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11.
Much of the knowledge about the wide-ranging finless porpoise species (Neophocaena phocaenoides) remains limited, as well as its phylogenetic relationship with another taxa (N. asiaeorientalis) in genus Neophocaena. Using 11 microsatellite loci, we first investigated population differentiation of N. phocaenoides within the Pearl River Estuary (PRE). We then used mtDNA control region (CR) and cytochrome b (cyt b) sequences from the PRE population (75) as well as those from other geographic populations to reveal the divergence level and phylogeny of the PRE N. phocaenoides. Pairwise F ST analysis with mtDNA CR sequences determined that the PRE population was highly differentiated from other putative populations (with the closest population 400-km away in the Taiwan Strait) (F ST = 0.388–0.764, p < 0.01). The level of genetic divergence between the PRE and its conspecific population was as high as comparisons between the two subspecies under N. asiaeorientalis (F ST = 0.361, p < 0.01). Our results also revealed contrasting demographic histories between the PRE and the other geographic finless porpoise populations (the Taiwan Strait population, the southern and northern Yellow Sea population and the middle Yangtze River population), which suggested stability in the warmer waters of the Indo-Pacific and expansions in the colder waters of the North Pacific. Phylogenetic trees created using cyt b data indicated that some haplotypes exclusive to the PRE population were basal to the rest of the genus. Based on these results, we argue that the genus Neophocaena originated in tropical waters (because the PRE is the most southern location sampled, i.e., the closest location to tropical waters).  相似文献   
12.
Harbor sediments containing large deposits of organotin compounds constitute a potential threat to the marine environment. Samples of harbor sediments were collected twice in the years 2003 and 2005 from the following locations: Zió?kowskiego, Siarkowe, Wi?lane, Weglowe, Chemików and Paliw P?ynnych Quays. The cores of 25cm length sliced into 2- and 5-cm segments were analyzed. After drying and homogenization, samples were split into two granulometric fractions, i.e. <2.00 and <0.063mm. The dominant fraction in whole sediment, i.e. fraction grain diameter <2.00mm, was sand (grain diameter 2.00-0.063mm). However, the highest concentrations of butyltin (BT) and phenyltin (PT) compounds were found in the fine sediment fraction. The mean values of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in the analyzed samples in the <2.00mm fraction were 2144.9, 434.7 and 148.1ngSng(-1)d.w., respectively, while the corresponding mean values in the <0.063mm fraction were 6556.4, 1593.7 and 450.0ngSng(-1)d.w. The mean concentrations of monophenyltin (MPhT) have been estimated at 29.0 and 49.9ngSng(-1)d.w. for the <2.00 and <0.063mm fraction sizes, respectively. The estimated content levels of diphenyltin (DPhT) and triphenyltin (TPhT) were in most cases below the detection limit of the applied method. The sediment cores collected from the locations characterized by high industrialization and intense exploitation (Wi?lane, Weglowe Quays) contained the highest concentrations of BT and PT.  相似文献   
13.
The investigations on spatial co-occurrence between Myodes (Clethrionomys) glareolus and Apodemus flavicollis conducted on Crabapple Island (NE Poland) in 1994 through 1999 reveal that: single mature females of both species often occur in the same places, whereas local groups of such females rarely cohabit the same place. Mature males of these species always avoid sites occupied by males of the other species. Immature males, however, seem to be mutually indifferent.  相似文献   
14.
Unilateral climate policy can be detrimental to global climate protection. Our objective is to provide insight into such a policy, to quantify the risk of carbon leakage, and to investigate the effects related to potential anti-leakage measures. We analyze existing definitions of carbon leakage and propose an alternative, rigorous one, which is different in three respects. The definition is then tested using computable general equilibrium analysis of the global economy and decomposition analysis. We identify a list of parameters that affect not only the magnitude but also the sign of the carbon leakage rate. Manipulating elasticities of substitution suggests that carbon leakage can be either positive or negative. Computable general equilibrium models, which are widely applied, including by the European Commission in this area, should be transparent, and their assumptions call for careful validation. We find that emission limits are properly distributed between sectors covered by the European Union Emissions Trading System and other sectors for the first commitment period (ended in 2012) but not for the second one (ending in 2020), where the target for the non-trading sectors should be reduced relative to the target for the trading sectors in order to equlize marginal abatement costs.  相似文献   
15.
Sediment samples were collected in two Polish ports of international significance--the Port of Gdańsk and the Port of Gdynia (Gulf of Gdańsk, Baltic Sea)--in order to assess their butyltin and phenyltin contamination; this was done in 2008, just after the total ban on using harmful organotins in antifouling paints on ships came into force. Altogether, 21 sampling stations were chosen to present a diversity of port sites: from port canals and shipyards to anchorages and dumping sites. The organic carbon content and grain size of all the sediment samples were determined, and some environmental parameters (oxygen content, salinity) were measured as well. Total concentrations of butyltin compounds in sediment samples were very different and ranged between 1 and 18,520 ng Sn g(-1) d.w. Phenyltin contents were distinctly lower and ranged from below the limit of detection (most samples) to 660 ng Sn g(-1) d.w. The highest concentrations of organotins were found in the shipyards, the maximum total organotin content (19,180 ng Sn g(-1) d.w.) being found in the Gdańsk Ship Repair Yard 'Remontowa'. Butyltin degradation indices indicate a recent tributyltin input into the port sediments. The results obtained from this work prove that the international ban on using organotins may not be enough to protect the marine environment. It is necessary to monitor organotin contamination in ports and establish concentration limits of these compounds for the disposal of dredged material at sea.  相似文献   
16.
Samples of small rodent populations inhabiting Crabapple Island on Beldany Lake in NE Poland revealed that Clethrionomys glareolus was continously present there, whereas Apodemus flavicollis and Microtus agrestis appeared, stayed for some period, vanished and reappeared. It appears that sexually mature females of the bank vole are strictly territorial, their numbers are limited, and immature individuals hardly disperse at high population size. Sexually mature females of the yellow-necked mouse seem to be territorial only at low population numbers, and their numbers increase linearly with population size. Sexually mature females of the field vole exhibit high level of aggregation, and their numbers increase in streight line with growing population size. We discuss the idea that different social organization of the rodent populations is connected with various strategies (sedentary and nomadic) supporting local population persistence.  相似文献   
17.
Recent studies on climate responses in ectothermic (cold-blooded) vertebrates have been few in number and focussed on phenology rather than morphology. According to Bergmann’s rule, endothermic (warm-blooded) vertebrates from cooler climates tend to be larger than congeners from warmer regions. Although amphibians are ectothermic vertebrates, weather and climatic conditions may also impact on their morphology, and thereby affect their survival rates and population dynamics. In this paper, we show, in a unique long-term study during the period 1963–2003 in an agricultural landscape in western Poland, that the body length of two water frog parental species (males of both Rana ridibunda and R. lessonae) increased significantly. However, their hybridogenetic hybrid R. esculenta did not show similar changes. A significant relationship with a large-scale climatic factor, the winter North Atlantic Oscillation index, was found positive for R. ridibunda males and R. lessonae females, and negative for R. esculenta females. Our findings, the first for amphibians, are consistent with other studies reporting that recent climate change has affected the morphology of animals. However, we also show that changes in amphibian phenotype linked to climate may vary independently between (even very similar) species.  相似文献   
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