scholarly journals Tournament and non-tournament anglers have little effect on a largemouth bass population compared to natural mortality

Author(s):  
Andrea L Sylvia ◽  
Stephen J. Dinsmore ◽  
Michael J Weber

Popularity of bass Micropterus spp. catch and release and tournament angling during the past decade has resulted in increased potential for these activities to induce population level effects. Understanding capture rates and mortality sources relative to total population mortality is essential to focus of management. We conducted monthly electrofishing, solicited non-tournament angler tag returns, and censused largemouth bass Micropterus salmoides tournaments at Brushy Creek Lake, IA, USA from April 2015 to June 2018. We used a multistate mark-recapture model to evaluate the effects of air temperature, water temperature, tournament bass per angler, and tournament initial mortality on non-tournament and tournament angler capture probability and natural, non-tournament angling, and initial and delayed tournament mortality. Average total annual mortality was 0.66 with natural mortality representing the largest mortality source (0.57) followed by delayed tournament mortality (0.06), non-tournament angling mortality (0.02), and initial tournament mortality (0.006). Our results reveal both non-tournament and tournament angling mortality are low compared to natural mortality in some lakes. Therefore, cumulative angling mortality likely has minimal population level effects on some bass populations.

1978 ◽  
Vol 35 (9) ◽  
pp. 1249-1261 ◽  
Author(s):  
G. H. Winters

From recent and historical data the natural mortality rate of adult harp seals (Pagophilus groenlandicus) is estimated to be 0.10 which is within the range of previous estimates (0.08–0.11). New estimates of bedlamer and 0-group natural mortality rates were not significantly different from those of adult seals. Pup production estimates from survival indices agreed well with those from sequential population analyses and indicated a decline from about 350 000 animals in the early 1950s to about 310 000 animals in the early 1970s. Over the same period the 1+ population size declined from 2.5 to 1.1 million animals but has been increasing at the rate of 3%/yr since the introduction of quotas in 1972. The relative contribution of the "Front" production to total ("Front" plus Gulf) production during the past decade has fluctuated from 49 to 87%, the average of 64% being very similar to the 61% obtained previously. These fluctuations suggest some interchange between "Front" and Gulf adults and it is concluded that homing in the breeding areas is a facultative rather than obligatory aspect of seal behavior. Thus the heavier exploitation of the "Front" production is probably sufficiently diffused into the total population to avoid serious effects on "Front" production. The maximum sustainable yield of Northwest Atlantic seals harvested according to recent patterns is estimated to be 290 000 animals (80% pups) from a 1+ population size of 1.8 million animals producing 460 000 pups annually. The sustainable yield at present levels of pup production (335 000 animals) is calculated to be 220 000 animals which is substantially above the present TAC of 180 000 animals and coincides with present harvesting strategies designed to enable the seal hunt to increase slowly towards the MSY level. Key words: mortality, production, sustainable yield, population dynamics, marine mammal


2017 ◽  
Vol 8 (1) ◽  
pp. 140-153 ◽  
Author(s):  
Joseph W. Love ◽  
Mary Groves ◽  
Branson D. Williams

Abstract Largemouth Bass Micropterus salmoides is arguably the most popular sport fish of inland waters in the United States. The majority of anglers in the fishery practice catch and release. Catch-and-release guidelines aim to reduce negative impacts of angling on individual fish, though such impacts on populations are not widely reported. We hypothesized that a decline in the population size for Largemouth Bass from a catch-and-release fishery from the Potomac River resulted from a period of greater fishing mortality followed by habitat loss that reduced the recovery of the population. After we analyzed several years of fishery-dependent and independent data (1999–2015), it was determined that fishing mortality and relative exploitation were greater than average in the latter half of the 2000s than in previous years. Fishery-independent survey results suggested a loss of large fish and decline in population size. The relative abundance of juveniles subsequently declined possibly because the area of submerged aquatic vegetation used as nursery habitat had declined after tropical storms. For management purposes, we suggest that fishing mortality not exceed 28% for a sustainable fishery (assuming similar levels of natural mortality) in the Potomac River. Negative impacts to Largemouth Bass populations could be lessened by reduced harvest and widespread enforcement of catch-and-release guidelines, especially during times when angler effort is high, fish are highly accessible to anglers in the fishery, and habitat loss limits recruitment.


<em>Abstract.</em>—Largemouth Bass <em>Micropterus salmoides</em> is typically thought of as a freshwater species, but populations occur in oligohaline portions of estuaries throughout the U.S. Atlantic and Gulf of Mexico coasts, often with popular fisheries. These coastal populations must deal with the physiological stresses associated with salinity variation and may be isolated from inland freshwater populations, increasing the potential for differentiation. To understand factors important to the ecology and management of these coastal populations, we quantified individual- and population-level parameters for Largemouth Bass across a natural salinity gradient in the Mobile-Tensaw River delta in southwestern Alabama during 2002–2009 (including population demographics, feeding ecology, movement, recruitment, and bioenergetics processes). Combining traditional mark–recapture and telemetry techniques with otolith microchemical analyses, we demonstrated that Largemouth Bass of all ages moved very little, even in response to increasing salinity (up to 15‰) in downstream areas. Large individuals were rare in our sampling across both fresh and brackish habitats (only 7 out of 9,530 individuals were >2.27 kg), and fish body condition increased downstream with increasing marine influence. Growth responses for fish across the estuary were more complex, varying with both fish age and salinity. Faster growth was observed in the brackish, downstream areas for fish ≤age 2, while growth of older fish was faster in freshwater upstream sites. Using bioenergetics modeling, we demonstrated that a complex combination of spatial variation in water temperature, prey energetic content, and metabolic cost of salinity was responsible for age-specific spatial variation in growth. Preliminary genetic analysis suggests that these coastal Largemouth Bass may differ genetically from inland fish. Coastal Largemouth Bass populations face a number of potential conservation concerns, and their management will require different approaches compared to their inland counterparts, including different goals and expectations, likely even requiring consideration as unique stocks.


<em>Abstract</em>.—Largemouth Bass (LMB) <em>Micropterus salmoides</em> is one of the most popular sport fish in the United States and is intensively managed across much of its range. Beginning in 1989, Wisconsin implemented more restrictive harvest regulations for LMB, including greater minimum length limits, reduced bag limits, and a catch-and-release-only season during the spawning period across much of northern Wisconsin. We tested for trends in LMB relative abundance, growth, and angler catch and harvest in relation to LMB management policies from 1990 to 2011. We also tested for potential sport fish community responses to changes in LMB abundances using Walleye (WAE) <em>Sander vitreus</em> as an example. Angler catch rates and electrofishing catch per unit effort of LMB greater than 8 and 14 in increased significantly statewide. Mean length of age-6 LMB decreased significantly statewide. Release rates of LMB increased from about 80% in 1991 and then plateaued at more than 96% from 2005 to 2011. Concurrent with increases in LMB, adult WAE densities declined in lakes containing LMB. Ongoing research is being conducted to test for interactions between LMB and WAE and to test for additional environmental drivers, such as climate warming, that may be associated with increased LMB abundances. Largemouth Bass abundances have increased in Wisconsin, possibly in response to changes in harvest regulations, angler behavior, and potentially other environmental drivers. These increases in LMB abundances have had negative intraspecific effects on growth and may be negatively affecting WAE stocks. We recommend that management goals for LMB consider intra- and interspecific consequences, particularly in water bodies where multispecies fisheries are desired.


<em>Abstract</em>.—Sustainability of trophy Muskellunge <em>Esox masquinongy </em>populations and fisheries was examined from Muskies, Inc. catch data (335,954) from 43 years (1971–2013), along with more than 35 years (late 1970s–2013) of trophy Muskellunge data and cleithra (2,633) submitted to the Cleithrum Project. Catch has increased substantially over the past five decades, but harvest has been greatly reduced because of increased size limits (e.g., in Ontario, set by using growth potential) and voluntary catch and release of legal-sized fish promoted by organized Muskellunge anglers. The Cleithrum Project exemplifies cooperative interaction; although fewer samples have been submitted in recent years, length, weight, and age have increased significantly. Pivotal change occurred in the mid-1990s (means for late 1970s–1994, total length 108.7 cm, total weight 9.7 kg, age 11.6 years; 1995–2013, 121.0 cm, 13.4 kg, 15.1 years). A predictive mortality rate–longevity relationship was used on the Cleithrum Project age data to estimate mortality rate of trophy Muskellunge. Annual mortality rate (<EM>A</EM>) of trophy Muskellunge usually ranged from 16% to 26% and corresponded to maximum ages of 24 to 14 years. Estimated annual mortality of the oldest Muskellunge increased slightly over the past 35 years—13.0% to 14.3%, with a decrease in maximum age from 30 to 27 years. Mortality was high to the mid-1990s but has decreased subsequently, even though angling pressure has increased. Size and mean age of trophy Muskellunge have increased substantially (10.2 to 15.8 years) with associated decreases in annual mortality (<EM>A</EM>, 31.0% to 21.9%), indicating an increase in the mature population and reproductive potential. To ensure sustainable trophy Muskellunge populations, fish younger than 15 years should not be exposed to fishing mortality and older fish should not have a fishing mortality rate that exceeds the rate of natural mortality (<EM>F ≯</EM> <EM>M</EM>). Management for large size (older age) by using excessive size limits, in combination with catch and release, can have unexpected outcomes because older fish are increasingly sensitive to stress (e.g., viral hemorrhagic septicemia [VHS] mortalities). If Muskellunge populations are managed for high reproductive capacity (protecting fish to larger size and older age), they will be more reproductively resilient, producing larger year-classes, better sustaining trophy populations and fisheries.


2018 ◽  
Vol 204 ◽  
pp. 95-102 ◽  
Author(s):  
Greg G. Sass ◽  
Jereme W. Gaeta ◽  
Micheal S. Allen ◽  
Cory D. Suski ◽  
Stephanie L. Shaw

2020 ◽  
Vol 77 (3) ◽  
pp. 520-533
Author(s):  
Christopher J. Sullivan ◽  
Daniel A. Isermann ◽  
Kaitlin E. Whitlock ◽  
Jonathan F. Hansen

Climate-related changes in fish communities can present new challenges for fishery managers who must address declines in cool- and cold-water sportfish while dealing with increased abundance of warm-water sportfish. We used largemouth bass (Micropterus salmoides) in Wisconsin lakes as model populations to determine whether angler harvest provides a realistic method for reducing abundance of a popular warm-water sportfish that has become more prevalent and has prompted management concerns around the globe. Model results indicate largemouth bass will be resilient to increased fishing mortality. Furthermore, high rates of voluntary catch-and-release occurring in most largemouth bass fisheries likely preclude fishing mortality rates required to reduce bass abundance at meaningful levels (≥25% reductions). Increasing fishing mortality in these scenarios may require more “stimulus” than merely providing anglers with greater harvest opportunities via less stringent harvest regulations. Angler harvest could result in populations dominated by small fish, a scenario that may be undesirable to anglers, but could provide ecological benefits in certain situations.


2011 ◽  
Vol 68 (4) ◽  
pp. 693-705 ◽  
Author(s):  
Constance M. O’Connor ◽  
Kathleen M. Gilmour ◽  
Robert Arlinghaus ◽  
Shuichi Matsumura ◽  
Cory D. Suski ◽  
...  

In this study, we explored the growth, survival, and potential population-level effects of short-term experimentally induced stress in largemouth bass ( Micropterus salmoides ). Cortisol implants [50 mg·(kg body mass)–1] were used to increase circulating stress hormones in a group of wild fish in a research lake for ∼6 d in June 2007. Through mark-and-recapture, we compared survival, growth, and plasma biochemistry of cortisol-treated, sham-treated, and control fish at liberty until October 2007. Cortisol-treated fish displayed persistent growth rate depression compared with other groups. However, neither plasma biochemistry nor mortality rates differed among treatments. In a complementary study, we found that the standard metabolic rates (SMR) of cortisol-treated fish were higher than control fish ∼56 h following treatment. Bioenergetics modelling revealed that a transient elevation in SMR alone was insufficient to explain the observed growth depression. Finally, we constructed a simple population model to explore the potential consequences of growth depression. We found that a 10% reduction in population growth rate is conceivable when 39% of the population experiences a stress causing the growth rate depression documented in this study. Our study is novel in highlighting that individual and potentially population-level growth depression can result from a single stress event of short duration.


<em>Abstract.-</em>The Arkansas Game and Fish Commission’s Family and Community Fishing Program was developed in 2002 after a 3-year pilot study. The program’s goal is to enhance or create destinations in highly populated areas so that excellent fishing is available to all Arkansans. The program has grown from stocking catchable fishes in 10 locations in 2002 to 36 locations in 2007. In 2007, approximately 68,000 channel catfish <em>Ictalurus punctatus </em>and 65,000 rainbow trout <em>Oncorhynchus mykiss </em>were stocked in spring/summer and winter, respectively, in 22 cities. Channel catfish and rainbow trout were both stocked at approximately 200 fish per acre per month. Hybrid striped bass <em>Morone saxatilis </em>x <em>M. chrysops </em>were stocked at 50-100 fish per acre when fish became available. Trophy blue catfish <em>Ictalurus furcatus </em>from 15 to 60 lb were stocked on occasion to increase media attention and generate angler excitement at Program locations. Anglers were permitted to harvest three channel catfish, three hybrid striped bass, and five rainbow trout per day with no length restrictions. Largemouth bass <em>Micropterus salmoides </em>were catch and release only and the sunfish <em>Lepomis </em>spp. daily limit was 25. Ten fishing derbies and 14 fishing clinics were provided free to the public in 2007 to facilitate angler education and family participation. The Program has provided an opportunity for thousands of Arkansans to fish with friends and family in convenient locations.


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