The Response of Macrobenthic Communities to Environmental Variability in Tropical Coastal Waters

The relative contributions of spatial and temporal fluctuations are different in shaping natural communities in a tropical coastal/estuarine system. Understanding how coastal communities respond to these fluctuations is still equivocal, and thus, available data are rare. Here, multiple analytical approaches were used to identify key spatial and temporal factors, and to quantify their relative roles in shaping a macrobenthic community through space (contamination degree, physical parameters, and sediment characteristics) and time (climatic factors, season, and year). A dataset of eight sampling times was analyzed over a period of 2 years, in which macrobenthic species abundances were sampled. A total of 33 species were identified, including 18 bivalves, 5 gastropods, and 4 crustaceans. The other taxa were less diverse. The results show that there were no significant temporal changes of macrobenthic community structure, but spatial changes were significant and synchronized with environmental factors (i.e., sediment characteristics, water depth, and the distance from anthropogenic sources). This study demonstrates that spatial factors played a primary role in structuring of macrobenthic assemblages, whereas the influence of temporal factors appeared less across geographically distinct sites. Thus, temporal variation of a coastal macrobenthic community appears to be controlled by partly different processes at different scales.     

In Situ Response of Phytoplankton to Nutrient Additions in a Tropical Coastal Lagoon, (La Mancha,Veracruz, Mexico)

An experimental in situ microcosm study was conducted in the tropical lagoon La Mancha (Gulf of Mexico) to determine whether or not nutrient limitation occurs and to examine the direct effect of an inorganic nutrient pulse on the phytoplankton community structure. The phytoplankton community response to the addition of four treatments with different combinations of nitrogen (N), phosphorus (P), and silica (Si) (+N-NH₄ ⁺, +P-PO₄ ^?, +Si-SO₃, and N:P16) showed that phytoplankton was N-limited as indicated by an increase in phytoplankton biomass (i.e., chlorophyll a) (range, 8–34 mg m^?3) during the dry season in two consecutive years (2006 and 2007). Picophytoplankton abundance significantly increased in the +N treatment (145.46 10³ cells L^?1), while microphytoplankton reached a maximum abundance (68.38 10³ cells L^?1) in the N:P16 treatment. Phytoplankton composition changed from a community initially dominated by dinoflagellates (e.g., Prorocentrum spp.) to another dominated by diatoms (Thalassiosira and Nitzschia longissima) in the N:P16 treatment. The +N treatment significantly increased Synechococcus sp. growth rates (1.3 divisions per day) (picocyanobacteria). Biomarker pigments measured in the experimental microcosms confirmed observed changes in phytoplankton groups. Our results reveal that La Mancha lagoon is a N-limited coastal system during the dry season and provides evidence of the temporal species successional patterns and mechanisms regulating the phytoplankton community response to nutrient enrichment pulses in this already eutrophic coastal lagoon.     

Factors Controlling Phytoplankton Biomass in a Subtropical Coastal Lagoon: Relative Scales of Influence

Patterns in phytoplankton biomass are essential to understanding estuarine ecosystem structure and function and are the net result of various gain and loss processes. In this study, patterns in phytoplankton biomass were explored in relation to a suite of potentially regulating factors in a well-flushed, subtropical lagoon, the Matanzas River Estuary (MRE) in northeast Florida. We examined temporal variability in water temperature, light availability, nutrient concentrations, phytoplankton productivity, and phytoplankton standing stock over 8 years (2003–2010) and explored relationships among variables through correlation analysis. Laboratory experiments in the spring and summer of 2009 quantified phytoplankton growth rates, nutrient limitation potential, and zooplankton grazing rates. The potential influence of oyster grazing was also examined by scaling up population metrics and filtration rate estimates. Results indicated that phytoplankton biomass in the study area was relatively low mainly due to a combination of low temperature and light availability in the winter and consistent tidal water exchange and bivalve grazing throughout the year. Relatively low levels of phytoplankton standing stock and small inter-annual variability within the MRE reflect a balance between gain and loss processes which provide a degree of resilience of the system to natural and anthropogenic influences.     

Geology and geochemical patterns of the Birimian gold deposits, Ghana, West Africa

A major gold province of the world exists in the Proterozoic Birimian and Tarkwaian supracrustal rocks of West Africa. The bulk of the gold comes from the primary lode occurrences of the Birimian rocks of Ghana (formerly The Gold Coast). Birimian lithofacies is characterised by subaqueous fine-grained sediments with bimodal volcanic material. Metasedimentary rocks include phyllites and metawackes. Metavolcanic rocks are predominantly tholeiitic basalts. Komatiites and banded iron formations (BIF) are absent.Gold is in 5 parallel, evenly spaced, more than 300 km long, northeast-trending volcanic belts separated by basins containing pyroclastic and meta-sedimentary units. The most prominent is the Ashanti volcanic “greenstone” belt, which hosts the Ashanti Goldfields Corporation mines at Obuasi (more than 800,000 kg Au since 1896), the Billiton Bogosu Gold mine at Bogosu, and the State Gold Mining Corporation mines at Prestea, Bibiani and Konongo.Gold, ranging from 2 to 30 ppm, is in quartz veins of laterally extensive major orebodies which deeply penetrate fissures and shear zones at contacts between metasedimentary and metavolcanic rocks. The veins consists mainly of quartz with carbonate minerals, green sericite, carbonaceous partings and metallic sulfides and arsenides of Fe, As, Zn, Au, Cu, Sb, and Pb. Gold occurs in carbonate fillings in fractured quartz veins. Country rocks, which contain rutile, anatase and granular masses of leucoxene, along ore channels, have been hydrothermally altered to carbonates, sericite, silica and sulfide minerals. Fluid inclusion evidences suggest that mineral deposition took place at about 350°C and 140 bar from dilute aqueous solutions. Timing deduced from ore textures, however, show complex multi-stage mineralization events, with higher temperature minerals commonly having formed later than lower temperature ones. Geochemical studies of materials produced by tropical processes, especially soils, are essential in prospecting poorly exposed terranes of west Africa. Trace and major element distributions at mines and mineral occurrences can indicate mineralization otherwise difficult to detect.This paper highlights the features of the Ghanaian gold deposits that may aid the current search for new deposits along the gold belts. Exploration based on geochemistry is highly important, but should be integrated with data from accompanying geological, lithologic, mineralogical, and structural studies.     

Temporal Variation in the Trophic Levels of Secondary Consumers in a Mediterranean Coastal Lagoon (Cabras Lagoon,Italy)

Trophic levels (TLs) of fish were estimated on three sampling dates (March, May, and August 2006) for different fish sizes in the Cabras Lagoon (Sardinia, Italy). A temporal TL variation for Atherina boyeri, Gobius niger, and Engraulis encrasicolus was observed. In March and May, the TL ranged from 3.3 to 3.4, characterizing these species as secondary consumers, while in August, this range moved to between 3.7 and 3.8, indicating a TL shift towards tertiary consumers. For Liza ramada, TL was consistently lower in small individuals (mean TL 2.5) than in larger individuals (mean TL 3.0). Increased TL of the fish species A. boyeri, G. niger, and E. encrasicolus in August was consistent with the seasonal changes in the macrobenthic assemblage in this system, with a dominance of primary consumers (benthic deposit feeders) in winter–spring and a dominance of secondary consumers (the nereidids Alitta succinea and Hediste diversicolor) in summer. These fish species took advantage of the high availability of nereidids leading to a rise in their TL values. Furthermore, the increase of TL with size of L. ramada, the most economically valuable fish species in the Cabras Lagoon, indicated an ontogenetic diet shift, the juveniles being omnivorous, while the adults being secondary consumers. We conclude that variability in the trophic levels of fish due to species traits, ontogenetic diet shifts, and variation in prey availability should be taken into account to further understand the food web structure of coastal lagoons.     

Sources of Salinity Variation in a Coastal Lagoon in a Karst Landscape

Bahia de la Ascension (BA) is a shallow, mangrove-fringed coastal bay connected to the Caribbean through two inlets, outlined by the Mesoamerican Barrier Reef System. This work represents an initial investigation of the relative contribution of hydrometeorological and hydrodynamic forcing on salinity variation in this lagoon. Our objective is to assess the sensitivity of the salinity in BA to fluctuations in freshwater inflow and coastal oceanography. Two field trips were undertaken during rainy and dry seasons in 2007. Surface salinity was mapped across the system and CTD deployments carried out within BA and in the sea end-member to characterize temperature, conductivity, and water level. Also, cross-sectional CTD profiles were implemented to examine vertical stratification. The water balance indicated that 16 % of rainfall over the drainage basin (DB) becomes groundwater discharge plus surface runoff into BA during dry season, while 68 % of the precipitation input to the DB is supplied through groundwater–surface runoff to the bay during rainfalls. This combined inflow showed larger fluctuations than direct rainfall and, thus, has a greater potential to alter the seasonal salinity variations within BA. The tidal signal is selectively attenuated within BA, as diurnal frequencies are more readily filtered out than semidiurnal frequencies. Mesohaline conditions in the southwest bay are associated with freshwater sources, while saline water masses in the inlet are influenced by prevalent SE winds in the region and tidal phase, establishing a strong horizontal SW-NE estuarine salinity gradient.     

Geology,geodynamics and orogenic gold prospectivity modelling of the Paleoproterozoic Kumasi Basin,Ghana, West Africa

This paper describes the geology and tectonics of the Paleoproterozoic Kumasi Basin, Ghana, West Africa, as applied to predictive mapping of prospectivity for orogenic gold mineral systems within the basin. The main objective of the study was to identify the most prospective ground for orogenic gold deposits within the Paleoproterozoic Kumasi Basin. A knowledge-driven, two-stage fuzzy inference system (FIS) was used for prospectivity modelling. The spatial proxies that served as input to the FIS were derived based on a conceptual model of gold mineral systems in the Kumasi Basin. As a first step, key components of the mineral system were predictively modelled using a Mamdani-type FIS. The second step involved combining the individual FIS outputs using a conjunction (product) operator to produce a continuous-scale prospectivity map. Using a cumulative area fuzzy favourability (CAFF) curve approach, this map was reclassified into a ternary prospectivity map divided into high-prospectivity, moderate-prospectivity and low-prospectivity areas, respectively. The spatial distribution of the known gold deposits within the study area relative to that of the prospective and non-prospective areas served as a means for evaluating the capture efficiency of our model. Approximately 99% of the known gold deposits and occurrences fall within high- and moderate-prospectivity areas that occupy 31% of the total study area. The high- and moderate-prospectivity areas illustrated by the prospectivity map are elongate features that are spatially coincident with areas of structural complexity along and reactivation during D4 of NE–SW-striking D2 thrust faults and subsidiary structures, implying a strong structural control on gold mineralization in the Kumasi Basin. In conclusion, our FIS approach to mapping gold prospectivity, which was based entirely on the conceptual reasoning of expert geologists and ignored the spatial distribution of known gold deposits for prospectivity estimation, effectively captured the main mineralized trends. As such, this study also demonstrates the effectiveness of FIS in capturing the linguistic reasoning of expert knowledge by exploration geologists. In spite of using a large number of variables, the curse of dimensionality was precluded because no training data are required for parameter estimation.     

Upwind return flow in a Coastal Lagoon: Seasonal-scale barotropic transport

Current and wind data collected during a 223-d study period from early June 1983 through early January 1984 are used to document net upwind return flow over seasonal time scales in the Indian River Lagoon near Sebastian Inlet on the Atlantic Coast of central Florida. Spectral analysis of wind and current meter data suggests that wind forcing accounts for the majority of nontidal flow. The two time series are highly coherent at periodicities of 2,3–3.5, 4, and 6 d. The serial correlation coefficient of ?0.49 is significant at the 99.9% confidence level. Historical water level and wind data recorded simultaneously at Sebastian Inlet and Eau Gallie, 34.5 km to the north, suggest that longitudinal pressure gradients are established in response to seasonal wind patterns. The upwind near-bottom return flow is interpreted as a response to the seasonal set up of the longitudinal pressure gradients. The study documents the importance of windstress in forcing low-frequency transport over seasonal time scales.     

西非海岸盆地群形成演化及深水油气田发育特征

西非海岸盆地群的形成演化受非洲板块构造演化和大西洋张裂的控制,总体上可以分为前裂谷阶段、裂谷阶段和后裂谷阶段。沿岸15个主要盆地从北往南可细分为5段,分别为北段盐盆、中段盆地、尼日尔三角洲、中南段盐盆、南段盆地。深水油气田主要发育于后裂谷阶段的上白垩统和第三系海退层序中,以油田为主。在尼日尔三角洲和中南段盐盆的下刚果盆地,所发现的油气田个数及可采储量均比较集中,个数占西非深水油气田总个数比例分别为55%和29%,占总可采储量的比例分别为48%和41%。烃源岩主要有裂谷阶段下白垩统的湖相烃源岩,后裂谷阶段上白垩统、第三系的海相烃源岩。绝大多数储层为浊积岩储层,类型以深水水道砂岩为主,其次为席状砂储层和砂质碎屑流储层。圈闭类型主要为构造-地层复合圈闭,其次为构造圈闭,另外还有地层-岩性圈闭,其所占比例较小。盐构造和泥岩塑性变形构造总体上控制了西非深水区大多数复合圈闭和构造圈闭的形成。     

Demography and biomass of the seagrass Zostera marina in a Mexican Coastal Lagoon

From January 1987 to February 1988 the annual biomass cycle and demography of the seagrass Zostera marina were assessed in San Quintin Bay, a shallow coastal lagoon on the Pacific coast of Baja California, Mexico. Shoot density and aboveground biomass were sampled monthly along two intertidal transects parallel to the shore. Belowground biomass was sampled every 2 mo. Shoot density differed between transects, ranging from 929±71 (SE) in July to 279 ±80 shoots m⁻² in December, at the deeper transect (I). At the shallow transect (II) there was not a significant difference through time, and a mean of 737 shoots m⁻² was calculated. Lateral shoots were present year round and represented between 1% and 30% of total density at transect I and between 3% and 25% at transect II. Reproductive shoots were present from March to September at both transects, with a density range of 77±28 shoots m⁻² (March) to 9±3 shoots m⁻² (September), and represented 5% of total shoot density. Neither aboveground biomass nor LAI (Leaf Area Index) differed between transects, with values ranging between 77±14.5 g dry wt m⁻² (October 1987) and 13±2.4 g dry wt m⁻² (February 1988) for aboveground biomass, and between 0.6±0.2 m² leves m⁻² substrate (January) and 2.7±0.3 m² leaves m⁻² substrate (September) for LAI. Neither root biomass nor rhizome biomass differed between transects, or as a function of time; the mean value for roots was 17 g dry wt m⁻² and for rhizomes 29 g dry wt m⁻². Belowground biomass represented 54% of total biomass. We found a significant correlation between aboveground biomass and LAI (r=0.949 for transect I, and 0.926 for transect II) as well as between total biomass (aboveground and belowground) and LAI (r=0.814), which allows us to consider using LAI as a predictor of these variables. Biomass changes were related to changes in shoot weight (r=0.676 at transect I; 0.582 at transect II), more than to changes in shoot number. Water temperature was found to be the driver of biomass changes in the aboveground compartment.     

Major Ion Chemistry in a Freshwater Coastal Lagoon from Southern Brazil (Mangueira Lagoon): Influence of Groundwater Inputs

This paper characterizes major ion distributions and investigates whether groundwater exerts a major control on the chemical functioning of Mangueira Lagoon, a large (90 km long), shallow (∼4–5 m deep), and fresh coastal lagoon in southern Brazil. Water volumes equivalent to ∼80% of the total annual input are used in the summer for irrigating nearby rice plantations, the most important regional economic activity. While Na⁺ and Cl⁻ are the major ions in local groundwater, Na⁺ and HCO₃⁻ are the most enriched ions in lagoon water. The ion concentrations measured in Mangueira Lagoon were homogeneous, except for a few samples affected by rainwater and groundwater inputs. A shore-normal transect starting at the pump house of a rice irrigation canal indicated strong groundwater input at this canal. In spite of the small volume contribution (∼2% of precipitation), groundwater discharge accounts for 50–70% of major ion inputs into the lagoon, with ∼70% of the groundwater inputs being anthropogenically derived (e.g., from the rice irrigation canals). This may have serious implications for the management of the coastal water resources from Mangueira Lagoon and other similar areas as groundwater associated with agricultural systems may be contaminated by fertilizers and pesticides. The results imply that groundwater should not be neglected in dissolved species’ budgets even when its volume contribution is small.     

Eutrophication of a Maryland/Virginia Coastal Lagoon: a Tipping Point,Ecosystem Changes,and Potential Causes

Water quality in the Maryland/Virginia Coastal Bays has been declining for many years from anthropogenic inputs, but conditions appear to have worsened abruptly following a shift from long-term dry to long-term wet conditions in the early 2000s. Annually and regionally averaged total nitrogen concentrations are approximately twofold higher, but ammonium (NH₄ ⁺) concentrations are up to an order of magnitude higher than in the early 1990s. Averaged nitrate concentrations, however, changed to a lesser degree throughout the time course; water column concentrations remain very low. Total phosphorus has only increased in some bay segments, but increases in phosphate (PO₄ ^3?) have been more pervasive. There were differences in the year in which large increases in each nutrient were first noted: PO₄ ^3? in ~2001–2002, followed by NH₄ ⁺ ~a year later. The effects of a combination of steadily increasing anthropogenic nutrient increases from development, superimposed on nutrient loads from farming and animal operations, and groundwater inputs were accelerated by changes in freshwater flow and associated, negatively reinforcing, biogeochemical responses. Regionally, chlorophyll a concentrations have increased, and submersed aquatic vegetation has decreased. The system is now characterized by sustained summer picoplanktonic algal blooms, both brown tide and cyanobacteria. The retentive nature of this coastal lagoon combined with the reducing nature of the system will make these changes difficult to reverse if the current dual nutrient management practices are not accelerated.     

Using an integrated method for the determination of environmental TCLP arsenic for sulphide-rich mine tailing remediation in Ghana,West Africa

Toxicity characteristic leaching procedure (TCLP) is a versatile short-term leaching protocol used to estimate the release of toxic metals from waste prior to disposal to a repository. This paper uses the integrated TCLP leachate data from tailings, tailings dam monitoring borehole data, and acidity ratio (AR) range of sulphide-rich ores to simulate the environmental TCLP As in tailings at the AngloGold Ashanti Obuasi mine in Ghana. The aim was to incorporate long-term leaching characteristics of tailings to minimise the risk of TCLP As test failure. The mean As concentration and pH value are 2.26 mg/l and 5.7 in TCLP leachate, 0.35 mg/l and 6.7 in monitoring boreholes, and?<?0.01 mg/l and 5.7 in control boreholes, respectively. The evaluation of the TCLP As data using a one-sample t test performed at 80% confidence interval has the upper confidence limit (UCL) of 2.41 mg/l; this value which constitutes the short-term characterised environmental TCLP As is below the USEPA criterion of 5 mg/l and, therefore, qualifies the waste as safe for disposal. Alternatively, TCLP leachate, borehole and AR data were integrated to simulate the long-term environmental TCLP As of 2.40 mg/l and pH value of 5.7, and As concentration and pH value of 0.01 mg/l and 6.7 in monitoring boreholes, respectively. Such laboratory simulations of TCLP As leaching aimed at achieving 0.01 mg/l in field monitoring data would provide a more robust predictive value for environmental management decision making due to long-term considerations.     

Conflicting evidence on the timing of mesothermal and paleoplacer gold mineralisation in early Proterozoic rocks from Southwest Ghana,West Africa

Rocks of early Proterozoic age (ca. 2100 Ma) host the major gold deposits in Ghana. The deposits are either located in mesothermal quartz vein systems or hosted in a quartz pebble conglomerate that represents a paleoplacer. Both types of mineralisation are largely confined to the Ashanti Belt, one of four parallel northeast-trending volcanic belts. While the stratigraphy and structure of the belts are similar, the Ashanti belt is characterised by a more tectonised northwest margin where most of the epigenetic gold deposits are located. In these deposits, gold mineralisation is located in faults that parallel the regional trend of the belts and were active late in the deformation history of the terrane. The auriferous quartz pebble conglomerate is part of a clastic sequence that is largely derived from the adjacent volcanic and plutonic rocks with the gold widely regarded as having originated from eroded vein deposits. Structural data, however, show that both the volcanic rocks and clastic sequence were deformed jointly prior to epigenetic gold mineralisation. Thus, the quartz vein deposits could not have been the source of the paleoplacer mineralisation. The paleoplacer gold could have originated from one of several possible sources but none has been unequivocally identified.     

Karibibite,a new FeAs mineral from South West Africa

Karibibite (ideally, Fe₂As₄O₉) occurs in vugs in massive loellingite of the Karibib pegmatite area, South West Africa. It is brownish yellow and finely fibrous. The thickness of the soft, single fibers is less than 1 micron, unsuitable for single-crystal X-ray study. Electron diffraction and X-ray powder pattern indicate that the mineral is orthorhombic, with $\text{a}{}_0\text{= 27.91}\text{A}\text{?}\text{, b}{}_0\text{= 6.53}\text{A}\text{?}\text{and c}{}_0\text{(}\text{fiber axis}\text{) = 7.20}\text{A}\text{?}$. The space group cannot be given. The mineral is paramagnetic with yellow fluorescence and is pleochroic with γ > 2.10, α = 1.96, 2V_α large, d = 4.07. It is soluble in acids and alkali hydroxide. Decomposition starts around 320 °C. The infra-red absorption spectrum indicates absence of AsO₄ groups. The mineral is classified tentatively as an oxide or arsenite.     

Sustainability of groundwater in Mali,West Africa

The following paper describes the goals and some preliminary work in the Bani sustainability study, an ongoing project in Mali, West Africa. Rural communities in Mali are increasingly relying on hand-pumps, which tap groundwater resources, as a means of obtaining potable water. The long-term sustainable yield of groundwater resources is not known but can be evaluated in sustainability study. In 2005, a groundwater sustainability study was established along the Bani River of Mali. The Bani study collected groundwater levels that were used in a conceptual groundwater flow model—the Bani model—to develop an understanding of current aquifer conditions and to make limited predictions of sustainability under various future scenarios. The Bani model showed the climatic parameters of recharge (derived from precipitation) and evapotranspiration to influence simulated groundwater levels and groundwater volume available, while increased pumping rates, due to population growth, showed little effect. When considered in the context of the actual Bani sustainability study area, the change in groundwater levels resulting from climatic parameters may have negative implications, especially during several consecutive years of decreased precipitation, such as drought, or if downward trends anticipated for precipitation continue.     

The Main Factors Affecting the Distribution of Oil Fields in the West Siberian Platform

It has been found that the main oil fields in Western Siberia are attributed to Triassic rifts, because the rifts drain the upper mantle, and the deformations of the sedimentary cover are determined by the basement. On average, the thickness of the basement is 14 times greater than that of the sedimentary cover. Taking into account the mean strength (153 ± 10 MPa) of the basement rocks, the basement strength is two orders of magnitude greater than the strength of the sedimentary cover. The sialic blocks, considered as Precambrian, are composed of light granites and metamorphic rocks. They ascend to the level of the upper crust at the time of Triassic rifting and continued to emerge. As a result, antiforms were formed above the sialic blocks in the sedimentary cover; these antiforms were filled with oil.     

Dust emission and transport in Mali, West Africa

Vertical dust fluxes were measured in the Inland Delta region of the Niger River, Mali, West Africa, during April-June, 1989 and 1990. Measurements of dust flux represent, for the most part, non-dust storm conditions or ‘dust haze’ periods. The observed concentration versus height relationships are similar to data presented by other investigators. The relationship between wind shear velocity (u_*, m s^?1) and vertical dust flux (F, μg m^?2 s^?1) can be described by a relationship in which F is proportional to u_*⁴. However, there is considerable scatter within the data set which is attributable to textural controls and surface conditions. The vertical dust fluxes measured in Mali are compared to dust fluxes measured in Texas, USA, and Yukon Territories, Canada. The significantly different values for the constant of proportionality (a) in the F α a u_*⁴ relationship for these geographically diverse areas is a function of surficial controls on the release of sediments to the air stream. Dust concentrations measured in Mali were found to be uniformly high and in general exceed WHO health standards for acceptable total suspended particulate loadings. As a result background dust may be considered a long term stress on health for the people of this region of Mali.     

The Decline and Restoration of a Coastal Lagoon (Lake Veere) in the Dutch Delta

The former tidal inlet Lake Veere was turned into a stagnant brackish lake in 1961. Ever since, the system has shown a continuous degradation. The current study shows the monitoring results for the macrozoobenthic communities and the abiotic conditions for the period 1990–2008. This includes the first step to remediation, the restoration of the exchange between the tidal marine Eastern Scheldt and Lake Veere in 2004. A continuous decline in water clearance co-occurring with decreasing macrofauna densities and richness was observed till 2004. Water quality (e.g., secchi depth, nutrient levels, and oxygen conditions) improved significantly after the measure at a higher salinity level with less variation. But the macrofauna densities, biomass, and diversity did not improve yet. First indications of changes in the benthic communities by arrival of new and returning species are however observed and show that restoration at macrofauna level follows the improved abiotic conditions with a delay of several years.