The Role of Suspended Matter in Assessing the Assimilative Capacity Case Study of Two Estuaries in the Adriatic Sea

Suspended particulate matter has been studied in two Adriatic river mouths to assess its role as a transport vehicle for waste disposal into the Adriatic sea.

The larger of the two, the Adige River (northwestern Adriatic coast, Italy), carries large quantities of solids and builds up a prodelta. the Krka River (eastern Adriatic coast, Croatia, Yugoslavia) is a typical karst river, and carries small quantities of suspended matter, since it drains carbonate terrains.

The resulting disposal of contaminants into the Adriatic sea is largely governed by the adsorption/desorption processes occurring in the estuarine mixing region. Surface adsorption properties, the specific surface area, and the nature and reactivity of the organic film coating determine the partitioning of pollutants between the dissolved and particulate state.

The observations reported point to the key role of particulates in transport of pollutants from land to sea. the concept of the assimilative capacity of the estuarine area requires detailed scientific knowledge on the geochemical behaviour of particulates.

In the Adige River mouth, lead, chromium, zinc, and nickel are accumulated in the prodelta sediments, and thus the loading of the sea with these metals is diminished, whereas in the Krka River estuary, desorption and mobilization of some trace metals occurs.     

A Review of Waste Tyre Utilisation in the Marine Environment

Waste tyres pose a major disposal problem on land creating a fire hazard and, in warmer climates, providing breeding pools for mosquitoes. the void space in tyres makes them unsuitable for land burial. Schemes to use shredded tyres for road bases and asphalt filler are being pursued in the USA. Tyre combustion for electricity production is being investigated in the UK.

The widespread availability and durability of tyres has led to their use in the marine environment for breakwaters/coastal defence structures and as artificial reefs for promoting fisheries.

Tyres have a low density and have been used in floating breakwaters. Schemes have been proposed to protect and strengthen shorelines with tyre structures.

The void space in tyres facilitates the construction of artificial reefs to attract fish. the most intensive use is in the south west Pacific and Australia. Tyre surfaces are colonised by algae and a wide range of faunal species, including corals and shellfish. the wide acceptance of tyres as a suitable reef construction material appears to be based largely on these observations. Experience of initial poor deployment practices in the USA led to tyres washing ashore after storms and resulted in the banning or restriction of their use in coastal states of the USA. A review of the scientific literature has yielded limited information on the environmental impact of tyres and in particular the leaching of heavy metals and organic compounds from tyres into sea water.

Preliminary results of tyre dust/sea water leaching studies are presented. These identify zinc as the major leachate (totalling 10mg/tyre after 3 months). Diluted leachates have not shown significant effects of the growth of the phytoplankton Phaeodactylum and Isocrysis.

Further work to characterise the sea water leaching of tyre compounds is recommended.     

Gypsum Waste Disposal: Land vs Sea or Recycling

The disposal of waste gypsum wallboard at landfill sites in British Columbia (B.C.), Canada, resulted in the generation of hydrogen sulphide gas and toxic leachates. Although some remedial measures were taken to reduce or eliminate problems resulting from past dumping practices, many landfill operators refused to accept new waste for fear of litigation over the pollution of nearby streams and rivers. with the availability of legitimate disposal sites greatly reduced, a serious waste management problem arose. the two most promising options for reducing the accumulating waste appeared to be recycling and ocean disposal.

Agricultural use of the waste for soil conditioning would account for only a small portion of the waste generated annually. Manufacturing plants were reluctant to accept waste gypsum with a high paper fibre content for fear it would lower the quality of the new wallboard product or interfere with the existing equipment and processes in the plants. the technology for economically removing and separating the paper from the used or substandard wallboard had yet to be developed.

The environmental implications of disposal at sea were assessed by a government advisory committee under the provisions of the Canadian Environmental Protection Act. Although results of a test dump in internal waters of B.C. were positive, the committee felt that valuable amenities of nearshore waters would only be assured by restricting dumping to a remote offshore location. an acceptable disposal method with minimal impact on the marine environment was eventually found with appropriate pretreatment of the waste and the use of remotely controlled bottom dump scows. Recent progress in the processing of waste wallboard to make it acceptable to the manufacturing industry should significantly reduce if not eliminate the need to dispose of gypsum wallboard wastes at sea.     

Application of High-Volume Fly Ash Concrete to Marine Structures

A new material with high content of fly ash named 'Ashcrete' has been developed. to examine the applicability of Ashcrete to marine structures, strength characteristics, resistance to sea water attack, and safety in the marine environment have been studied. the following results have been obtained:

1) the strength characteristics of high-volume fly ash concrete depend upon the type and proportions of chemical activators as well as curing conditions.

2) Ashcrete using sodium chloride (NaCI) as a chemical activator shows high initial strength and good strength development with age.

3) Ashcrete containing NaCI activator shows good resistance to sea water from the viewpoint of its strength characteristics, volume changes and microstructurcs.

4) Since 1980 many types of large-scale artificial reefs made of Ashcrete have been installed in the sea. As a result of long-term studies and underwater observations, the Japanese Government has demonstrated the durability of the material, safety in the marine environment and attractiveness to fish.

5) It is therefore proposed that Ashcrete might be used in constructing large-scale sea mounts in deep water for the purpose of generating upwelling.     

Environmental Pollution Due to Natural Factors: A Case Study in A Volcanic Area (Vulcano Island, Italy)

A major influence on the environment of active volcanic areas is expected from continuous input of chemical species pertaining to fumarolic activities occurring during inter-eruptive intervals.

The systematic investigations carried out during thirteen years in the island of Vulcano (Italy) showed also substantial contributions to phreatic waters and soils of minor constituents and trace metals from volcanic rocks with no negligible influence on growing crops.

Greater extents of these phenomena have been observed for products of hydromagmatic volcanic activity or of long-lasting weathering processes.     

Fish Disease Monitoring in the Dutch Part of the North Sea in Relation to the Dumping of Waste From Titanium Dioxide Production

Gross pathologies were recorded in a total of 5942 individual common dab (Limanda limanda L.) at 5 sites in and around Dutch coastal waters, in spring, from 1986 to 1988. Two of these sites (an offshore dumping ground and an inshore site influenced by direct river discharge) received large quantities of diluted acids of titanium dioxide waste (TDW); the other three were selected as reference sites for comparison.

The main diseases recorded were epidermal hyperplasia/papilloma, lymphocystis, liver nodules (pre-neoplastic and neoplastic lesions), and infections caused by the protozoan Glugea sp. Frequencies of disease were analysed using a logit model. There was a consistently high prevalence of epidermal hyperplasia/papilloma in dab from the two sites that received TDW when compared to the other sites. However, no dear relationships were found between the prevalence of epidermal hyperplasia/papilloma and dumping-associated heavy metals or other relevant environmental and biological factors. No significant spatial trend was revealed for liver nodules, although there was a statistically significant association between the occurrence of epidermal hyperplasia/papilloma or of lymphocystis and that of liver nodules in individual fish. Prevalences of lymphocystis were usually higher at offshore sites than in inshore areas, while prevalences of Glugea showed the opposite trend.

Although at first sight the pattern of disease prevalence would appear to furnish a strong case for a cause-and-effect relationship between TDW and epidermal hyperplasia/papilloma, interpretation of the data is complicated by interference from riverine inputs, long-distance dispersion of discharged wastes, local hydrographic conditions, and possible local migration of dab. On the basis of present results, therefore, the possibility that discharges of TDW contributed to the occurrence of this disease cannot be proven or discounted.     

Sedimentary Pigments and Organic Matter in Relation to Benthic Fauna in the Tan-Shui Estuary, Taiwan

The benthic ecological structure of the Tan-Shui estuary, Taiwan is changed due to long term effects of dumping of urban wastewater and of engineering actions. to monitor these changes, we sampled and analyzed benthos and sediment from 12 stations on the estuary.

The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.

Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments.     

Environmental Impact on Coastal Waters off Rio De Janeiro Due to Sewage Discharge via Submarine Outfall

A survey was made in an area of 28 km² around the outlest of Ipanema's submarine outfall in order to evaluate the impact of the raw domestic sewage effluent on coastal waters. Nutrient concentrations, dissolved oxygen, particulate matter and other physico-chemical parameters were measured monthly for 15 months. Copper and lead concentrations were also determined for two of the samplings.

The outfall has been in operation for 18 years, and the parameters measured within the observation area appear to be in steady state. From the observed radial concentration gradients within the survey area, a real extension of the steady state distribution of particulate matter and of sewage-derived nitrogen was estimated. the stationary cloud of particulate organic matter was about 150 km². From its total inventory and the discharge rate, a mean residence time of the particles in the sea of 56 days is estimated, prior to their being decomposed by bacterial action or settling to the bottom. for sewage derived N (as ammonia or nitrate), the steady state amount (above background) covers an area of about 60 km² and leads to a mean residence time of 5 ± 1 days in the ocean. Phosphorus is readily absorbed by the phytoplankton.

The presence of temperature gradients established by cold upwelling waters controls the dispersion of the sewage material and the rising of the sewage plume to the surface waters.     

Acoustic Observations of Bottom Surge From Dredged Material Discharge in the Open Ocean

Bottom surges generated from dredged material discharges in the open ocean have been observed using high frequency acoustic concentration profilers in several field studies during the past five years. the locations, water depths, bottom slopes, oceanographic conditions, and dredged material composition differed from study to study. Observed surges at three dredged material disposal sites may develop more than one surge peak for a single discharge. for water depths of the order of 10 m, surge height of the leading peak was estimated to be about one quarter of the water depth. for water of greater depth, of the order of 100 m, surge height reached 70 m, about 70% of the water depth. Surge height is established instantaneously when dredged material hits the bottom, and remains relatively constant as the surge advances horizontally. Total surge length reached 150 m for water depths of 10 m when measured from the impact point to the leading edge. for water depths of more than 100 m, the surge length reached more than 100 m. Length of the leading surge peak was as large as 45 m at this water depth.

Dimensional analysis was applied to relate the surge height of the leading surge peak to discharge parameters and oceanographic conditions. Results showed that the ratio of surge height to water depth was proportional to 1/10 power of the ratio of discharge volume to the third power of water depth.     

Holly (Ilex Aquifolium L.) As Zinc and Cadmium Accumulative Indicator in Biogeochemical Prospecting

The results of previous investigations in mineralized and sterile areas of Tuscany (Italy) appeared to point out the special aptitude of holly (Ilex aquifolium L.) in concentrating cadmium and zinc. in the present paper this behaviour has been verified in a mineralized area of Lombardy (Northern Italy).

Samples of leaves, twigs and barks from holly trees were collected, and metal contents (Zn, Cd, and Pb) have been determined by differential pulse anodic stripping voltammetry (DPASV). for comparison, some samples of wood anemone (Anemone nemorosa L.) and soil were also analyzed.

The data obtained confirm a preferential cadmium and zinc accumulation by holly (up to 16 and 1400 μg g^-1 dry weight, respectively) also depending on different vegetal organs and vegetative stages of plants. Highest contents of lead have been recovered in the outer portion of bark.     

The Determination of Heavy Metals in the Ligurian Sea. III. Distribution of Copper, Iron, and Nickel in the 0-200 Metre Layer in Open Sea

Dissolved Cu, Fe and Ni were determined in sea water samples from 9 stations in the Ligurian Sea located along the two traverses Imperia-Capo Corso and Nice-Calvi and at depths between 0 and 200 m. The samples were preconcentrated from small volumes of sea water by complexation with ammonium pyrrolidine-dithiocarbammate (APDC), extraction with CCl₄ and determination by AAS with electrothermal atomisation. The geographical distribution shows that in the central part of the inner traverse there is a maximum of Cu and Fe concentration; the vertical distribution shows no significant depletion of the dissolved elements in the epithalassa.

The results allow for a first approach to the more general problem of the distribution of the trace elements in the Ligurian Sea.     

Chemical Tracking and Marine Environmental Impact of Ocean Disposal of Calcium Carbonate Residue in the North Yellow Sea

The objective of this study is to determine the sedimentation rate and dispersion area of calcium carbonate residue dumped at sea and the impact to marine environment of dumping by a laboratory simulation experiment; chemical tracking in the field with the help of acoustic and optical tracking; and a comparative study of baseline conditions and marine environmental impact after dumping. Turbidity, pH and phosphate are selected as the chemical tracers to be monitored.

Results show that in the dumping area of 15 square miles with water depth of 50 m, if 217 t calcium carbonate residue is dumped (spot dumping) in the presence of a pycnocline with a current velocity of 60 cm/s (close to the maximum) the maximum dispersion distance of the calcium carbonate residue plume front is less than 2100 m; the dispersion area is less than 0.56 km²; and the maximum dispersion time is about 60 min when the turbidity and pH in the whole dispersion area return to background level. Therefore, the ocean disposal of calcium carbonate residue is feasible.     

Landbased Pollution Sources and Marine Environmental Quality in the Caribbean

The near shore coastal and marine environment of several Caribbean islands is their most biologically productive and economically important zone. However, almost all landbased activities possess the real potential of degrading the quality of near shore waters and ultimately diminishing the utility of the marine resource. This condition is largely attributed to the individual smallness of the islands and their geographic proximity to each other.

Available sanitary water quality data from across the region indicated that while recreational areas are in general safe for water contact activities, bacterial densities in excess of several international criteria are consistently recorded in harbours. Organochlorine pesticide residues were generally in the 5 ng l^-1 range in unfiltered sea water but were significantly higher (1-100) ng g^-1 in limited samples of sediment and biota. Additional data requirements to gain further insight into the current state of the Caribbean environment are also identified.

A summary of the major land based sources of marine pollution (including sewage, industrial effluents and agricultural run-off) in the insular Caribbean is presented.     

The Reuse of Urban and Industrial Waste in Tai-Lin-Pu Reclamation Project, Taiwan

This study introduces the principles of KMG's (Kaoshiung Municipal Government) dealing with the non-poisonous urban and industrial waste through reclamation of shore land in reinforcing a sense of coastal protection and land development in Tai-Lin-Pu coastal area, southern Taiwan.

Through a series of experimental studies, we found that substitutes of coarse aggregate with a broad spectrum of integrating slag powder, fly ash, and cementitious material can be obtained with a benefit up to 80% saving of cement. the integrated aggregates from the non-poisonous industrial wastes were subsequently made into armour units and used in the field tests at Tai-Lin-Pu coastal area, where the shorelines are seriously eroded. After being subjected to several severe typhoon advents, the results showed that the waste-made units used as the protection breakwater, together with construction wastes and excavated soil as the filling material, prove to be an effective practice in utilizing recycled urban waste to reclaim erosive shore lands. Moreover, this study also demonstrates that through detailed analysis of the waste characteristics, scrap material could be turned into valuable construction aggregates, and highlights the value of non-poisonous urban and industrial waste as a alternative resource for the shore protection engineering.     

Applications of Satellite Remote Sensing to Marine Pollution Studies

There are two approaches in the application of satellite sensors to marine pollution studies. Satellite sensors are used to observe and characterize ocean pollutants such as industrial wastes and oil. in addition, satellite observations provide information useful in illuminating processes such as eutrophi-cation or air-sea exchange of CO₂, that are important in determining the distribution and fate of pollutants.

Satellite technology is an important tool in monitoring and studying ocean pollution. Visible sensors have been used to observe and characterize sewage sludge and industrial wastes dumped at sea. Oil slicks have been observed with Landsat, AVHRR and SAR imagery. Besides directly detecting pollutants, satellite sensors are useful for analyzing ocean processes that are influential in the fate of pollutants. These processes include eutrophication of coastal waters and the distribution of suspended matter. the fate of excess CO₂ can be addressed using scatterometer-derived estimates of wind speeds to determine the CO₂ exchange coefficient at the sea surface on a global scale.     

Overview of Radioactive Waste Disposal at Sea

For hundreds of years, the seas have been used as a place to dispose of wastes from human activities. Although no high level radioactive waste has been disposed of into the sea, variable amounts of packaged low level radioactive wastes have been dumped at 47 sites in the northern part of the Atlantic and Pacific Oceans. in 1946 the first sea dumping operation took place at a site in the North-East Pacific Ocean. the last dumping operation was in 1982, at a site off the European continental shelf in the Atlantic Ocean. Between these two dates, an estimated 46 PBq (1.24 MCi) of radioactive waste coming from research, medical, military and industrial activities have been disposed of at sea. the present trend, through the Convention for the Prevention of Marine Pollution by Dumping of Wastes and other Matter and other Regional Conventions, points towards the prohibition of the dumping of any radioactive waste into the marine environment.     

Overview of Radioactive Waste Disposal at Sea

For hundreds of years, the seas have been used as a place to dispose of wastes from human activities. Although no high level radioactive waste has been disposed of into the sea, variable amounts of packaged low level radioactive wastes have been dumped at 47 sites in the northern part of the Atlantic and Pacific Oceans. in 1946 the first sea dumping operation took place at a site in the North-East Pacific Ocean. the last dumping operation was in 1982, at a site off the European continental shelf in the Atlantic Ocean. Between these two dates, an estimated 46 PBq (1.24 MCi) of radioactive waste coming from research, medical, military and industrial activities have been disposed of at sea. the present trend, through the Convention for the Prevention of Marine Pollution by Dumping of Wastes and other Matter and other Regional Conventions, points towards the prohibition of the dumping of any radioactive waste into the marine environment.     

VALIDATION OF AN ENZYME LINKED IMMUNOSORBENT ASSAY (ELISA) FOR CYPRINUS CARPIO L. VITELLOGENIN, AS A BIOMARKER OF REPRODUCTIVE DISORDERS

Vitellogenin is a female sex-specific protein, and a validated and suitable method for its assay can be applied as a biomarker of reproductive disorders in male and female aquatic animals. Therefore, the present study was designed to validate an ELISA for measuring plasma vitellogenin in wild carp ( Cyprinus carpio L.) living in the Lake of Trasimeno (Umbria, Italy); plasma samples were taken during pre-spawning, spawning, and post-spawning periods; in addition to vitellogenin, in both male and female carps, plasma changes of estradiol-17 βwere monitored together with those of estrogen receptor density in the liver.

In females, VTG showed high seasonality, reaching the highest levels in March during the pre-spawning period; the VTG levels correlated with those of estradiol-17 β( E 2 ), and with the changes of gonadosomatic index (GSI), while a non parallel trend was found in the liver estrogen receptor (ER) density. In forty percent of males, VTG was found to be present in the plasma and changes of ER density in the liver were observed.

The data here reported suggest that the common carp can be a useful sentinel species for biomonitoring studies of environmental estrogens, and of their effects on its reproductive biology.     

Phosphorus in Sediments of Lake Edku, Egypt. The Influence of Chemical and Grain Size Parameters

Lake Edku is one of the Nile Delta shallow brackish water coastal lagoons with communications with the southeastern Mediterranean.

Sediment samples were recovered from the top 10 cm of the lake bottom to study principally their total, inorganic and organic phosphorus. Related sediment parameters such as particle size, organic carbon, carbonate and iron contents were also studied in detail.

It is shown that the lake sediments are generally a sand-silt-clay mud enriched with carbonate (11.4-42%), organic carbon (0.9-11.4%) and iron (1.6-5.6%).

The total phosphorus content in these sediments is 503-1329 μg/g, inorganic phosphorus, 468-954 μg/g and organic phosphorus, 35-526 μg/g.     

Heavy Metal Concentrations in Sea Urchin Tissues From Egypt, Ireland and United Kingdom

Sea urchins (Paracentrotus lividus) were collected from the Mediterranean coast off Alexandria, Egypt and the Atlantic coast of Ireland to the west of Galway. Samples of another urchin species, Psammechinus miliaris, were collected from the entrance to Southampton Water, U.K. Both the Alexandria coast and Southampton Water receive domestic and industrial waste water inputs whilst the western Irish coast is relatively unpolluted.

Sampled animals were dissected to separate coelomic fluids, Aristotle's lantern, gonads and tissue (digestive tract plus connective tissue). the concentrations of heavy metals (cadmium, copper, lead, nickel and zinc) in the different parts were measured using flame atomic absorption spectroscopy.

Many levels of heavy metals in the different parts were similar in specimens taken across the wide range of sites and the two species. A notable exception was the high level of copper (33 μg g^-1 dry wt.) and zinc 328 μg g^-1- dry wt.) in urchin tissue from Southampton Water.

The metal concentrations in the gonads of Paracentrotus lividus are of particular interest because of human consumption of this species. the highest levels of copper (3.3-5.2 g^-1- dry wt.) and zinc (74-181 μ g^-1- dry wt.) dry wt.) in gonads were found in the samples from Egypt. Data from this study are compared with other results reported from the Mediterranean.

A simple, short term, elevated water column copper uptake experiment was undertaken with Paracentrotus lividus which showed an increase in gonad concentrations of this element.