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1.
Abstract Patterns of change in angler participation and demographics were examined for the recreational Atlantic salmon, Salmo salar L., fishery in Newfoundland and Labrador, Canada. An analysis of a licence stub return system, 1994–2010, showed a significant decline in resident angler participation, but this was not consistent across all regions of the Province. Mean age of anglers increased significantly, varying from 39.0 years in 1994 to 46.5 years by 2010. In some regions, mean age rose by over 12 years since the mid‐1990s, reflecting a decline in the recruitment of younger anglers. The return rate of angler logs also declined over time and was found to vary by age, sex and area of angler residence. Women and older anglers, and those living in specific rural areas had a greater tendency to return a record of their catch history than men and younger anglers. Identified changes in participation and demographics, which can affect exploitation and ultimately abundance, could be used to develop management measures that would maximise both harvest and socio‐economic benefits to the varied users of the resource.  相似文献   

2.
Conservation spawning requirements (limits) for Atlantic salmon, Salmo salar L., have been developed for a number of rivers in Newfoundland. Status of stocks is evaluated against these limits and scientific advice and recommendations on levels of recreational catch provided to resource managers. A critical factor in this process is the determination of total returns. This has been accomplished for 30–40% of the rivers in question over the years through the use of fish counting fences and traps installed in fishways. In Newfoundland, it is not logistically or financially possible to operate fish counting facilities in all of the approximately 200 Atlantic salmon rivers. Thus angling catch data have been used as an alternative means of estimating total returns to rivers without counting facilities. Estimates of total returns were three to four times higher than the actual values for one of the two rivers studied and deviated from the actual by as much as 60% for the other. Management implications of the approach are discussed.  相似文献   

3.
Abstract Inland fisheries in England and Wales have high economic and social values. Managing participation to maximise fishery performance is key to maintaining this status. The capital value of fishing rights for migratory salmonid fisheries is €165 million. Coarse fisheries contribute €1030 million to the economy. The central tenet to increasing participation in recreational salmonid fisheries is that an increase in stock size will result in more anglers accessing the fishery. This was examined for salmon on the rivers Usk and Lune where exploitation restrictions increased the number of salmon available to anglers. On the River Lune, the number of salmon available post‐intervention increased by 66%. There was no significant increase in catch while the number of anglers decreased by 16.3%. On the River Usk, the closure of the net fishery potentially resulted in an additional ～1200 salmon being available. Following closure, there was no significant change in rod catch or in the number of anglers. Increased participation is dependent less upon stock manipulation for coarse fisheries and more upon facilitating the activity. In recent years, urban fishery development programmes have provided improved access to local fishing opportunity. Also, new anglers have been targeted through campaigns such as Get Hooked on Fishing and the Scout Angler Badge.  相似文献   

4.
Warming water temperatures, combined with increased mortality following catch and release, could have synergistic consequences if rivers remain open to catch and release at high water temperatures, and catchability of fish remains similar across water temperatures. Here archived data for Atlantic salmon, Salmo salar L., were used to (a) quantify the influence of water temperature on catchability and (b) refine estimates of absolute catch and release mortality to incorporate the relationship between temperature and catchability. A significant decline in the number of Atlantic salmon caught at warmer water temperatures was found after accounting for the effects of river water height, fishing effort, run duration and year-to-year differences in fish abundance. Overall, absolute catch and release mortalities were predicted to be infrequent at cool river temperatures. At river temperatures sometimes associated with fishing closures, mortality due to the catch and release ranged from 6% to 14%. Although post-release mortality increases with water temperature, it is somewhat compensated by the reduced catchability of Atlantic salmon. Thus, the catchability component of catch and release is an integral consideration when evaluating the effectiveness of river closure temperature thresholds when managing catch and release angling.  相似文献   

5.
The bullhead, Cottus gobio L., was observed in the River Utsjoki in the far north of Finland for the first time in 1979. This river is a tributary of the sub-Arctic River Teno, which flows into the Arctic Ocean and is one of the most important salmon rivers in northern Europe. The bullhead does not belong to the natural fish fauna of the Finnish river systems flowing into the Arctic. It was probably introduced by anglers as bait or accidentally during the water exchange activities as salmon fry were transferred from Finnish hatcheries to northern Norway. A viable bullhead population has dispersed through the River Utsjoki catchment. In 1995 its range extended from the lowest part of the river to a point 43 km upstream. It is highly probable that it has also entered the mainstem of the River Teno.  相似文献   

6.
Salmon catch and effort data for 1977 from ten private fisheries on the River Wye are analysed and discussed. The 555 salmon caught represent 10.7% of the total Wye rod catch and the mean angling success rate of 0.045 ± 0.022 salmon per angler-hour, equivalent to about 22 h per salmon, compares favourably with that for other rivers in Britain and Canada. Over 75% of all salmon caught were 2 sea-winter fish, the age distribution of salmon caught in the sample being similar to those for the whole river. Angling success in the upper reaches during July and August may have been reduced by limited availability affected by water temperatures too high for migration, Flows most suitable for successful angling in each fishery are compared in relation to distance from the estuary and long-term average daily flows. Salmon appeared to be caught nearer the crest of a spate in the upper compared with the lower reaches of the river and this difference is discussed.  相似文献   

7.
Atlantic salmon, Salmo salar L., stocks are decreasing worldwide, and major efforts are underway to conserve populations that are threatened. In a recent effort to conserve the Norwegian salmon, the Norwegian government implemented in 2007 a scheme called National Atlantic Salmon Watercourses and Fjords (NASW), where 52 rivers were given special protection. Here, the scheme is described and it is evaluated if and to what extent the scheme has led to changes in management practice. After the implementation of the NASW scheme, fewer plans for development (e.g. hydropower plants, water abstraction, flood and erosion control) at the within‐river level were accepted for NASW‐rivers than for rivers not in the scheme. However, at the same time, there was a tendency for fewer plans overall being sanctioned in all types of rivers probably due to overall changes in management practices not related to the NASW scheme. In total, these changes could lead to increased protection of Norwegian Atlantic salmon populations.  相似文献   

8.
The Neosho River at Chetopa Dam, Kansas, USA, supports a tailwater paddlefish, Polyodon spathula (Walbaum), snag fishery that is open annually to harvest from 15 March to 15 May and managed to provide anglers with maximum catch. Paddlefish inhabiting this portion of the river are presumed upstream spawning migrants from Grand Lake of the Cherokees, Oklahoma. Angler success in a paddlefish snag fishery is dependent on fish density, a factor that is likely influenced by river hydrology. However, links between river flow regime and angler harvest remain largely unquantified. In this study, hydrological factors that significantly affected paddlefish harvest were identified by regressing paddlefish harvest data from 1992 to 2005 against discharge variables. Two variables describing number of days discharge exceeded a critical threshold that allowed fish to pass a migratory barrier and frequency of discharge increases following decreases combined to explain 53% of variation in harvest. These results can be applied to promote more effective management of this population through increased understanding of relationships between hydrology and harvest. Specifically, anglers can be informed of factors leading to increased harvest in an attempt to increase satisfaction, and cooperating agencies can use these results to develop future water management plans in an effort to increase harvest.  相似文献   

9.
Abstract Variations in the age structure and number of Atlantic salmon, Salmo salar L., running into the River Eo in northern Spain were assessed from catch records of sport fisheries for the period 1949 to 1991. The analysis focused on two periods (1951–1960 and 1981–1991) for which more complete data on fish number, size and age were available. Over the whole period, no evidence for a decline in the total salmon run was found, but the last few years revealed significant changes in both the number and age structure of salmon caught. The catches were mainly composed of multi-sea-winter salmon, and this did not change from the 1950s to the 1980s as the proportion of grilse remained unchanged. However, since 1980, there was a marked decline in both the proportion of 3-sea-winter salmon (versus 2-sea-winter fish) and the frequency of previous spawners among the multi-sea-winter salmon. These changes were probably linked because most of the previous spawners re-entered the river as 3-sea-winter or older salmon. River age of salmon caught in the 1950s was low and constant (about 90% of the catch had smolted at one year) but the mean age of smolting increased in the 1980s.  相似文献   

10.
Releases of hatchery-reared smolts of Atlantic salmon, Salmo salar L., in the Rivers Orkla, Gaula and Alta, Norway yielded large percentages of strays (194, 13.7 and 13.8% respectively), based on recaptures from anglers. Homing precision to the rivers of release was independent of the release site on the river. Distribution of recaptured adult salmon within the rivers was dependent on the release site; upstream releases yielded more upstream recaptures than did downstream releases.  相似文献   

11.
The anadromous, or sea‐going, life history form of brown trout, or sea trout ( Salmo trutta), may lead to potential mixing of populations while foraging at sea. In this article, we assess the potential that multiple populations are using common semi‐enclosed estuaries and quantify the potential levels of straying (i.e. dispersal) of foreign‐produced individuals into populations by using otolith chemical signatures as natural ‘tags’. To do so, we created a database of juvenile fish otolith chemistry (a marker of freshwater production) from four rivers and compared the chemistry of harvested fish in two estuaries important to anglers, the Renews River and Chance Cove Brook, to the database. A discriminant function analysis revealed significant differences in the otolith chemistry of juvenile fish inhabiting the four rivers with a 97% cross‐validated accuracy when classifying individual juveniles to their natal river, indicating our baseline was robust. When assigning adults caught over 3 years (2007–2009) in the recreational fishery in the Renews River estuary, it was determined that over 95% of the fish caught each year originated from Renews River. In contrast, harvested fish in Chance Cove during 2009 were disproportionately comprised of fish produced in Renews River, suggesting the potential for source‐sink population dynamics in Newfoundland. Taken as a whole, these results indicate limited population mixing in nearshore estuaries of this region, but also highlight the potential for some populations to subsidise the harvest by anglers in different areas.  相似文献   

12.
The proportion of angled Atlantic salmon Salmo salar L. being caught and released has increased. If individuals are repeatedly captured, this may have fish welfare consequences. Of 995 Atlantic salmon tagged during catch and release in eight Norwegian rivers, 10% were captured twice, while 3% were captured three times within the same fishing season. The probability that released salmon were captured again decreased with decreasing time left of the fishing season, decreased for larger‐sized fish and varied among rivers/years. Increased exploitation rates within the river, indicating an increased fishing pressure, strongly increased the probability that fish would be recaptured. However, the proportion of salmon caught a second time was much lower than the total exploitation rates in the same rivers (which was on average 46%). For fish tagged in the sea, the likelihood of being angled decreased with time since entering the river, which may explain why the recapture rates of caught and released fish were lower than the total exploitation rates.  相似文献   

13.
Atlantic salmon, Salmo salar L., stocks worldwide have dwindled, and stricter recreational fishing regulations have been implemented. This study estimates the recreational value of salmon fishing under different regulatory schemes and identifies factors explaining changes in net economic value of sport fishing. A Contingent Valuation mail survey in the Verdal River, Norway, asked anglers their willingness-to-pay for increased fishing expenditures or willingness-to-accept compensation in reduced fishing expenditures, to estimate recreational value. The average annual recreational value per angler decreased under stricter regulations from about €420 (in 2007–2009) to €280 (2010–2012) to €180 for the future scenario (2013–2015). Although an overall net decline in recreational value was found with stricter regulations, anglers have heterogeneous preferences. Anglers with non-catch motives or high place attachment have higher recreational value with stricter regulations than others. If stricter regulations remain over time, younger, less consumptive-oriented anglers would probably dominate the fishery.  相似文献   

14.
Abstract The catch by anglers of adult Atlantic salmon, Salmo salar L., was studied over a 5-year period in the River Gaula, Norway. Atlantic salmon were caught over a wide range (23–570 m3 s?1) of the observed extent of river discharge (13–950 m3 s?1) and throughout the range of temperature (4–23 °C), but both factors strongly affected catch rate. Significant correlations between the number of Atlantic salmon caught daily, and water temperature (r = 0.33) and river discharge (r = ?0.42) were found in 1987 and 1989, respectively. The highest daily catch occurred between 50 and 150 m3 s?1, and at temperatures between 13 and 16 °C. Threshold values for water discharge and temperature were found to exist at 250 m3 s?1 and 8 °C, with the highest catches below and above these values, respectively.  相似文献   

15.
Abstract. Monthly catches of Atlantic salmon, Salmosalar L., and sea trout, Salmo trutta L., by anglers in a west of Ireland fishery were analysed. Data were available for 50 months from the years 1971 to 1981. The most important single determinant of catch was found to be fishing effort measured in boat-days. An additional 10 boat days were found to correspond to a catch of almost 6 salmon and 23 sea trout. The relationship between catch and stock was weaker, though a relatively high catchability of sea trout at low stock levels was recorded. Slock levels, fishing effort and environmental factors accounted for much, but not all, of the variation in catch from month to month and from year to year. Most of the effect of rainfall, sunshine and water level was attributable to variations in fishing effort associated with these factors.  相似文献   

16.
The debate over Atlantic salmon, Salmo salar L., stocking in Britain centres on the trade‐off between enhancing rod fisheries and harming wild populations. This article informs the debate by quantifying the relationship between stocking and angler catch statistics for 62 rivers over 15 years. After controlling for environmental factors affecting adult abundance, the 42 rivers with stocking had non‐significantly lower mean catch statistics than the 20 rivers without stocking. This difference increased with the age of stocked fish. Among stocked rivers, weak relationships between mean stocking effort and catch statistics also became more negative with the age of stocked fish. For stocked rivers, there was no evidence for a generally positive relationship between annual stocking efforts and catch statistics. Those rivers for which stocking appeared to improve annual rod catches tended to have lower than expected mean rod catches. The results suggest the damage inflicted on wild salmon populations by stocking is not balanced by detectable benefits to rod fisheries.  相似文献   

17.
Abstract  Reliability of underwater snorkel counts of adult Atlantic salmon, Salmo salar L., was analysed in the tributaries of the River Teno, close to the spawning period. In small (width 5–20 m) rivers, the replicated total counts of salmon were reasonably precise (CV = 5.4–8.5%), while in the medium-sized river (width 20–40 m) the precision of the counting method was considerably lower (CV = 15.3%). Low precision in a medium sized river was also observed in an experiment using marked live fish where the observation efficiency varied between 36.4% and 70.0%. In a small river, the detection efficiency of artificial fish silhouettes (test salmon) was almost perfect in pools (98%), but decreased in rapids (84%). Separate counts of males, females, grilse and large salmon were usually more variable than total counts, indicating that divers were more capable of locating a fish than properly identifying its sex and sea-age. The behaviour of adult salmon was favourable to conduct snorkel counts, as fish normally stayed still, or after hesitating, moved upstream (>95%of the cases) when encountering a diver. The high observation efficiency (>90%) and precision, favourable behaviour of salmon and congruence between snorkel counts and catch statistics in small rivers suggest that reliable data on Atlantic salmon spawning stock can be collected by snorkeling provided that the environmental conditions are suitable and the divers are experienced.  相似文献   

18.
Abstract. Analysis of 4 years’ club records shows that, on average, the anglers fishing for brown trout in the lower River Don, Aberdeenshire, Scotland made 9 trips/y of 4 hours duration, caught 0·8 fish/trip at the rate of 0·2 fish/h, making a total of 7 fish/season, having an average weight of 350g. There was, however, considerable variation in the results. Guests tended to fish for longer, and to catch less, than regular members. Most (95%) of the fish were caught by only 30% of the anglers, who accounted for 80% of the fishing effort. Angler efficiency increased with the number of seasons spent fishing the club waters during the period; it decreased with increase in water temperature and flow and, early in the season, tended to decrease slightly with increase in catch in the preceding month.  相似文献   

19.
Angling catch data was gathered by a postal questionnaire system from angling clubs holding competitions in three sections of the River Severn over a period of 3 years (1975–78). Angling success was measured as the percentage of anglers taking part that caught fish and as the overall catch rate (g/man/h) of the competing anglers. Species composition of the catch was also recorded. Angling success was closely related to water temperature. Parabolic regressions were fitted to the data. Optimum temperatures for angling success were between 18 and 20°C, except for the Lower Severn section where maximum catch rates were achieved at 14.9°C. Flow had little effect upon angling success until a critical flow was reached, above which success was considerably reduced. Critical flows for the upper, mid and lower sections were approximately 3,000, 5,000 and 10,000 Ml/day, respectively. Species composition of catches within river sections was influenced by water temperature. Some species (bleak, bream, dace and eels) were relatively more abundant in catches made at high temperatures whilst others (chub and roach) predominated at tow temperatures. It is suggested that the percentage of anglers catching fish is the most reliable indicator of angling success.  相似文献   

20.
Abstract  For a number of rivers in Newfoundland, Atlantic salmon, Salmo salar L., is managed in relation to river-specific conservation spawning requirements. One such river is the Gander River, where between 1989 and 1999, the escapement of Atlantic salmon, a major factor in assessing the status of stock, was determined using a fish counting fence. In 2000, the counting fence was discontinued and alternative means of calculating total returns were explored. Regression and simulation methods, using relationships between total returns and salmon counts at an upstream tributary during 1989–99, formed the basis for estimates of returns for 2000, and the uncertainty around estimates. The accuracy of methods is evaluated by retrospective comparisons with actual total returns between 1989 and 1999. Estimates of total returns deviated from the actual by as much as 50–60%, depending on the method. Management implications of the approach are discussed.  相似文献   

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