A New Species of Platymantis (Anura: Ranidae) from Quaternary Deposits On Viti Levu, Fiji

Fossil bones of the frog Platymantis are reported for the first time. Platymantis megabotoniviti sp. nov. is described from fossil bones of late Quaternary age from caves on Viti Levu, Fiji, south-west Pacific, where it was associated with fossils of the extant P. vitianus P. vitiensis . The new species is much larger than any extant congeners, and its robust form indicates that it was a ground-dwelling frog. It appears to have become extinct in the late Holocene after humans arrived on Fiji with commensal rodents.     

Polyclad turbellarians collected on the Osaka University Expedition to Viti Levu,Fiji, in 1985, with remarks on distribution and phylogeny of the genus Discoplana

We report the first records from Viti Levu, Fiji, for four species of polyclad turbellarians: Discoplana gigas (Schmarda), Paraplanocera oligoglena (Schmarda), Cestoplana cuneata Sopott-Ehlers et Schmidt, and Pericelis byerleyana (Collingwood). D. gigas has the widest distribution in the Indo-West Pacific among the six described species of Discoplana, and shows a wider range of color variation than has been attributed to it before. Analysis of morphological features in these species reveals that Discoplana can be divided hierarchically into several sister-species groups based upon differences in structure of the vagina and of the penis. Four species, occurring mainly in the Pacific, share an apomorphic feature of the vagina, a feature not seen in the other two from the Indian Ocean. This suggests that Discoplana originated in the Indo-West Pacific.     

Discovery of a multispecies shark aggregation and parturition area in the Ba Estuary,Fiji Islands

Population declines in shark species have been reported on local and global scales, with overfishing, habitat destruction and climate change posing severe threats. The lack of species‐specific baseline data on ecology and distribution of many sharks, however, makes conservation measures challenging. Here, we present a fisheries‐independent shark survey from the Fiji Islands, where scientific knowledge on locally occurring elasmobranchs is largely still lacking despite the location's role as a shark hotspot in the Pacific. Juvenile shark abundance in the fishing grounds of the Ba Estuary (north‐western Viti Levu) was assessed with a gillnet‐ and longline‐based survey from December 2015 to April 2016. A total of 103 juvenile sharks identified as blacktip Carcharhinus limbatus (n = 57), scalloped hammerhead Sphyrna lewini (n = 35), and great hammerhead Sphyrna mokarran (n = 11) sharks were captured, tagged, and released. The condition of umbilical scars (68% open or semihealed), mean sizes of individuals (±SD) (C. limbatus: 66.5 ± 3.8 cm, S. lewini: 51.8 ± 4.8 cm, S. mokarran 77.4 ± 2.8 cm), and the presence of these species over recent years (based on fishermen interviews), suggest that the Ba Estuary area is a critical habitat for multiple species that are classified as “Near Threatened” or “Endangered.” Specifically, the area likely acts as a parturition ground over the studied period, and potentially as a subsequent nursery area. We identified subareas of high abundance and found that temperature, salinity and depth acted as small‐scale environmental drivers of shark abundance. The data suggests a tendency for species‐specific spatial use, both horizontally (i.e., between sampling areas) and vertically (i.e., across the water column). These results enhance the understanding of shark ecology in Fiji and provide a scientific basis for the implementation of local conservation strategies that contribute to the protection of these threatened species.     

Crustacea Decapoda of the Paripe River Estuary, Pernambuco, Brazil

The Paripe river estuary is located in Itamaracá Island, north coast of Pernambuco, northeastern Brazil. Its Crustacea Decapoda fauna was studied during several years. In the estuary there are mangroves, mud- and sandbanks, and tidal creeks. The fauna comprises a total of 64 species in 20 families. The coexistence of these species confirms the ecological importance of this small estuary, only 1.6 km long and 0.5 km wide. The ecology of each species in the estuary is presented.     

福建闽江河口湿地水禽群落组成及迁徙动态研究

2012—2015年在福建闽江河口湿地采用直接计数法开展了48次水禽调查,共记录水禽175 325只次,隶属7目14科91种。群落主要组成物种包括斑嘴鸭Anas poecilorhyncha、黑腹滨鹬Calidris alpina、三趾滨鹬Calidris alba、环颈鸻Charadrius alexandrinus和铁嘴沙鸻Charadrius leschenaultii等11种,常见种15种,偶见种31种。研究区域11月至翌年2月为越冬期,水禽数量最多,3—6月为春季迁徙期,水禽数量下降,4—9月为夏候鸟栖息期和繁殖期,7—9月部分候鸟和旅鸟开始迁徙过境,数量先升后降,10—11月冬候鸟快速增加,7—11月为秋季迁徙期。     

Length-weight relationships of 11 fish species from the Min River Estuary and its adjacent waters,Fujian Province,China

Length-weight relationships (LWRs) were estimated for 11 fish species from the Min River Estuary and its adjacent waters, Fujian Province, China. All samples were collected using gillnets (mesh size 45 mm) and bottom trawls (mesh sizes 45 mm at the main webbing and 25 mm at the cod end) seasonally in 2017 and 2018. The parameters for the LWRs were estimated, along with the basic Statistical analyses for total length and weight ranges as well as the 95% confidence intervals for the intercept (a) and the slope (b) of the regression lines. Further, the coefficient of correlation indicated that the LWRs were highly significant (all r² > .95, p < .001). This study provides the new maximum total lengths (TL_max) for Coilia grayii (33.0 cm), Johnius taiwanensis (20.9 cm), Johnius trewavasae (22.0 cm) and Cynoglossus sibogae (22.0 cm).     

黑龙江呼兰河口湿地自然保护区夏季鸟类群落结构及多样性

2011年至2013年每年的5—8月,采用样线法对黑龙江呼兰河口湿地自然保护区夏季鸟类的群落组成与结构进行了研究。野外调查共记录鸟类13目33科91种,其中国家重点保护鸟类11种。区内夏季鸟类以非雀形目鸟类居多,共有18科53种,占总种数的58%;雀形目鸟类15科38种,占总种数的42%。从居留型来看,保护区夏季鸟类群落中留鸟16种,夏候鸟75种。在地理区系构成上,保护区以古北界物种为主,共有47种,占总种数的51.6%,其次是广布种,共有41种,占45.1%,东洋界物种仅有3种。连续3年的多样性指数呈下降趋势,推测人为活动干扰增加与河口湿地公园建设可能是导致鸟类数量减少的最主要因素。     

福建漳江口红树林和盐沼湿地的多毛类动物群落

为了比较漳江口4种植物生境之间多毛类动物群落的差异性,2010年对漳江口潮间带秋茄、桐花树、白骨壤和互花米草4种植物生境的多毛类动物进行4个季度的定量取样.共获得15种多毛类动物,4个季度在4种植物生境中均出现三角洲双须虫、溪沙蚕、拟突齿沙蚕、凿贝才女虫、小头虫和加州中蚓虫.多毛类动物栖息密度、生物量、丰度指数、均匀度指数和多样性指数的季节变化不明显;但4种植物生境之间多毛类动物栖息密度、生物量、丰度指数、均匀度指数和多样性指数有显著差异,且互花米草生境与3种红树林生境之间多毛类动物优势种不同.Pearson相关分析表明,漳江口红树林和盐沼湿地除了多毛类物种数与泥温显著相关外,多毛类动物栖息密度、生物量、丰度指数、均匀度指数和多样性指数均与泥温、盐度、总有机碳、总氮无显著相关关系,其原因是漳江口4种植物生境多毛类动物常见种小头虫、加州中蚓虫和溪沙蚕均是广温、广盐及耐高有机质含量的种类.     

Pollution and tidal benthic communities of the James River Estuary,Virginia

Distribution of benthic communities in the estuarine portion of the James River was controlled mainly by salinity. Pollution effects were localized and difficult to assess because of a rigorous physical environment. Mesohaline and oligohaline communities were very similar to those in other estuaries of the eastern United States. Macrobenthic densities were most severely depressed in tidal freshwater habitats near Richmond & Hopewell, where the major portion of the pollution load enters the river. Cluster analysis of species distributional patterns and ordination of pollution and physical parameters produced similar results, dividing the river into mesohaline, oligohaline, and upper and lower tidal freshwater zones. Further analysis of only the tidal freshwater portion indicated the distribution of benthic communities reflected the location and concentration of pollution sources along the river. Tidal freshwater communities were dominated by the Asiatic clam, Corbicula fluminea, tubificid oligochaetes of the genus Limnodrilus and the chironomid insect larva Coelotanypus scapularis. The fauna of the freshwater zones was very eurytopic with respect to sediment type and has a great resemblance to the fauna of eutrophic lakes. The classical concept of a sharp increase in number of species occurring from oligohaline to freshwater zones was found to be misleading. This increase does not occur until free flowing (or lotic) freshwater areas of greater habitat diversity are reached.     

Distribution of Nitrogen-Fixing Microorganisms along the Neuse River Estuary,North Carolina

Nitrogen fixation genes (nifH) were amplified and sequenced from DNA extracted from surface water samples collected from six stations along the length of the Neuse River Estuary, North Carolina, in order to determine the distribution of nitrogen-fixing organisms in the transition from fresh-to saltwater. Nitrogenase genes were detected in all samples by a nested polymerase chain reaction method, and the amplification products from the upriver, midriver, and downriver stations were cloned, sequenced, and used for phylogenetic analysis. The composition of nifH clone libraries from upriver, midriver, and downriver stations (each composed of 14 randomly selected clones) were very diverse (samples from upriver and midriver stations were composed of 14 unique sequences, downriver station composed of 7 unique sequences) and differed among the stations. Some phylotypes were found at more than one station, but were usually found in the upriver and midriver stations or in the midriver and downriver stations, indicating that the phylotypes were probably transported along the river. Cyanobacterial nifH were not found at the most upriver site, but were a large fraction of sequences (50%) recovered from the downriver station, where nitrate concentration was an order of magnitude lower and salinity was higher. In contrast, γ proteobacteria nifH sequences were much more common at the midriver and upriver sites (58% and 64%, respectively), compared to the downriver site (14%). Results indicate that substantially different nitrogen-fixing assemblages are present along the river, reflecting differential watershed hydrological inputs, sedimentation, and environmental selection pressures, along the salinity gradient.     

Juvenile Salmon Usage of the Skeena River Estuary

Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2–8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that use the estuary, then numerous fisheries would also be negatively affected.     

Benthic phosphorus regeneration in the Potomac River Estuary

The flux of dissolved reactive phosphate from Potomac riverine and estuarine sediments is controlled by processes occurring at the water-sediment interface and within surficial sediment.In situ benthic fluxes (0.1 to 2.0 mmoles m⁻² day⁻¹) are generally five to ten times higher than calculated diffusive fluxes (0.020 to 0.30 mmoles m⁻² day⁻¹). The discrepancy between the two flux estimates is greatest in the transition zone (river mile 50 to 70) and is attributd to macrofaunal irrigation. Bothin situ and diffusive fluxes of dissolved reactive phosphate from Potomac tidal river sediments are low while those from anoxic lower estuarine sediments are high. The net accumulation rate of phosphorus in benthic sediment exhibits an inverse pattern. Thus a large fraction of phosphorus is retained by Potomac tidal river sediments, which contain a surficial oxidized layer and oligochaete worms tolerant of low oxygen conditions, and a large fraction of phosphorus is released from anoxic lower estuary sediments. Tidal river sediment pore waters are in equilibrium with amorphous Fe (OH)₃ while lower estuary pore waters are significantly undersaturated with respect to this phase. Benthic regeneration of dissolved reactive phosphorus is sufficient to supply all the phosphorus requirements for net primary production in the lower tidal river and transition-zone waters of the Potomac River Estuary. Benthic regeneration supplies approximately 25% as much phosphorus as inputs from sewage treatment plants and 10% of all phosphorus inputs to the tidal Potomac River. When all available point source phosphorus data are put into a steady-state conservation of mass model and reasonable coefficients for uptake of dissolved phosphorus, remineralization of particulate phosphorus, and sedimentation of particulate phosphorus are used in the model, a reasonably accurate simulation of dissolved and particulate phosphorus in the water column is obtained for the summer of 1980.     

珠江广州河段轮虫的时空分布研究

2004年4月-2007年3月,对珠江广州河段轮虫群落结构的时空变化进行了三年的调查研究。调查期间,共发现轮虫56种。优势种为裂痕龟纹轮虫(Anuraeopsis fissa),微型多突轮虫(Proalides subtilis),西式三肢轮虫(Filinia novaezealandiae),角突臂尾轮虫(Brachionus angularis),尾突臂尾轮虫(Brachionus caudatus),暗小异尾轮虫(Trichocerca pusilla),蛭态目(Bdelloidea sp.)和萼花臂尾轮虫(Brachionus calyciflorus)。调查发现,珠江径流量对轮虫密度有重要影响。在丰水期,两个采样站点(分别为中大码头和黄埔码头)的轮虫密度变化不大,而在枯水期,位于下游的黄埔码头的轮虫密度显著低于上游的中大码头。轮虫的密度高峰出现在秋季(9月底至12月初)。中大码头轮虫的最高峰出现在2004年12月初,为5975ind./L;黄埔码头的轮虫高峰出现在2004年4月中旬,为5877ind.·L^-1。轮虫密度变化范围为4~5975 ind.·L^-1。中大码头轮虫密度的平均值为1627±233 ind.·L^-1;而黄埔码头的平均值为1051±147 ind.·L^-1。     

Distribution patterns of the fish assemblage in the Mamanguape River Estuary,North-eastern Brazil

The Mamanguape River Estuary was studied along a continuum ranging from shallow sandstone reefs adjacent to the river mouth up to the limit of influence of seawater, the upper portions of the estuary. Fish samples were gathered using three types of nets along 17 sample sites, grouped in four regions according to salinity range (reefs and low, middle and upper estuaries), to seasonality (dry and rainy seasons) and to habitat usage (marine visitor, marine estuarine-opportunist, marine estuarine-dependent, estuarine resident and estuarine &; marine). Differences were found in the fish assemblages along the estuarine-reef gradient, with most species (n?=?30) being considered marine, estuarine-opportunists or estuarine-dependent, according to its abundance and distribution. A low number of species (n?=?11) were considered estuarine residents. Some species exhibited significant differences in spatial distribution pattern, in which juveniles and adults predominated in different portions of the estuary, suggesting an ontogenetic migration both in relation to the adjacent reef area and across estuarine regions. Several species were newly recorded in the Mamanguape Estuary: Anchoa spinifer, Halichoeres poeyi, Hyporhamphus roberti, Scomberomorus cavalla, Sphyraena barracuda and Ocgocephalus vesperilio.     

Phytoplankton and zooplankton of the Westport River Estuary,Massachusetts (USA)

Zooplankton and phytoplankton samples were simultaneously collected at approximately biweekly intervals over most of an annual cycle in the Westport River Estuary, Massachusetts. Phytoplankton numbers were overwhelmingly dominated throughout the study by athecate nanoplankton <5 µm in diameter. The zooplankton was primarily composed of copepod nauplii. Periods of occurrence of other zooplankters such as adult copepods, marine cladocerans, meroplankters and ctenophores were similar to those recorded for adjacent estuaries. Our results emphasize the abundance of smaller plankters that have been historically undersampled.     

Covariance Analysis of Chlorophyll Distribution in the Sundays River Estuary,Eastern Cape

Summary

An analysis of covariance performed on chlorophyll a distribution data from the Sundays River estuary identified five persistent water masses with significantly different chlorophyll a contents. These corresponded to different hydrodynamic regions within the estuary. The relationship between salinity and chlorophyll a was used to identify a transition zone between the low-salinity upper estuary and the brackish riverine inflow. Chlorophyll a concentrations ranged from <6 μg 1^?1 near the mouth to >100 μg 1^?1 in the middle and upper reaches. High variance of chlorophyll a data in this region was the result of temporal chlorophyll a fluctuations in two time scales. The first related to the daily ebb/tide and the second to the lunar spring/neap tidal cycle. Unlike its importance in larger and deeper estuaries, light played only a minor role in the horizontal distribution of chlorophyll a. The presence of a chlorophyll a maximum in the turbid low salinity region is explained in terms of the relatively constant photic depth/mixed depth ratio along the estuary and the high residence time of water in this region.     

金门浯江溪口鸟类的多样性

在福建省金门岛西岸的滨海滩地浯江溪口进行了为期2年的调查,采用每月2次的定点调查,获得鸟类30科105种的记录,2000年为27科89种5514只;2001年为28科84种9079只,两年种类和数量起伏月变动曲线都有2个高峰,一是在春季,另一是在秋季,虽两年高峰点有前后之差,但曲线的模式,基本上是一致的,滩地的冬候鸟和旅鸟最为显著,优势种包括普通鸬鹚（Phalacrocorax carbo),环颈Xing（Charadrius alexandrinus),白腰杓鹬（Numenius arquata),中杓鹬（Numenius phaeopus),翻石鹬（Arenaria interpres),黑腹滨鹬（Calidris alpina)等,物种多样性指数均以春季最高,秋季次之,夏季最为贫瘠。     

长江口九段沙潮间带底栖动物的功能群

采用<全国海岸带和海涂资源综合调查简明规程>(1986)中"岸带生物调查方法",于2001年5月～2002年10月对长江口九段沙(上沙、中沙和下沙)潮间带4个潮区底栖动物做了调查.根据食性类型将底栖动物划分为浮游生物食者(Pl)、植食者(Ph)、肉食者(C)、杂食者(O)和碎屑食者(D)5个功能群;用经典的多样性特征指数对其测度和分析.共获底栖动物38种,其中甲壳动物20种,软体动物12种,多毛类4种,其他2种.各功能群数量占总数的百分比依次是Ph>Pl>O>D>C,而种类占全部种类的百分比依次又是Ph>O>Pl>C>D.功能群的物种多样性指数和种类丰度:中沙>上沙>下沙,中潮区>高潮区A(芦苇)和低潮区>高潮区B(互花米草).但功能群种类组成,上、中、下沙无显著差异,各潮区有显著差异.证实了底栖动物功能群结构是潮间带生境梯度及环境因子变化的综合反映(Engle ＆ Summers,1999).     

Phytoplankton uptake of ammonium, nitrate and urea in the Neuse River Estuary, NC, USA

Uptake rates of ammonium, nitrate and urea were measured during the spring, summer and autumn (2001) in the eutrophic, nitrogen (N) limited Neuse River Estuary (NRE), North Carolina, USA. Ammonium was the dominant form of N taken up during the study, contributing approximately half of the total measured N uptake throughout the estuary. Nitrate uptake declined significantly with distance downstream comprising 33% of the total uptake in the upper estuary but only 11 and 16% in the middle and lower estuary, respectively. Urea uptake contributed least to the total pool in the upper estuary (16%), but increased in importance in the middle and lower estuary, comprising 45 and 37% of the total N taken up, respectively. The importance of regenerated N for fuelling phytoplankton productivity in the mesohaline sections of the NRE is demonstrated. The contribution of urea to the regenerated N pool suggests that internal regeneration of dissolved organic N may support a large proportion of the phytoplankton primary production and biomass accumulation in the middle and lower NRE. These results suggest that N-budgets based on dissolved inorganic N uptake rates alone will seriously under estimate phytoplankton N uptake.     

Distribution and activity of bacteria in the headwaters of the Rhode River Estuary,Maryland, USA

A transect along the axis of the headwaters of a tidal estuary was sampled for microbial, nutrient, and physical parameters. Chlorophylla averaged 42g 1^–1 and phytoplankton comprised an estimated 80% of the total microbial biomass as determined by adenosine triphosphate (ATP). Bacterial concentrations ranged from 0.3–53.9×10⁶ cells ml^–1 and comprised about 4% of the total living microbial biomass. Bacterial production, determined by³H-methyl-thymidine incorporation was about 0.05–2.09× 10⁹ cells 1^–1 h^–1, with specific growth rates of 0.26–1.69 d^–1. Most bacterial production was retained on 0.2m pore size filters, but passed through 1.0m filters. Significant positive correlations were found between all biomass measures and most nutrient measures with the exception of dissolved inorganic nitrogen nutrients where correlations were negative. Seasonal variability was evident in all parameters and variability among the stations was evident in most. The results suggest that bacterial production requires a significant carbon input, likely derived from autotrophic production, and that microbial trophic interactions are important.