Insights into the life history and ecology of a large shortfin mako shark Isurus oxyrinchus captured in southern California

2015 ◽  
Vol 87 (1) ◽  
pp. 200-211 ◽  
Author(s):  
K. Lyons ◽  
A. Preti ◽  
D. J. Madigan ◽  
R. J. D. Wells ◽  
M. E. Blasius ◽  
...  
2011 ◽  
Vol 62 (12) ◽  
pp. 1383 ◽  
Author(s):  
Wen-Pei Tsai ◽  
Chi-Lu Sun ◽  
Sheng-Ping Wang ◽  
Kwang-Ming Liu

Biological reference points (BRPs) are commonly used to assess the harvest level and stock status of marine fish populations. However, BRP estimates may be influenced by uncertainties about life-history parameters and fishing practices. The shortfin mako shark, Isurus oxyrinchus, is one of the most important by-catch species for tuna longline fisheries; however, its stock status remains poorly understood. To understand its population dynamics, the present study examined fishery statistics data and biological measurements of the shortfin mako in the north-western Pacific, and evaluated the impact of uncertainties associated with various sources of uncertainty, by using a simulation approach. The simulations indicated that BRPs are especially sensitive to changes in weight–length relationship and the growth parameters. Failure to take this into account may lead to inaccurate estimates and have serious consequences for management decision-making. To improve the accuracy of BRP estimates, biological measurements and life-history parameters should be updated regularly to account for changes in size composition and population structure. Further research could focus on increasing the sex-ratio sample size, updating the weight–length relationship and growth equations, incorporating ageing error into BRP calculations and determining BRPs by using appropriate levels of spawning-potential ratio.


1993 ◽  
Vol 44 (6) ◽  
pp. 901 ◽  
Author(s):  
DB Holts ◽  
DW Bedford

Recreational and commercial fishing effort directed at the shortfin mako shark, Isurus oxyrinchus, off the coast of southern California increased markedly in the mid 1980s. However, very little is known about the population size, stock structure or movements of these sharks in the northern Pacific. It is important to determine their role in these waters because the southern California bight may be an important pupping and nursery area for shortfin mako sharks. Acoustic telemetry was used to identify short-term horizontal and vertical movements of three shortfin mako sharks in the southern California bight during the summer of 1989. All three sharks were two-year-old juveniles and were tracked for periods of from 18 to 25 h. They spent 90% of their time in the mixed layer, with only infrequent excursions below the thermocline. Vertical and horizontal movements did not indicate any diel activity pattern associated with distance to the shore or nearby islands or with bottom topography.


2019 ◽  
Vol 16 (5) ◽  
pp. 965-965 ◽  
Author(s):  
Patricia Fernandez-Waid ◽  
Guzman Diez ◽  
Iñigo Bidaguren ◽  
Urtzi Izagirre ◽  
Jesus Maria Blanco ◽  
...  

2018 ◽  
Vol 59 (2) ◽  
pp. 237-243
Author(s):  
David Udovičić ◽  
Pero Ugarković ◽  
Frane Madiraca ◽  
Branko Dragičević

Eight individuals of the shortfin mako shark, Isurus oxyrinchus (Rafinesque, 1810) have been recorded in the period from 2014 to 2017 in the Adriatic Sea. The specimens presented in the paper were identified on the basis of photographic evidence. Occurrences of juvenile specimens suggests that Adriatic Sea could serve as a nursery area for this species, especially its eastern part. A review of the previously documented occurrences of this species in the Adriatic Sea is given in this article.


2013 ◽  
Vol 20 (6) ◽  
pp. 843-847 ◽  
Author(s):  
Pandian Ramesh ◽  
S. S. Sundaresan ◽  
Pon. Sathya Moorthy ◽  
M. Balasubramanian ◽  
M. N. Ponnuswamy

2003 ◽  
Vol 60 (6) ◽  
pp. 670-675 ◽  
Author(s):  
Aaron W Schrey ◽  
Edward J Heist

Microsatellite analysis of the shortfin mako shark (Isurus oxyrinchus) revealed very weak evidence of population structure. Samples collected from the North Atlantic, South Atlantic, North Pacific, South Pacific, and Atlantic, and Pacific coasts of South Africa were screened at four microsatellite loci. Multilocus measures of population subdivision were much lower than expected (FST = 0.0014, P = 0.1292; RST = 0.0029, P = 0.019). Power analysis revealed that the study had a high level of power (>0.995) to detect the magnitude of FST expected based on a previous study of mtDNA and assumptions of equal male and female dispersal. Thus, integrating the results from microsatellite- and mitochondrial-based studies may provide evidence for gender-biased dispersal for the shortfin mako.


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