, Andy (Marine Institute, 2011)
      This survey represents the first dedicated exploratory research survey for boarfish (Capros aper) undertaken along the western seaboard. The commercial fishing vessel the MFV Felucca, an active participant in the fishery was equipped with a calibrated scientific echosounder. A consultant biologist from the Killybegs Fisherman’s Organisation (KFO) and a Marine Institute scientist headed the biological and acoustic research respectively during the cruise. Exploratory fishing for boarfish by Irish vessels began in the later 1980s when commercial quantities were encountered during the spring horse mackerel (Trachurus trachurus) and mackerel (Scrombrus scomber) fishery in northern Biscay. Several landings were made into Ireland for fishmeal during this time but due to logistical problems related to handling (prominent dorsal spines) this species was not favoured by processors. Interest increased again around the mid 1990s when Dutch pelagic vessels landed frozen samples to determine if a market could be developed for human consumption. From the early 1970s onwards the abundance of boarfish was seen to increase exponentially and distribution ever increasingly spread northwards along the western seaboard (Blanchard and Vandermeirsch, 2005). With this increase in abundance boarfish were taken as bycatch in both the pelagic and demersal fisheries in ever increasing quantities and this caused serious problems relating to damaged target species due to the aforementioned formidable dorsal spines. During the early 2000s the Irish landings were relatively small (<700t per yr) and it wasn’t until 2006 that the directed fishery developed in earnest. Fishing was undertaken primarily by vessels from the Castletownbere and Killybegs based RSW fleets (refrigerated seawater vessels) which targeted boarfish from northern Biscay to the southern Celtic Sea. In 2007-08 Scotland and Denmark also began targeting boarfish in quantity. Irish landings are primarily landed into fishmeal plants in Denmark and the Faroe Islands with increasing amounts being landed in Killybegs. The boarfish fishery bridged an important gap between the short season fisheries for horse mackerel, mackerel and blue whiting (Micromesistius poutassou) affectively extending the fishing season for the RSW fleet from late August through to May. A precautionary interim management plan was adopted in November 2010 covering ICES Divisions VI, VII and VIII and an EU TAC of 33,000t was set. Of this the Irish allocation for 2011 was 22,000t. This precautionary TAC was based on 50-75% of total landings from the period 2007-2009 which peaked at over 83,400t (2009). Landings in 2010 reached over 137,000t in a scramble to build up a track record in the fishery prior to a fixed quota allocation. In 2010 Sweden now also shares the TAC allowance with those actively involved in the fishery. In addition to the TAC control, seasonal closures were also implemented; from September 1-October 31 ICES (area VIIg) to protect herring feeding and pre spawning aggregations and from March 15–August 31 where mackerel are frequently encountered as a large bycatch. A catch rule ceiling of 5% bycatch was also implemented within the fishery where boarfish are taken with other TAC controlled species. Data from this survey, in addition to the extensive biological research carried out on this species forms part of a larger program aimed at increasing the knowledge of this species and its abundance outside of the commercial fishery. Data from this survey will be presented for inclusion into the ICES Planning Group meeting for North Atlantic Pelagic Ecosystem Surveys in August 2011 (WGNAPES) and for the ICES assessment Working Group for Widely Distributed Stocks (WGWIDE) also meeting in August 2011.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2004

      O'Donnell, Ciaran; Griffin, Karen; Clarke, Maurice; Lynch, Deirdre; Ulgren, Jenny; Goddijn, Lonneke; Wall, David; Mackey, Mick (Marine Institute, 2004)
      In the Celtic Sea and ICES Division VIIj, to the south and southwest of Ireland, herring is an important commercial species and currently Ireland is the only country targeting this species in this area. Herring in this region comprise both autumn and winter spawning components. Commercial fishing has targeted the fish during spawning times, though in most recent years fish have been targeted during the summer feeding phase too. In VIIj, fishing has traditionally taken place in October, and concentrated in the bays and inlets. In contrast, fishing in VIIaS has mainly been in December to January, though in VIIg the fishery traditionally takes place from November to January. The protracted spawning period of herring and the overlap between the two spawning socks in this area (October to February) means that it is difficult to design a survey that covers all spawning fish in one specific survey. The stock structure and discrimination of herring in this area is not fully understood. It is known that fish in the eastern Celtic Sea recruit from nursery areas in the Irish Sea and tagging studies have shown linkages between these areas also. For the purpose of stock assessment and management these areas have been combined since 1982. A project is currently underway to describe stock structure and discrimination of herring around Ireland. The results of this project may have implications for the design of this survey and for the stock assessment. For a period in the 1980’s, egg and larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and the current survey is the 15th in the series. In addition to the survey track a small component (Baginbun) was intensively surveyed using acoustic and multibeam mapping techniques. The Baginbun area is located east of Waterford Harbour in ICES division VIIaS. Baginbun has supported a large winter fishery for many years and is one of the most important and well known winter spawning areas on the south coast. This year for the first time the RV Celtic Explorer was to survey the area. This allowed a more extensive degree of coverage in the time allocated, the survey was further complemented with a number of hydrographic transects concentrating along the bays in the west and southwest and also along the southern coastline.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2005

      O'Donnell, Ciaran; Doonan, Ian; Johnston, Graham; Lynch, Deirdre; Dransfeld, Leonie; Wall, David (Marine Institute, 2005)
      In the Celtic Sea and ICES Division VIIj, to the south and southwest of Ireland, herring are an important commercial species to the pelagic fleet. The local fleet is composed of dry hold polyvalent vessels and a number of purpose built RSW (Refrigerated seawater) vessels. This stock is composed of both autumn and winter spawning components. The commercial fishery has historically taken place within 6nmi (nautical miles) of the coast and focused on aggregated schools within the spawning cycle. In recent years the RSW fleet has actively targeted offshore summer feeding grounds in the south Celtic Sea. In division VIIj, the fishery traditionally begins in early October and is concentrated within several miles of the shore bays and inlets. The division VIIaS fishery peaks towards the year end in December, but may be active from mid October depending on location. In division VIIg, along the south coast herring are targeted from October to January at a number of known spawning sites and surrounding areas. Overall, the protracted spawning period of the two components extends from October through to January, with annual variation of up to 3 weeks. Spawning occurs in successive waves in a number of well known locations including large scale grounds and small discreet spawning beds. The stock structure and discrimination of herring in this area is not fully understood. It is known that fish in the eastern Celtic Sea recruit from nursery areas in the Irish Sea and tagging studies have shown linkages between these areas also. For the purpose of stock assessment and management these areas have been combined since 1982. For a period in the 1980’s, egg and larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and the current survey is the 16th in the series. The autumn 2005 survey is the most comprehensive survey carried out in the current time series. The geographical confines of the annual 21 day survey were expanded to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects were increased over the entire south coast survey areas. The acoustic component of the survey was complimented by a continuation of the detailed hydrographic work carried out in the Celtic Sea in 2004. In addition a second inshore survey was carried out along the southern coast using a chartered commercial fishing vessel (FV Regina Ponti). This second survey focused on area between 0.5nmi and 10nmi offshore and covered the main autumn and winter spawning areas along the south coast.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2008

      O'Donnell, C; Saunders, R; Lynch, D; Lyons, K; Wall, D (Marine Institute, 2008)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. The local fleet is composed of dry hold polyvalent vessels and a small number of purpose built RSW (Refrigerated seawater) vessels. The stock is composed of both autumn and winter spawning components and the fishery targets pre-spawning and spawning aggregations. The Irish commercial fishery has historically taken place within 1-20nmi (nautical miles) of the coast and focused on aggregated schools within the spawning cycle. In recent years the larger RSW vessels have actively targeted offshore summer feeding aggregations in the south Celtic Sea. In VIIj, the fishery traditionally begins in mid September and is concentrated within several miles of the shore including many bays and inlets. The VIIaS fishery peaks towards the year end in December, but may be active from mid October depending on location. In VIIg, along the south coast herring are targeted from October to January at a number of known spawning sites and surrounding areas. Overall, the protracted spawning period of the two components extends from October through to January, with annual variation of up to 3 weeks. Spawning occurs in successive waves in a number of well known locations including large scale grounds and small discreet spawning beds. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented by detailed hydrographic and marine mammal and seabird work programs first initiated during this survey in 2004.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2010

      Saunders, R; O'Donnell, C; Campbell, A; Lynch, D; Egan, A; Lyons, K; Wall, D (Marine Institute, 2010)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. The local fleet is composed of dry hold polyvalent vessels and a small number of purpose built Refrigerated seawater vessels (RSW). The stock is composed of both autumn and winter spawning components and the fishery targets pre-spawning and spawning aggregations. The Irish commercial fishery has historically taken place within 1-20 nmi (nautical miles) of the coast and focused on aggregated schools within the spawning cycle. In recent years the larger RSW vessels have actively targeted offshore summer feeding aggregations in the south Celtic Sea. In VIIj, the fishery traditionally begins in mid September and is concentrated within several miles of the shore including many bays and inlets. The VIIaS fishery peaks towards the year end in December, but may be active from mid October depending on location. In VIIg, along the south coast herring are targeted from October to January at a number of known spawning sites and surrounding areas. Overall, the protracted spawning period of the two components extends from October through to January, with annual variation of up to 3 weeks. Spawning occurs in successive waves in a number of well known locations including large-scale grounds and small discreet spawning beds. The stock structure and discrimination of herring in this area has been investigated recently. Hatfield et al. (2007) has shown the Celtic Sea stock to be fairly discrete. However, it is known that fish in the eastern Celtic Sea recruit from nursery areas in the Irish Sea, returning to the Celtic Sea as young adults (Brophy et al. 2002; Molloy et al., 1993). The stock identity of VIIj herring is less clear, though there is evidence that they have linkages with VIIb and VIaS (ICES, 1994; Grainger, 1978). Molloy (1968) identified possible linkages between young fish in VIIj and those of the Celtic Sea herring. For the purpose of stock assessment and management divisions VIIaS, VIIg and VII j have been combined since 1982. For a period in the 1970s and 1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and this survey is the 19th in the overall acoustic series or the sixth in the modified time series (i.e. conducted in October). The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented by detailed hydrographic and marine mammal and seabird work programs first initiated during this survey in 2004.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2013, 07 - 27 October, 2013

      O’Donnell, C.; Nolan, C.; Mullins, E.; Lyons, K.; Volkenandt, M.; Keogh, N.; McAvoy, S.; Williams, D. (Marine Institute, 2013)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j),herring acoustic surveys have been carried out since 1989. This survey was undertaken in early October. The geographical confines of the annual 21 day survey program have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented since 2004 by detailed hydrographic and marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2014, 06-26 October 2014.

      Nolan, Cormac; O'Donnell, Ciaran; Lynch, Deirdre; Lyons, Kieran; Keogh, Niall; McAvoy, Stephen; Cronin, Ciaran; Hunt, William (Marine Institute, 2014)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j),herring acoustic surveys have been carried out since 1989. This survey was undertaken in early October. The geographical confines of the annual 21 day survey program have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented since 2004 by detailed hydrographic and marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2015, 02-22 October 2015

      O’Donnell, C.; Lynch, D.; Lyons, K.; Keogh, N.; O’Donovan, M. (Marine Institute, 2015)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j),herring acoustic surveys have been carried out since 1989. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and this survey is the 21st in the overall acoustic series or the tenth in the modified time series conducted exclusively in October. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complemented since 2004 by detailed hydrographic, marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2016, 07-27 October 2016

      O'Donnell, C.; Sullivan, M.; Lyons, K.; Keogh, N.; Quinn, M. (Marine Institute, 2016)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. For a period in the 1970s and1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989. Since 2004 the survey has been fixed in October and carried out onboard the RV Celtic Explorer. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complemented since 2004 by detailed hydrographic, marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2017, 15-04 November 2017

      O'Donnell, C.; O'Malley, M.; Lynch, D.; Lyons, K.; Keogh, N.; O’Driscoll, D. (Marine Institute, 2017)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. For a period in the 1970s and1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989. Since 2004 the survey has been fixed in October and carried out onboard the RV Celtic Explorer. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complemented since 2004 by detailed hydrographic, marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2018, 08 - 28 October, 2018

      O'Donnell, C.; Mullins, E.; Lynch, D.; Lyons, K.; Keogh, N.; O'Callaghan, S. (Marine Institute, 2018)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. For a period in the 1970s and1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989. Since 2004 the survey has been fixed in October and carried out onboard the RV Celtic Explorer. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complemented since 2004 by detailed hydrographic, marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2019, 09 - 29 October, 2019

      O'Donnell, C.; Mullins, E.; Lynch, D.; Lyons, K.; Connaughton, P.; Power, J. (Marine Institute, 2019)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. For a period in the 1970s and1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989. Since 2004 the survey has been fixed in October and carried out onboard the RV Celtic Explorer. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complemented since 2004 by detailed hydrographic, marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report 2020, 04 - 24 October, 2020

      O’Donnell, C.; Mullins, E.; Lyons, K.; Connaughton, P.; Perez Tadeo, M. (Marine Institute, 2020)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. For a period in the 1970s and1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989. Since 2004 the survey has been fixed in October and carried out onboard the RV Celtic Explorer. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complemented since 2004 by detailed hydrographic, marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey Cruise Report and Biomass Estimate, 2007

      O'Donnell, C; Egan, A; Lynch, D; Dransfeld, L; Boyd, J; Lyons, K; Wall, D (Marine Institute, 2007)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. The local fleet is composed of dry hold polyvalent vessels and a small number of purpose built RSW (Refrigerated seawater) vessels. The stock is composed of both autumn and winter spawning components and the fishery targets pre-spawning and spawning aggregations. The Irish commercial fishery has historically taken place within 1-20nmi (nautical miles) of the coast and focused on aggregated schools within the spawning cycle. In recent years the larger RSW vessels have actively targeted offshore summer feeding aggregations in the south Celtic Sea. In VIIj, the fishery traditionally begins in early October and is concentrated within several miles of the shore including many bays and inlets. The VIIaS fishery peaks towards the year end in December, but may be active from mid October depending on location. In VIIg, along the south coast herring are targeted from October to January at a number of known spawning sites and surrounding areas. Overall, the protracted spawning period of the two components extends from October through to January, with annual variation of up to 3 weeks. Spawning occurs in successive waves in a number of well known locations including large scale grounds and small discreet spawning beds. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented by detailed hydrographic and marine mammal and seabird work programs first initiated during this survey in 2004.
    • Celtic Sea Herring Acoustic Survey RV Celtic Explorer 1st – 21st October 2006

      O'Donnell, C; Doonan, I; Lynch, D; Egan, A; Boyd, J; Wall, D; Ullgren, J (Marine Institute, 2006)
      In the Celtic Sea and ICES Division VIIj the herring fishery is divided into 3 main catching seasons. In quarters four and one, the fishery is focused on autumn and winter pre-spawning and spawning aggregations. In the 2004/05 season 34 vessels participated in the fishery, ranging from small dry hold polyvalent vessels (<20m) to purpose built RSW (Refrigerated seawater) vessels of 23-40m. Single and pair midwater trawling are common, with the latter representing the preferred catching method. In recent years a quarter-3 summer fishery has developed targeting offshore feeding aggregations, 78nmi (nautical miles) offshore on the Labadie Bank. This offshore fishery is restricted to the RSW fleet on the grounds of product quality delivered to processors. The 2006 autumn survey is the most comprehensive survey carried out in the current time series. The geographical extent of the annual 21 day survey was extended further offshore to include areas to the south of the main coastal spawning grounds to target winter spawning fish on an inward spawning migration. Spatial resolution of acoustic transects were increased over the entire south coast survey areas, with a special focus on spawning grounds throughout the survey confines. The acoustic component of the survey was complimented by a continuation of the detailed hydrographic work first established in the Celtic Sea in 2004.
    • Celtic Sea Herring Acoustic Survey, 07 - 28 October, 2011

      O'Donnell, Ciaran; Lynch, Deirdre; Lyons, Kieran; Ni Riogain, Paula; Volkenandt, Mareike (Marine Institute, 2011)
      In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and this survey is the 20th in the overall acoustic series or the seventh in the modified time series (i.e. conducted in October). The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented since 2004 by detailed hydrographic and marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey, 09 - 29 October, 2012

      O’Donnell, Ciaran; Nolan, Cormac; Sullivan, Mairead; Lyons, Kieran; McKeogh, Enda; McAvoy, Stephen; Ingham, Sarah (Marine Institute, 2012)
      In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989. This survey was undertaken in early October. The geographical confines of the annual 21 day survey program have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented since 2004 by detailed hydrographic and marine mammal and seabird surveys.
    • Celtic Sea Herring Acoustic Survey, Cruise Report 2009

      Saunders, R; O'Donnell, C; Campbell, A; Lynch, D; Lyons, K; Wall, D (Marine Institute, 2009)
      In the southwest of Ireland and the Celtic Sea (ICES Divisions VIIaS, g & j), herring are an important commercial species to the pelagic and polyvalent fleet. The local fleet is composed of dry hold polyvalent vessels and a small number of purpose built Refrigerated seawater vessels (RSW). The stock is composed of both autumn and winter spawning components and the fishery targets pre-spawning and spawning aggregations. The Irish commercial fishery has historically taken place within 1-20 nmi (nautical miles) of the coast and focused on aggregated schools within the spawning cycle. In recent years the larger RSW vessels have actively targeted offshore summer feeding aggregations in the south Celtic Sea. In VIIj, the fishery traditionally begins in mid September and is concentrated within several miles of the shore including many bays and inlets. The VIIaS fishery peaks towards the year end in December, but may be active from mid October depending on location. In VIIg, along the south coast herring are targeted from October to January at a number of known spawning sites and surrounding areas. Overall, the protracted spawning period of the two components extends from October through to January, with annual variation of up to 3 weeks. Spawning occurs in successive waves in a number of well known locations including large scale grounds and small discreet spawning beds. The stock structure and discrimination of herring in this area has been investigated recently. Hatfield et al. (2007) has shown the Celtic Sea stock to be fairly discrete. However, it is known that fish in the eastern Celtic Sea recruit from nursery areas in the Irish Sea, returning to the Celtic Sea as young adults (Brophy et al. 2002; Molloy et al., 1993). The stock identity of VIIj herring is less clear, though there is evidence that they have linkages with VIIb and VIaS (ICES, 1994; Grainger, 1978). Molloy (1968) identified possible linkages between young fish in VIIj and those of the Celtic Sea herring. For the purpose of stock assessment and management divisions VIIaS, VIIg and VII j have been combined since 1982. For a period in the 1970s and1980s, larval surveys were conducted for herring in this area. However, since 1989, acoustic surveys have been carried out, and currently are the only tuning indices available for this stock. In the Celtic Sea and VIIj, herring acoustic surveys have been carried out since 1989, and this survey represents the 18th in the overall acoustic series or the fourth in the modified time series. The geographical confines of the annual 21 day survey have been modified in recent years to include areas to the south of the main winter spawning grounds in an effort to identify the whereabouts of winter spawning fish before the annual inshore spawning migration. Spatial resolution of acoustic transects has been increased over the entire south coast survey area. The acoustic component of the survey has been further complimented by detailed hydrographic and marine mammal and seabird work programs first initiated during this survey in 2004.
    • Fish species recorded during deepwater trawl surveys on the continental shelf and the Porcupine Bank, 2006-2008

      Johnston, G.; O'Hea, B.; Dransfeld, L. (Marine Institute, 2012)
      The Marine Institute and the National University of Ireland, Galway conducted a deepwater survey each September from 2006-2008 from the RV Celtic Explorer using BT184 deepwater nets with type-D ground gear (ICES 2006). Fish, benthic and hydrographic data were collected. Two-hour fishing trawls (time on bottom) took place in three locations on the continental slope to the north and west of Ireland, and on the Porcupine Bank. The survey objectives were to collect biological data on the main deepwater fish species and invertebrates. In total 166 taxa were recorded over the three years, with a maximum of 129 in 2008.