Book reviews     

Robert N. Varney  Billy M. McCormac  C. A. Barlow  Roland E. Meyerott  Elmer Robinson  K. C. Pillai  Robert A. Ragotzkie  Ronald D. Kinsey  CLarence G. Golueke  John S. Gray  M. Benarie  Germund Tyler 《Water, air, and soil pollution》1976,5(3):367-382

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Recreational charter fishery attributes and variation in key species catches and discards: Resource management considerations          下载免费PDF全文

C. A. Gray  S. J. Kennelly 《Fisheries Management and Ecology》2017,24(5):403-415

Strategic long‐term sampling programmes that deliver recreational catch, effort and species demographic data are required for the effective assessment and management of recreational fisheries and harvested organisms. This study used a spatially and temporally stratified observer programme to examine variation in the rates, quantities and lengths of retained and discarded catches of key species in a recreational charter fishery. Geographic region, but not season, significantly influenced catch rates of key demersal species, being driven by temporally persistent latitudinal clines in environmental conditions influencing species distributions. There was considerable trip‐to‐trip variation in catch rates that were attributed to localised differences in fishing operations, locations, environmental conditions and client preferences. Broad trends in retained and discarded catch rates were nevertheless, similar across different fishing effort standardisations (per‐trip, per‐hour, per‐client, per‐client/fished hour), demonstrating that the coarsest unit of effort could be used in fishery assessments. Discard rates of organisms were variable and driven by a combination of mandated legal lengths, individual client and operator preferences for particular species and sizes of organisms, and not due to attainment of catch quotas or high‐grading. This study has identified important fishery attributes that require consideration in assessing charter fisheries and stocks of recreational fish species.  相似文献   

Age,growth, maturity and the overfishing of the iconic sciaenid,Argyrosomus japonicus,in south-eastern,Australia     

V. Silberschneider  C.A. Gray  J. Stewart 《Fisheries Research》2009,95(2-3):220-229

Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L₅₀ of 68 cm, whereas males matured at 2–3 years of age with a L₅₀ of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.  相似文献   

Endothall behavior in Myriophyllum spicatum and Hydrilla verticillata     

Mirella F Ortiz  Scott J Nissen  Cody J Gray 《Pest management science》2019,75(11):2942-2947

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Unanticipated departures from breeding designs can be detected using microsatellite DNA parentage analyses     

Andrew K. Gray  John J. Joyce  Alex C. Wertheimer 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):71-75

Using microsatellite analysis, a partial pedigree was constructed from an experiment designed to evaluate differences between hatchery Chinook salmon (Oncorhynchus tshawytscha) and their wild donor stocks. First generation (F₁) progeny were created by crossing both hatchery and wild females with hatchery and wild males to create hybrid and control lines. The pedigree analysis revealed an accidental switch of a half-sib control and hybrid F₁ family, which most likely occurred during incubation and led to the misclassification of individuals in those families. The experimental error propagated into the F₂ lines. The pedigree also revealed a number of unintended full-sib matings in the F₂ crosses. This resulted from the small numbers (5 females, 14 males) of wild fish available for the experiment and differential family survival of the F₁ fish. Because researchers used group-specific physical marks to track typed crosses and not family groups, and because physical marks cannot detect inadvertent movement of fish until they are large enough to mark, experimental error occurred that would have influenced the results had a DNA-based analysis not been employed to verify the integrity of the experiment.  相似文献   

Tributyrin‐supplemented high‐soya bean meal diets of juvenile black sea bream,Acanthopagrus schlegelii: Study on growth performance and intestinal morphology and structure     

Josie Ancella Volatiana  Lei Wang  Neveen Gray  Shengli Tong  Gangwei Zhang  Qingjun Shao 《Aquaculture Research》2020,51(1):135-146

An 8‐week growth trial was conducted to evaluate the effects of different levels of tributyrin supplementation in a high‐soya bean meal diet on juvenile black sea bream (11.30 ± 0.16 g). The positive control (PC) diet contained 45% fishmeal and 20% soya bean meal, while the negative control (NC) contained 12% fishmeal and 45% soya bean meal. Graded levels of tributyrin were added to the NC diet at 0.05% (TB 0.05), 0.1% (TB 0.1), 0.2% (TB 0.2), 0.4% (TB 0.4) and 0.8% (TB 0.8). Ultimately, the fish fed the PC diet had a higher weight gain and specific growth rate than the fish fed other diets. The fish fed the NC diet had the lowest growth, and TB 0.05–TB 0.2 diets increased growth performance while TB 0.4–TB 0.8 diets caused reduction in growth. Dietary tributyrin supplementation improved protease activity and enhanced antioxidant capacity. Compared with the fish fed the NC diet, the fish fed the tributyrin‐supplemented diets had improved gut morphology and structure, and the results were similar to those of the fish fed the PC diet. Furthermore, the analysis of the dose response with second‐order polynomial regression indicated that the optimum tributyrin supplementation for juvenile black sea bream is 2.24 g/kg in the 45% soya bean meal diet.  相似文献   

Pleistocene extinction of genyornis newtoni: human impact on australian megafauna     

GH Miller  JW Magee  BJ Johnson  ML Fogel  NA Spooner  MT McCulloch  LK Ayliffe 《Science (New York, N.Y.)》1999,283(5399):205-208

More than 85 percent of Australian terrestrial genera with a body mass exceeding 44 kilograms became extinct in the Late Pleistocene. Although most were marsupials, the list includes the large, flightless mihirung Genyornis newtoni. More than 700 dates onGenyornis eggshells from three different climate regions document the continuous presence of Genyornis from more than 100,000 years ago until their sudden disappearance 50,000 years ago, about the same time that humans arrived in Australia. Simultaneous extinction of Genyornis at all sites during an interval of modest climate change implies that human impact, not climate, was responsible.  相似文献   

Blood parameters of clinically normal captive bobcats (Felis rufus).     

D L Miller  B D Leopold  M J Gray  B J Woody 《Journal of zoo and wildlife medicine》1999,30(2):242-247

Data on blood parameters were obtained from 56 (32 female, 24 male) clinically healthy, captive bobcats (Felis rufus). The animals were housed under ambient conditions at the Mississippi State University Captive Bobcat Facility. Samples were collected opportunistically between 1982 and 1995. Differences (P < or = 0.05) in blood parameters existed between sexes, among age classes (kitten, subadult, adult, and geriatric), and among stages in the reproductive cycle (breeding, parturition, recycling, and anestrus). Blood parameters for bobcats were similar to reported values for domestic cats (Felis catus). These results can be used as as reference to indicate when blood parameter aberrations exist in bobcats.  相似文献   

Solubility,sorption and desorption of native and added cadmium in relation to properties of soils in New Zealand     

C. W. Gray  R. G. Mclaren  A. H. C. Roberts  L. M. Condron 《European Journal of Soil Science》1999,50(1):127-137

Solution cadmium (Cd) concentrations and sorption and desorption of native and added Cd were studied in a range of New Zealand soils. The concentration of Cd in solution and the concentrations and patterns of native soil Cd desorbed and added Cd sorbed and desorbed varied greatly between the 29 soils studied. Correlation analysis revealed that pH was the most dominant soil variable affecting solution Cd concentration and sorption and desorption of native and added Cd in these soils. However, organic matter, cation exchange capacity (CEC) and total soil Cd were also found to be important. Multiple regression analysis showed that the log concentration of Cd in solution was strongly related to soil pH, organic matter and total Cd, which in combination explained 76% of the variation between soils. When data from the present study were combined into a single multiple regression with soil data from a previously published study, the equation generated could explain 81% of the variation in log Cd solution concentration. This reinforces the importance of pH, organic matter and total Cd in controlling solution Cd concentrations. Simple linear regression analysis could at best explain 53% of the total variation in Cd sorption or desorption for the soils studied. Multiple regression analysis showed that native Cd desorption was related to pH, organic matter and total Cd, which in combination explained 85% of the variation between soils. For sorption of Cd (from 2 μg Cd g^–1 soil added), pH and organic matter in combination explained 75% of the variation between soils. However, for added Cd desorption (%), pH and CEC explained 77%. It is clear that the combined effects of a range of soil properties control the concentration of Cd in solution, and of sorption and desorption of Cd in soils. The fraction of potentially desorbable added Cd in soils could also be predicted from a soil’s K_d value. This could have value for assessing both the mobility of Cd in soil and its likely availability to plants.  相似文献   

Sparganosis in feral hogs (Sus scrofa) from Florida.     

M L Gray  F Rogers  S Little  M Puette  D Ambrose  E P Hoberg 《Journal of the American Veterinary Medical Association》1999,215(2):204-208

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