Lake Trout Ecosystems in a Changing Environment - Chapter 11 ppsx

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Lake Trout Ecosystems in a Changing Environment - Chapter 11 ppsx

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© 2004 by CRC Press LLC section III Biological effects and management reactions © 2004 by CRC Press LLC chapter eleven The control of harvest in lake trout sport fisheries on Precambrian Shield lakes Charles H. Olver Ontario Ministry of Natural Resources (retired) Daniel J. Nadeau Société et de la faune et des parcs du Québec Henri Fournier Société et de la faune et des parcs du Québec Contents Introduction Angling seasons Winter fishing Access control Size limits Catch limits Quotas Gear Population models Conclusions Recommendations Acknowledgments References Introduction Despite increasingly comprehensive and complex legislation intended to regulate exploi- tation, it is the most critical stress affecting the lake trout Salvelinus namaycush across the Precambrian Shield. The two main contributing factors are the lake trout’s innate vulner- ability to exploitation and the rapid growth of recreational fishing following the end of World War II. For instance, angling almost quadrupled in Ontario between 1950 and the © 2004 by CRC Press LLC early 1970s (Ontario Ministry of Natural Resources and Environment Canada, 1976). With the development and expansion of highways and forest access roads, the advent of the snow machine and the all-terrain vehicle, and the ready availability of aircraft, few lake trout lakes are inaccessible to anglers. The sensitivity of lake trout to exploitation has been described by several authors (see, for example, Fry, 1949; Daley et al., 1965; Martin and Olver, 1980). Lake trout are easily caught by angling, so stocks can be depleted with only a moderate amount of fishing pressure (MacKay, 1956; Eschmeyer, 1964). Certain biological characteristics of the species (slow growth, late maturity, and low reproductive potential) and the unproductive nature of the waters it inhabits (low nutrient levels, cold temperatures) also contribute to the vulnerability of lake trout to exploitation. As a result of these limiting factors, lake trout occur in a small number of Precambrian Shield lakes, where they form sparse populations with low annual sustainable yields. The main purpose of angling regulations is to ensure the perpetuation of fish stocks through regulation of the harvest. Simply stated, it is the kill of fish that needs to be controlled. Within this context, the intent of the regulations is to provide a continuing supply of fishing opportunities and to distribute the catch fairly among the participants. Regulations also prescribe the “rules of the game” and impart a sense of ethics by empha- sizing the sporting aspects of angling. Christie (1978) observed that short of closing lakes to fishing it is difficult to control angling effort given the open access, common property nature of resource management (e.g., Hardin, 1968). This is also true of lakes where stocks have been depressed because residual pressure may be sufficient to prevent their recovery. In open access fisheries, Christie also noted that traditional harvest control regulations (e.g., seasons, daily catch limits) work well until their effectiveness is undermined by large increases in the demand for recreational fishing. Anglers also often fail to appreciate the significance of their catch relative to the total harvest (Christie, 1978). The growth of sport fishing for lake trout, and for many other species, has exceeded the ability of most agencies to be proactive. Attempts by managers to control exploitation pressures by introducing almost annual revisions to the angling regulations have resulted in a loss of credibility with anglers, who have become somewhat suspicious of managers’ motives. Anglers usually see proposals for harvest reduction mainly in terms of a loss of fishing opportunities, whereas to the manager these proposals are seen as necessary to maintain the resource (Ontario Ministry of Natural Resources, 1978a). Harvest is controlled by applying such methods as (1) limiting fishing opportunities (manipulating season length and regulating physical access); (2) using size-based regula- tions to exert biological control of the harvest; (3) applying daily catch limits to apportion the catch; (4) implementing quota controls to match actual harvest with maximum equi- librium yields; and (5) imposing gear restrictions to make anglers less efficient or to increase the survival of released fish. These measures are reviewed and directions for experimental management proposed. Angling seasons The establishment of a fishing season with fixed opening and closing dates is a common regulatory measure for most sport fish, including the lake trout. Ideally, the length of a fishing season indicates how intensively a species should be managed. It also reflects the social values and traditions that have developed for a particular sport species and its fishery. Seasons may be closed because a species may be especially vulnerable to exploi- tation at certain times of the year (such as the ice-out period for lake trout) or to protect mature fish during their spawning season. © 2004 by CRC Press LLC In Manitoba and Saskatchewan, lake trout fishing is generally closed for only a short period of time in April or May (Table 11.1). Long seasons are also the norm in Ontario, where winter fishing is permitted in 30 of 35 fishing divisions. However, winter fishing for lake trout is not permitted in Quebec (with few exceptions), is confined to certain areas in Minnesota, and is confined to specified waters in New York. Lakes closed to late fall fishing are usually closed by or before September 30. Presumably the closing date selected is designed to protect lake trout from exploitation just prior to and during the spawning season. In an attempt to reduce catch by about 30%, a number of measures were applied to free-access lake trout waters in southern Quebec in 1989. These are waters in which no access provisions apply, and no daily or annual fees other than a provincial fishing license are required to fish legally. These measures included closing the winter season, opening the summer season on June 1 (a loss of about 5 weeks of ice-free fishing), and lowering the daily catch limit to two fish. Season reductions were expected to have the most effect. A creel census was conducted on two lakes in 1991 to measure the changes in the fisheries. In Lac Matapédia there was no winter fishery, while in Lac des Trente et un Milles there were both winter and open-water fisheries. Changes in fishing effort (angler-hours), CUE (catch-per-unit-effort), and estimated harvest (number) were observed as follows: Table 11.1 General Summary of Open Seasons for Lake Trout Angling in the Precambrian Shield Area of North America a Jurisdiction Seasons Comments/exceptions Saskatchewan May 16–March 31 Central zone May 25–March 31 Northern zone Manitoba May 16–April 30 North-central and northwest divisions Generally all year Northeast division Ontario January 1–September 30 Most common, but 12 different seasons, 4 split seasons (closed in late winter, reopened in spring) 5 divisionwide winter closures, approximately 50+ lakes elsewhere with specific winter closures Quebec April 25–September 1, 7, 14, or 30 Seasons may vary slightly in wildlife reserves and ZECs Minnesota May 9–September 30 Lakes both inside and outside and partly outside Boundary Waters Canoe Area adjacent to Ontario border have winter seasons New York April 1–October 15 All year in Finger Lakes, Lake Champlain Ice fishing permitted in designated trout waters Note: ZECs, Zones d’Exploitation Controlée. a Regulations pertaining to Great Lakes waters are not included. These regulations may have changed in recent years. Check with your local management agencies for updates. Lac Matapédia 1985 1991 Difference (%) Effort 3800 4883 +22 CUE 0.53 0.84 +59 Harvest 2016 4077 +102 Lac des Trente et un Milles 1991 Average 1979–1987 Summer Difference (%) Winter Summer Total Summer Total Effort 5,449 6,054 11,503 7,037 +10 −39 CUE 0.16 0.41 0.29 0.55 +34 +90 Harvest 874 2,472 3,346 3,885 +57 +16 © 2004 by CRC Press LLC In Lac Matapédia, despite the loss of 5 weeks of spring fishing, effort, fishing success, and harvest all increased substantially. In Lac des Trente et un Milles, although the winter fishery was closed and total fishing effort decreased substantially, a large increase in fishing success in summer resulted in an overall increase in total harvest. These examples show that anglers can quickly adapt to changes in season regulations, and that exploitation can still be quite high even when seasons are reduced. A different approach to harvest control than in-year season changes has been the closure of lakes to fishing in alternate years. This system was instituted on a number of lake trout and brook trout Salvelinus fontinalis lakes in Algonquin Park, Ontario, in response to concerns that the large catches of mature fish in some of these lakes might adversely affect production and recruitment. Spawning escapement was not measurably enhanced because there was little difference in the size of year-classes produced in open and closed years (Martin and Baldwin, 1953). The quality of lake trout angling in lakes subject to alternate-year closure was also similar to that experienced in lakes open to fishing each year. A later study by Martin (1966) produced the same results. He suggested that a system of alternate-year closure might be most beneficial in intensively fished lakes that have fast growing fish and stable year-class production. He also noted that in lakes open for 2 consecutive years then closed for 1 year, the angling quality declined substan- tially in the second open year. Winter fishing One of the contentious issues of lake trout management is that of winter fishing. In the early 1950s, Fenderson (1953) noted that the effects of ice fishing on trout and salmon have been controversial for a long time in Maine. Concerns about the effect of ice fishing on lake trout stocks in Ontario arose shortly after winter open seasons for lake trout were established in inland lakes in 1957 (Armstrong, 1961). Hughson (1961) reported that in the Sudbury area, fishery managers were concerned with the large increase in winter fishing in recent years (primarily for lake trout and walleye, Stizostedion vitreum vitreum) and with the poor-quality angling occasionally experienced for these species during the summer. Ryder (1957), on the basis of a winter creel survey of 19 lakes in 1957, suggested that winter fishing did not overexploit lake trout populations in the Thunder Bay, Ontario, area as winter harvests were only about a tenth of those experienced during open water. However, some 15 years later the impact of winter fishing had changed dramatically. Ryder and Johnson (1972), citing just one example, estimated that 2 to 4 years of annual lake trout production was removed from one such Thunder Bay area lake by ice fishermen in 1 day. The impact that winter angling can have on a small Precambrian Shield lake trout lake is shown in Figure 11.1. A similar exploitation pattern occurred in 1980 in Nelson Lake, a 308-ha rehabilitated lake trout lake also near Sudbury, Ontario (Gunn et al., 1988). Winter effort, harvest, and yield were estimated at 28,137 angler hour, 2132 fish, and 3.26 kg ha −1 , respectively. Catch rates (number/angler hour), mean fork length (FL), and mean weight of fish sampled generally declined monthly from January through March. The authorities responded by closing the lake to winter fishing. The closure is still in effect, and the lake is heavily fished in the spring. The rapid response of anglers and the resultant “high grading” that occurs when a closed lake is opened to uncontrolled fishing (by either new access or removal of sanctuary status) is a familiar pattern. It was also a common occurrence, at least in Ontario throughout the 1960s, because lake trout regulations were liberalized and the use of mechanized forms of winter travel allowed anglers access to previously inaccessible lakes. © 2004 by CRC Press LLC One of the earliest studies comparing winter and open-water lake trout fisheries occurred on Algonquin Park lakes in the late 1940s and early 1950s. Martin (1954) found that in lakes where lake trout mature at a young age (5 years) and a small size (28 to 30.5- cm FL), as in Canisbay and Louisa Lakes, a summer fishery leaves a greater proportion of the mature fish to spawn each year than the winter fishery. In these lakes, harvests were generally greater in the winter. The catches sampled in the winter were made up of smaller trout and had a larger proportion of immature fish than in the summer fisheries. For example, in Canisbay and Louisa Lakes 60 and 50%, respectively, of the lake trout caught in winter had fork lengths less than 30 cm compared to 15 and 10%, respectively, in the summer fishery. These results in part contributed to the closure of Algonquin Park lakes to winter fishing after 1955. Martin (1954) found that plankton feeding was generally at a low level during the winter, and with the absence of thermal barriers the smaller and more numerous plank- tivorous lake trout were able to feed on minnows more frequently. These fish are especially vulnerable to capture by anglers using bait fish. Lakes with an abundance of small lake trout (usually the smaller lakes) may attract more anglers and have greater effort on a per-unit-area basis than other lakes because the higher catch rates on such lakes provide the angler with “lots of action” and increase the likelihood of limit catches. The high Figure 11.1 Impact of winter anglers on a remote lake trout lake near Sudbury, Ontario. Michaud Lake is a 148-ha lake accessible by a 26-km forestry road (12 km are used as a snowmobile trail in the winter). The lake was closed to angling for 7 years (1991–1997) to allow the lake trout population to be rehabilitated by hatchery stocking. The lake opened to fishing (without any public notice) on January 1, 1998, under the standard regulations for this area (unlimited access and entry, three fish per person daily catch [bag] limit). Catch rates were very high the first week of January (0.4 fish/angler-hour), but declined rapidly as more and more people (>90 people the 4th week) learned about the fishing in the lake. In spite of poor fishing late in the winter season, anglers continued to fish the lake until ice breakup occurred. They then returned for one last try in early spring. Catch rates were initially high in early spring (0.17 fish/angler-hour the first week of May), but declined again to zero by the third week of May. A creel survey was conducted every weekend day and on two random weekdays per week. A total of 384 harvested lake trout (2.6 kg/ha) were observed by the creel survey crew. By extrapolation, the estimated total harvest was 515 fish (3.8 kg/ha). Based on a marking program conducted in fall 1997 (220 fish marked and released), the adult population was reduced by about 72% (from 765 to 210) by anglers in the first few months that the lake was open. (Modified from Gunn and Sein, 2003; See Gunn and Sein, Chapter 14, this volume.) © 2004 by CRC Press LLC harvests in some lakes during the winter may also be taken into account by the observation of Ryder and Johnson (1972) that “lake trout tend to form close schools in the winter, which, once located, can be harvested at will.” This supports Martin’s (1954) observation that the winter catch of lake trout in large lakes may be lower in part because of the difficulty in locating the fish. An assessment of winter and summer lake trout fisheries was done by Schumacher (1961) on four lakes in Minnesota. In the lake with the longest time series (9 years) he found that both winter angling pressure and catchability were twice that of summer and resulted in the capture of five times the number of fish. Winter anglers took smaller trout, and nearly two-thirds of the fish caught were immature. Winter anglers were also the first to exploit each new year-class entering the fishery. Schumacher concluded that these lakes were overexploited. Many other authors have observed that effort, fishing success, and catch tend to be higher in winter fisheries than in open-water fisheries and that winter catches contain higher proportions of small, young, and immature fish. Goddard et al. (1987) found that fishing effort is the most important factor affecting lake trout harvest in Ontario lakes, accounting for 73% of the annual variation in angler catch among lakes. Evans et al. (1991), in their review of Ontario lake trout sport fisheries, found that a disproportionate amount of annual effort occurred in winter because effort on lake trout was about 25% greater in winter than in spring and summer combined. Lake trout are also very vulnerable to angling when the ice fishing season first opens, which is usually in January. A disproportionate amount of effort and harvest in winter lake trout fisheries has been observed in that month. In four Ontario lakes, for example, about one-half of the effort and one-half to two-thirds of the harvest occurred in the first month of the season (Vozeh, 1965; Samis, 1968; Purych, 1975; Bernier, 1977). Corresponding catch rates were from one-third to three times higher in January than in February or March in three of the four lakes. A similar pattern was observed in Michaud Lake (Figure 11.1). Catch rates and harvests may be lower in February and March simply because fewer fish are available for capture. If the season was not open until February or March, initial catch rates and harvests might also be as high as in January, although the cumulative harvest might be less because of a shorter season. A high proportion of lake trout caught in winter angling fisheries are also immature. For example, Purych (1975) found that 80.7% of the lake trout sampled from the angler’s catch at Summers Lake, Ontario were immature, and Walker (1978) reported that 77% of the lake trout caught at Lake Manitou, Ontario were immature. This could have a major effect on recruitment, as Martin and Fry (1973) have shown that in Lake Opeongo year- class strength is significantly related to spawning escapement, which is in turn largely governed by exploitation. There is little doubt that winter fishing for lake trout has been harmful to many lake trout stocks. Evans et al. (1991) concluded that yields of lake trout in many Ontario lakes, especially for winter fisheries and small lakes, appear to be well above self-sustaining limits. As Schumacher (1961) pointed out, the winter angler is the first to catch each new year-class as it becomes vulnerable to fishing, and thus the winter fishery may have the dominating effect on the summer fishery as well as the total fishery. Allocating the resource among winter and summer anglers is a social, not a biological, issue. As Christie (1978) noted, it makes little difference what time of year a fish is harvested as the same loss to the spawning population occurs whether it is caught many months before or just prior to the spawning season. DeRoche (1973) contended that winter fishermen have as much “right” to the resource as summer (open-water) anglers. In general, in winter most anglers tend to be local residents. Larger economic benefits may accrue in summer fisheries that attract a larger proportion of tourists. Social and economic © 2004 by CRC Press LLC interests may not be compatible with biological concerns, and compromises are inevitable. Managers must balance the demands of anglers with the demands of those who have an economic interest in the fisheries. However, more than 40 years ago, Weir and Martin (1961) noted that if the issues associated with winter fishing for lake trout are to be resolved, biological considerations should take precedence over nonbiological concerns. There is justification for curtailing winter fishing in some manner because of the potential biological impact on lake trout stocks. This does not mean that winter fishing for lake trout should be eliminated across all lakes. Nevertheless, a reduction in the length of the winter fishing season in areas or on small lakes where exploitation is excessive, or even winter closures on individual lakes, may be an effective harvest control mechanism. In Ontario, for example, a review of lake trout management strategies (Olver et al., 1991) recommended that winter lake trout seasons be reduced to 1 month (February 15 to March 15) on all lake trout lakes less than 1000 ha, and that lake trout lakes less than 100 ha be closed to winter fishing. These recommendations have not been implemented. One method to reduce harvest has been to delay the “traditional” opening date of January 1 to sometime in February or March and continue the season uninterrupted through to the fall. However, shortening the winter season from a few months to a few weeks might cause anglers to compress a similar amount of effort observed in a long season into a shortened season if opportunities to fish nearby open lake trout lakes are not available. Local conditions (sufficient ice cover, snow conditions, weather conditions) may also vary considerably from month to month, year to year, and lake to lake within the same fishing division, thereby making it difficult to establish regulations that are effective or suitable over broad areas. Another option is to have a split season in which the season is closed for a period of time prior to the spring breakup of ice and then is reopened some time after the ice goes out. This approach deserves closer scrutiny, as the intent is to reduce harvest during a period when the lake trout appear to be especially vulnerable to angling. Regardless of whether season adjustments are applied across a fishing division or to individual lakes, the fine tuning of seasons by manipulating the opening and closing dates is a viable option to control harvest. Access control Access controls, in addition to fishing regulations, can be used to control harvest. These types of measures are usually designed to limit or to impede access to water bodies, restrict access of certain user groups, and limit development in remote areas or lakes. The tradi- tional means of access control have been restrictions on travel by motorized road vehicles, road closures, and the siting of access roads away from relatively unexploited lakes. Access controls that may be used to lower fishing pressure include controls on the use of snow machines and power boats, the establishment of daily travel quotas at access points, the control of boats cached on public land, the allocation of fish in remote lakes or areas to specific outfitters, and the limitation of development or accommodation at outpost camps. Access controls are used in Quebec, but they are part of the quota management strategy used there and are discussed in that context. Use of publicly owned access roads is usually permitted, although travel on such roads may be closed for various reasons. On private access roads, such as those owned by logging companies, public travel can be denied or negotiated between a private com- pany and a government agency or potential local users. Road closures, however, often have not come into effect until after overexploitation has already occurred. Also, locating forest access roads away from lakes containing lake trout, as well as other species, is no longer an effective deterrent to exploitation in Ontario (Ontario Ministry of Natural © 2004 by CRC Press LLC Resources, 1982) because of the ready availability of motorized vehicles that do not require roads for travel. Regulations have also been enacted in some parks (such as Algonquin Park, Ontario), which prohibit the operation of snow machines and power boats or limit the horsepower of motor boats on certain lakes or to specified times of the year. The last restriction, for example, while primarily intended to separate canoe trippers and outboard motor users, also limits the ability of anglers to troll for lake trout on some of the larger lakes in the park. In Quetico Park, Ontario, which is much further from major population centers than Algonquin Park, access controls have also apparently had a strong influence on exploita- tion. Maher (1985) noted that in Quetico Park, the prohibition on power boats and snow machines reduced fishing pressure to a noncritical level. In Algonquin Park, quotas have also been established that limit the number of canoeing/camping parties entering the park interior from designated access points on any day at certain times of the year. The closure of Algonquin Park to winter fishing in 1955 and the use of access controls in more recent years are probably the major factors contributing to the retention of quality fishing in that park, as overexploitation of lake trout is largely confined to lakes adjacent to road access. Limiting the numbers and locations of boats cached or left unattended on public lands is another form of access control that could also act as a harvest control mechanism on lakes where fishing pressure by anglers using such boats has contributed to the overex- ploitation of fishery resources. This idea has been used since the early 1980s in the northwestern part of Ontario (Ontario Ministry of Natural Resources, 1996), where all boats cached on public land must be authorized and identified by means of a validation decal. On some lakes boat caches may not be permitted, while on other lakes the number of boats and the conditions of use may be regulated. Outpost camps on remote lakes may be allocated to specific tourist outfitters. The basic intent is to support the tourist industry by limiting competition and to prevent overexploitation. Agreements between government agencies and the tourist industry may also result in limits on the number of overnight accommodation units at these outpost camps. This in effect places a quota on the number of anglers who have access to these facilities. The intent is to maintain high-quality fishing by keeping projected harvests below annual production. In summary, fishing pressure and ultimately harvest depend, in part, on accessibility. Hence, access controls to curb overexploitation offer a viable alternative to additional or more stringent angling regulations. They may also be used to complement existing angling regulations to effect the same result. Many types of access control have evolved in response to “local” problems. Consequently, they often lack a sense of perspective and can prolif- erate independently of one another and therefore have not been used to their full potential (Ontario Ministry of Natural Resources, 1982). A study of the role of these controls relative to the harvest of fishery resources would be both appropriate and timely. Size limits Size limit regulations have important management implications, because the size and age of recruitment and the entry of year-classes into a fishery can be determined and thus manipulated. Size-based regulations infer the release of live fish. Their use to achieve a particular social or biological goal is based on the assumption that the survival rate of released fish is sufficient to ensure sustainability of wild fish. Although studies that test that assumption are not reviewed in detail, a few comments are presented to show the importance of hooking mortality to size-based regulations. Studies in large lakes during spring and summer have shown hooking mortality rates in the range of 7.0% (Great Bear and Great Slave Lakes, Northwest Territories; Falk et al., © 2004 by CRC Press LLC 1974) to 14.9% (Lakes Huron, Michigan, and Superior; Loftus et al., 1988). Unpublished Quebec and Ontario studies on smaller lakes of the Precambrian Shield have shown similar or slightly higher mortality rates. The higher mortality in some of the Ontario lakes was attributed to prolonged handling times, poor handling practices, and entanglement prob- lems with tethering gear used to retain lake trout for assessment of delayed hooking mortality. In addition to hooking mortality, Lee and Bergersen (1996) noted that the release and subsequent high mortality of lake trout in late summer in lakes with inadequate thermal and dissolved oxygen refugia may nullify the intended benefit of size-based regulations. Hooking mortality of lake trout during the winter may be higher than during the open-water period, especially when set-lining (i.e., still fishing) using a bait (usually cyprinids, dead rainbow smelt Osmerus mordax, or lake herring Coregonus artedi). In Gun- flint Lake, Minnesota (Persons and Hirsch, 1994) the observed mortality rate using this method was 32.0%, and fish were still dying at the end of the 6-day holding period. In contrast, jigging caused a mortality rate of only 9%. Jigging is a more active method than still fishing, the line is closely tended, and the fish has less chance or time to deeply ingest the bait (as it must strike a moving target) before the hook is set. With still fishing, the fish generally swallows the bait before the hook is set, and the bait tends to be deeply ingested and may be difficult to remove without causing further injury or death. As noted, anglers tend to catch smaller lake trout in the winter than in open-water even in the same lake. The mortality rate of released small fish is generally considered greater than that for larger fish. Additional studies of winter lake trout hooking mortality are required. Hook placement (i.e., location) and hook size are important aspects of hooking mortality and need to be studied further. It would seem prudent for anglers to leave deeply imbedded hooks in any fish they intend to release (at any time of the year) because removal is likely to induce bleeding or cause further injury or death. Lake trout that are bleeding should not be released unless required by a size-based regulation. The importance of effective techniques for hook removal, handling, and release of fish should be promoted through public education programs. The general purpose of minimum length limits, in which all fish below some desig- nated size must be released, is to permit fish to mature and spawn at least once before reaching legal size. In theory, some of the released sublegal fish will be harvested when they attain legal size or will increase catches by contributing to future spawning stocks. These length limits are generally applied in fisheries where growth is good and recruitment has been reduced because of high exploitation. Maximum size limits, in which all fish above a specified size must be released, are used to protect brood stock or to counter a decline in age and size of spawning stock. They are applied to stocks for which growth potential is large, but high exploitation has resulted in a low density of mature fish and limited recruitment. Conversely, these limits may be used to maintain the population structure of unexploited stocks, especially in large lakes where large body size can be attained. A combination of minimum and maximum size limits is the slot limit. A size range in which anglers may only keep fish below or above specified lengths is called a protected slot. All fish within the protected slot must be released. The intent is to protect the brood stock while still allowing anglers access to the more numerous, smaller fish and the less abundant large or trophy-size fish. The capture of fish below the slot should, in theory, reduce density, increase growth, and allow escapement into the protected slot size. Repro- duction of adults in the slot should increase recruitment. A harvested slot in which only fish between a specified minimum and maximum size may be kept has not, to our knowledge, been applied to lake trout. [...]... to their seasonal or annual quota An individual tag-and-quota system for lake trout has been in effect since 1991 in Clearwater Bay and adjacent Echo Bay and Cul de Sac, Lake of the Woods, Ontario, to curtail the harvest of trophy-size lake trout (Mosindy, 1998) Catch-and-release fishing for lake trout is in effect except for tag holders, who are selected by an annual draw No more than one tag, which... Lands and Forests, Sylva 12:25–28 Maher, T., 1985, Management options for small lake trout lakes in the Atikokan District, in 1985 Lake Trout Seminar North Central Region, Ontario Ministry of Natural Resources, Thunder Bay Martin, N.V., 1954, Catch and winter food of lake trout in certain Algonquin Park lakes, Journal of the Fisheries Research Board of Canada, 11: 5–10 Martin, N.V., 1966, The significance... growth makes it impractical to set a single minimum legal length to protect immature fish over a broad geographic area Across the total range of the lake trout, first maturity has been reached at lengths from 18 cm (FL) in stunted populations in national parks in western Canada (Donald and Alger, 1986) to 66–76 cm (TL) in fast-growing lake trout in Seneca Lake, New York (Royce, 1951) Even in a relatively... Table 11. 3 Daily Catch Limits for Lake Trout in Small, Forested Precambrian Shield Lakes a Jurisdiction Number Comments/exceptions Saskatchewan 4 Only one may be larger than 65 cm (TL) In Lac la Ronge, two/day, four annually In catch-and-release lakes One with conservation license One in high-quality management lakes Two in 19 divisions, three in 16 divisions, 1 fish in fewer than 10 lakes in province... only one lake trout larger than 65 cm (TL) may be kept However, a maximum size limit (65-cm TL) is in effect across one fishing division and in designated high-quality lakes in another fishing division (Table 11. 2) In these lakes, all lake trout larger than 65 cm (TL) must be released Limiting the catch of large lake trout may be a useful regulatory device where anglers target on large lake trout or... may have changed in recent years 2004 by CRC Press LLC Table 11. 5 Gear Restrictions for Lake Trout Angling in Small Forested Precambrian Shield Lakesa Jurisdiction Comments Saskatchewan Barbless hooks mandatory on catch-and-release waters Proposed that use of barbless hook be mandatory provincewide in 2000–2001 angling season Anglers must be within 25 m of fishing line Barbless hooks provincewide Barbless... prohibited in three divisions In one division (Algonquin Park), this restriction is primarily directed at retaining the integrity of the native fish fauna, particularly brook trout, and has little to do with control of exploitation of lake trout A ban on live bait fish seems to be particularly applicable in areas or lakes where native salmonids such as lake trout and brook trout have coadapted Presumably,... Rocky Mountains, Canadian Journal of Fisheries and Aquatic Sciences, 43:608–612 Duckworth, G .A. , 1982, Lake Temagami and Cross Lake Summer Creel Census Report 1981 Including an Assessment of the Annual Lake Trout Fishery on Lake Temagami, Ontario Ministry of Natural Resources, Temagami District, Ontario Eschmeyer, P.H., 1964, The Lake Trout (Salvelinus namaycush), United States Department of the Interior,... York 2 a © Comments/exceptions In line in winter in one division and specified lakes Generally no ice fishing for lake trout Two through ice except on designated trout lakes and streams Two hand lines and five tip-ups may be used where ice fishing permitted Two hand lines and 15 tip-ups permitted while ice fishing on Lake Champlain Regulations pertaining to Great Lakes waters are not included Regulations... (1993) on low- (77 µS/cm) lakes in northwestern Ontario suggested that managers may need to restrict the harvest of females larger than 55 cm (FL) in low-conductivity lakes and of females larger than 60 cm (FL) in high-conductivity lakes Lake trout in the former lakes had slower growth, matured at an older age, attained maturity at similar or smaller body sizes, and were . their seasonal or annual quota. An individual tag-and-quota system for lake trout has been in effect since 1991 in Clearwater Bay and adjacent Echo Bay and Cul de Sac, Lake of the Woods, Ontario,. open-water lake trout fisheries occurred on Algonquin Park lakes in the late 1940s and early 1950s. Martin (1954) found that in lakes where lake trout mature at a young age (5 years) and a small. 1 day. The impact that winter angling can have on a small Precambrian Shield lake trout lake is shown in Figure 11. 1. A similar exploitation pattern occurred in 1980 in Nelson Lake, a 308-ha rehabilitated

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  • Boreal Shield Watersheds: Lake Trout Ecosystems in a Changing Environment

    • Table of Contents

    • Section III: Biological effects and management reactions

    • Chapter 11: The control of harvest in lake trout sport fisheries on Precambrian Shield lakes

      • Introduction

      • Angling seasons

      • Winter fishing

      • Access control

      • Size limits

      • Catch limits

      • Quotas

      • Gear

      • Population models

      • Conclusions

      • Recommendations

      • Acknowledgments

      • References

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