Arrow Lakes Reservoir Angler Creel Survey 2018. Report prepared by Ministry of Forests, Lands, Natural Resource Operations and Rural Development for the Fish and Wildlife Compensation Program

Author: Arndt S

Creel surveys have been conducted annually at selected access locations since 1976. They provide essential information for evaluation and monitoring of the actions listed under Objectives 1 and 3 of the FWCP plan, and the status indicators for Bull trout, piscivorous Rainbow Trout, Kokanee, and Burbot.4 Specific objectives of the angler survey are to provide: estimates of angling effort, harvest, catch rate, and size for the four main species, an index of feeding conditions for apex predators, estimates of the social and economic value of the fishery, and a measure of the contribution of fin-clipped Rainbow Trout released into the reservoir from 2005 to 2010.5 This report summarizes results for the 2018 calendar year. Multi-year analyses with greater detail are provided in Arndt and Schwarz (2011) and Arndt (2014a); previous results are provided in Sebastian et al. 2000, Arndt 2002, 2004a, Arndt 2014b, Arndt 2015, Arndt 2016, Arndt 2017, Arndt 2018).

In 2018, ALR supported 12,100 angler-days, providing important recreational opportunities for local, provincial and some non-resident anglers, and a food harvest of 7.5 tonnes. Expenditures related to the fishery were estimated at up to $2.8 million including major purchases wholly or partially attributable to the fishery. This level of angling effort is an increase compared to the previous three years, although still below the early years of the nutrient restoration program (Figure 3, also see top panel Appendix 5).
Numerical harvests for Bull Trout in 2018 increased to a level approaching harvests prior to 2014, however, Rainbow Trout and Kokanee harvests remained well below those earlier in the nutrient program. The Kokanee fishery remains a small fraction of that in the 1980s and early 1990s (Figure 13). The small size of Kokanee in recent years is unusual because density and biomass in the reservoir have been relatively low (MFLNRORD file data); average length of harvested fish was only slightly less than Kokanee spawners in Deer Creek, suggesting that the harvest was comprised of similar age classes to the spawners (2+ and 3+).
A large part of angling effort prior to the nutrient program was targeting Kokanee (Fig. 13b), and the decline in Kokanee effort is a significant component of the overall decline. One hypothesis is that changes in angler demographics or species preferences may be the reason for reduced interest in Kokanee fishing, however, a 2016 discrete choice survey of ALR stakeholders suggests an alternative explanation. The largest group of respondents were classified as casual consumptive anglers who expressed an overall preference for high quality Kokanee fishing experiences; both Kokanee catch rates and size were important to this group (Nelitz and Beardmore 2017). A positive relationship of Kokanee effort to size has also been documented by this creel survey (Fig. 14). Comments of respondents also indicated an interest in fishing opportunities suitable for introducing children to fishing. Therefore there may be potential for increased angler-days on ALR, if Kokanee size and catch rate could be increased (Nelitz and Beardmore 2017, p. 38).
In 2017, there was a strong improvement in Bull Trout and piscivorous Rainbow Trout catch and size. In 2018, Bull Trout catch continued to improve but piscivorous Rainbow Trout catch declined; condition (Kn) of Bull Trout also declined slightly. These changes coincide with a spawning escapement of over 700,000 Kokanee in 2017 (more than triple the annual escapements for the last five years) and a decline in Kokanee escapement in 2018 (<300,000). The quality of the fishery for the apex predators, particularly the large Rainbow Trout, is linked to Kokanee escapement (see Appendix 6 for more detail). ALR fishery yield by weight continued to increase in 2018, although it is still below the 2001 2011 range (Figure 21). Fishery yield in a given year is comprised of four main species, from more than one trophic level, produced over varying time periods. The majority of yield in most years is from Bull Trout, which are at the fourth trophic level, with harvested fish ranging from age-4 to over 10, (MFLNRORD unpublished data). Therefore it is not expected to be directly linked to the nutrient conditions in a single year. Yield is also to some extent a reflection of fishing effort and release rates.9 Nevertheless in general, periods of higher yield imply higher primary production at the lowest trophic level, and/or improved transfer efficiency from lower to upper trophic levels (e.g., Giacomini et al. 2013). Several hypotheses have been suggested to explain variable fish production in ALR since the beginning of the nutrient program. These include: region-wide weather patterns, a weather or disease-related Kokanee mortality event in 2012, increased entrainment (of nutrients and subsequent production at all trophic levels) and reduced Kokanee survival related to high flows and reduced water residence time, variable spawning channel fry production, and variable nutrient additions starting in 2004.10 Analyses of these hypotheses are ongoing using existing data; however, an adaptive management experiment may be necessary to address some questions (Hansen et al. 2015). In such an experiment, inputs under management control (e.g., amount and timing of phosphorus added from fertilizer, spawning channel fry production) should be held constant at specified levels for a period of time while maintaining ongoing monitoring. Four years for each experimental treatment would allow completion of one Kokanee life cycle for the majority of fish maturing at age 3+. Some initiatives towards improved understanding of ALR compensation initiatives are underway. For example, predator diet samples, collected from 2003 2006, were added to the creel survey again for 2014 - 2018. This sampling should be continued through periods of contrasting Kokanee abundance and size structure to resolve questions related to optimal prey size and density. Data analysis is ongoing as time permits (see Appendix 6). As previously noted, a survey of stakeholder views on ALR fishery management objectives was completed in 2017 as a separate MFLNRORD initiative (Nelitz and Beardmore 2017). Overflight boat counts conducted from 20032005 and in 2011-2012 provided the expansion factors used for whole reservoir effort, harvest and catch estimates. The pattern of air/interviewed boat ratios in the 2011-2012 flights was very similar to the earlier flights, so all boat count data between 2003 and 2012 have been included when computing a common monthly correction factor for the three access sites (Arndt 2014a). Given recent improvements to some of the smaller boat ramps on the reservoir and the possibility of unknown factors affecting angler access over time, overflight counts are occurring in the 2019/20 fiscal to ensure that the interviewed/total boat expansion ratios are accurate.

In 2018, ALR supported 12,100 angler-days, providing important recreational opportunities for local, provincial and some non-resident anglers, and a food harvest of 7.5 tonnes. Expenditures related to the fishery were estimated at up to $2.8 million including major purchases wholly or partially attributable to the fishery. This level of angling effort is an increase compared to the previous three years, although still below the early years of the nutrient restoration program (Figure 3, also see top panel Appendix 5).
Numerical harvests for Bull Trout in 2018 increased to a level approaching harvests prior to 2014, however, Rainbow Trout and Kokanee harvests remained well below those earlier in the nutrient program. The Kokanee fishery remains a small fraction of that in the 1980s and early 1990s (Figure 13). The small size of Kokanee in recent years is unusual because density and biomass in the reservoir have been relatively low (MFLNRORD file data); average length of harvested fish was only slightly less than Kokanee spawners in Deer Creek, suggesting that the harvest was comprised of similar age classes to the spawners (2+ and 3+).
A large part of angling effort prior to the nutrient program was targeting Kokanee (Fig. 13b), and the decline in Kokanee effort is a significant component of the overall decline. One hypothesis is that changes in angler demographics or species preferences may be the reason for reduced interest in Kokanee fishing, however, a 2016 discrete choice survey of ALR stakeholders suggests an alternative explanation. The largest group of respondents were classified as casual consumptive anglers who expressed an overall preference for high quality Kokanee fishing experiences; both Kokanee catch rates and size were important to this group (Nelitz and Beardmore 2017). A positive relationship of Kokanee effort to size has also been documented by this creel survey (Fig. 14). Comments of respondents also indicated an interest in fishing opportunities suitable for introducing children to fishing. Therefore there may be potential for increased angler-days on ALR, if Kokanee size and catch rate could be increased (Nelitz and Beardmore 2017, p. 38).
In 2017, there was a strong improvement in Bull Trout and piscivorous Rainbow Trout catch and size. In 2018, Bull Trout catch continued to improve but piscivorous Rainbow Trout catch declined; condition (Kn) of Bull Trout also declined slightly. These changes coincide with a spawning escapement of over 700,000 Kokanee in 2017 (more than triple the annual escapements for the last five years) and a decline in Kokanee escapement in 2018 (<300,000). The quality of the fishery for the apex predators, particularly the large Rainbow Trout, is linked to Kokanee escapement (see Appendix 6 for more detail). ALR fishery yield by weight continued to increase in 2018, although it is still below the 2001 2011 range (Figure 21). Fishery yield in a given year is comprised of four main species, from more than one trophic level, produced over varying time periods. The majority of yield in most years is from Bull Trout, which are at the fourth trophic level, with harvested fish ranging from age-4 to over 10, (MFLNRORD unpublished data). Therefore it is not expected to be directly linked to the nutrient conditions in a single year. Yield is also to some extent a reflection of fishing effort and release rates.9 Nevertheless in general, periods of higher yield imply higher primary production at the lowest trophic level, and/or improved transfer efficiency from lower to upper trophic levels (e.g., Giacomini et al. 2013). Several hypotheses have been suggested to explain variable fish production in ALR since the beginning of the nutrient program. These include: region-wide weather patterns, a weather or disease-related Kokanee mortality event in 2012, increased entrainment (of nutrients and subsequent production at all trophic levels) and reduced Kokanee survival related to high flows and reduced water residence time, variable spawning channel fry production, and variable nutrient additions starting in 2004.10 Analyses of these hypotheses are ongoing using existing data; however, an adaptive management experiment may be necessary to address some questions (Hansen et al. 2015). In such an experiment, inputs under management control (e.g., amount and timing of phosphorus added from fertilizer, spawning channel fry production) should be held constant at specified levels for a period of time while maintaining ongoing monitoring. Four years for each experimental treatment would allow completion of one Kokanee life cycle for the majority of fish maturing at age 3+. Some initiatives towards improved understanding of ALR compensation initiatives are underway. For example, predator diet samples, collected from 2003 2006, were added to the creel survey again for 2014 - 2018. This sampling should be continued through periods of contrasting Kokanee abundance and size structure to resolve questions related to optimal prey size and density. Data analysis is ongoing as time permits (see Appendix 6). As previously noted, a survey of stakeholder views on ALR fishery management objectives was completed in 2017 as a separate MFLNRORD initiative (Nelitz and Beardmore 2017). Overflight boat counts conducted from 20032005 and in 2011-2012 provided the expansion factors used for whole reservoir effort, harvest and catch estimates. The pattern of air/interviewed boat ratios in the 2011-2012 flights was very similar to the earlier flights, so all boat count data between 2003 and 2012 have been included when computing a common monthly correction factor for the three access sites (Arndt 2014a). Given recent improvements to some of the smaller boat ramps on the reservoir and the possibility of unknown factors affecting angler access over time, overflight counts are occurring in the 2019/20 fiscal to ensure that the interviewed/total boat expansion ratios are accurate.