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.

Age and growth of the dusky shark, Carcharhinus obscurus, in the western North Pacific Ocean was estimated based on 434 specimens (213 females and 256 males) collected between September 2002 and November 2003 at the Nanfanao fish market, in northeastern Taiwan. Sex-specific relationships between body weight (W) and total length (TL) were estimated as follows: W = 2.03 × 10-6 TL 3.216 (n = 209, p < 0.01) for females and W = 8.01 × 10-6 TL 2.957 (n = 294, p < 0.01) for males. The relationship between TL and the vertebral centrum radius (R) for both sexes ("sexes-combined" data) was described using the following equation TL = 14.74 + 20.31R (n = 399, p < 0.01). Growth band pairs (including translucent and opaque bands) in precaudal vertebrae were determined to form once annually, based on centrum edge analysis and verified by statistical analysis. The maximum number of growth band pairs was 29 for females and 24 for males. The Robertson growth function best fit the observed length-at-age data. Sex-specific growth equations were not significantly different; thus, the combined growth parameters for both sexes were estimated as: asymptotic length (L ∞) = 369.4 cm TL, b = 0.912, growth coefficient (k R) = 0.126 yr-1 (n = 385, p < 0.01). Age at maturity was estimated to be 16.6 yrs for females and 15.5 yrs for males.

Globally, the continental shelf occupies less than 10% of the total sea surface, but supports substantial primary production and fisheries. Photosynthetic picoeukaryotes (PPE) are important primary producers in marine ecosystems, and chlorophytes make a significant contribution to PPE abundance. Although the distribution of chlorophytes has been widely studied, little is known about how their community composition varies along the coastal-offshore gradient in subtropical continental shelf waters. To better understand their spatial variations, we employed metabarcoding data of 18S rRNA V4 gene to examine chlorophyte composition within the surface and deep chlorophyll maximum (DCM) layers over the continental shelf in the East China Sea (ECS) with high-resolution sampling. Our results indicate a higher chlorophyte diversity in the surface layer than in the DCM. In addition, we found that chlorophytes in oligotrophic Kuroshio surface water were the most diverse, with a higher percentage of Chloropicophyceae, prasinophyte clade V, prasinophyte clade IX, Palmophyllophyceae and Chlorodendrophyceae. In more eutrophic waters along the coast and within the DCM layer, chlorophytes were dominated by Mamiellophyceae. A significant spatial variation in community composition occurred along the nutrient gradient in the subtropical continental shelf ecosystem, varying from Mamiellophyceae-dominant in coastal water to Chloropicophyceae-dominant in offshore water. Furthermore, at a low saline coastal station, which had the lowest chlorophyte diversity, Picochlorum (Trebouxiophyceae) was dominant. Overall, chlorophyte diversity was positively correlated with temperature, and negatively correlated with silicate concentration. This study revealed that terrestrial input into continental systems influences chlorophyte diversity in the subtropical northwestern Pacific Ocean.

Cetacean and shark depredations in a small-scale longline fishery in the southeastern Taiwan waters were estimated based on interviews of 21 fishermen and logbooks of 12 sampling vessels, including 649 operations (681,310 hooks) from October 2009 to December 2010. Cetacean depredations were more serious than shark depredations, with damage rates of 19.26% and 11.56%, respectively. The depredation rates in number and weight from cetaceans were estimated to be 2.21% and 3.23%, respectively, and were significantly higher than those from sharks, which were estimated to be 0.51% and 0.47%, respectively. The depredation indices from cetacean and shark were estimated to be 0.93 and 0.22 per 1000 hooks, respectively. The dolphinfish and yellowfin tuna were the top two species depredated by cetaceans and sharks. The annual economic loss of the small-scale longline fishery due to cetacean and shark depredations was estimated to be USD 441.9 thousand and USD 58.8 thousand, respectively, which corresponded to 4.5% and 0.6% of the total sales of the longline fishery at Hsinkang fishing port, southeastern Taiwan. The catch in number of dolphinfish and the operation depth were significant factors that affected cetacean depredations.