Nitrous oxide concentration and nitrification and denitrification in Zhujiang River Estuary, China

1 Introduction Estuaries have been subject to intense anthro- pogenic influences over recent decades by inputs of ni- trogen as a consequence of fertilizer usage and sewage/waste input (Howarth et al., 1996). Thus, the capacity of an estuary to buffer or alleviate additional nutrients is of importance in modifying the load of ni- trogen in the marine ecosystem. The role of microor- ganisms in regulating fluxes of nitrogen from land to sea through estuaries has received increased attention (Ni…     

Phosphorus and nitrate run‐off in hill pasture and forest catchments,Taita, New Zealand

Abstract

Phosphorus and nitrogen were measured in stream run‐off from the four catchments of the Taita Experimental Basin (41° 11′ S, 174° 58′ E). The land is used as exotic conifer forest, native forest, and hill pasture. Multiple regression analysis was used to estimate chemical losses per unit area in floods and at low flows.

At low flows, the hill pasture (fertilised with lime at 630 kg·ba^?1·y^?1, and superphosphate at 380 kg·ha^?1·y^?1) tended to lose more phosphorus and nitrate than the forested land, but differences were small, and not always significant. During large floods, the hill pasture (No. 5 Catchment) lost about 3 times as much reactive phosphate and 2–5 times as much total phosphorus as the forested land, and 130–190 times as much nitrate as land in the Exotic Forest and Native Forest 2 Catchments. Nitrate losses from land in the No. 4 Catchment (mainly native forest) were as high as those from the hill pasture, so high nitrate loss is not associated solely with agriculture.

Losses of total phosphorus via the catchment streams were estimated as: No. 5 Catchment (hill pasture), 293 g·ha^?1·y^?1; Native Forest 2 Catchment, 201 g·ha^?1·y^?1; No. 4 Catchment, 124 g·ha^?1·y^?1; Exotic Forest Catchment, 71 g·ha^?1.y^?1. Nitrate‐N losses were estimated to have been 1356 g·ha^?1·y^?1, 11.5 g·ha^?1·y^?1, 1436 g·ha^?1·y^?1, and 44 g·ha^?1·y^?1 respectively. Phosphorus and nitrate concentrations were similar in the Exotic Forest and Native Forest 2 streams, but the Exotic Forest tended to lose smaller amounts because it yielded about 50% less water per unit area.

Over the 2‐y study, an estimated 47–70% of phosphorus losses and up to 83% nitrate losses occurred in large floods; 31% and 48% respectively were apparently lost from the hill pasture catchment in a single flood. Less than 20% of estimated phosphorus losses and as little as 1% of nitrate losses occurred at low flows.

Run‐off of phosphorus and nitrate was spasmodic, and this should be considered in assessing the impact of surface run‐off on the biology and chemistry of receiving waters.     

Species Diversity and Abundance Distribution of Pelagic Siphonophores in Nan Wan Bay of Taiwan, China, in Late Autumn and Early Winter

Zooplankton surveys were carried out on November 2-3 and December 8-10, 2001 at 12 stations in the Nan Wan Bay of Taiwan, China. Altogether 92 quantitative zooplankton samples were collected from subsurface water and bottom water layers with two conical plankton nets （180 cm in length, 45 cm in opening diameter, 333μm and 200 larn in mesh size）. A total of 31 species of Siphonophores were identified, among them 7 species are new records in the waters around Taiwan Island, of which Rocacea cymbiformis is a new record in China. Dominated by Chelophyes appendiculata, Bassia bassensis, Diphyes bojani, Diphyes dispar, Abylopsis eschscholtzi and Chelophyes contorta, these species accounted for over 76 % and 63 % of the total abundance in November and December. The species number and Siphonophores abundance in December （25 species, 1.99 inds/m3） were more than those in November （19 species, 0.438 inds/m3）, and they were more in the surface water layer than in the bottom layer at most sampling stations. In early winter, the offshore high salinity water mass was a main factor influencing the distribution. The sampling efficiency for two plankton nets is discussed and the seasonal variation of species number and abundance in the Nan Wan Bay is compared with that in the neighboring waters.     

Relationships between chlorophyll a, bacteria, ATP, POC and respiration rates in the Changjiang Estuary and the plume

Bacteria abundance, chlorophyll a, ATP and POC concentrations and respiration rates of microorganisms in the Changjiang Estuary and the plume were determined in July 1986. The high values of bacteria abundance occurred in the river mouth in association with suspended matter. It is assumed that bacteria were the major contributor to ATP and the main consumer of dissolved oxygen, and that the relationship between ATP and POC was present in that area. In the dilution zone (salinity; 25-30), instead of bacteria, phytoplankton was the major contributor to ATP and respiration rates, due to diatom bloom. Close relationships between Chi a and ATP, and ATP and POC were observed. Contribution of microbial carbon to POC was also estimated.     

‘All in’: Snow crab,capitalization, and the future of small-scale fisheries in Newfoundland

The collapse of cod stocks off the coast of Newfoundland and Labrador in the early 1990s has been widely identified as one of the greatest human-ecological catastrophes of the 20th century. In the aftermath of the crisis, heated debates took place about how the fishery should be structured in the future in order to facilitate the recovery of stocks and sustain coastal livelihoods. In the end, the trade union representing fishers and fish processing plant workers in the province proved successful in resisting pressures from fish processing companies to introduce full-scale privatization. It was also able to expand access to the lucrative snow crab fishery, thereby improving incomes for most remaining independent fishers in the province. Nevertheless, this paper argues that policy changes made shortly after cod moratorium, in combination with changing environmental, demographic, and market conditions, have created a situation which now threatens to undermine the capacity for small-scale fishing enterprises to remain independently owned and operated into the future.     

Vertical Variability of Primary Production and Features of the Subsurface Chlorophyll Maximum in the Laptev Sea in August–September, 2015, 2017, and 2018

Oceanology - The vertical distribution of phytoplankton primary production (PP) and chlorophyll a (Chl) was studied based on the data carried out in August–September 2015, 2017, and 2018. The...     

Present state,basic theories, methods and progresses of investigation and assessment on marine hazardous geology in China

The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China. The importance, research value and presentday studies of marine hazardous geology, a newly developing branch of geoscience, are well expatiated.Several often confused concepts and theories are explained and redefined here. The comment on the means of investigations, assessment of marine hazardous geology, as well as its evolution, innovation,existing questions and future tasks are also introduced and presented. The concepts of “hazard geology“,“geohazard“, “map of marine hazard geology“, “integrated evaluaton on seafloor stablity“ are respectively discussed, including their definition, research objects, methods and contents. The types and classification of marine hazardous geology, principles and methods of marine hazardous geology map compilation, the assessment methods and models of marine hazardous geology environment and seafloor stability and so on are also discussed.     

Abundance and biomass of heterotrophic microbes in the Kongsfjorden, Svalbard

1Introduction Heterotrophicmicrobesarenowconsideredtobe significantcomponentsofthestructureandfunctionof marinepelagicecosystems.Heterotrophicbacteriacon- stituteamajorpoolofbiomassinopenecosystem (WilhelmandSuttle,1999).Theyconsumealargepor- tionofprimaryproduction(Li,1998;Sherryetal., 2002;Lietal.,2004),andtheymineralizemostofthe dissolvedorganiccarbonthattheyconsume(Azamet al.,1983;Richetal.,1997;Azam,1998).Therolesof planktonicprotists,suchasheterotrophicflagellates andciliates,inmicro…     

Distribution of moretene, sterere, fernene, hopene and dienoic carboxylic acid in marine sediments in sea area of the Southern Ocean

The soluble organic matters were extracted from marine sediments in the sea area of Southern Ocean by using organic solvents. The hydrocarbon and carboxylic acid fractions were separated with the thin layer chromatography. The organic compounds of 170(H), 21α(H)- bishomomoretene, cholest - 5 - ene, 24 - methyl - cholestene, 24 - ethylcholestene, hop-17(21)-ene, neohop - 13(18)-ene, fern-8-ene, fern-7-ene, 170(H), 210 (H) - hop - 22(29)-ene (diplotene), steranes, β, β-hopanes C29 -C31 and unsaturated carboxylic acids C18:2Δ9.12 , C18:1Δ9,C18:1Δ11 , have been identi-fied in the hydrocarbon and carboxylic acid fractions by means of gas chromatography and gas chromatography - mass spec-trometry - data system. The distributions of 3, a - bishomomoretene, β,β- hopene and β,β- hopane are characteristic of immature organic matter. The sterane, C29 20S/20R epimer ratio 0. 6 indicate that the organic matter had experienced a thermal evolution in the early sedimentation. The unsaturated fatty acids espec     

Creeping in? Neoliberalism,indigenous realities and tropical rock lobster (kaiar) management in Torres Strait,Australia

This article examines current neoliberal forces in the Torres Strait tropical rock lobster (TRL) fishery and their likely impacts on the lives of indigenous Islanders. It describes how neoliberal principles of market governance, commodification of natural resources, profit maximization, individualization and property rights are at odds with Islander rights, values, sense of place, and institutions of knowledge, tenure and practice. It argues that proposed fisheries measures based on neoliberal imperatives could cause important conflicts and create high social, political, and economic costs. The TRL fishery is integral to Islanders’ aspiration of self-determination and economic autonomy. A more holistic vision inclusive of Islander perspectives is necessary if management of the TRL fishery is to be truly socially and culturally appropriate.     

Morphology, reproduction, ecology and isoenzyme electrophoresis of Capitella complex in Qingdao

-Morphology, reproduction, ecology and isoenzyme electrophoresis of a Capitella complex in Qingdao were examined from 1983 to 1984. We determined that the Capitella complex in Qingdao was composed of at least three sibling species: Capitella cf capitata, Capitella sp. I and Capitella sp. IT. Although these three species are very similar in morphology, they differ in: three kinds of isoenzyme electrophoresis, staining reactions, developmental pattern, larval morphology and dispersal, reproductive strategies, breeding season and population ecology. In addition, they show a series of minor quantitative variations in adult morphology, especially in number and morphology of setae. Such differences can be detected only at the population level. Some ecological data such as density, growth rate, mortality and sex distribution are also provided in this paper.     

Underway Measurement of Sea Surface Temperature and Salinity in the Taiwan Straits in August,1999

The distributional features of sea surface temperature and salinity(SST and SSS) in the Taiwan Straits have been analyzed using the SST and SSS underway measurements in August,1999.The characteristics of SST and SSS are summarized as foloows:There are several upwellings and diluted water in the Taiwan Straits.The upwellings are divided into two kinds:those along the western coast of the Taiwan Straits and those around the Taiwan Shoal.There are three sources of diluted water:diluted water of the Jiulongjiang River,diluted water of the Zhujiang River and diluted water of the Minjiang River.     

Analytical procedures to classify organic pollutants in natural waters, sediments, and benthic organisms

Procedures are described to extract, fractionate and analyze organic pollutants in environmental samples. The methods are based on organic solvent extraction to isolate the pollutants, liquid-solid adsorption chromatography to separate the various pollutants into four fractions, and analyses of the fractions using glass capillary gas-chromatography. Based on a number of considerations, the procedures were found suitable for the analyses of trace level organic pollutants in a variety of sample types. The data from these studies has provided important information on the biogeochemistry of organic pollutants in the aquatic environment.     

Dissolved Cu, Pb, Zn and Cd in the South China Sea surface waters

The understanding of the distribution of trace heavy metals in the world ocean has greatlyimProved in the past decades. But most of the data are of vertical profiles of certain stations(Bruland, l980; Paul et al., l992; RObert et al., l990) and large--scale study of temporaland spatial variability of trace heaVy metals in the ocean is rather few. In fact, affected by ver-tical mixing by upwelling or convection, biogenic removal, atmospheric fallout and continentalinput frorn rivers, the dist…     

Ecological studies on the Hydromedusae, Siphonophores and Ctenophores in the Xiamen Harbour and adjacent waters

- This paper deals with species composition, seasonal change and horizontal distribution of the Hydromedusae (Hyd.), Siphonophores (Sip.) and Ctenophores (Cte.) and their relationship to the environmental factors. Materials from 17 stations in the Xiamen Harbour and adjacent waters were taken once monthly for the period from Sep. 1980 to Aug. 1981. The results indicate that for the dominant species of Phialidium folleatum, Lensia subtiloides and Pleurobrachia globosa , the total annual number of species has one peak and the total annual number of individual has one peak and two secondary peaks. On the basis of their ecological characteristice, the Hydromedusae, Siphonophores and Ctenophores found in the region investigated may be divided into the following ecological groups: estuarine group, neritic group and oceanic group. Their seasonal succession is correlated with the relative intensity of several water systems.     

Petrology, Geochemistry and Nd-Sr-Pb Isotopic Properties of Volcanic Rocks in Daheishan Island, Penglai, Shandong Province

The major elements, trace elements, K-Ar age and Sr-Nd-Pb isotopic systems of the Cenozoic volcanic rocks in Daheishan Island and Cishan, Penglai, Shandong Province are measured. The volcanic rocks ( olivine-nephelinite and nepheline-basanite ) in DaheishanIsland erupted periodically in an interval of 0.32 Ma, from 8.72 Mm 8.39 Ma, 8.08 Ma to 7.73Ma. The volcanic rocks are all rich in light REEs. They are similar to the OIB-type alkali basalt in the trace elements normalized model by primordial mantle: rich in high field elements such as Nb and Ta, and imcompatible elements such as Cs, Rb, Ba, Th, U. The volcanic rocks show a depletion of K and Rb elements. It is suggested by the trace elements that the olivine-nephelinite in Daheishan Island is originated fi‘om deep resources under the continental mantle, ε Nd (0) values of the volcanic rocks in Daheishan Island and Cishan are 5.31 - 8.51 and 7.33 respectively, suggesting that the volcanic rocks are from the depleted mantle resources, which have higher Sm/Nd ratios than the CHUR. ^143Nd /^144Nd ratios of Daheishan Island olivine-nephelinite and Cishan alkali basalts are 0.512 910 - 0.513 074 and 0.513 014 resoeetivelv. The ^87Sr /^86Sr of Daheishan lsland volcanic rocks are lower than that of Cishan, 0.703 427 - 0.703 482 and 0.703 895 respectively. The Daheishan Island olivinenephelinite has the Pb isotopic values as follows: ^206Pb /^204pb= 18.028 9 ～17.972 8,^207Pb /^204Pb= 15,435 8 - 15.402 2 and ^208Pb /^204Pb=38.087 6 - 37.997 5, lower than those of Cishan basanite. The Cishan basanite has ^206Pb / ^204Pb = 18.240 1, ^208Pb /^204Pb = 15.564 5 and ^208Pb /^204Pb=38.535. The authors suggest that the olivine-nephelinite in Daheishan Island is similar to the E-type MORB or Hawaii OIB, and the alkali basalts in Cishan similar to the Kerguelen OIB. The dominant mantle components of DM PREMA and perhaps DM( Dupal type ) are the dominant mantle components for volcanic rocks in Daheishan Island and Cishan. The PREMA component plays an important role.     

Holocene sea level changes and coastline snitts in Zhejiang Province, China

In the present paper, the Holocene sea level changes and coastline shifts in Zhejiang, China are discussed, based on the ancient coastline evidence related with sea level changes and 21 14C dat-ings of shell, peat or mud and wood samples along the Zhejiang coast. The development of Zhejiang coastline during the Holocene period can be divided into four stages. A lot of data of historical period and modern times have shown that tracing coastline shifts back to its source, we have to consider tremendous effects of man's activities besides natural factors, such as elevation and subsidence of the earth crust, sea level changes, supply of sediment, and littoral hydrodynamics.     

The use of GPS for marine positioning in Germany—requirements,experience, and concepts

Abstract

While beginning to establish a German Civil GPS Information and Observation Service in 1990, the actual and (near) future GPS market in Germany was analyzed. In addition, the feasibility of using GPS for water authority tasks has been studied during past years. Typical capabilities in this area are real‐time positioning for hydrographic surveying (kinematic application) and precise transfer of levels to tide gauges and verification at offshore positions.

The article describes the user interests, the requirements, some of the test campaigns, and the derived concepts for future applications.     

Gas seeps in Lake Baikal—detection, distribution, and implications for water column mixing

Echo sounders served to locate a large number of shallow- and deepwater gas seeps at the bottom of all three basins of Lake Baikal during the years 2005 to 2008. A substantial proportion of the shallow gas seeps was located near the delta of the Selenga River, and at the Posolskii uplift. Deepwater gas seeps were recorded at the lake bed both inside and outside of areas where a bottom-simulating reflector was identified in seismic profiles. By monitoring the activity of gas emissions at the gas seeps, times of episodic gas ebullition could be distinguished from times of persistent gas bubble streams. A maximum gas flare height of more than 950 m above the bottom was recorded at the St. Petersburg mud volcano located in the central basin of Lake Baikal. Based on calculations from echo sounder data, the ascent velocity of gas bubbles reached 40 cm/s. In the area of gas seepage, there was a thick near-bottom layer, in which the gradient of water temperature was equal to the adiabatic gradient. This implies complete mixing of the water close to the lake bed, resulting from ascending gas bubbles released at seep sites. Analyses of vertical temperature profiles indicate possibly localized upwelling up to the lake surface when gas emissions are intensive.