Motivations of Fur Trappers in Interior Alaska

Understanding how and why trapping effort varies among fur trappers is necessary to accurately interpret trends in fur harvest for wildlife management. We mailed questionnaires to 1,760 fur trappers in interior Alaska to characterize motivations for trapping and primary factors affecting trapping effort. A cluster analysis revealed four groups with distinct motivations for trapping: wildlife management (17% of trappers), recreation (39%), subsistence (18%), and solitude (26%) trappers. Perceived furbearer abundance had the greatest effect on trapping effort, while access to land and human conflicts were the most important social issues to trappers. Economic gain was the least important motivation for trapping among respondents. Because trapping effort mirrored furbearer abundance, harvest-based abundance indices may amplify true changes in population sizes. Our findings also suggested that managers seeking to maintain or increase satisfaction among trappers should focus on reducing human conflicts and maximizing the non-monetary benefits of trapping.     

The relationship between fishing methods, fisheries management and the estimation of maximum sustainable yield

The allocation of effort among fishing gears is as important as controlling effort with respect to both sustainable yield and ecosystem management. Differences in age‐specific vulnerability to the fishing method can modify the maximum sustainable yield (MSY) that is obtainable from a fish stock. Different gears or methods are more or less selective for the species targeted, and MSY is rarely, if ever, attainable simultaneously for all species. The different fishing methods capture different types of nontarget species. Some methods will often be more profitable than others, and different user groups will prefer different methods. In many fisheries, it is unlikely that fishing can be limited to a single gear or method, so compromises among them will be required. Global MSY is discussed as a possible reference point for fisheries management. The yellowfin tuna fishery in the eastern Pacific Ocean (EPO) shows all the above characteristics and is used to illustrate effort allocation among fishing methods.     

蚊子湖及淖尔特湖卤虫资源量的研究

本研究了蚊子湖及淖尔特湖卤虫及卤虫卵的资源状况，提出捕捞时应注意的事项，为合理有效地开发利用当地的卤虫资源．避免酷捕滥捞，使其能持续稳定地发展提供了科学依据。     

Diel patterns in the feeding and habitat use of O-group fishes in a regulated river: the River Great Ouse, England

Feeding and habitat use behaviour of juvenile O+ fishes, principally Rutilus rutilus (L.) and Leuciscus cephalus (L.) was analysed at 4-h intervals for a period of 24 h on 29 June, 27 July, and 13 September 1994 at a regulated site on the River Great Ouse, UK. Twenty-five random point samples were taken by electrofishing during each sampling period from a 250 m reach of the river. Catch per unit effort decreased at night for both R. rutilus and L. cephalus. The number of prey items in the gut and the number of taxa found also decreased at night except for R. rutilus on one occassion. Habitat use remained near constant, with only slight increases in depth and distance from the bank at night. Use of Nuphar lutea by roach increased at night. Chub tended to avoid Nuphar lutea and were positively associated with emergent macrophyte and algal cover both during the day and night.     

Use of individual types of fishing effort in analyzing catch and effort data by use of a generalized linear model

Fishing effort is a function of many (continuous) variables which fishers can manipulate. However, when catch and fishing effort data are analysed using a generalized linear model, individual types of fishing effort usually enter as a composite quantity. But not all quantities can be combined into a composite quantity. Use of such data this way generally leads to a loss of information and incurs a model bias. In this paper, I analyse catch and effort data for the blue swimmer crab off South Australia by a direct use of individual types of fishing effort to extract a relative index of biomass, and use the concept of homogeneous functions to present some of the results. I also give formulae for choosing a combination of different types of fishing effort to effect a specified level of catch in both absolute and relative terms. Assuming that catch follows an independent gamma, normal, negative binomial, or Poisson distribution, fitting of a generalized linear model with a log-link function to the commercial catch and effort data suggests that: (1) the exploitable biomass remained relatively constant from 1 July 1983 to 30 June 1996; (2) the relative instantaneous rate of fishing mortality of a particular sex and age (if gear selectivity was constant over time) slightly increased over time; (3) a 1% increase in the number of days fished gave about 0.85% increase in catch whereas a 1% increase in the number of people on a boat led to only about a 0.45% increase in catch. This implies that use of a composite measure of fishing effort such as boat days and man days when analysing catch and effort data is inappropriate for this fishery. Although a generalized linear model may be a reasonable first-order approximation, catch and effort data are best interpreted through a process model.     

渔具材料专业标准体系现状与发展对策

本文介绍了我国渔具材料专业标准体系的研究现状及存在问题，就标准体系表的研究过程、组成、结构和层次，以及今后工作等作了简要分析和探讨。为进一步发展我国渔具材料标准体系，在采用国际和国外先进标准，加大经费投入力度，加快已落实项目的工作进度，加强产品标准与方法标准的衔接，加大标准的宣传、贯彻和监督力度，以及加强同标准化各主管部门的联系等方面提出了合理化建议。     

广东建设社会主义新农村着力点探讨

建设广东社会主义新农村是一个惠及广东4000多万农民的系统工程。建设的着力点是科学地利用广东优越的自然资源、充足的财力、产业梯度转移区位优势和农业产业化经营的典型范式;充分发挥各级党委、政府的主导作用,千方百计调动建设主体——广大农民群众的积极性和主动性;选优配强“两委”班子,形成民主管理新机制;积极创建和培育农民专业合作经济组织,大力发展农业产业化经营;统筹区域、城乡发展规划,实现产业梯度转移等。     

广东建设社会主义新农村着力点探讨

建设广东社会主义新农村是一个惠及广东4000多万农民的系统工程。建设的着力点是科学地利用广东优越的自然资源、充足的财力、产业梯度转移区位优势和农业产业化经营的典型范式;充分发挥各级党委、政府的主导作用,千方百计调动建设主体——广大农民群众的积极性和主动性;选优配强“两委”班子,形成民主管理新机制;积极创建和培育农民专业合作经济组织,大力发展农业产业化经营;统筹区域、城乡发展规划,实现产业梯度转移等。     

The effects of short intensive exercise on plasma free amino acids in standardbred trotters

The aim of this study was to investigate the effect of short intense exercise on plasma amino acid concentrations in trotters and to test the repeatability of plasma amino acids concentration in samples obtained on two independent days under field conditions. Plasma amino acid concentrations were analysed in blood samples of 36 standardbred trotters before and after intense exercise over a distance of 2000 m. Sampling was repeated in 20 horses after 35 days. Exercise intensity was estimated from post‐exercise lactate levels. Horses were divided in two groups according to a cut‐off lactate concentration at 15 mmol/l. The plasma concentrations of alanine, aspartate, glutamate, isoleucine, leucine, lysine and taurine increased and arginine, asparagine, citrulline, glutamine, glycine, histidine, methionine, serine, tryptophan and 3‐methylhistidine decreased after exercise. Ornithine, threonine, tyrosine, phenylalanine and valine concentrations remained constant. Higher intensity of exercise significantly decreased tryptophan and increased taurine concentrations. Sampling day had a significant effect on the absolute pre‐ and post‐exercise amino acid concentrations. Exercise had a significant influence on the concentrations of most plasma amino acids in trotters. These changes could reflect shifts between the free amino acid compartments, but there were also some indications for muscle catabolism. The amino acid supply of sporting horses could be of specific significance for maintaining muscle integrity and for the improvement of post‐exercise recovery of competition horses.     

阿根廷滑柔鱼（Illex argentinus）适宜栖息地模型比较及其在渔场预报中的应用

根据2003–2007年1–5月西南大西洋阿根廷滑柔鱼生产统计数据以及表温(SST)、海面高度(SSH)等海洋遥感数据,以作业次数为基础采用外包络法建立SST、SSH的适应性指数模型。分别采用算术平均法(AMM)和几何平均法(GMM)建立栖息地指数(HSI)模型,并对2003–2007年1–5月的HSI值与实际产量和作业次数作比较。研究结果显示,AMM和GMM均拟合较好,HSI>0.6时,AMM的产量和作业次数比例分别为86.75%和89.82%;GMM的产量和作业次数比例分别为84.30%和85.80%,AMM稍优于GMM。利用2008年1–5月的阿根廷滑柔鱼生产数据进行实证分析,结果显示,作业渔场主要分布在HIS>0.6的海域,其产量占总产量的64%以上,作业次数占总作业次数的68%以上;基于SST和SSH的AMM 栖息地指数模型可用于阿根廷滑柔鱼中心渔场的实时动态预报,为该资源的高效开发提供科学依据。