Managing Centrarchid Fisheries in Rivers and Streams

2019 ◽  
Author(s):  
Mike Reed ◽  
A.J. Pratt
Keyword(s):  
High Growth ◽  
Smallmouth Bass ◽  
Population Characteristics ◽  
Natural Mortality ◽  
Micropterus Dolomieu ◽  
Return Rates ◽  
Rate Functions ◽  
One Year ◽  
Mean Time ◽  
Mortality Estimates

<em>Abstract.</em>—Angler harvest and population characteristics of Smallmouth Bass <em> Micropterus dolomieu </em>were assessed through electrofishing surveys and tagging 3,027 fish with reward tags at six sites on five Ozark streams. Growth, exploitation, and mortality were estimated for each site. Predicted population responses to higher length limits were simulated using Fishery Analysis and Modeling Simulator software. Tag return rates ranged between 37% and 64%, angler release rates ranged between 63% and 94%, and annual exploitation ranged between 5% and 26%. The median time at-large for tags returned within one year of tagging ranged from 22 to 47 d of the tagging date. Growth rates were relatively slow, as mean time to reach 305 mm was 4.9 years and mean time to reach 381 mm was 7.8 years. Total annual mortality estimates ranged from 37% to 55%. Annual natural mortality estimates ranged from 13% to 33%. Predicted responses to higher length limits varied considerably by site because of differences in estimated rate functions. Although simulations predicted small increases (0.54–2.73 fish/100 recruits >381 mm) in the number of larger fish with the 381-mm length limit at five of six sites, predicted increases were substantial (17 fish/100 recruits >381 mm) and yield increased 6% at the Current River-Powder Mill site. Individuals in the Current River-Powder Mill site were not reaching their full growth potential due to growth overfishing, while simulations of the remaining five populations indicated no growth overfishing under current conditions and regulations. The combined effects of natural mortality and slow growth limited the effectiveness of higher length limits. Under most conditions, the statewide length limit of 305 mm was adequate to balance the desire of quality fishing and harvest opportunities on most Ozark streams. Our study indicates that fisheries at select stream reaches may be improved by higher length limits where exploitation is high, growth is adequate, and natural mortality is low.

Influence of errors in natural mortality estimates in cohort analysis

1997 ◽  
Vol 54 (7) ◽  
pp. 1608-1612 ◽  
Author(s):  
G Mertz ◽  
R A Myers
Keyword(s):  
Mortality Rate ◽  
Similar Pattern ◽  
Cohort Analysis ◽  
Transient Behavior ◽  
Natural Mortality ◽  
Exact Formulation ◽  
Fishing Mortality ◽  
Bias Factor ◽  
Special Case ◽  
Mortality Estimates

The accuracy of the estimation of cohort strength from catch data may be greatly degraded if a poor estimate of the natural mortality rate is entered into the calculation. A straightforward, exact formulation for the error in cohort reconstruction due to a misspecified natural mortality rate is presented. The special case of constant fishing mortality is particularly transparent, allowing the error to be segmented into easily interpreted terms. A change in the fishing mortality may result in a distinct hump in the transient behavior of the bias factor, rather than a simple monotonic adjustment. This implies a similar pattern in estimated cohort strength.

Impacts of road access on lake trout (Salvelinus namaycush) populations: regional scale effects of overexploitation and the introduction of smallmouth bass (Micropterus dolomieu)

2009 ◽  
Vol 66 (2) ◽  
pp. 212-223 ◽  
Author(s):  
Scott D. Kaufman ◽  
Ed Snucins ◽  
John M. Gunn ◽  
Wayne Selinger
Keyword(s):  
Lake Trout ◽  
Scale Effects ◽  
Regional Scale ◽  
Winter Season ◽  
Salvelinus Namaycush ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Excessive Pressure ◽  
Fishing Activity ◽  
Remote Lakes

In lake trout ( Salvelinus namaycush ) lakes of northeastern Ontario, Canada, aerial surveys of fishing activity on individual lakes (N = 589) and quantitative gillnet surveys (N = 65) were used to assess the effects of road access on angling effort and the presence of introduced smallmouth bass ( Micropterus dolomieu ). Angling effort, particularly during the open-water season, was highest and often exceeded estimated sustainable levels on lakes with good road access. Approximately 25% of the remote lakes also received excessive pressure during the winter season. Angler numerical responses to lake trout abundance were detected in remote lakes, but not in road-accessible lakes. Smallmouth bass were more prevalent in lakes with road access and human settlement (either cottages or lodges), supporting the theory that they were introduced into these lakes. Lake trout populations were depleted throughout much of the study range. Even without road access or smallmouth bass, lake trout abundance was still 47% lower than in unexploited reference lakes. When bass and (or) road access were present, lake trout abundance decreased by 77%. Remote lake trout populations in this area are clearly vulnerable to the negative impacts of improved access, a vector for both overexploitation and species introductions.

scholarly journals River Otter, Lontra canadensis, Food Habits in the Missouri Ozarks

2008 ◽  
Vol 122 (4) ◽  
pp. 303 ◽  
Author(s):  
Nathan M. Roberts ◽  
Charles F. Rabeni ◽  
John S. Stanovick ◽  
David A. Hamilton
Keyword(s):  
Smallmouth Bass ◽  
Lontra Canadensis ◽  
Micropterus Dolomieu ◽  
Widespread Occurrence ◽  
River Otters ◽  
Lepomis Megalotis ◽  
Rock Bass ◽  
Longear Sunfish ◽  
The Mean ◽  
Ambloplites Rupestris

The reintroduction of River Otters (Lontra canadensis) between 1982 and 1992 resulted in widespread occurrence of the species throughout the Missouri Ozarks. This study examined otter diets from the vicinity of two Ozark streams in relation to seasonal and spatial trends. Otter scats (N = 4750) were collected and analyzed from the Osage Fork River and Big Piney River during the summer and winter seasons of 2001 and 2002. During the winter (January-March), fish occurred in 86% of the samples. During the summer (June–August), occurrence of fish dropped to approximately 15% for both rivers. Seven families of fish were identified in the diets, with Centrarchidae being most common regardless of river or season. Within the Centrarchidae, the genus Lepomis (mostly Longear Sunfish, Lepomis megalotis) was most common, with Micropterus (mostly Smallmouth Bass, Micropterus dolomieu) and Rock Bass (Ambloplites rupestris) also well represented. The mean age of Ambloplites consumed (mean = 3.3 years) was consistently older than that of either Micropterus (mean = 2.54 years) or Lepomis (mean = 2.78 years). Crayfish were recovered from a mean of 85.2% of scats in the winter and 99% in the summer. Smaller fish and crayfish were more common from the upper reaches of the streams while larger fish were prevalent in the lower reaches.

Black Bass Diversity: Multidisciplinary Science for Conservation

2015 ◽  
Keyword(s):  
Population Dynamics ◽  
Management Strategies ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Spawning Period ◽  
Sampling Gear ◽  
Gray Literature ◽  
Black Bass ◽  
Effective Conservation ◽  
Conservation And Management

<em>Abstract</em>.—We reviewed the published and gray literature associated with Neosho Smallmouth Bass <em>Micropterus dolomieu velox</em> and the genetically distinct Ouachita lineage. Substantial interstream variation appears to occur among these populations, particularly related to age. The Neosho subspecies is more abundant, grows faster, and lives longer than the genetically distinct Ouachita lineage. Recruitment is highly variable among streams for both populations and appears to be related to some undescribed aspects of hydrology but also likely reflect bias due to sampling gear. Information on annual and seasonal trends is lacking for the Neosho subspecies and the Ouachita lineages, particularly as related to the spawning period. Conservation efforts for these lineages might benefit from agencies partnering to achieve goals that extend beyond a particular agency’s responsibilities and state boundaries. Recognition of spatial and temporal considerations, combined with a better understanding of the population dynamics as related to abundance, growth, mortality and reproduction, would benefit the creation of more effective conservation and management strategies for genetically distinct populations of Smallmouth Bass <em>M. dolomieu</em>.

scholarly journals Responses of the Black Bengal goat (Capra hircus) to PMSG and surgical embryo recovery within MOET technique

1970 ◽  
Vol 4 (2) ◽  
pp. 107-115 ◽  
Author(s):  
MO Faruk ◽  
FY Bari ◽  
M Shamsuddin ◽  
MGS Alam ◽  
MF Islam
Keyword(s):  
Dose Rate ◽  
Research Work ◽  
Capra Hircus ◽  
Corpora Lutea ◽  
Embryo Recovery ◽  
The Mean ◽  
One Year ◽  
Natural Service ◽  
Mean Time ◽  
Black Bengal Goat

The aim of the present study was to determine the responses of Black Bengal Goat following synchronization with alfaprostol, superovulation with PMSG and embryo collection with surgical procedure. This research work was carried out at the Department of Surgery and Obstetrics, Bangladesh Agricultural University (BAU) during the period from January to December 2001. Three Flushing schedules have been carried out in one-year time consisting of 5 donor and 4 recipients in Flush I, 2 donors and 4 recipients in Flush II, and 4 donors and 3 recipients in Flush III. The donors as well as the recipients were synchronized with Gabbrostim® (Alfaprostol, VETEM, Italy) at the dose rate of 2-mg equivalent to 1ml/goat. Among 11 donors only 6 donors responded following first injection, but all donor responded with second and third injection of Gabbrostim®. The mean time of onset of oestrus and duration of oestrus in donor were 29.9 ± 9.20h, 50.0 ± 5.94h, 47.8 ± 4.05h and 20.9 ±5.10h, 27.9 ± 1.19h, 29.4 ± 1.36h respectively. Among 11 recipient does, only 6 responded following first injection of Gabbrostim, while that of second injection was 9. The mean time of onset of oestrus and duration of oestrus were 28.6 ± 9.69h, 40.1 ± 8.95h and 17.1 ± 5.05h, 22.5 ± 3.45h respectively. All 9 recipients responded in third injection and the mean time of onset of oestrus and duration of oestrus were 39.9 ± 5.06h and 27.4 ± 1.32h respectively. In all flushing schedules, superovulation was performed using PMSG (Folligon®, Intervet International B.V, Holland) at the dose rate of 900 IU, 800 IU and 700 IU respectively. Both natural service and AI was performed to fertilise the ovum after onset of oestrus. The superovulatory response was determined by counting the number of corpora lutea (CL) during collection of embryos. The percent of superovulatory donor goats were 100, 50 and 25% respectively. The mean number of ovulation was 13.6 ±3.6, 10.5 ± 8.5 and 3.5 ± 3.2 respectively. The embryos were collected surgically by using 50 ml Phosphate buffer saline (PBS). The embryos were counted and graded under stereomicroscope. The embryo collection rates varied from 0-100%. The recovered embryos were of 100% fertile. The total number of embryos recovered was 4, 8 and 8 with the percent of recovery 6, 38 and 61.5% respectively. In Flush I among 4 recovered embryos, 3 were Grade 1 morula and the rest embryo was Grade 2 late morula. In Flush II among 8 recovered embryos, 7 were Grade 2 early morula and rest embryo was Grade 2 late morula. In Flush III among 8 recovered embryos, 5 were Grade 2 morula and rests 3 were Grade 2 late morula. Key words: Black Bengal goat, PMSG, embryo, MOET DOI = 10.3329/bjvm.v4i2.1293 Bangl. J. Vet. Med. (2006). 4 (2): 107-115

scholarly journals Effects of storms, angling, and nest predation during angling on smallmouth bass (Micropterus dolomieu) nest success

2005 ◽  
Vol 62 (11) ◽  
pp. 2649-2660 ◽  
Author(s):  
Geoffrey B Steinhart ◽  
Nancy J Leonard ◽  
Roy A Stein ◽  
Elizabeth A Marschall
Keyword(s):  
Nest Predation ◽  
Lake Erie ◽  
Nest Success ◽  
Nest Survival ◽  
Survival Rates ◽  
Round Goby ◽  
Smallmouth Bass ◽  
Micropterus Dolomieu ◽  
Daily Survival ◽  
Daily Nest Survival

We studied how storms, angling, and nest predation during angling affected smallmouth bass (Micropterus dolomieu) nest survival in the Bass Islands, Lake Erie, Ohio, USA. Increasing angler effort and introduction of an exotic nest predator, round goby (Neogobious melanostomus), have raised concerns about smallmouth bass recruitment in Lake Erie. We surveyed smallmouth bass nests and calculated daily survival rates for nests assigned to different angling treatments: control, angling without predation, or angling with predation treatments. Only 30% of control nests were successful compared with 11% of angling without predation and 14% of angling with predation treatments. We used the Mayfield method and maximum likelihood models in the program MARK to estimate the survival rates for nests of different treatments and exposed to different numbers of storms. Although nest predators consumed about 35% of broods during angling, daily nest survival rates of both angling treatments were similar. Angling reduced nest survival compared with controls by approximately 5%. Storms reduced both nest success and daily survival. The best model predicting daily nest survival included the added effects of angling treatment and number of storms. Thus, whereas storms and angling affected smallmouth bass nest survival, nest predation during angling did not.

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