Relationships between Stocking and Anglers' Catches in Draycote Water Trout Fishery

The trout fishery at Draycote Water was investigated during the 1980 fishing season. Fish stocked were batch-marked according to the date of introduction by freeze branding, and catch data were obtained by the cooperation of anglers. Population estimates were made at the end of the fishing season using gill nets and mark-recapture techniques. Of the 32,960 marked brown and rainbow trout stocked, 69.8% were caught and declared by anglers. Returns of rainbow trout were better (78.1%) than those of brown trout (44.2%). Over 90% of all fish caught were taken within 45 days of stocking. Catch per unit effort fluctuated widely but was closely associated with stockings of fish. Catchability (Q) of stocked fish was found to diminish rapidly with time after stocking. At the end of the fishing season the estimated population of marked trout was 4045 (2 × SE = 250), compared with a theoretical number (stock less total catch) of 10,802, giving a mean daily apparent natural mortality, made up of the true natural mortality plus the undeclared catch, of 1.36%.     

The relationship between stock and catch and the effect of bait on catch as determined for a UK recreational catch and release fishery

Abstract Twelve anglers fishing in a UK navigation canal for a total of 42 h caught 567 fish, mainly gudgeon, Gobio gobio (L.) ( n =306) and roach, Rutilus rutilus (L.) ( n =253) at an average catch rate of 13.4 fish angler-h⁻¹ or 128.5 g angler-h⁻¹. The species and size of fish caught were compared with the numbers determined by depletion estimates at six sections of canal using micromesh seine netting. Fifty four percent of fish caught in the net were < 60 mm FL. Gudgeon (60–99 mm) were over-represented in the anglers' catches whilst roach (60–99 mm) were under-represented. The size distribution of roach and gudgeon caught by anglers using two types of bait (small maggots and chironomid larvae) was examined and smaller fish were found to be caught using the latter.     

Catching sharks: recreational saltwater angler behaviours and attitudes regarding shark encounters and conservation

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The risk of individual fish being captured multiple times in a catch and release fishery

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.     

中东大西洋中部海域中上层鱼类资源结构与渔场分布

为了解中东大西洋中部海域中上层鱼类资源结构与渔场分布,对2007-2014年入渔FAO34渔区3.11和1.32小区(毛里塔尼亚专属经济区)从事中上层鱼类捕捞的7艘国内渔船的生产数据进行了分析。结果表明,我国入渔船只数量、入渔渔船总产量和作业渔船平均日产量均呈现先增加、后减少的趋势,且在2011年入渔渔船总产量和作业渔船平均日产量到达最大值,2012年入渔船只数量到达最大值。渔获种类主要包括沙丁鱼(Sardina pilchardus)、短体小沙丁鱼(Sardinella maderensis)、金色小沙丁鱼(Sardinella aurita)、日本鲭(Scomber japonicus)和竹筴鱼(Trachurus trachurus),各渔获种类的渔获量年际间波动较为明显。月均产量在17.2~23.6 t/haul,最高值和最低值分别出现在12月和8月;月均总产量在1 279.0~2 414.2 t,最高值和最低值分别出现在1月和8月,12月至次年3月为渔汛旺期。渔场季节变化现象明显,夏秋季向北移动,冬春季向南移动,20.0°~20.8°N、17.4°~18.0°W区域为高产量海域。该海域中上层鱼类洄游现象明显,这可能主要与该海域的不同洋流在不同月份的强弱变化有关,该海域整体渔业资源呈现一定衰退现象。建议渔船入渔该海域从事中上层鱼类捕捞持谨慎态度,加强该海域渔业资源的研究与保护。     

The commercial exploitation of sea trout, Salmo trutta L.

Abstract. The net and coble catch of sea trout in the River North Esk was sampled between 1977 and 1979. A comparison of the length frequency distribution of these samples with those of sea trout taken in a trap which was assumed to be unselective revealed that the net and coble fishery was very selective. Only isolated fish below 35·0 cm were encountered in the commercial catch samples, yet between 25% and 41% of the upstream migratory sea trout taken in the trap during the netting season were below this length. The sea trout in the commercial catch samples were predominantly maiden, one-sea-winter fish. The dominant age class each year was the 2·1 + group, 3·1 + fish comprising the other major age class. The freshwater age of the maiden sea trout sampled declined as the season progressed. The proportion of previously spawned fish in the samples ranged between years from 12% to 15%. The mean length and mean weight of sea trout sampled from each year's catch showed little variation, ranging from 42·9 cm to 43·3 cm and 971 g to 972 g, respectively. The ratio of males to females in the 1979 sample was 1·00:2·18. The use of morphometric characteristics, including head length, pectoral fin length and adipose fin length was investigated with the aim of distinguishing the sex of fish taken early in the season from external features alone. Although in each month the mean head length as a percentage of fork length of males was greater than that of females, this difference was not sufficient to enable the rapid determination of sex during commercial catch sampling routines. The exploitation rate of sea trout reaching the most upstream major fishing station, Morphie Dyke, was estimated from the recapture of upstream adult sea trout removed from a trap and released in the main river 2 km downstream of Morphie Dyke. The percentage exploitation rate at this fishing station was found to range between 6·4% and 12·2%, and the percentage exploitation rate for the entire net and coble fishery was at a level of approximately 30% during the period of the study. The sea trout statistics of the North Esk net and coble fishery for the period 1925–1979 were examined, and the effect of a change in fishing effort on these figures is described. Recent catch figures, although below those reported during the mid-1960s, are above the level of catches reported prior to 1952.     

Migration route of Pacific saury Cololabis saira inferred from the otolith hyaline zone

In order to establish the migration route of Pacific saury Cololabis saira, we measured the radius of otolith annual rings (ROA) in fish collected from areas off the Japanese coast up to 165°W in June and July (pre-fishing season) and from fishing grounds in August?CNovember (fishing season). The average ROA for six sea areas that each spanned 10° of longitude sampled during the pre-fishing season were compared with data obtained during each month of the fishing season. The average ROA decreased from west to east and also decreased monthly from August to November. The average ROA of fish caught after October at the peak of the fishing season was equivalent to that of the fish caught in the areas east of 160°E or 170°E. We conclude that Pacific saury caught by Japanese fishing vessels during the peak of the fishing season migrate from an area east of 160°E.     

The Effect of Cyprinid Introductions on Angler Success in the River Derwent, Derbyshire

In an attempt to increase fish standing crop and improve angler-catch, stocking was undertaken in the middle reaches of the River Derwent in Derbyshire using four cyprinid species. Each fish was marked with a dyespot, and nearly 2000 fish were introduced before the 1980–81 fishing season began. Bankside observations and catch return sheets were used to collect information on the number of marked and unmarked fish taken by angling. The percentage of captured fish that were marked reached 50% during summer 1980, although this was lower during winter 1980–81. A relatively small proportion of the fish caught were taken in angling matches. Anglers reported that the fishing had improved from‘poor’to‘good', and catches by a single angler in one day exceeded 20 kg. It is thought that the success of the operation was due to the fact that the stock fish were obtained from local rivers, were of a large size (> 20 cm) and were introduced when the river was at normal level. The implications of the results on management options are considered, and it is suggested that the quality of sport demanded by anglers in rivers of this type may be most easily sustained by periodic stocking with suitable fish.     

An assessment of catches and harvest of recreational shore angling in the north of Portugal

Abstract  Recreational shore angling in the Atlantic Ocean between Moledo and Aveiro (Portugal) was examined using roving creel surveys (March/September 2001). Cooperation was high (90% of 2310 anglers approached). At least 39 species of fish were caught at a rate of approximately 0.5 fish angler h⁻¹. An estimated 7319 kg of Dicentrarchus labrax (L.), with 45.6% below the minimum legal size, and 2040 kg of sea breams (genus Diplodus ), correspond to 5.75% and 1.19% of the commercial landings in the same geographical area, respectively. The results shed light on a number of issues relevant to integrated coastal management, including temporal and spatial distribution of fishing effort, species caught, sizes of fish, catch rates, and factors influencing catches and angler satisfaction. Whilst the results suggest that the catches of sea breams and sea bass by day-time recreational shore angling in northern Portugal are small compared with commercial fishing, other recreational activities, such as boat fishing and spear-fishing, must be assessed.     

Tracing possible drivers of synchronously fluctuating species catches in individual logbook data

Abstract Recreational fisheries statistics can provide valuable information on the dynamics of fish stocks and their exploitation. For some reservoirs in the Czech Republic, there are conspicuous synchronous fluctuations in catches of different species that might be caused by fishing skills and strategies. This study describes a method that could detect signatures of such phenomena in individual logbooks. It classifies anglers by species reported during 1 year and compares the resulting angler groups by group size, fishing effort, catch per unit effort (CPUE) and annual catch. The method is illustrated by data from one reservoir, showing that the number of generalist anglers who caught several species was higher than expected. Generalists also had higher catches and effort but lower CPUE than specialists who caught only one of the species. The results indicate that generalist anglers with a low degree of specialisation and high effort could contribute to long‐term correlations in species catches.     

Temporal changes in fishing motivation among fishing club anglers in the United States

Responses from freshwater anglers (n = 4287) to a nationwide survey of the US fishing club members were used to assess differences in the importance of 16 fishing motivation items between 1987 and 1997, dates that preceded and followed a period of substantial decline in recreational fishing participation in the US. Comparison of respondents’ motivations for fishing in 1997 and 10 years earlier indicated consistency in the paramount importance of being outdoors, relaxation and the experience of the catch. However, the importance of family recreation and being with friends in 1987 were replaced by escape items in 1997. Anglers with fewer dependents and living in areas with higher population density were more likely to decrease the importance of family recreation. Younger anglers were more likely to decrease the importance of being with friends. Anglers who had higher household income, fished more and had higher fishing expenditures were more likely to decrease the importance of obtaining fish to eat. The results of this study suggest that managers should be less concerned about angler opposition to liberal regulations that allow anglers to harvest fish, and that heightened efforts to recruit and retain recreational anglers, which presently focus on family recreation, should be broadened to include outdoor experience, relaxation and escape aspects of fishing.     

Effect of fishing effort on catch rate and catchability of largemouth bass in small impoundments

Largemouth bass Micropterus salmoides (Lacepède) catch rates decline with sustained fishing effort, even without harvest. It is unclear why declines in catch rate occur, and little research has been directed at how to improve catch rate. Learning has been proposed as a reason for declining catch rate, but has never been tested on largemouth bass. If catch rate declines because fish learn to avoid lures, periods of no fishing could be a management tool for increasing catch rate. In this study, six small impoundments with established fish populations were fished for two May to October fishing seasons to evaluate the effect of fishing effort on catch rate. Closed seasons were implemented to test whether a 2‐month period of no fishing improved catch rates and to determine whether conditioning from factors other than being captured reduced catch rate. Mixed‐model analysis indicated catch rate and catchability declined throughout the fishing season. Catch rate and catchability increased after a 2‐month closure but soon declined to the lowest levels of the fishing season. These changes in catch rate and catchability support the conclusion of learned angler avoidance, but sustained catchability of fish not previously caught does not support that associative or social learning affected catchability.     

Do recreational fisheries metrics vary on differently sized fishing grounds?

This study aimed to assess the relationship between basic metrics in recreational fishing and the size of the fishing ground. Data were obtained from individual angling logbooks collected by the Czech Fishing Union over 12 years on 212 fishing grounds located in the regions of Prague and Central Bohemia in the Czech Republic. Small fishing grounds had the highest catch, yield, numbers of fishing visits and numbers of angling guard controls per hectare. Medium‐sized fishing grounds had the highest catch, yield, and numbers of both fishing visits and angling guard controls per fishing ground. Anglers returned to medium‐sized fishing grounds most frequently. The percentage of anglers who caught and took home at least one fish decreased with increasing size of the fishing ground. In conclusion, basic metrics in recreational fishing are related to the size of the fishing ground, which thus plays an important role in fisheries management.     

Contribution of Stocked Legal-sized Trout to the Sport Fishery of Three Small Wisconsin (U.S.A.) Lakes*

Legal-sized trout stocked in spring in three lakes in Wisconsin U.S.A. provided a short-term, popular, sport fishery. Frequently, half or more of the stocked fish were caught in the first month of the Fishing season, and few were caught thereafter. Separate estimates of the percentage of numbers (and weight) returned in the first month of the fishing season were 46 (47), 73 (76), 62 (113), and 31 (22) for rainbow trout (Salmo gairdneri) and 64 (81) for brook trout (Salvelinus foutinalis). Most anglers interviewed at two of the lakes were fishing primarily for trout, including in one case 95% of the anglers interviewed over the 9-month season, even though the trout fishery persisted for less than 2 months. Fishing pressure also was highest at the opening of the angling season and declined exponentially thereafter. Of an estimated total of 7,906 angler-hours in one lake, 67% occurred in the first month of the season and 79% in the first 2 months. Because the trout were harvested rapidly, relatively little of the productive capacity of the lakes were channelled into production of trout flesh. Therefore, the stocked trout provided a put-and-take fishery at tittle expense to the existent warmwater fishery.     

Population assessment of sockeye salmon Oncorhynchus nerka caught by recreational angling and commercial fishery in Lake Toya, Japan

ABSTRACT: We carried out mail and access point surveys to estimate the catch numbers, angling effort of recreational angling and the population of sockeye salmon Oncorhynchus nerka in Lake Toya in 1998 and 1999. The mail survey questions in questionnaires distributed to anglers with a recreational angling license included date of angling, caught fish species and size, and catch number. In the access point survey we also asked anglers if they had a license. We measured the fork length and weight of caught fish. The catch rate (catch number in a day by each angler) from both surveys showed no significant difference, suggesting no bias for the catch rate between surveys. The estimated total angling effort was 1760 people (1998), and 1516 people (1999). The estimated recreational catch was 28 889 (1998) and 5455 (1999), that is, two or three times larger than the commercial catch. The fish population was estimated by using the DeLury method as 60 262 (1998) and 10 806 (1999). The total exploitation rate was 62% (1998) and 78% (1999). The size of caught fish was much larger in 1999 than 1998 because of the difference in age composition.     

Deep hooking,landing success and gear loss using inline and offset circle and J hooks when bait fishing for white sturgeon

The issue of deep hooking is of concern in white sturgeon, Acipenser transmontanus Richardson, fisheries because nearly all anglers use bait with a stationary presentation on the river bottom to catch them, and bait fishing is often associated with higher instances of deep hooking and hooking mortality. Deep hooking rates, landing success and catch rates were investigated for anglers bait fishing for white sturgeon using circle and J hooks with inline and offset alignments fished with both active and passive hook‐setting methods. Anglers hooked 578 white sturgeon and landed 508 fish, ranging in size from 60 to 316 cm total length (mean = 137 cm). Deep hooking rates averaged 0.6% and did not differ between hook types, hook alignments or hook‐setting methods. Landing success (the proportion of hooked sturgeon that were successfully landed) and catch rates were also equivalent between hook types, hook alignments and hook‐setting methods; landing success averaged 88% and catch rates averaged 0.27 fish/hr. Results of this study indicate that deep hooking is rare when angling for white sturgeon using standard bait‐fishing gear regardless of hook‐setting method or whether circle or J hooks were used; regulations restricting hook type in sturgeon bait fisheries are therefore unwarranted.     

The Effects of Water Temperature and Flow upon Angling Success in the River Severn

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.     

南海北部金线鱼流刺网渔业情况分析

根据“粤阳东18023”渔船2006年1月至2007年12月的渔获销售记录,结合春、秋2季的渔获抽样测量数据,对使用单片刺网在南海北部作业的大型金线鱼流网船的生产情况进行了分析。结果显示,渔获以底层和近底层种类为主,带鱼Trichiurus haumela、长尾大眼鲷Priacanthus tayenus和金线鱼Nemipterus virgatus为渔获优势种,占产量的29．7％、13．3％和10．5％,占产值的27．4％、24．4％和15．7％;渔船全年作业,汛期在11月至翌年3月,其中1月为旺汛期,休渔期的产量和产值在全年中所占比重很小;优势种渔获以成鱼为主,其CPUE的高值期与汛期基本一致。     

Effect of trawling with traditional and ‘T90’ trawl codends on fish size and on different quality parameters of cod <Emphasis Type="Italic">Gadus morhua</Emphasis> and haddock <Emphasis Type="Italic">Melanogrammus aeglefinus</Emphasis>

The effect of trawling on fish size and on different quality parameters of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) was evaluated after conducting 16 valid hauls using two trawls in a double rig fitted with a traditional and a novel ‘T90’ codend, respectively. The total catch volume during the fishing period was 47.6 metric tons, with an average catch per codend of 1.5 (range 0.5–2.9) tons. The mean haul duration was 5 h. The catch was assessed according to fish size, mortality, external damage, initial white muscle pH and development of rigor mortis. Fillet quality (colour, blood spots, gaping) was assessed after 1 week of freeze-storage. Our results showed there was no difference between the two types of nets in terms of catch volume, but significantly slightly bigger fish were caught with T90 than with the traditional trawl net (p < 0.05). Haddock caught with the traditional trawl net had more external injuries related to the trawl gear than haddock caught with the T90 gear (p < 0.05). The gaping frequency for cod caught with the traditional trawl net tended to be higher than cod caught with the T90 gear, but the difference was not significant (p = 0.07). No other differences in fish quality between fish caught in the trawl nets were observed.     

Performance of rainbow trout, Salmo gairdneri Richardson, in a put-and-take fishery, and influence of anglers' behaviour on catchability

Abstract. Stock, catch and fishing effort statistics for a 12·5-ha lowland pul-and-lake trout fishery have been used to compute the ‘catchability’ of rainbow trout, Salmo gairdneri Richardson, during the fishing seasons 1980–1983. Seasonal trends in the fishes’ susceptibility to capture by fly-fishing are apparent but there was no indication that, in this fishery, newly stocked fish were more vulnerable than the longer-term residents. This consistency of recapture rates of rainbow trout, relative to the population available, is a function both of the fish's behaviour and that of the anglers themselves, and it is suggested that for management purposes the latter must be taken into account. In the fishery studied rainbow trout grew well at fish densities below 60 kg ha^?1, but even with overall recapture levels exceeding 80% the yield of the fishery was less than the weight of fish stocked. The selection of strains of rainbow trout which satisfy the requirements of sport fisheries is discussed.