William Roche - Academia.edu (original) (raw)
Papers by William Roche
Endangered Species Research, 2019
The angel shark Squatina squatina was historically common in coastal waters from the British Isle... more The angel shark Squatina squatina was historically common in coastal waters from the British Isles to northwestern Africa, including the Mediterranean. Reported commercial landings from northern Europe reduced to near-zero before the species was added to the EU Prohibited Species list and subsequently listed as Critically Endangered by the IUCN. S. squatina is encountered rarely in offshore trawl surveys, probably because of low spatial overlap with coastal populations and habitats. An alternative source of monitoring data is angling vessels, which can operate in discrete inshore areas. Analyses of 2 unique > 40 yr time series of angler tagging and specimen catch data from Irish waters, with catch and effort records from voluntary charter angling logbooks, reveal a sharp decline in S. squatina catches. Only 1 individual has been tagged since 2011. Almost all reports were from Tralee Bay and Clew Bay (western Ireland), where anecdotal sightings still occur. These historical hotspots may be significant to international angel shark conservation efforts.
Estuarine, Coastal and Shelf Science
ICES Journal of Marine Science: Journal du Conseil, 2016
Sea trout are parasitized by two species of caligid copepod sea lice, Lepeophtheirus salmonis and... more Sea trout are parasitized by two species of caligid copepod sea lice, Lepeophtheirus salmonis and Caligus elongatus. Generally, levels of lice infestation are low and few adverse effects on the host have been reported. However, with the advent of marine salmon farming since the 1980s, there have been many published accounts of L. salmonis sea lice epizootics on salmonids in aquaculture areas. Few large-scale studies are available on levels of sea lice infestation of sea trout in areas without salmon farms or before their development. Understanding natural background lice levels on sea trout is important to interpret lice levels on trout in aquaculture areas. The Celtic Sea Trout Project, an INTERREG IVA Ireland Wales EU funded project, examined the status, distribution, genetics, and ecology of sea trout around the Irish Sea and provided an opportunity to assess levels of lice on sea trout spatially and temporally in an area without marine salmon farming. The prevalence of L. salmon...
The authors consider approaches to environmental remediation of the abandoned copper mines at Avo... more The authors consider approaches to environmental remediation of the abandoned copper mines at Avoca in Ireland and at Amlwch in Wales, UK in terms of balancing the interests of various stakeholder groups. Water and water quality are essentially heritage concerns. The legacy of mining at Avoca creates the most significant river pollution in Ireland. The problems of Avoca have been considered in their various aspects at different times, generating copious data from various fields of interest. This 'heritage' is currently being explored by scientists from different disciplines through The Celtic Copper Heritage (CCH) initiative which has obtained funding under the EU INTERREG 111A Programme. Heritage and remediation potential is also afforded by combining international understanding with approaches to a similar ore body in Wales which has been worked for the same minerals over history. The similarity of the two places extends to the fact of their both being worked by the same company, owners, miners and mining engineers. The mine sites at Amlwch are included in the International Commission on Monuments and Sites' Register of Landscapes of Outstanding Historic Importance in Wales. The surviving mining heritage has close parallels with that of Avoca. Many studies have been made of both places and their mining impacts. Recently, in Avoca, a pilot water treatment operation was commissioned by the CCH project to quantify process material and costs. A conclusive study for the remediation of the mine water which will include recommendations for the mine sites is soon to be commissioned by the Department of Communications Marine and Natural Resources (DCMNR). Local heritage issues will feature in this. Actions to treat the mine water discharges will needs to consider a number of variables, including the characteristics and disposal of the residual products of the proposed treatment process.
Molecular Phylogenetics and Evolution, 2013
Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully f... more Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully freshwater life. The only landlocked shad population in Northwestern Europe is found in a lake in Ireland, Lough Leane. The Killarney shad, Alosa killarnensis (or Alosa fallax killarnensis, as it is mostly referred to) displays a level of morphological divergence that indicates a long-term isolation in the lake. Microsatellites and mtDNA control region sequences were used within a coalescent framework (BEAST and Approximate Bayesian Computation (ABC)) to investigate its colonization history and to clarify its taxonomic status. Results indicate that the lake was likely colonized in two independent events, the first coinciding with the retreat of the ice sheet from the area after the Last Glacial Maximum and the second after the Younger Dryas. Microsatellite data has shown that these two landlocked lineages have completely admixed within the lake, and have started diverging significantly from their closest ancestor, the twaite shad. We argue that our molecular results (together with the life-history and physiological divergence between Killarney and twaite shad) are conspicuous enough to view the landlocked population as a new species, and one whose future existence would certainly not be insured by its sister taxon.
ICES Journal of Marine Science, 2004
Ireland has one of the last remaining commercial salmon driftnet fisheries in the North Atlantic,... more Ireland has one of the last remaining commercial salmon driftnet fisheries in the North Atlantic, with recent catches averaging 162 000 salmon (1997–2003), approximately 20% of the total landings of salmon in the entire North Atlantic. Since 2001, the Irish commercial salmon fishery has been managed on the basis of Total Allowable Catch (TAC) in each of 17 salmon fishing districts. This has been made possible by applying a number of new and innovative techniques to the estimation of conservation limits (CLs) and pre-fishery abundance (PFA) for combined stocks in each district. Stock and recruitment parameters from well-monitored European rivers were “transported” to all Irish rivers using a Bayesian hierarchical stock and recruitment (BHSRA) model. This provided the posterior probability distributions of the model parameters and related reference points, including individual river CLs. District PFA and the number of spawners were estimated for a baseline period of 1997–2003, using d...
Hydrobiologia, 2008
Four Special Areas of Conservation (SACs) have been designated in the Republic of Ireland for Twa... more Four Special Areas of Conservation (SACs) have been designated in the Republic of Ireland for Twaite shad, Alosa fallax (Lacépède), based on recent historical information on spawning activity—the estuarine reaches of the Rivers Munster Blackwater, Suir, Barrow–Nore and Slaney. The spawning status of some of these populations is considered to have declined substantially in recent years, and no known spawning
Aquatic Conservation: Marine and Freshwater Ecosystems, 2001
1. This paper highlights the recent extinctions of two native Arctic charr populations in the Wes... more 1. This paper highlights the recent extinctions of two native Arctic charr populations in the West of Ireland, one population from the Lough Conn catchment, and a second from the Lough Corrib catchment, respectively. 2. The distribution of charr populations in the two catchments is reviewed. The current distribution information is drawn from recent fish stock surveys (Lough Corrib in 1996, and Lough Conn in 1997 and 1998). Previous records of charr in the literature and unpublished data are described to place the current distribution of charr within these catchments into a historical perspective. 3. The importance of the charr population in Lough Mask (Lough Corrib catchment) is emphasized, as it is one of the last extant examples of charr from a large Irish alkaline lake. 4. Impacts on charr populations in both catchments are discussed and conservation measures proposed.
Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully f... more Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully freshwater life. The only landlocked shad population in Northwestern Europe is found in a lake in Ireland, Lough Leane. The Killarney shad, Alosa killarnensis (or Alosa fallax killarnensis, as it is mostly referred to) displays a level of morphological divergence that indicates a long-term isolation in the lake. Microsatellites and mtDNA control region sequences were used within a coalescent framework (BEAST and Approximate Bayesian Computation (ABC)) to investigate its colonization history and to clarify its taxonomic status. Results indicate that the lake was likely colonized in two independent events, the first coinciding with the retreat of the ice sheet from the area after the Last Glacial Maximum and the second after the Younger Dryas. Microsatellite data has shown that these two landlocked lineages have completely admixed within the lake, and have started diverging significantly from their closest ancestor, the twaite shad. We argue that our molecular results (together with the life-history and physiological divergence between Killarney and twaite shad) are conspicuous enough to view the landlocked population as a new species, and one whose future existence would certainly not be insured by its sister taxon.
Biology and Environment: …, 1996
There is a paucity of published information on the population biology of salmonids in Irish uplan... more There is a paucity of published information on the population biology of salmonids in Irish upland soft-water streams despite their relative importance as salmonid nursery areas and their susceptibility to acidification. This paper describes the characteristics of brown trout populations in ...
Endangered Species Research, 2019
The angel shark Squatina squatina was historically common in coastal waters from the British Isle... more The angel shark Squatina squatina was historically common in coastal waters from the British Isles to northwestern Africa, including the Mediterranean. Reported commercial landings from northern Europe reduced to near-zero before the species was added to the EU Prohibited Species list and subsequently listed as Critically Endangered by the IUCN. S. squatina is encountered rarely in offshore trawl surveys, probably because of low spatial overlap with coastal populations and habitats. An alternative source of monitoring data is angling vessels, which can operate in discrete inshore areas. Analyses of 2 unique > 40 yr time series of angler tagging and specimen catch data from Irish waters, with catch and effort records from voluntary charter angling logbooks, reveal a sharp decline in S. squatina catches. Only 1 individual has been tagged since 2011. Almost all reports were from Tralee Bay and Clew Bay (western Ireland), where anecdotal sightings still occur. These historical hotspots may be significant to international angel shark conservation efforts.
Estuarine, Coastal and Shelf Science
ICES Journal of Marine Science: Journal du Conseil, 2016
Sea trout are parasitized by two species of caligid copepod sea lice, Lepeophtheirus salmonis and... more Sea trout are parasitized by two species of caligid copepod sea lice, Lepeophtheirus salmonis and Caligus elongatus. Generally, levels of lice infestation are low and few adverse effects on the host have been reported. However, with the advent of marine salmon farming since the 1980s, there have been many published accounts of L. salmonis sea lice epizootics on salmonids in aquaculture areas. Few large-scale studies are available on levels of sea lice infestation of sea trout in areas without salmon farms or before their development. Understanding natural background lice levels on sea trout is important to interpret lice levels on trout in aquaculture areas. The Celtic Sea Trout Project, an INTERREG IVA Ireland Wales EU funded project, examined the status, distribution, genetics, and ecology of sea trout around the Irish Sea and provided an opportunity to assess levels of lice on sea trout spatially and temporally in an area without marine salmon farming. The prevalence of L. salmon...
The authors consider approaches to environmental remediation of the abandoned copper mines at Avo... more The authors consider approaches to environmental remediation of the abandoned copper mines at Avoca in Ireland and at Amlwch in Wales, UK in terms of balancing the interests of various stakeholder groups. Water and water quality are essentially heritage concerns. The legacy of mining at Avoca creates the most significant river pollution in Ireland. The problems of Avoca have been considered in their various aspects at different times, generating copious data from various fields of interest. This 'heritage' is currently being explored by scientists from different disciplines through The Celtic Copper Heritage (CCH) initiative which has obtained funding under the EU INTERREG 111A Programme. Heritage and remediation potential is also afforded by combining international understanding with approaches to a similar ore body in Wales which has been worked for the same minerals over history. The similarity of the two places extends to the fact of their both being worked by the same company, owners, miners and mining engineers. The mine sites at Amlwch are included in the International Commission on Monuments and Sites' Register of Landscapes of Outstanding Historic Importance in Wales. The surviving mining heritage has close parallels with that of Avoca. Many studies have been made of both places and their mining impacts. Recently, in Avoca, a pilot water treatment operation was commissioned by the CCH project to quantify process material and costs. A conclusive study for the remediation of the mine water which will include recommendations for the mine sites is soon to be commissioned by the Department of Communications Marine and Natural Resources (DCMNR). Local heritage issues will feature in this. Actions to treat the mine water discharges will needs to consider a number of variables, including the characteristics and disposal of the residual products of the proposed treatment process.
Molecular Phylogenetics and Evolution, 2013
Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully f... more Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully freshwater life. The only landlocked shad population in Northwestern Europe is found in a lake in Ireland, Lough Leane. The Killarney shad, Alosa killarnensis (or Alosa fallax killarnensis, as it is mostly referred to) displays a level of morphological divergence that indicates a long-term isolation in the lake. Microsatellites and mtDNA control region sequences were used within a coalescent framework (BEAST and Approximate Bayesian Computation (ABC)) to investigate its colonization history and to clarify its taxonomic status. Results indicate that the lake was likely colonized in two independent events, the first coinciding with the retreat of the ice sheet from the area after the Last Glacial Maximum and the second after the Younger Dryas. Microsatellite data has shown that these two landlocked lineages have completely admixed within the lake, and have started diverging significantly from their closest ancestor, the twaite shad. We argue that our molecular results (together with the life-history and physiological divergence between Killarney and twaite shad) are conspicuous enough to view the landlocked population as a new species, and one whose future existence would certainly not be insured by its sister taxon.
ICES Journal of Marine Science, 2004
Ireland has one of the last remaining commercial salmon driftnet fisheries in the North Atlantic,... more Ireland has one of the last remaining commercial salmon driftnet fisheries in the North Atlantic, with recent catches averaging 162 000 salmon (1997–2003), approximately 20% of the total landings of salmon in the entire North Atlantic. Since 2001, the Irish commercial salmon fishery has been managed on the basis of Total Allowable Catch (TAC) in each of 17 salmon fishing districts. This has been made possible by applying a number of new and innovative techniques to the estimation of conservation limits (CLs) and pre-fishery abundance (PFA) for combined stocks in each district. Stock and recruitment parameters from well-monitored European rivers were “transported” to all Irish rivers using a Bayesian hierarchical stock and recruitment (BHSRA) model. This provided the posterior probability distributions of the model parameters and related reference points, including individual river CLs. District PFA and the number of spawners were estimated for a baseline period of 1997–2003, using d...
Hydrobiologia, 2008
Four Special Areas of Conservation (SACs) have been designated in the Republic of Ireland for Twa... more Four Special Areas of Conservation (SACs) have been designated in the Republic of Ireland for Twaite shad, Alosa fallax (Lacépède), based on recent historical information on spawning activity—the estuarine reaches of the Rivers Munster Blackwater, Suir, Barrow–Nore and Slaney. The spawning status of some of these populations is considered to have declined substantially in recent years, and no known spawning
Aquatic Conservation: Marine and Freshwater Ecosystems, 2001
1. This paper highlights the recent extinctions of two native Arctic charr populations in the Wes... more 1. This paper highlights the recent extinctions of two native Arctic charr populations in the West of Ireland, one population from the Lough Conn catchment, and a second from the Lough Corrib catchment, respectively. 2. The distribution of charr populations in the two catchments is reviewed. The current distribution information is drawn from recent fish stock surveys (Lough Corrib in 1996, and Lough Conn in 1997 and 1998). Previous records of charr in the literature and unpublished data are described to place the current distribution of charr within these catchments into a historical perspective. 3. The importance of the charr population in Lough Mask (Lough Corrib catchment) is emphasized, as it is one of the last extant examples of charr from a large Irish alkaline lake. 4. Impacts on charr populations in both catchments are discussed and conservation measures proposed.
Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully f... more Typically anadromous, the twaite shad (Alosa fallax) can become landlocked and adapt to a fully freshwater life. The only landlocked shad population in Northwestern Europe is found in a lake in Ireland, Lough Leane. The Killarney shad, Alosa killarnensis (or Alosa fallax killarnensis, as it is mostly referred to) displays a level of morphological divergence that indicates a long-term isolation in the lake. Microsatellites and mtDNA control region sequences were used within a coalescent framework (BEAST and Approximate Bayesian Computation (ABC)) to investigate its colonization history and to clarify its taxonomic status. Results indicate that the lake was likely colonized in two independent events, the first coinciding with the retreat of the ice sheet from the area after the Last Glacial Maximum and the second after the Younger Dryas. Microsatellite data has shown that these two landlocked lineages have completely admixed within the lake, and have started diverging significantly from their closest ancestor, the twaite shad. We argue that our molecular results (together with the life-history and physiological divergence between Killarney and twaite shad) are conspicuous enough to view the landlocked population as a new species, and one whose future existence would certainly not be insured by its sister taxon.
Biology and Environment: …, 1996
There is a paucity of published information on the population biology of salmonids in Irish uplan... more There is a paucity of published information on the population biology of salmonids in Irish upland soft-water streams despite their relative importance as salmonid nursery areas and their susceptibility to acidification. This paper describes the characteristics of brown trout populations in ...