Seasonal Movements of Coarse Fish in Lowland Rivers and their Relevance to Fisheries Management

Author(s):  
M.C. Lucas ◽  
T. Mercer ◽  
G. Peirson ◽  
P.A. Frear

<em>Abstract</em>.—At the extreme southern boundary of its range, the lake sturgeon <em>Acipenser fulvescens </em>was once an important biological component of the Coosa River system of Georgia–Alabama. During the 1970s, the population was extirpated by the combined effects of overfishing and degraded water quality. Over the past 20 years, water quality has improved, and in 2002, the Georgia Department of Natural Resources initiated a lake sturgeon reintroduction program with the goal of establishing a self-sustaining population within 20 years. From 2004 to 2007, we evaluated the initial phase of this reintroduction program by quantifying poststocking survival and seasonal habitat use of juvenile lake sturgeon in the Coosa River. We used gill nets and trammel nets to capture juveniles at several locations in both riverine and reservoir habitats. Fourteen individual juveniles were randomly selected for surgical implantation of radio tags to monitor their seasonal movements and habitat use. Over the 3 years of the study, we captured a total of 597 juvenile lake sturgeon measuring 231–790 mm total length. Using capture probabilities calculated from Program MARK (White and Burnham 1999), we estimated a total abundance of 789 (690–889, 95% confidence interval) juvenile lake sturgeon in 2006. Survival of each cohort from date stocked to summer 2006 varied from 1% to 14%, depending on year and size of fish stocked. Seasonal movements of juveniles varied; however, most fish occupied a relatively short reach in the lower river during summer months when water temperatures were more than 258C. At least 1% of fish stocked in each cohort have survived, and the population appears to be gradually increasing with each additional year of stocking. Further studies are needed to monitor annual recruitment and to evaluate reproductive success as first cohorts reach maturity.


Author(s):  
Jan-Michael Hessenauer ◽  
Cleyo Harris ◽  
Stephen Marklevitz ◽  
Matthew D. Faust ◽  
Michael W. Thorn ◽  
...  

2015 ◽  
Vol 538 ◽  
pp. 257-272 ◽  
Author(s):  
C Longo ◽  
S Hornborg ◽  
V Bartolino ◽  
MT Tomczak ◽  
L Ciannelli ◽  
...  

2017 ◽  
Vol 573 ◽  
pp. 203-213 ◽  
Author(s):  
BJ Lyon ◽  
RG Dwyer ◽  
RD Pillans ◽  
HA Campbell ◽  
CE Franklin

2015 ◽  
Vol 64 (2) ◽  
pp. 112-122 ◽  
Author(s):  
Pavel Jurajda ◽  
Zdeněk Adámek ◽  
Zdenka Valová ◽  
Michal Janáč ◽  
Kevin Roche

2008 ◽  
Vol 2 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jorge Iván Sánchez-Botero ◽  
Danielle Sequeira Garcez ◽  
Wesllen Chaves Cortezão

This study evaluates the total length of tambaqui (Colossoma macropomum ) captured in the middle Solimões river and traded during seven years (1993, 1997 and 2000 to 2005) in the Tefé market, Amazon, Brazil. The Mamirauá Institute of Sustainable Development obtained measurements of the total lengths from 42207 individuals. The length average was 45.23 ± 6.29 cm (minim um of 13 cm and maximum of 105.5 cm ) and the mode was 45 cm . From the total tambaquis, 92.86% were smaller than 55 cm and 7.14% measured 58.24 ± 5.41 cm on average. Medium and standard deviation of the lengths recorded in all years showed sizes below the established by the environmental federal agency. The Kruskal Wallis test showed that there is no significant difference between the abundances and medium sizes of the captures during all months of the year. The historical data of the tambaqui fisheries for the middle Solimões region indicate that individuals of this species have been constantly captured at sizes below the minim um length of reproduction. Nine recommendations for tambaquis fisheries management in the region related to more efficient mechanisms of inspection, auto-ecology studies of the species, environmental protection, reduction of fishery pressure, diffusion and educational cam paigns that aim to correct exploitation of this resource are presented in this manuscript.


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