Atlantic Salmon Fishery Research Articles

An analysis of genetic stock identification on a small geographical scale using microsatellite markers, and its application in the management of a mixed‐stock fishery for Atlantic salmon Salmo salar in Ireland

A genetic stock identification (GSI) study was undertaken in a fishery for Atlantic salmon Salmo salar to determine the effects of restrictive fishery management measures on the stock composition of the fishery, and if accurate and precise stock composition estimates could be achieved on the small geographical scale where this fishery operates, using a suite of only seven microsatellite loci. The stock composition of the Foyle fishery was shown to comprise almost exclusively of Foyle origin fish in the 3 years after restrictive measures were introduced in 2007, compared to 85% the year before. This showed that the restrictive measures resulted in the Foyle fishery being transformed from a mixed-stock fishery to an almost exclusively single-stock fishery, and showed how GSI studies can guide and evaluate management decisions to successfully manage these fisheries. Highly accurate and precise stock composition estimates were achieved in this study, using both cBAYES and ONCOR genetic software packages. This suggests accurate and precise stock composition is possible even on small geographical scales.

ASSESSING THE CUMULATIVE IMPACTS OF HYDROPOWER REGULATION ON THE FLOW CHARACTERISTICS OF A LARGE ATLANTIC SALMON RIVER SYSTEM

ABSTRACTWe assessed the influence of hydropower on the flow characteristics of the river Tay, one of the UK's most heavily regulated catchments and important Atlantic salmon fisheries. Hydropower developments in the mid‐20th century preceded flow data collection, resulting in knowledge gaps over how far regulated flows deviate from natural and how ecosystem functioning might have been impacted. We used 29 unregulated catchments in and around the Tay to assess the relationships between hydroclimatic conditions, landscape structure and the overall flow regime, as well as the annual, monthly and daily flow metrics. This allowed the identification of flow characteristics by using an integrated suite of regression approaches (nonlinear, MLR and random forests) to assess likely impacts at 11 regulated sites. The results showed that the impacts of regulation are highly variable in both space and time. Headwater sub‐catchments are most heavily affected, and water imports or exports as part of hydropower schemes can increase or decrease annual runoff by up to 50%, respectively. On a monthly basis, regulation primarily increased summer low flows; winter high flows increased in catchments affected by water imports and reduced where there was a net water export. At larger catchment scales, impacts were relatively small, as unregulated tributaries re‐naturalize the flows and the effects of intra‐basin transfers balance. Non‐stationarity in climate and water use in the catchment dictates that adaptive management of flows may be necessary to protect ecosystems services. Copyright © 2013 John Wiley & Sons, Ltd.

Revisiting the marine migration of US Atlantic salmon using historical Carlin tag data

Abstract Miller, A. S., Sheehan, T. F., Renkawitz, M. D., Meister, A. L., and Miller, T. J. 2012. Revisiting the marine migration of US Atlantic salmon using historical Carlin tag data. – ICES Journal of Marine Science, 69: 1609–1615. The development of a fishery for Atlantic salmon (Salmo salar) in the sea at West Greenland in the early 1960s prompted the start of a US tagging programme in 1962. Between 1962 and 1996, more than 1.5 million salmon from New England rivers, primarily hatchery-reared smolts, were tagged and released. Overall, the rate of tag recovery was 0.55%, with 23.2% of the tags recovered from Canada, 26.0% from Greenland, and 50.8% from the United States. A generalized additive model was used to analyse marine survival based on returns of tagged salmon to the Penobscot River. The month and year of release, sea age, smolt age, and environmental variables, such as the North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO) indices and local sea surface temperatures (SSTs), were assessed to explain the variability in the return rate. The AMO and NAO indices, SST, sea age, and time across years all affected survival assessed in terms of returns to the Penobscot River. The results provide information to support the management of Atlantic salmon stocks on a spatial and temporal scale in US rivers and the fishery at West Greenland.

An ecological–economic model on the effects of interactions between escaped farmed and wild salmon (Salmo salar)

AbstractThis study explores the ecological and economic impacts of interactions between escaped farmed and wild Atlantic salmon (Salmo salar, Salmonidae) over generations. An age‐ and stage‐structured bioeconomic model is developed. The biological part of the model includes age‐specific life‐history traits such as survival rates, fecundity and spawning successes for wild and escaped farmed salmon, as well as their hybrids, while the economic part takes account of use and non‐use values of fish stock. The model is simulated under three scenarios using data from the Atlantic salmon fishery and salmon farming in Norway. The social welfare is derived from harvest and wild salmon while the economic benefits of fishing comprise both sea and river fisheries. The results reveal that the wild salmon stock is gradually replaced by salmon with farmed origin, while the total social welfare and economic benefit decline, although not at the same rate as the wild salmon stock.

Perceptions and costs of seal impacts on Atlantic salmon fisheries in the Moray Firth, Scotland: Implications for the adaptive co-management of seal-fishery conflict

Abstract The Moray Firth Seal Management Plan (MFSMP) was introduced in Scotland in 2005 as a pilot for resolving conflict between Atlantic salmon fisheries and conservation imperatives for protected harbour and grey seals. This adaptive co-management model is now being applied nationally through the Marine (Scotland) Act (2010). However, no information exists on salmon fishery stakeholders’ perceptions of seal predation impacts and related costs, which could influence the success of the MFSMP and other similar initiatives. In 2006 a questionnaire survey of the 95 salmon rod fisheries in seven major Moray Firth rivers was undertaken, and all 20 active salmon netting stations in the Firth. Forty-five fishery owners, 39 ghillies, 120 anglers and 11 netsmen (representing 17 netting stations) responded. The majority (81%) believed that seals had a significant or moderate impact on stocks and catches, 77% believed that all seals were responsible and 47% supported seal culling. Seals were sighted by 38% of rod fisheries, and 18% lost angler days from seal interference. Overall, 0.2% of total reported angler days were lost annually. The estimated direct cost of seal interference for responding rod fisheries was £14,960 annum −1 , and losses of catches and damage to nets was £16,500 annum −1 for responding netsmen. Stakeholders’ perceptions were largely inconsistent with their low direct costs and the aims of the MFSMP. Possible reasons for this are discussed, and implications for the governance of future adaptive co-management initiatives for seal-fishery conflict.

Probabilistic-based genetic assignment model: assignments to subcontinent of origin of the West Greenland Atlantic salmon harvest

AbstractSheehan, T. F., Legault, C. M., King, T. L., and Spidle, A. P. 2010. Probabilistic-based genetic assignment model: assignments to subcontinent of origin of the West Greenland Atlantic salmon harvest. – ICES Journal of Marine Science, 67: 537–550. A multistock Atlantic salmon (Salmo salar) fishery operates off the coast of West Greenland and harvests fish of North American and European origin. Annual landings peaked in 1971 at 2700 t, but declined to 22 t in 2003. Biological data are collected to characterize the catch and its stock composition. Multilocus genotypes, generated via microsatellite DNA analysis, are used to derive statistics on continent of origin and less accurate finer-scale assignments. We developed a probabilistic-based genetic assignment (PGA) model to estimate the contribution of salmon from individual North American rivers in the 2000–2003 West Greenland catch. Uncertainty associated with finer-scale assignments is addressed by incorporating estimated misclassification rates and by reporting results as distributions generated via Monte Carlo resampling. US-origin fish represented ∼1% (by number) of the salmon harvested at West Greenland during the years 2000–2003. The resulting loss of spawners to this stock complex was approximately half the estimated adult returns in 2001, but was below 4% in the other 3 years. This is the first attempt to partition the US component of the West Greenland mixed-stock fishery to its finer parts. The approach can be used to identify the effects of fishing on individual stocks within any multistock complex where genetic samples of known origin are available.

ON THE ECONOMICS OF BIOLOGICAL INVASION: AN APPLICATION TO RECREATIONAL FISHING

Abstract The paper demonstrates four general mechanisms that may affect economically valuable species when exposed to biological invasion. We distinguish between an ecological level effect and an ecological growth effect. In addition, we present an economic quantity effect working through demand. Finally, we suggest that there is an economic quality effect that reflects the possibility that invasions affect the harvesting agents directly through demand‐side forces. For example, this may occur because the state of the original species or the ecosystem is altered. We depart from the existing literature by revealing ecological and economic forces that explain why different agents may lack incentives to control invasions. The theoretical model is illustrated by the case where escaped farmed salmon (EFS) influence wild Atlantic salmon fisheries.

Sustainable management of wild Irish Atlantic salmon: Keys found through the looking-glass

The recent moratorium on the commercial at-sea driftnet fishery for wild Irish Atlantic salmon (Salmo salar L.) attempts to halt the decline witnessed in these stocks over the past three decades. The research investigated stakeholder attitudes to the perceived effects on stock recovery, in Irish rivers and estuaries, of seal predation and seal culling. Structured interviews conducted with 10 key stakeholders during June 2007 revealed divisive attitudes and a feeling of powerlessness in relation to stock recovery, which are impeding successful management of salmon stocks. However, areas of common ground exist between stakeholders, which lay the foundation for a sustainable way forward.

Reconciling economic and biological modeling of migratory fish stocks: Optimal management of the Atlantic salmon fishery in the Baltic Sea

The paper puts forward a model of the Atlantic salmon fishery in the Baltic Sea that integrates the salient biological and economic characteristics of migratory fish stocks. Designed to be compatible with the framework used for actual stock assessments, the model accounts for age-structured population dynamics, the seasonal harvest and competing harvesting by commercial and recreational fishermen. It is parameterized for the Simojoki River stock. The socially optimal policy for maximizing discounted net benefits from the fishery within an uncertain environment is determined using a dynamic programming approach and numerical solution method. Our results indicate that substantial economic benefits could be realized under optimal management without compromising stock sustainability.

Atlantic salmon fisheries in the White and Barents Sea basins: Dynamic of catches in the 17–18th Century and comparison with 19–20th Century data

Catches of Atlantic salmon, Salmo salar, recorded in historical documents from the 17–18th Centuries have been analysed in four locations in the basins of the White and Barents Seas. Atlantic salmon was one of the most valuable products of the local economy in the 17–18th Centuries in the northern Russia. Therefore, catches were well recorded in the account books of state departments and monasteries. Salmon were fished mostly in the lower parts of rivers, using weirs which technologically were not changed over the centuries. This makes fishing effort commensurable and allows comparison of historical catch data of the 17–18th Centuries with statistical data available since the last quarter of the 19th Century. Notable fluctuations of catches, average weight and ratio of different seasonal forms of salmon were revealed. Decreasing catches tended to coincide with relatively colder periods. Comparison of historical and statistical data has shown that catches Atlantic salmon and therefore changes in size of their populations were most probably driven by natural factors before middle of the 20th Century.

Management measures and fishers' commitment to sustainable exploitation: a case study of Atlantic salmon fisheries in the Baltic Sea

Fisheries management aimed at sustainable exploitation may affect fish populations indirectly by influencing human behaviour. We propose a methodology that includes stakeholders’ opinions, perceptions, and resulting behaviour, within assessment models designed to evaluate the impact of different management measures on the stocks. Based on interviews and a questionnaire, we use a Bayesian belief network to examine which factors determine fishers’ commitment to sustainable fisheries goals, what impact commitment has on exploitation rate, and what measures can be taken to improve commitment. In addition to exploring alternative management measures, the analysis evaluates knowledge actions (providing information to fishers) and commitment actions (intended to increase trust, consensus, and cooperation). The method is applied in a Baltic Sea case study in which commitment is important for successful recovery of Atlantic salmon (Salmo salar) stocks. The results indicate that the more fishers rely on fishing as their source of income, the less is their commitment and the smaller is the impact of changes in commitment on subsequent catches. The results suggest that commitment can be improved by selecting management measures favoured by fishers and by combining them with commitment and knowledge actions.

Landscapes of Sport, Landscapes of Exclusion: The "Sportsman's Paradise" in Late-Nineteenth-Century Canadian Painting

This essay deals with a group of late-nineteenth-century landscape paintings that were painted for members of club movement, who leased salmon rivers in Atlantic Canada for sport fishing. In Canada, as elsewhere, removal of Native rights to animal world, through introduction of policies and laws restricting hunting and fishing technologies and access, went hand in hand with aesthetic appropriation of environment as For this reason it can be argued that in picturing Atlantic Canada as recreational landscape of these elite tourists-a sportsman's paradise-paintings of region are also products of history of Native exclusion from Atlantic salmon fishery. Thus they provide a point of access to complex history of Native-settler interaction for public art galleries in Canada currently involved in incorporation of Native North American material into existing public narrative of Canadian art. Le present article porte sur un groupe de peintures paysagistes du dernier quart du XIXe siecle qui ont ete realisees par des membres du mouvement des clubs de sportifs qui louaient des rivieres a saumon dans le Canada atlantique pour faire de la peche recreative. Au Canada, comme ailleurs, la suppression resultante des droits autochtones au monde animal-par l'introduction de politiques et lois restreignant les technologies et l'acces a la chasse et a la peche-est allee de pair avec l'affectation esthetique de l'environnement comme paysage. Pour cette raison, on peut avancer qu'en montrant le Canada atlantique comme le paysage recreatif de ces touristes d'elite (un paradis des sportifs), les peintures de cette region sont egalement un produit de l'histoire de l'exclusion autochtone des peches au saumon atlantique. Ces peintures fournissent donc un point d'acces a l'histoire complexe des interactions entre les Autochtones et les colons pour les galeries d'art publiques au Canada qui essaient presentement d'incorporer du materiel autochtone nord-americain dans le recit public actuel de l'art canadien. Landscape as a cultural medium ... has a double role with respect to something like ideology: it naturalizes a social and cultural construction, representing an artificial world as if it were simply given and inevitable, and it also makes that representation operational by interpellating its beholder in some more or less determinate relation to its givenness as sight and site. Thus, landscape (whether urban or rural, artificial or natural) always greets us as a space, as environment, as that within which (figured as the figures in landscape) find-or lose-ourselves. An account of landscape understood in this way therefore ... has to trace process by which landscape effaces its own readability and naturalizes itself and must understand that process in relation to what might be called the natural histories of its own beholders. [It is a question of] what we have done and are doing to our environment, what environment in turn does to us, how we naturalize what we do to each other, and how these doings are enacted in media of representation we call landscape. W.J.T. Mitchell (1994, 2) This essay focusses on a significant body of landscape paintings from last quarter of nineteenth century that depict, or were painted for, recreational fishermen from central Canada and northeastern United States who leased salmon rivers in Atlantic Canada for sport fishing. The pictures, which deal with common subject matter, were painted for art patrons and collectors who were active participants in sportsmen's club that swept northeastern North America in mid-1870s. Each reproduces motivating ideas of movement, giving visual expression to contemporary notions of wilderness as a therapeutic environment, an antidote to debilitating effects of urban-industrial civilization. It was in pursuit of this wilderness experience that movement organized elite tourists into private clubs for pursuit of sport, which was conceptualized as a form of personal involvement in rhythms of nature and for preservation of game, which they saw as threatened by same urban-industrial capitalism that compelled their periodic retreat to wilderness. …

Landscapes of Sport, Landscapes of Exclusion: The “Sportsman’s Paradise” in Late-Nineteenth-Century Canadian Painting

This essay deals with a group of late-nineteenth-century landscape paintings that were painted for members of the sportsmen’s club movement, who leased salmon rivers in Atlantic Canada for sport fishing. In Canada, as elsewhere, the removal of Native rights to the animal world, through the introduction of policies and laws restricting hunting and fishing technologies and access, went hand in hand with the aesthetic appropriation of the environment as landscape. For this reason it can be argued that in picturing Atlantic Canada as the recreational landscape of these elite tourists—“a sportsman’s paradise”— paintings of the region are also products of the history of Native exclusion from the Atlantic salmon fishery. Thus they provide a point of access to the complex history of Native-settler interaction for public art galleries in Canada currently involved in the incorporation of Native North American material into the existing public narrative of Canadian art.

A ‘Very Determined Opposition to the Law’: Conservation, Angling Leases, and Social Conflict in the Canadian Atlantic Salmon Fishery, 1867–1914

A ‘Very Determined Opposition to the Law’: Conservation, Angling Leases, and Social Conflict in the Canadian Atlantic Salmon Fishery, 1867–1914

Les souches du virus de l'hépatite C associées aux lymphoproliférations B monoclonales présentent des particularités génétiques

At present there is no fishery for Atlantic salmon (Salmo salar L.) in the Faroes Exclusive Economic Zone. However, where national or stock-complex management units can achieve their Conservation Limits, there is potential for there to be a managed exploitable surplus in the area. In order to inform management decisions a study was undertaken to extract DNA from historical scale samples caught in the Faroes long-line fishery and, using microsatellites, to perform genetic assignments to estimate the historical stock composition of the catch. Two genetic reference baselines were used. An Atlantic-wide cross-range baseline using six microsatellite loci was established using 1930 fish from 12 regions on the western Atlantic and the same number of fish from 34 sites on the eastern Atlantic. An eastern Atlantic baseline was developed using 14 microsatellites and the same 1930 fish from the 34 eastern Atlantic sites. Mixed stock fishery analysis was based on 656 scale samples collected during two fishing seasons, 1993/4 and 1994/5 and assigned to a both the cross-range and European reference baselines. This study provides the first direct measure of the proportion of North American salmon in catches within the Faroes EEZ, with overall 16% of the total samples being identified as of North American origin and 84% as European. Of the European fish, 62% were identified as coming from the Northern Europe (Russia, Finland, Norway and Sweden), 37% from Southern European (UK, Ireland, France and Spain) and 1% from Iceland. The study also found significant variation in stock proportions across years and through seasons. This study has provided useful estimates of historical fishery composition in the absence of contemporary samples.

'Care, Control and Supervision': Native People in the Canadian Atlantic Salmon Fishery, 1867-1900

During the decades after Canadian Confederation, Native people in Nova Scotia, New Brunswick, and Quebec were systematically excluded from the Atlantic salmon harvest. Their exclusion was a result of federal fisheries policies that favoured elite salmon anglers over Native people and other groups of resource users. The regulations banning sparing and other Native harvesting practices were aggressively pursued by the angling fraternity and grew out of the ‘code of the sportsman,’ which viewed these as ‘villainous practices.’ After 1870, elite sport fishermen solidified their position at the top of the hierarchy of resource users by leasing prized salmon waters and paying for surveillance and the prosecution of poachers. If Native people were demonized as destroyers of the salmon fishery, they were also highly valued by the elite angling fraternity, and not only for their labour as guides. As important, the Native guides who accompanied salmon anglers served an ideological/cultural function. An integral part of the code was that each ‘true sportsman’ also be a naturalist, that he fully understand the habits of his quarry as well as the environment. Virtually without exception, the sporting-travel literature of the period (1850–1900) that concerns salmon fishing also contains information on the racial characteristics, living habits, customs, and mythology of Native people. Sportsmen of the Victorian era were fixated on comparing their modem existence with the supposed primitive world of Native people. Thus, the economic necessity of Native people and the imagination of tourists and tourism promoters created a class of Native seasonal workers who served, as conduits, to lead elite anglers into the spiritual realm of the wilderness, and as domestic servants, to provide comforts in the temporal world. Abstract: Au cours des decennies qui ont suivi la creation de la Confederation canadienne, les Autochtones de Nouvelle-Ecosse, du Nouveau-Brunswick et du Quebec ont ete systematiquement exclus de la peche au saumon de l’Atlantique. Cette exclusion resultait des politiques federales en matiere de peches, politiques qui favorisaient les pecheurs elitaires de saumon a la ligne par rapport aux Autochtones et a d’autres groupes d’utilisateurs de cette ressource. Les associations de peche sportive firent tout pour mettre en place des reglements interdisant la peche au harpon ainsi que d’autres methodes autochtones de prelevement Ces reglements decoulaient en fait du «code de la peche sportive », qui voyait dans la peche autochtone des « pratiques ignobles ». Apres 1870, des adeptes de la peche sportive elitaire consoliderent leur position au sommet de la pyramide des utilisateurs de ressources en louant a bail des eaux poissonneuses et en payant pour le controle du braconnage et les poursuites judiciaires qui en decoulaient. Si les Autochtones etaient percus comme des demons qui aneantissaient la peche au saumon, ils etaient egalement tres apprecies du groupe de pecheurs sportifs elitaires, et ce, pas uniquement en raison de leur travail de guides. Tout aussi important, les guides autochtones qui accompagnaient les pecheurs de saumon a la ligne avaient une fonction ideologique/culturelle. Une partie integrante du code etait que tout « chasseur et pecheur dans l’âme» devait aussi etre un naturaliste, comprendre les habitudes de sa proie de meme que son milieu naturel. Pratiquement sans exception, la documentation sur la chasse et la peche de cette epoque (1850–1900) portant sur la peche au saumon renferme aussi des renseignements sur les caracteristiques raciales, les habitudes de vie, les coutumes et mythes des Autochtones. Les adeptes de la chasse et de la peche de l’epoque victorienne etaient obsedes par la comparaison de leur existence moderne avecle monde qu’ils supposaient primitif des Autochtones. C’est ainsi que les besoins economiques de ces derniers et l’imagination des touristes et des promoteurs du tourisme creerent une classe de travailleurs autochtones saisonniers, qui faisaient office a la fois de guides conduisant les pecheurs sportifs elitaires au royaume spirituel de la grande nature, et de domestiques voyant a leur confort physique dans un monde temporel.

Sport and Commercial Fishing Allocations for the Atlantic Salmon Fisheries of the Miramichi River

The Atlantic salmon has been harvested by both commercial and recreational fishers for many years on the river systems of the province of New Brunswick on Canada 's Atlantic coast. The commercial fisheries were closed and controls were placed on the recreational fisheries following the 1983 collapse of the salmon stocks. This management policy remains in effect. A preliminary analysis using a linear control model showed this to be an economically efficient harvest allocation policy on New Brunswick's Miramichi River. The analysis is extended to the more realistic nonlinear framework here to determine whether the harvest allocation decision would be significantly changed. Both fisheries are found to generate positive net economic benefits, although the recreational fishery is determined to be more valuable than the commercial fishery. Permanent closure of the commercial fishery is not indicated.

Effects of late-season catch and release angling on anaerobic metabolism, acid–base status, survival, and gamete viability in wild Atlantic salmon (Salmo salar)

The effects of catch and release angling on muscle physiology, survival and gamete viability were examined in wild Atlantic salmon (Salmo salar), just prior to spawning. Lactate in the white muscle increased to 37.4 μmol∙g−1after angling and recovered within 4 h. Muscle pH decreased from 7.46 at rest to 6.80 following angling, but returned to resting levels within 2 h. White muscle concentrations of PCr, ATP, and glycogen were depleted by 74, 46, and 73%, respectively, following angling. ATP and PCr returned to resting levels within 2 h, but glycogen did not recover until 12 h. The absence of significant changes in blood glucose indicated that the stress response was minimal in salmon angled under these conditions (6 °C). There were also no mortalities among 20 salmon that were angled and transported to the hatchery. Multi-sea-winter (MSW) salmon (> 63 cm) required a longer period to angle to exhaustion than grilse (< 63 cm), but the physiological disturbance was less in MSW salmon. The survival of eggs from angled and nonangled salmon was 98 and 97%, respectively. Together, these results support the strategy of a late-season catch and release fishery for Atlantic salmon.

Evaluation of the impacts of major management changes in the Atlantic salmon (Salmo salar L.) fisheries of Newfoundland and Labrador, Canada, 1984-1988

Evaluation of the impacts of major management changes in the Atlantic salmon (Salmo salar L.) fisheries of Newfoundland and Labrador, Canada, 1984-1988

Exhaustive Exercise in "Wild" Atlantic Salmon (Salmo saiar): Acid–Base Regulation and Blood Gas Transport

Wild Atlantic salmon (Salmo salar) collected during their spawning migration were transported to the laboratory to investigate effects of exhaustive exercise on acid–base regulation and blood gas transport. Exhaustive exercise resulted in a very large extracellular acidosis which lasted for about 4 h. Blood lactate levels were extremely high and remained significantly elevated for at least 8 h after exercise. The degree of erythrocyte pH regulation was minimal and there was a significant fall in both erythrocyte pH and haemoglobin:oxygen carriage during the recovery period. Together, the significant decrease in erythrocyte pH and a significant reduction in the arterial partial pressure of oxygen resulted in a significant fall in arterial oxygen content immediately after exercise. Thereafter, arterial oxygen content was maintained by a significant increase in hematocrit and an increase in the arterial partial pressure of oxygen. Despite the extremely large lactacidosis in these wild fish, there were no mortalities during the recovery period. However, significant mortality has been reported in studies on domestic salmonids, and this suggests that wild salmonids may be better adapted for exhaustive exercise. This result supports the rationale of a "catch and release" recreational fishery for Atlantic salmon.