title: Estimating Finite Rate of Population Increase for Sharks Based on Vital Parameters.
abstract: The vital parameter data for 62 stocks, covering 38 species, collected from the literature, including parameters of age, growth, and reproduction, were log-transformed and analyzed using multivariate analyses. Three groups were identified and empirical equations were developed for each to describe the relationships between the predicted finite rates of population increase (λ') and the vital parameters, maximum age (Tmax), age at maturity (Tm), annual fecundity (f/Rc)), size at birth (Lb), size at maturity (Lm), and asymptotic length (L∞). Group (1) included species with slow growth rates (0.034 yr(-1) < k < 0.103 yr(-1)) and extended longevity (26 yr < Tmax < 81 yr), e.g., shortfin mako Isurus oxyrinchus, dusky shark Carcharhinus obscurus, etc.; Group (2) included species with fast growth rates (0.103 yr(-1) < k < 0.358 yr(-1)) and short longevity (9 yr < Tmax < 26 yr), e.g., starspotted smoothhound Mustelus manazo, gray smoothhound M. californicus, etc.; Group (3) included late maturing species (Lm/L∞ ≧ 0.75) with moderate longevity (Tmax < 29 yr), e.g., pelagic thresher Alopias pelagicus, sevengill shark Notorynchus cepedianus. The empirical equation for all data pooled was also developed. The λ' values estimated by these empirical equations showed good agreement with those calculated using conventional demographic analysis. The predictability was further validated by an independent data set of three species. The empirical equations developed in this study not only reduce the uncertainties in estimation but also account for the difference in life history among groups. This method therefore provides an efficient and effective approach to the implementation of precautionary shark management measures.
authors.affiliation: Institute of Marine Affairs and Resource Management, National Taiwan Ocean University, Keelung 202, Taiwan.|George Chen Shark Research Center, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 202, Taiwan.|Center of Excellence for the Oceans, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 202, Taiwan.
authors.forename: Kwang-Ming
authors.initials: KM
authors.lastname: Liu
authors.affiliation: Institute of Oceanography, Nation Taiwan University, Taipei 106, Taiwan.|Fisheries Research Institute, Council of Agriculture, 199, Heyi Road, Keelung 202, Taiwan.
authors.forename: Chien-Pang
authors.initials: CP
authors.lastname: Chin
authors.affiliation: Institute of Marine Affairs and Resource Management, National Taiwan Ocean University, Keelung 202, Taiwan.
authors.forename: Chun-Hui
authors.initials: CH
authors.lastname: Chen
authors.affiliation: School of Marine Sciences, University of Maine, Orono, Maine 04469, United States of America.
authors.forename: Jui-Han
authors.initials: JH
authors.lastname: Chang
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D016000:Cluster Analysis; D015999:Multivariate Analysis; D010802:Phylogeny; D011157:Population Dynamics; D012044:Regression Analysis; D012754:Sharks / Q000254:growth & development*; D013045:Species Specificity