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Effect of bis(tributyltin)oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia

Chinese Journal of Oceanology and Limnology 2010年第2期28卷 280-287页

作者：黄瑛朱丽岩邱旭春张天文 College of Marine Life Sciences Ocean University of China Department of Resource and Environment Research Center Chinese Academy of Fishery Sciences

A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis（tributyltin） oxide （TBTO）. The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L＂1 were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L-1. The percentages of ovigerous females were reduced compared with the control （P〈0.01） after 24 days exposure to concentrations higher than 10 ng TBTO L-1. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase （rm）, from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration （60 ng LI）, where all females aborted their egg sacs, 20 ng TBTO L-1 was the only concentration that significantly decreased rm compared with that of control （an effect associated with decreased sex ratio）. The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.

关键词： tributyltin reproduction population growth rate gonad Schmackeria poplesia toxicity testing

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Petroleum hydrocarbons and their effects on fishery species in the Bohai Sea, North China

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Journal of Environmental Sciences 2011年第4期23卷 553-559页

作者： Sisi Xu Jinming Song Huamao Yuan Xuegang Li Ning Li Liqin Duan Yu Yu Key Laboratory of Marine Ecology and Environmental Sciences Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Systematic studies on the changes in concentrations of petroleum hydrocarbons （PHs） and their effects on fishery species in the Bohai Sea during 1974–2004 are presented. Changes in PHs concentrations were closely related to Yellow River runoff. Concentrations of PHs accumulated in fish and shrimp increased by about 0.712 mg/kg dry weight when trophic level of fish and shrimps increased by 1. Attention should also be paid to the high PHs concentrations in mollusks along the coastal waters of the Bohai Sea. Average concentration of PHs in the adjacent coastal waters of Tianjin City during 1996–2005 decreased the population growth rates of fish, crustaceans and mollusks in the Bohai Sea by 2.58%, 6.59% and 2.33%, respectively. Therefore, PHs have significantly contributed to the decline in fisheries in the Bohai Sea, and they must be reduced to realize the sustainable fisheries.

关键词： petroleum hydrocarbons fishery resources population growth rate toxicity Bohai Sea

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Reducing the loss of genetic diversity associated with assisted colonization-like introductions of animals

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Current Zoology 2015年第5期61卷 827-834页

作者： Jaana KEKKONEN Jon E. BROMMER Department of Biosciences University of Helsinki Helsinki Finland Department of Biology University of Turku Turku Finland

Translocations, especially assisted colonizations, of animals are increasingly used as a conservation management tool. In many cases, however, limited funding and other logistic challenges limit the number of individuals available for transloeation. In conservation genetics, small populations are predicted to rapidly lose genetic diversity which can deteriorate population survival. Thus, how worried should we be about the loss of genetic diversity when introducing small, isolated populations？ Historical species introductions provide a means to assess these issues. Here we review 13 studies of ＂assisted colonization-like＂ introductions of animals, where only a small known number of founders established an isolated population without secondary contact to the source population. We test which factors could be important in retaining genetic diversity in these cases. In many cases, loss in heterozygosity （-12.1%） was detected, and more seriously the loss in allelic richness （-27.8 %）. Number of founders seemed to have an effect but it also indicated that high population growth rate could help to retain genetic diversity, i.e. future management actions could be effective even with a limited number of founders if population growth would be enhanced. On the contrary, translocated organisms with longer generation times did not seem to retain more genetic diversity. We advocate that, where possible, future studies on translocated animals should report the loss of genetic diversity （both heterozygosity and allelic richness）, which is essential for meta-analyses like this one for deepening our understanding of the genetic consequences of assisted colonization, and justifying management decisions [Current Zoology 61 （5）： 827-834, 2015].

关键词： Introduced species Loss of genetic diversity Number of founders Conservation management population growth rate Generation time

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近代中国的经济增长与收入分布

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经济史 2018年第1期 19-35页

作者：汪建雄

基于近代中国1776-1953年间6个时点的省、府两级人口和州府经纬度数据，通过混合回归、面板回归和空间面板回归，我们发现：人口密度越高的地区，人口增长率越低，且该模式在战乱时期比和平时期更显著；和平时期邻近地区的人口密度对本... 详细信息

基于近代中国1776-1953年间6个时点的省、府两级人口和州府经纬度数据，通过混合回归、面板回归和空间面板回归，我们发现：人口密度越高的地区，人口增长率越低，且该模式在战乱时期比和平时期更显著；和平时期邻近地区的人口密度对本地区人口增长率有正向影响，战乱时期则有负向影响。我们认为在和平时期，导致高人口密度地区出现低人口增长的高死亡率和高净人口迁出率，很可能源自这类地区有着较低的人均收入。而战乱时期的模式，还可能源于高人口密度地区居民更为积极地参与战乱，这同样源于这类地区有着较低的人均收入。故而，人口密度与人口增长率之间的实证结果，可作为工业化之前近代中国经济发达地区的居民收入水平更低的证据。

关键词：近代中国人口密度人口增长率居民收入 recent China population density population growth rate residential income

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