Heavy metals (Cu,Zn, Cd,Pb) in sediment of the Java sea,estuarine and coastal areas of East Java and some deep-sea areas

The concentrations of copper, zinc, cadmium and lead were measured in the bulk sediment and the silt fraction of the surface sediment (upper 2 cm) from the riverine and estuarine zones of the rivers Brantas and Solo and in the adjacent coastal areas around East Java. The levels of contamination of the sediments with heavy metals were also determined in the Java Sea, some sites in the Bali Sea and the Indian Ocean.The concentrations of the trace elements were consistently higher in the silt fraction than in the bulk sediment. Trace element levels were higher in riverine and estuarine sediments than in sediment from coastal waters and the Java Sea. Increased copper, zinc and cadmium concentrations were measured in surface sediment from deep-sea areas.There were no or only minor differences in the metal concentrations in the sediment (both bulk sediment and the silt fraction) between the dry and the wet monsoon.     

Input of selected chlorinated hydrocarbons into the coastal area of East Java and adjacent waters: Distribution patterns in the dissolved and suspended phase

Selected organochlorines were analysed in water and suspended particulate matter collected at stations in two rivers on East Java, the adjacent coastal zone, the Java Sea and the Indian Ocean. The sampling period covered the dry monsoon and the beginning of the wet monsoon. Concentrations of dissolved polychlorinated biphenyls (PCBs) were in the same range as in Western Europe and North America. In contrast, the concentrations of all measured organochlorines in suspended matter were lower and often not detectable.p,p′-DDT and its metabolites p,p′-DDD and p,p′-DDE showed the highest concentrations of all compounds determined. The rivers Bengawan Solo and Kali Porong can be considered sources of these compounds for the coastal environment, although their impact is restricted to a small area.Significant differences between the dry and wet monsoon were only observed for dissolved PCBs in the river Porong.     

Structure and energy demand of the benthic soft-bottom communities in the Java Sea and around the islands of Madura and Bali,Indonesia

In July 1984 benthic research was carried out in the Java Sea and around the islands of Madura and Bali.The aim was to describe the structure of the benthic communities in terms of numerical density (numbers of dominant macrofaunal groups and meiofauna per square metre) and biomass (g ashfree dry weight (AFDW) per square metre), and in relation to geographical position and main ambient factors, i.e. water depth, bottom temperature and sediment characteristics.In addition attempts were made to estimate the activity of these benthic ecosystems, and to show their relation to the pelagic.Box-core samples, collected along west-east axis in the Java Sea and in the Strait of Madura, showed relatively poor benthic communities. The average densities of macrofaunal organisms (> 1 mm) did not exceed 250 specimens·m⁻²; the total biomass was below 1 g AFDW·m⁻²; small polychaetes and crustaceans were the dominant groups.A number of larger organisms have developed very remarkable adaptations to the muddy environment. Meiofaunal organisms (nematodes being the dominant group) numbered 0.06·10⁶ to 0.46·10⁶ specimens·m⁻². In general there is a trend from west to east towards somewhat richer communities. The actual carbon demand of the benthic ecosystem in the area investigated is tentatively estimated at an average of 38 g C·m⁻²·y⁻¹, which amounts to about 40% of the primary production.Both the very soft fluid-mud bottoms in the central Java Sea and in Strait Madura, and the relatively low amount of energy available for growth, probably prevent the establishment of well developed benthic communities.     

Trace oxyanions and their behaviour in the rivers Porong and Solo,the Java Sea and the adjacent Indian Ocean

During the Snellius-II Expedition (theme 5) dissolved and particulate concentrations of As(III), As(V), Sb(III), Sb(V), Se(IV), Mo, U, V, Au and W were measured in the Kali Porong and Bengawan Solo, Strait Madura, the Java Sea and the adjacent Indian Ocean.The estuarine mixing behaviour of Mo, U and V was found to be conservative. Arsenic behaved in a conservative manner during the wet period, while removal was observed in the high salinity region of the Solo and Porong during the dry season. The exceptionally high vanadium concentration in the rivers Porong and Solo, which is more than 10 times higher than that in the world rivers, is connected with leaching of volcanic rock; dissolved concentrations of Au, W and Mo are also higher. Apart from V and Au, the dissolved concentrations in the Java Sea and in the Indian Ocean compare well with average ocean values.     

The importance of rivers as nursery grounds for 0- and 1-group flounder (Platichthys flesus L.) in comparison to the Wadden sea

From May 1988 to June 1989 selected areas of the German Wadden Sea, the Ems, Weser, Elbe and Eider estuaries as well as in Elbe tributaries were sampled for 0- and 1-group flounder (Platichthys flesus L.). Estuarine and Wadden Sea sampling was conducted on board commercial shrimp vessels equipped with beam trawls. The Elbe river system was sampled on board a research boat equipped with a similar 3-m beam trawl. Density indices were calculated for the various areas. To estimate the importance of rivers as nursery areas for flounder, river surface area was compared to the area of tidal flats in the Wadden Sea.In all surveys, there was no relationship between fish densities and tow directions with respect to tide. In the Elbe river system flounder densities were not correlated to substrate types but increased significantly with decreasing salinity. Abundances were always lowestt in polyhaline habitats and increased up to 10-fold in mesohaline estuarine areas. In the limnetic tidal sections of the Elbe river and its tributaries densities increased again by factors of 3 to 10. The succession of 1-group modal lengths from limnetic to polyhaline habitats demonstrated that smaller fish preferred less saline waters. 0-group specimens lagging behind in growth did not leave the limnetic river section in winter. The onset of the spawning migration in November was determined by monitoring the length-frequency distributions throughout the year.The possible sources of bias are discussed and gear efficiency is estimated from literature sources. The contribution of rivers to the 0- and 1-group flounder population on the tidal flats of the Wadden Sea is estimated at about 35.1%.     

Soft-bottom benthic community in the estuarine waters of East Java

During the Snellius-II Expedition, both in the period July–August and in the period November–December 1984, the structure of the macrobenthic communities in the estuaries of the rivers Porong, Wonokromo and Solo was investigated. The numerical densities of the benthic organisms (>0.5 mm) from the Porong, Wonokromo, and Bengawan Solo estuaries during the Snellius-II Expedition varied between 87 and 5787 ind·m⁻²; biomasses between 0.4 and 602 g DW·m⁻². The high numerical density (1573 ind·m⁻²) found at st.2 of the Porong estuary in period I (July–August 1984) was attributed to the dense population of the bivalve Varicorbula rotalis. Consequently a very high biomass (602 g DW·m⁻²) was measured at this station.The mollusc Theora lata and the polychaetes Ancistrosyllis parva, Nepthys dibranchis, Paraprionospio pinnata, and Sternaspis laevis occurred at almost every station during the investigation periods.Paraprionospio pinnata and Theora lata, which are considered indicator species of disharmonic environments, were found at almost every station of the study areas in both periods. Species diversity at all the stations was low, ranging form 0.1 to 1.6.     

The importance of estuaries in life histories of flatfish species on the Southern Coast of Africa

This paper reviews the ecology of flatfish species associated with estuaries in southern Africa. Information from estuarine and coastal studies carried out in this region over the past 25 years indicates that only 4 of the 56 flatfish species occurring in the region utilize estuaries during part of their life histories. The suitability of estuaries and their role as nursery grounds for juvenile flatfish is assessed in terms of the proportion of the life cycle that each species spends within estuarine systems. Biological data on Pseudorhombus arsius, Bothus pantherinus, Heteromycteris capensis and Solea bleekeri extracted from broad based estuarine studies in the warm temperate and subtropical regions of southern Africa are presented in support of the thesis that in the absence of calm, shallow, turbid, marine shelf areas, juveniles of these species utilize estuaries as nursery grounds.     

Distribution of dissolved and particulate minor and major elements in the river and coastal environment of East Java during the Snellius-II expedition

The concentration and distribution of dissolved Cu, Zn, Cd, Ni, Pb and Fe, and Cu, Zn, Cd, Ni, Pb, Cr, Fe, Si, Ca, Mg, Mn and K in suspended matter have been determined in the rivers Porong and Solo and in Strait Madura (East Java), during the dry- and wet-monsoon periods. Based on element/Al ratios, the suspended matter supplied by each of the two rivers can be traced offshore. The main source of material supplied to the coastal area is the Solo river. The distribution of the trace-metal content in suspended matter collected in the rivers can be described as a mixture of metal-rich, organic-rich particles and a metal-poor, detrital fraction. Due to the presence of mud barriers at the river mouths, particles with high trace-element contents are trapped in the estuaries. Compared to European rivers the dissolved trace-metal concentrations in these rivers are relatively low. The dissolved concentrations of the different trace elements in Strait Madura show no uniform distribution pattern during the two sampling periods.     

Cyclic organochlorines in epibenthic organisms from coastal waters around East Java

Polychlorinated biphenyls (PCBs), organochlorine pesticides and their persistent metabolites were identified in epibenthic animals from the estuaries of the rivers Brantas and Solo and from Strait Madura, Strait Bali and the Java Sea in July and November 1984.Samples of different phyla showed similar general geographical trends for the compounds investigated. Contamination with p,p′-DDE was of major importance in the river Porong, a distributary of the Brantas river system. Increased concentrations of PCBs were found near Surabaya.In Strait Madura, p,p′-DDE and PCBs were increased only in animals from the western part. Therefore the dispersion of the contaminants in biota appeared to be determined by the residual currents caused by the SE trade winds prevailing in both periods of sampling (July and November 1984).Generally no differences existed between the two sampling periods, except in the Java Sea, where PCBs were only detected during the November cruise. Compared to the animals from Strait Madura, the PCB patterns showed increased contributions of tri- and tetrachlorobiphenyls. This could not be related to differences in PCB-patterns of water or suspended particles.The compounds QCB, HCB, α-HCH, ß-HCH, o,p′-DDD, methoxychlor and several cyclodienes were generally below detection limits.     

Suspended matter and bottom deposits in the Mahury estuarine system (French Guiana): Environmental consequences

As part of a study carried out on the major rivers in French Guiana to identify and estimate the respective share of local rivers in the sedimentation of estuaries and the inshore continental shelf, results are reported on the Mahury after 2 periods of fieldwork carried out during one dry and one rainy season.The specific characteristics of the whole Mahury fluvio-estuarine system can be summed up as follows: the sands have invariable annual characteristics; they show evidence of a long history, first marine, then continental and finally fluviatile. They play little part in sedimentation on the continental shelf, and what part they do play is limited to the beaches. The fine sediments too have invariable annual characteristics. They fall, if we consider their mineralogical and elemental composition, on either side of a limit separating the fluviatile and estuarine zones. Here, the sediment stocks are respectively authigenic and allothogenic, while the clay association and elemental composition in the latter zone are evidence of an Amazonian origin.The contribution of the Mahury (Comté-Orapu) to fine estuarine sedimentation thus appears at present to be a very limited one, the Amazon being predominant over vast coastal areas, including the French Guiana estuaries.     

Transport of river-derived trace metals through the coastal zone

This paper discusses approaches to estimating the transport of river-derived trace metals through coastal areas, taking account of particle-water exchanges and remobilization from sediments. Models of the transport of several trace metals through a semi-enclosed marginal sea and across western North Atlantic continental shelves are used to examine the fluxes of metals through the coastal zone. The relationships between metals and salinity, in both nearshore and offshore areas, are also used to exemplify the consequences of mixing processes in estuaries and to determine apparent riverine end-member compositions on larger spatial scales. Comparisons are then made between the riverine influxes to the ocean deduced from metal-salinity relationships and generalized coastal zone transport models. The results of the application of both approaches are discussed in the context of geochemical processes operating in the coastal zone.     

Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the sivash,Ukraine

Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding depend on wind conditions. In hypersaline lagoons the benthic and pelagic fauna was very poor, consisting mainly of chironomid larvae (0.19 g AFDM·m⁻²) and brine shrimps Artemia salina, respectively. Brine shrimp abundance was correlated with salinity, wind force, wind direction and water depth. Dunlin Calidris alpina and curlew sandpiper Calidris ferruginea were the only species feeding on brine shrimp. As brine shrimp densities are higher in deeper water, smaller waders such as broad-billed sandpipers Limicola falcinellus are too short-legged to reach exploitable densities of brine shrimp. In brackish lagoons the benthic and pelagic fauna was rich, consisting of polychaetes, bivalves, gastropods, chironomid larvae, isopods and amphipods (8.9 to 30.5 g AFDM·m⁻²), but there were no brine shrimps. Prey biomass increased with the distance from the coast, being highest on the site that was most frequently inundated. Dunlin, broad-billed sandpiper and grey plover Pluvialis squatarola were the most abundant birds in the brackish lagoon. Due to the effects of wind-tides only a small area was usually available as a feeding site. Gammarus insensibilis was the alternative prey resource in the water layer, and their density varied with wind direction in the same way as brine shrimp. Curlew sandpipers and dunlins in the hypersaline lagoons and broad-billed sandpipers in the brackish lagoons often changed feeding sites, probably following the variation in prey availability. Only because of the large size and variety of lagoons are waders in the Sivash always able to find good feeding sites.     

Organic carbon in the upper 100 m and downward flux in the banda sea; monsoonal differences

Organic carbon was measured in the upper 100 m and its downward flux from the euphotic zone recorded, as part of a multidisciplinary study in the Banda Sea on monsoonal differences in the upper water layers.All 35 stations occupied showed on average 1.5 times higher POC values in August 1984 (4.9 g·m⁻², SE monsoon, upwelling period) than in February/March 1985 (3.3 g·m⁻², NW monsoon, downwelling period) for the 0 to 100 m water column. Monsoonal variation in POC was confined to the surface layer and related to a variation in phytoplankton content; it can be explained by — local— upwelling during the SE monsoon. At 100 m no seasonal variation occurred.Contrary to POC, average figures for DOC in February/March were almost twice the average observed in August (66.5 against 37.5 g·m⁻² for the 0 to 100 m water column). In February/March spatial variation was more pronounced than in August with highest values occurring in the NE part (>100 g·m⁻², 0 to 100 m), with a subsurface maximum. In this period the NW monsoon causes a surface current to the east. This might cause a westward subsurface countercurrent of Arafura Sea water rich in riverine or benthic layer DOC, influencing the eastern Banda Sea.At 100 m depth daily sedimentation amounted to ∼50 mg C·m⁻². The limited number of data do not indicate a difference between the 2 periods. On average the daily downward flux at 100 m depth amounted to 1.2% of POC and 0.8% of chlorophyll present in the 0 to 100 m water column, and equalled 5% of the daily primary production.     

Primary production and nitrogen assimilation in the North sea during July 1987

An extensive survey of the whole of the North Sea, carried out in July 1987, is described. The study concentrated on the measurement of surface water inorganic nutrient concentrations and concomitant rates of primary production (¹⁴C) and nitrogen assimilation (¹⁵N). Primary production was investigated using size fractionation techniques. Three vertical profiles of primary production and nitrogen assimilation were also investigated.Much of the North Sea exhibed thermal stratification. Surface nutrient concentrations were low and chlorophyll concentrations typically <1 mg m⁻³. More than 75% of the primary production was attributable to cells <5 μm in diameter. Ammonium assimilation accounted for most of the nitrogen assimilation.The water column was vertically well mixed in the coastal zones. Here, inorganic nitrogen concentrations were high (e.g. up to 25 μmol NO₃⁻ with chlorophyll concentrations up to 10 mg⁻³, and organisms >5 μm diameter accounted for most of the primary production. As in offshore regions ammonium accounted for the major part of the nitrogen assimilated.A 115 km section obtained using an undulating oceanographic recorder showed that in certain regions of the North Sea physical features acted to increase the dependence of the phytoplankton on nitrate.     

North Sea Scyphomedusae; summer distribution,estimated biomass and significance particularly for 0-group Gadoid fish

Data on the by-catch of Scyphomedusae from pelagic trawls was collected during the routine ICES International 0-group Gadoid Surveys of the North Sea, in June and July of the years 1971–1986 (except 1984). These data are used to describe the distributions, abundances and biomasses of three common North Sea Scyphomedusae: Aurelia aurita (L.), Cyanea capillata (L.) and C. lamarckii (Péron & Lesuer). Information is also presented on inter-annual variability, size (umbrella diameter) frequencies and, for the Cyanea species, umbrella diameter: wet weight relationships. The general role and ecological significance of Scyphomedusae is discussed and, given the well known ‘shelter’ relationships between Scyphomedusae and certain 0-group fish, whiting (Merlangius merlangus) and haddock (Melanogrammus aeglefinus), in particular. The data were examined for evidence of such relationships.Aurelia aurita, although fairly widespread in the northern North Sea was virtually absent from the central North Sea but very abundant in coastal waters. This species was particularly abundant off the Scottish east coast and especially in the Moray Firth.Cyanea lamerckii was most abundant in the southern and eastern North Sea. More widespread than Aurelia, this species was also most abundant in coastal regions, particularly off the Danish west coast.Cyanea capillata, with a more northern distribution was also more widely distributed and abundant offshore. This species was most abundant in the area between the Orkney/Shetland Isles and the Norwegian Deep and in shelf waters of the north west approaches to the North Sea. As with C. lamarckii it was also, in some years, abundant off the Scottish east coast and west of Denmark.The abundance and the size frequency of the jellyfish show considerable inter-annual variability, and variability between regions of the North Sea. It is considered that hydrographic variability and differences in food supply to both medusae and to their sessile benthic polyps, are the major causes of the observed differences between years and areas.The impact of Scyphomedusae on fishing and recreational activities is discussed.     

红透山铜矿矿区土壤重金属污染状况研究初报

通过实地调查和室内分析，研究了红透山铜矿区土壤重金属含量状况，并采用单因子指数法和内梅罗指数法对红透山铜矿区土壤重金属污染程度进行评价。研究结果表明，该研究区土壤Cu、Zn、Pb、Cd平均含量高于当地土壤背景值，其中，土壤已受Cu、Cd重污染，Zn为轻污染，Pb为安全。不同区域土壤重金属含量存在较大差异，各片区重金属综合污染递降顺序依次为：尾矿区>选矿区>采矿区>周围农田区。     

The biology of Solea bleekeri (Teleostei) in Lake St Lucia on the southeast coast of Africa

Several aspects of the biology of Solea bleekeri in Lake St Lucia were investigated, these included occurrence, distribution, reproduction and recruitment, food and feeding, size frequency distribution and the role of estuaries in the species' life cycle. Solea bleekeri was found to occur throughout the system in muddy turbid areas and was largely absent from the eastern shores of the lake where clear water sandy substrata occur. The preferred diet of the species was bivalve siphon tips of the species Solon cylindraceus, when these were in abundant supply. However, when numbers of large (length > 20 mm) specimens were not available then S. bleekeri fed on whatever prey was available in or near the substratum. Analysis of stomach contents under the latter conditions showed that food consumption reflected the composition of the benthos. Large numbers of S. bleekeri spend their entire post-larval and juvenile phases as well as the greater part of their adult life within estuaries. Evidence is presented to support the idea that S. bleekeri breeds in certain areas of the lake and that spawning takes place between September and November. The current data suggest that there may be two populations in St Lucia: one migrates from the system to spawn at sea during winter along with the other marine fish species which utilize estuaries as nursery areas, while the other population breeds within the system. Alternatively there may simply be a single population which normally breeds at sea, but which may breed within the system when conditions are suitable. Recruitment of S. bleekeri into the St Lucia estuarine system takes place from the muddy offshore marine banks and possibly from within the system as well. Solea bleekeri appears not to be totally dependent on estuaries for the completion of its life cycle. The advantages of utilizing these systems for their development relate to the shallow, calm, turbid food-rich areas which estuaries offer. The fact that breeding takes place within St Lucia means that adults and juveniles are present in varying numbers throughout the year.     

The summer uptake and release of nitrogen by an intertidal oyster reef

It has long been speculated that oyster reefs process estuarine nutrients, but direct observation of this has been difficult. With a plastic tunnel (BEST - Benthic Ecosystem Tunnel), input/output concentrations of nitrogen and water velocities over an oyster reef were measured for 7 tidal cycles during summer conditions. Ammonia was always released from the oyster reef and average rates varied from 2825 to 15 304 μmol·m⁻²·h⁻¹. Ammonia release was usually higher on the ebb tide than the flood tide. It is speculated that nitrogen uptake and release may be a function of not only feeding and digestive behaviour, but also of water velocity. The magnitude of ammonia release is much higher than any previous observations on natural benthic systems, suggesting that oyster reefs may be important components in nitrogen cycling in estuaries.     

Phytoplankton biomass and potential nutrient limitation of phytoplankton development in the southeastern North Sea in spring 1985 and 1986

The vernal phytoplankton bloom was observed during cruises to the southeastern part of the North Sea (east of 6°20' E, south of 56°50'N) in 1985 and 1986. Maximum phytoplankton biomass expressed as phytoplankton carbon was similar in both years (14.5 and 17 g PPCm⁻² respectively). In 1985 the bloom was located in the less saline coastal water close to the North Frisian coast. Phytoplankton was dominated by Coscinodiscus concinnus and Thalassiosira nordenskiöldii. In 1986, highest phytoplankton biomass was observed northwest of the island of Sylt, where Thalassiosira nordenskiöldii was the dominant phytoplankton species. Within the areas of high phytoplankton standing stock, concentrations of the inorganic dissolved nutrients phosphate and silicate had dropped to nearly undetectable concentrations, whereas both in 1985 and 1986 the water was still rich (10 – 20 μM.dm⁻³) in inorganic nitrogen (DIN). This, as well as the high ratios of DIN:PO₄ and DIN:Si(OH)₄ (> 50) point to phosphate and silicate as potential limiting nutrients during the spring phytoplankton bloom. The ratios of total nitrogen (TN) to total phosphorous (TP) (> 30) indicate also that phosphorous might then be in short supply. Phosphate and silicate have to be considered as potentially limiting nutrients during the vernal plankton bloom in the coastal waters of the southeastern North Sea, with nitrogen being present in surplus at that time of the year. However, in the more offshore areas nitrogen may be considered the potentially limiting element at the same time.     

The role of small,low density particles on the partition of selected PCB congeners between water and suspended matter (North Sea area)

The dissolved and particulate suspended concentrations of five PCB congeners (with 3–7 chlorine atoms) in the Southern Bight (North Sea) are interpreted in terms of an equilibrium partitioning model. K_d values for riverine/coastal samples generally increase with chlorine number of the congeners (K_d = 10⁴–10⁶). Values are more than an order of magnitude larger at the low suspended matter concentrations offshore (< 1 mg·dm⁻³). This is interpreted in terms of the presence of different SPM fractions with different contents of PCB: a fraction consisting of low size/density particles carrying high contents of PCBs, dominates at low SPM concentrations. The contribution of particulate forms to the total PCB concentration per unit volume may, therefore, be significant even at low SPM concentrations.