Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and co... more Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and compared in the context of landings in Europe and the North American H. americanus fishery. H. gammarus fishing has provided essential income for over a century to many Irish coastal communities. There have been significant fluctuations (greater than 460%) in recorded landings over this time and the relative importance of H. gammarus fishing has changed with the establishment of ancillary crustacean fisheries. In 1994, H. gammarus landings reached an alltime high of 714 tonnes, with a landed value of IR £6.3 million; in 1999 landings were 597 tonnes valued at IR £6.15 million. Current Republic of Ireland lobster fishery regulations are: (a) minimum carapace length of 85 mm, (b) ban on landing lobsters that have been 'V-notched' or have a mutilated tail fan, and (c) prohibition of capturing lobsters by SCUBA diving. Chronological details on recent legislation, regulations and landings relating to Ireland's lobster fishery sector are reviewed. In the last 40 years landings of H. gammarus in the Republic of Ireland exhibit signs of an overexploited stock characterised by a reduction in catch per unit effort and there has been a general decline of total landings for H. gammarus throughout Europe. This contrasts with North America, where many regulations govern the H. americanus fishery and landings appear to be in a healthier state.
The restocking or enhancement of Homarid populations has been the focus of several research proje... more The restocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m 2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m 2 of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day 'exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
The restocking or enhancement of Homarid populations has been the focus of several research proje... more The restocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m 2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m 2 of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day 'exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancemen... more Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancement of clawed lobsters (Homarus gammarus); development of juvenile lobster production methodologies. NINA Report no. 211, 39 pp. European lobsters (Homarus gammarus) are a highly prized and gastronomically appreciated marine organism. As a result of intense fishing pressure lobster landings have declined considerably in many European regions. This decrease has been particularly dramatic in the southern and northern areas of Europe. Releases of artificially raised lobster juveniles have been shown to have the potential to contribute to re-establishment or enhancement of depleted lobster stocks. However, one of the key problems for successful stock enhancement has been the lack of cost effective methodologies for producing juveniles. After the planktonic stage of their life cycle, the total length of the European lobster ranges from 1.5 to 2 cm. These small early benthic stage animals are ex...
Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and co... more Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and compared in the context of landings in Europe and the North American H. americanus fishery. H. gammarus fishing has provided essential income for over a century to many Irish coastal communities. There have been significant fluctuations (greater than 460%) in recorded landings over this time and the relative importance of H. gammarus fishing has changed with the establishment of ancillary crustacean fisheries. In 1994, H. gammarus landings reached an alltime high of 714 tonnes, with a landed value of IR £6.3 million; in 1999 landings were 597 tonnes valued at IR £6.15 million. Current Republic of Ireland lobster fishery regulations are: (a) minimum carapace length of 85 mm, (b) ban on landing lobsters that have been 'V-notched' or have a mutilated tail fan, and (c) prohibition of capturing lobsters by SCUBA diving. Chronological details on recent legislation, regulations and landings relating to Ireland's lobster fishery sector are reviewed. In the last 40 years landings of H. gammarus in the Republic of Ireland exhibit signs of an overexploited stock characterised by a reduction in catch per unit effort and there has been a general decline of total landings for H. gammarus throughout Europe. This contrasts with North America, where many regulations govern the H. americanus fishery and landings appear to be in a healthier state.
The restocking or enhancement of Homarid populations has been the focus of several research proje... more The restocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m 2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m 2 of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day 'exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
The re-stocking or enhancement of Homarid populations has been the focus of several research proj... more The re-stocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m2of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day `exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
... in the practical day to day work with the lobsters during the 1990's; Du... more ... in the practical day to day work with the lobsters during the 1990's; Duncan Brown, Eileen Noonan, Oliver Nee, Padraig Casey, Stephen Barrett, Gerald Blake, Vera O'Donovan, Siobhan Curran, Paul Casburn, Maeve McGuiness, Leire Barruetabeaia, Esteban Martinez, Aisling ...
Journal of the Marine Biological Association of the UK
This study examined the role of predation in restricting early benthic phase (EBP) lobsters to sh... more This study examined the role of predation in restricting early benthic phase (EBP) lobsters to shelter-providing substrata. In the field, the survival of animals provided with cover in the form of cobble and gravel substrata was significantly higher than unsheltered controls. Small benthic fish, particularly gobies Pomatoschistus minutus and rockling Ciliata mustela were the primary predators subtidally while crabs Carcinus maenus appeared to be the dominant intertidal predator. Predatory attack primarily occurred within minutes of the lobsters being deployed. The study reinforces the role played by predation in restricting EBP European lobsters to shelter-providing substrata.
Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancemen... more Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancement of clawed lobsters (Homarus gammarus); development of juvenile lobster production methodologies. NINA Report no. 211, 39 pp. European lobsters (Homarus gammarus) are a highly prized and gastronomically appreciated marine organism. As a result of intense fishing pressure lobster landings have declined considerably in many European regions. This decrease has been particularly dramatic in the southern and northern areas of Europe. Releases of artificially raised lobster juveniles have been shown to have the potential to contribute to re-establishment or enhancement of depleted lobster stocks. However, one of the key problems for successful stock enhancement has been the lack of cost effective methodologies for producing juveniles. After the planktonic stage of their life cycle, the total length of the European lobster ranges from 1.5 to 2 cm. These small early benthic stage animals are extremely vulnerable to predation if released directly into the sea. For this reason it is thought important to rear the lobsters to a length of at least 4 to 5 cm before they are released into the wild in an effort to increase their chances of survival. The purpose of this project was to develop and improve existing methodologies used to produce viable lobster juveniles that are fit for release into the wild. This project was a part of the AquaReg programme within the framework of the Community initiative programme INTERREG IIIC and it began in 2004. The methodologies used both in the hatchery setting and field were based on rearing the juveniles from metamorphosis until a suitable size for release either in individual compartments suspended from mussel rafts (sea cages or baskets) or communally in natural seawater. Both of these culture techniques involved the postlarval lobsters feeding on naturally occurring plankton and epibiotic fouling organisms. The results demonstrate that survival to a size suitable for release is high when rearing lobsters in suspended baskets (oyster cages). The lobsters also grew well both in sea cage based culture and in communal rearing, despite the fact that lobsters cultured in submerged cages in the open sea were not fed artificial feed during the course of the study. The methodologies developed represents a cost-effective way of producing lobster juveniles for re-establishment or enhancement efforts, since labour expense, constructions and feeding costs are minimized and the production efficiency is high.
The re-stocking or enhancement of Homarid populations has been the focus of several research proj... more The re-stocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m2of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day `exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
Biology & Environment: Proceedings of the Royal Irish Academy, 2003
Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and co... more Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and compared in the context of landings in Europe and the North American H. americanus fishery. H. gammarus fishing has provided essential income for over a century to many Irish coastal communities. There have been significant fluctuations (greater than 460%) in recorded landings over this time and the relative importance of H. gammarus fishing has changed with the establishment of ancillary crustacean fisheries. In 1994, H. gammarus landings reached an alltime high of 714 tonnes, with a landed value of IR £6.3 million; in 1999 landings were 597 tonnes valued at IR £6.15 million. Current Republic of Ireland lobster fishery regulations are: (a) minimum carapace length of 85 mm, (b) ban on landing lobsters that have been 'V-notched' or have a mutilated tail fan, and (c) prohibition of capturing lobsters by SCUBA diving. Chronological details on recent legislation, regulations and landings relating to Ireland's lobster fishery sector are reviewed. In the last 40 years landings of H. gammarus in the Republic of Ireland exhibit signs of an overexploited stock characterised by a reduction in catch per unit effort and there has been a general decline of total landings for H. gammarus throughout Europe. This contrasts with North America, where many regulations govern the H. americanus fishery and landings appear to be in a healthier state.
A bottleneck for re-establishment or enhancement of lobster (Homarus gammarus L.) populations thr... more A bottleneck for re-establishment or enhancement of lobster (Homarus gammarus L.) populations through release of hatchery-produced juveniles is ineffective and expensive juvenile production. In this study, we cultured lobster juveniles from stage V to a size being suitable for re-establishment or enhancement purposes (40-50 mm total length) in cages submerged under existing facilities for culture of bivalves. The lobsters were not feed or tended during the culture period (6-14 months). The survival and growth rates were similar or higher compared to what has been achieved with other methods used for culture of lobster juveniles in the past. The highest survival (82-89%) and fastest growth (4-5 cm total length over 190-250 days) were achieved using commercial oyster baskets. It is believed that the juveniles fed on naturally occurring plankton and organisms growing inside the cages. Thus, the current study shows that it is possible to culture lobster juveniles for reestablishment or enhancement purposes in a way that would involve less investments and operational costs than earlier used methods as there would be no need for artificial heating of water, for large buildings or for continuous feeding and tending of large numbers of juveniles.
Many of the techniques and structures described evolved over the period of this research. Observa... more Many of the techniques and structures described evolved over the period of this research. Observations on aspects of lobster biology pertinent for hatchery consideration are also presented in this report.
Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and co... more Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and compared in the context of landings in Europe and the North American H. americanus fishery. H. gammarus fishing has provided essential income for over a century to many Irish coastal communities. There have been significant fluctuations (greater than 460%) in recorded landings over this time and the relative importance of H. gammarus fishing has changed with the establishment of ancillary crustacean fisheries. In 1994, H. gammarus landings reached an alltime high of 714 tonnes, with a landed value of IR £6.3 million; in 1999 landings were 597 tonnes valued at IR £6.15 million. Current Republic of Ireland lobster fishery regulations are: (a) minimum carapace length of 85 mm, (b) ban on landing lobsters that have been 'V-notched' or have a mutilated tail fan, and (c) prohibition of capturing lobsters by SCUBA diving. Chronological details on recent legislation, regulations and landings relating to Ireland's lobster fishery sector are reviewed. In the last 40 years landings of H. gammarus in the Republic of Ireland exhibit signs of an overexploited stock characterised by a reduction in catch per unit effort and there has been a general decline of total landings for H. gammarus throughout Europe. This contrasts with North America, where many regulations govern the H. americanus fishery and landings appear to be in a healthier state.
The restocking or enhancement of Homarid populations has been the focus of several research proje... more The restocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m 2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m 2 of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day 'exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
The restocking or enhancement of Homarid populations has been the focus of several research proje... more The restocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m 2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m 2 of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day 'exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancemen... more Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancement of clawed lobsters (Homarus gammarus); development of juvenile lobster production methodologies. NINA Report no. 211, 39 pp. European lobsters (Homarus gammarus) are a highly prized and gastronomically appreciated marine organism. As a result of intense fishing pressure lobster landings have declined considerably in many European regions. This decrease has been particularly dramatic in the southern and northern areas of Europe. Releases of artificially raised lobster juveniles have been shown to have the potential to contribute to re-establishment or enhancement of depleted lobster stocks. However, one of the key problems for successful stock enhancement has been the lack of cost effective methodologies for producing juveniles. After the planktonic stage of their life cycle, the total length of the European lobster ranges from 1.5 to 2 cm. These small early benthic stage animals are ex...
Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and co... more Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and compared in the context of landings in Europe and the North American H. americanus fishery. H. gammarus fishing has provided essential income for over a century to many Irish coastal communities. There have been significant fluctuations (greater than 460%) in recorded landings over this time and the relative importance of H. gammarus fishing has changed with the establishment of ancillary crustacean fisheries. In 1994, H. gammarus landings reached an alltime high of 714 tonnes, with a landed value of IR £6.3 million; in 1999 landings were 597 tonnes valued at IR £6.15 million. Current Republic of Ireland lobster fishery regulations are: (a) minimum carapace length of 85 mm, (b) ban on landing lobsters that have been 'V-notched' or have a mutilated tail fan, and (c) prohibition of capturing lobsters by SCUBA diving. Chronological details on recent legislation, regulations and landings relating to Ireland's lobster fishery sector are reviewed. In the last 40 years landings of H. gammarus in the Republic of Ireland exhibit signs of an overexploited stock characterised by a reduction in catch per unit effort and there has been a general decline of total landings for H. gammarus throughout Europe. This contrasts with North America, where many regulations govern the H. americanus fishery and landings appear to be in a healthier state.
The restocking or enhancement of Homarid populations has been the focus of several research proje... more The restocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m 2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m 2 of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day 'exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
The re-stocking or enhancement of Homarid populations has been the focus of several research proj... more The re-stocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m2of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day `exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
... in the practical day to day work with the lobsters during the 1990's; Du... more ... in the practical day to day work with the lobsters during the 1990's; Duncan Brown, Eileen Noonan, Oliver Nee, Padraig Casey, Stephen Barrett, Gerald Blake, Vera O'Donovan, Siobhan Curran, Paul Casburn, Maeve McGuiness, Leire Barruetabeaia, Esteban Martinez, Aisling ...
Journal of the Marine Biological Association of the UK
This study examined the role of predation in restricting early benthic phase (EBP) lobsters to sh... more This study examined the role of predation in restricting early benthic phase (EBP) lobsters to shelter-providing substrata. In the field, the survival of animals provided with cover in the form of cobble and gravel substrata was significantly higher than unsheltered controls. Small benthic fish, particularly gobies Pomatoschistus minutus and rockling Ciliata mustela were the primary predators subtidally while crabs Carcinus maenus appeared to be the dominant intertidal predator. Predatory attack primarily occurred within minutes of the lobsters being deployed. The study reinforces the role played by predation in restricting EBP European lobsters to shelter-providing substrata.
Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancemen... more Uglem, I., Perez Benavente, G. and Browne R. A regional development strategy for stock enhancement of clawed lobsters (Homarus gammarus); development of juvenile lobster production methodologies. NINA Report no. 211, 39 pp. European lobsters (Homarus gammarus) are a highly prized and gastronomically appreciated marine organism. As a result of intense fishing pressure lobster landings have declined considerably in many European regions. This decrease has been particularly dramatic in the southern and northern areas of Europe. Releases of artificially raised lobster juveniles have been shown to have the potential to contribute to re-establishment or enhancement of depleted lobster stocks. However, one of the key problems for successful stock enhancement has been the lack of cost effective methodologies for producing juveniles. After the planktonic stage of their life cycle, the total length of the European lobster ranges from 1.5 to 2 cm. These small early benthic stage animals are extremely vulnerable to predation if released directly into the sea. For this reason it is thought important to rear the lobsters to a length of at least 4 to 5 cm before they are released into the wild in an effort to increase their chances of survival. The purpose of this project was to develop and improve existing methodologies used to produce viable lobster juveniles that are fit for release into the wild. This project was a part of the AquaReg programme within the framework of the Community initiative programme INTERREG IIIC and it began in 2004. The methodologies used both in the hatchery setting and field were based on rearing the juveniles from metamorphosis until a suitable size for release either in individual compartments suspended from mussel rafts (sea cages or baskets) or communally in natural seawater. Both of these culture techniques involved the postlarval lobsters feeding on naturally occurring plankton and epibiotic fouling organisms. The results demonstrate that survival to a size suitable for release is high when rearing lobsters in suspended baskets (oyster cages). The lobsters also grew well both in sea cage based culture and in communal rearing, despite the fact that lobsters cultured in submerged cages in the open sea were not fed artificial feed during the course of the study. The methodologies developed represents a cost-effective way of producing lobster juveniles for re-establishment or enhancement efforts, since labour expense, constructions and feeding costs are minimized and the production efficiency is high.
The re-stocking or enhancement of Homarid populations has been the focus of several research proj... more The re-stocking or enhancement of Homarid populations has been the focus of several research projects in recent years. However, despite being able to successfully rear lobsters in captivity, there are few reports of newly settled European lobsters (Homarus gammarus) in the wild. This is of serious concern for fishery managers when trying to ascertain if restocking or enhancement programmes are successful at the fishery level. Based on published work from the western Atlantic seaboard, cobble and boulder substrata have been identified as an important nursery habitat for early benthic phase (EBP) American lobsters (Homarus americanus). This paper, based on an E.U. funded research project (LEAR), describes the results of quantitative airlift suction sampling from cobble habitat in Norway, Ireland the U.K., and Italy. In total, 67 m2 of cobble was sampled, but no EBP lobsters were found. Overall, crustaceans and molluscs were the most abundant species in all countries. While the collective densities of animals per m2of cobble were similar to that of the United States, the species diversity in Europe was noticeably higher. Among the crustacea, the reptant decapods dominated at all sites. These findings tend to support the modern day `exclusion hypothesis' that competition and predation from other species limits the successful recruitment of EBP European lobster to the benthos. The results highlight the need to go beyond the single species approach to understanding the factors that influence the recruitment of Homarus gammarus.
Biology & Environment: Proceedings of the Royal Irish Academy, 2003
Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and co... more Historical developments of the Republic of Ireland's Homarus gammarus fishery are reviewed and compared in the context of landings in Europe and the North American H. americanus fishery. H. gammarus fishing has provided essential income for over a century to many Irish coastal communities. There have been significant fluctuations (greater than 460%) in recorded landings over this time and the relative importance of H. gammarus fishing has changed with the establishment of ancillary crustacean fisheries. In 1994, H. gammarus landings reached an alltime high of 714 tonnes, with a landed value of IR £6.3 million; in 1999 landings were 597 tonnes valued at IR £6.15 million. Current Republic of Ireland lobster fishery regulations are: (a) minimum carapace length of 85 mm, (b) ban on landing lobsters that have been 'V-notched' or have a mutilated tail fan, and (c) prohibition of capturing lobsters by SCUBA diving. Chronological details on recent legislation, regulations and landings relating to Ireland's lobster fishery sector are reviewed. In the last 40 years landings of H. gammarus in the Republic of Ireland exhibit signs of an overexploited stock characterised by a reduction in catch per unit effort and there has been a general decline of total landings for H. gammarus throughout Europe. This contrasts with North America, where many regulations govern the H. americanus fishery and landings appear to be in a healthier state.
A bottleneck for re-establishment or enhancement of lobster (Homarus gammarus L.) populations thr... more A bottleneck for re-establishment or enhancement of lobster (Homarus gammarus L.) populations through release of hatchery-produced juveniles is ineffective and expensive juvenile production. In this study, we cultured lobster juveniles from stage V to a size being suitable for re-establishment or enhancement purposes (40-50 mm total length) in cages submerged under existing facilities for culture of bivalves. The lobsters were not feed or tended during the culture period (6-14 months). The survival and growth rates were similar or higher compared to what has been achieved with other methods used for culture of lobster juveniles in the past. The highest survival (82-89%) and fastest growth (4-5 cm total length over 190-250 days) were achieved using commercial oyster baskets. It is believed that the juveniles fed on naturally occurring plankton and organisms growing inside the cages. Thus, the current study shows that it is possible to culture lobster juveniles for reestablishment or enhancement purposes in a way that would involve less investments and operational costs than earlier used methods as there would be no need for artificial heating of water, for large buildings or for continuous feeding and tending of large numbers of juveniles.
Many of the techniques and structures described evolved over the period of this research. Observa... more Many of the techniques and structures described evolved over the period of this research. Observations on aspects of lobster biology pertinent for hatchery consideration are also presented in this report.
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