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Hall N.G.,Murdoch University | Bartron C.,Murdoch University | White W.T.,Murdoch University | White W.T.,CSIRO | And 2 more authors.
Journal of Fish Biology

Biological data were recorded for 1265 silky sharks Carcharhinus falciformis collected from fish landing sites in eastern Indonesia. These represented catches taken in most calendar months by gillnetting and longlining in the eastern Indian Ocean and contained individuals ranging from embryos to fully mature adults. The growth zones in centra, which were shown to form annually, were counted in the vertebrae in a sub-sample of 200 fish for ageing purposes. The embryo lengths in the 5 months for which there were such data, and the presence of neonates in virtually all months, however, indicated that birth occurs throughout the year and thus there was no well-defined birth date for ageing individual fish. The approximate birth date of each individual was thus estimated from a combination of the total length (L T) at capture and backcalculated L T at the formation of the birth zone and at the first and last growth zones in the vertebral centra, together with the period that had elapsed between the formation of those last two growth zones. The number of eggs or embryos in uteri ranged from two to 14, with a mean of 7·2. The estimated mean L T at birth of females (811 mm, range: 799-823 mm) and males (812 mm, range: 794-830 mm), derived from the backcalculations corresponding to the birth zones in the centra, were not significantly different (P > 0·05). The L T ranges in the catches of post-natal females (570-2592 mm) and males (553-2289 mm) taken by gillnetting were wider than those of the females (1177-2623 mm) and males (1184-2409 mm) taken by longlining. The oldest female and male were 19 and 20 years-old, respectively. The von Bertalanffy growth curves for the two sexes did not differ significantly. The growth coefficient, k, and the asymptotic length, L T∞. were 0·066 year -1 and 2994 mm for the curve fitted to the combined data for females and males. The lengths L T50 and ages A 50 at which C. falciformis attained maturity were 2156 mm and 15 years for females and 2076 mm and 13 years for males. The very high proportion of C. falciformis with lengths Source

Prescott J.,Australian Fisheries Management Authority | Riwu J.,Office of Marine Affairs and Fisheries | Stacey N.,Charles Darwin University | Prasetyo A.,Agency for Marine and Fisheries Research and Development
Reviews in Fish Biology and Fisheries

Traditional fisheries stock assessment methods and fishery independent surveys are costly and time consuming exercises. However fishers trained in data collection and utilising other skills can reduce costs and improve fishery assessments and management. A data collection program was conducted by Australian and Indonesian scientists with small-scale Indonesian sea cucumber fishers to evaluate the approach and then capture its benefits. The data fishers recorded allowed for the first stock assessment of this trans-boundary fishery during its centuries-long existence at Scott Reef in north-western Australia. The program also included interviews with fishers capturing the social, economic, and demographic aspects of the fishery. Economic inputs to fishing were complemented by fishery revenue data voluntarily submitted when fishers returned to port and sold their catch. Catch data recorded by fishers demonstrated much higher abundances than estimates obtained using standard visual transect methods and accurately reflected the true catch composition. However, they also showed extreme rates of exploitation. Interviews revealed social and economic factors that would be important considerations if management interventions were made. The program’s approach and the time scientists spent on the fishers’ vessels were key ingredients to fishers’ participation and the utility of the results. Despite the program’s achievements the information generated has not led to improved management or had any direct benefits for the participants. Sustaining the program in the longer term requires that its value is better captured. © 2016 The Author(s) Source

Li J.,First Institute of Oceanography | Li J.,Key Laboratory of Marine Bioactive Substances | Sha Y.,First Institute of Oceanography | Sha Y.,Key Laboratory of Marine Bioactive Substances | And 5 more authors.
Journal of Microbiology and Biotechnology

An extracellular agarase was purified from Bacillus sp. BI-3, a thermophilic agar-degrading bacterium isolated from a hot spring in Indonesia. The purified agarase revealed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular mass of 58 kDa. The optimum pH and temperature of the agarase were 6.4 and 70°C, respectively. The activity of the agarase was stable at high temperatures, and more than 50% activity was retained at 80°C for 15 min. Furthermore, the enzyme was stable in the pH range of 5.8-8.0, and more than 60% of the residual activity was retained. Significant activation of the agarase was observed in the presence of K+, Na+, Ca2+, Mg2+, and Sr2+; on the other hand, Ba2+, Zn2+, Cu2+, Mn2+, Co2+, Fe2+, and EDTA inhibited or inactivated the enzyme activity. The components of the hydrolytic product analyzed by thin-layer chromatography showed that the agarase mainly produced neoagarobiose. This study is the first to present evidence of agarolytic activity in aerobic thermophilic bacteria. © 2014 by The Korean Society for Microbiology and Biotechnology. Source

Susanto R.D.,Lamont Doherty Earth Observatory | Wei Z.,State Oceanic Administration | Adi R.T.,Agency for Marine and Fisheries Research and Development | Fan B.,State Oceanic Administration | And 2 more authors.
Acta Oceanologica Sinica

In order to quantitatively estimate the volume and property transports between the South China Sea and Indonesian Seas via the Karimata Strait, two trawl-resistant bottom mounts, with ADCPs embedded, were deployed in the strait to measure the velocity profile as part of the South China Sea-Indonesian Seas transport/exchange (SITE) program. A pair of surface and bottom acoustic modems was employed to transfer the measured velocity without recovering the mooring. The advantage and problems of the instruments in this field work are reported and discussed. The field observations confirm the existence of the South China Sea branch of Indonesian throughflow via the Karimata Strait with a stronger southward flow in boreal winter and weaker southward bottom flow in boreal summer, beneath the upper layer northward (reversal) flow. The estimate of the averaged volume, heat and freshwater transports from December 2007 to March 2008 (winter) is (-2.7±1.1)×106 m3/s, (-0.30±0.11) PW, (-0.18±0.07)×106 m3/s and from May to September 2008 (summer) is (1.2±0.6)×10 6 m3/s, (0.14±0.03) PW, (0.12±0.04) ×106 m3/s and for the entire record from December 2007 to October 2008 is (-0.5±1.9)×106 m3/s, (-0.05±0.22) PW, (-0.01±0.15)×106 m3/s (negative/positive represents southward/northward transport), respectively. The existence of southward bottom flow in boreal summer implies that the downward sea surface slope from north to south as found by Fang et al. (2010) for winter is a year-round phenomenon. © 2013 The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg. Source

Li J.,First Institute of Oceanography | Hu Q.,Qingdao University of Science and Technology | Seswita-Zilda D.,Agency for Marine and Fisheries Research and Development
Biotechnology Letters

Purpose of work The purpose of this study is to report a thermostable λ-carrageenase that can degrade λ-carrageenan yielding neo-λ-carrabiose at 75 °C. A thermophilic strain Lc50-1 producing λ-carrageenase was isolated from a hot spring in Indonesia and identified as a Bacillus sp. The λ-carrageenase, Cga-L50, with an apparent molecular weight of 37 kDa and a specific activity of 105 U/mg was purified from the culture supernatant. The optimum pH and temperature of Cga-L50 were 8.0 and 75 °C, respectively. The enzyme was stable from pH 6-9 and retained ~50 % activity after holding at 85 °C for 10 min. Significant activation of Cga-L50 was observed with K+, Ca2+, Co2+, and Na+; whereas, the enzyme activity was inhibited by Sr2+, Mn2+, Fe2+, Cu2+,Cd2+, Mg2+, and EDTA. Cga-L50 is an endo-type λ-carrageenase that hydrolyzes β-1,4-linkages of λ-carrageenan, yielding neo-λ-carrabiose as the main product. This study is the first to present evidence of thermostable λ-carrageenase from hot spring bacteria. © 2014 Springer Science+Business Media Dordrecht. Source

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