Temperate Coastal Lagoon Research Articles

Growth and Grazing Mortality of Microbial Plankton in a Shallow Temperate Coastal Lagoon (Ria Formosa, SW Iberia)

Microzooplankton grazing is widely recognized as an important process of heterotrophic prokaryote and phytoplankton biomass removal. However, few studies have specifically addressed microbial mortality in the Ria Formosa coastal lagoon. This study aimed to assess the growth and mortality of heterotrophic prokaryotes and phytoplankton in this ecosystem using the dilution technique. The results revealed significant seasonal variations in the growth and grazing rates of both heterotrophic prokaryotes and phytoplankton, with mean grazing rates slightly exceeding the mean potential instantaneous growth rates. This indicates that microzooplankton consume a substantial proportion of both microbial groups in the lagoon. For specific phytoplankton taxa, the wide range of observed grazing rates suggests grazer selectivity, highlighting the need for future research to examine the dynamics of each phytoplankton group more closely.

Pesticides in a temperate coastal lagoon in southwest Europe (Ria de Aveiro, Portugal) – Risk assessment and acute assays with Artemia and Daphnia

The Ria de Aveiro lagoon has been considered one of the most important Southern European long-term monitoring sites (LTER-site) concerning climate change and anthropogenic pollution. Nevertheless, studies concerning pesticide contamination herein are few and mostly outdated. Here, 56 pesticides dissolved in the aqueous phase (DAP) and suspended particulate matter (SPM) were examined to fill the knowledge gap, considering the hydrophobic nature of most evaluated compounds. Water samples were taken seasonally from eight sites, and both DAP and SPM fractions were analysed by gas-chromatography-mass spectrometry. The annual average concentrations of fungicides, herbicides and insecticides were ≈57 ng/L, ≈409 ng/L and ≈1058 ng/L in DAP and ≈7 μg/g, ≈28 μg/g and ≈67 μg/g in SPM. These pesticides and the excessive phosphate concentrations suggest that the lagoon's water quality may be hazardous to biota and humans. Invertebrates were identified as the most threatened trophic level using deterministic risk assessment, with chlorpyriphos and chlorfenvinphos being the primary culprits. Acute experiments with Artemia and Daphnia supported the suppositions.

Short-Term Effects of Climate Change on Planktonic Heterotrophic Prokaryotes in a Temperate Coastal Lagoon: Temperature Is Good, Ultraviolet Radiation Is Bad, and CO2 Is Neutral.

Planktonic heterotrophic prokaryotes (HProks) are a pivotal functional group in marine ecosystems and are highly sensitive to environmental variability and climate change. This study aimed to investigate the short-term effects of increasing carbon dioxide (CO2), ultraviolet radiation (UVR), and temperature on natural assemblages of HProks in the Ria Formosa coastal lagoon during winter. Two multi-stressor microcosm experiments were used to evaluate the isolated and combined effects of these environmental changes on HProk abundance, production, growth, and mortality rates. The isolated and combined effects of increased CO2 on HProks were not significant. However, HProk production, cellular activity, instantaneous growth rate, and mortality rate were negatively influenced by elevated UVR and positively influenced by warming. Stronger effects were detected on HProk mortality in relation to specific growth rate, leading to higher HProk net growth rates and abundance under elevated UVR and lower values under warming conditions.

The Role of Cymodocea nodosa and Caulerpa prolifera Meadows as Nitrogen Sinks in Temperate Coastal Lagoons

In coastal lagoons, marine benthic macrophyte meadows can be an important element in the resistance to eutrophication of the ecosystem, as they can function as temporary nitrogen sinks, limiting the availability of this nutrient for opportunistic organisms. The role of nitrogen sinks for two dominant macrophyte species of Mediterranean coastal lagoons, the seagrass Cymodocea nodosa and the seaweed Caulerpa prolifera, was analysed by two different approaches: (i) studying nitrate (NO3-) and ammonium (NH4+) uptake kinetics of aboveground tissues in a laboratory and (ii) estimating nitrogen stocks and demands of meadows under natural conditions. The studies were carried out in the coastal lagoon of the Mar Menor, which has been subjected to high anthropogenic nitrogen inputs for decades. While both macrophytes were efficient in exploiting NH4+ from the water column, only C. prolifera showed a high NO3- uptake capacity. Large N pools in the C. nodosa and C. prolifera meadows of the Mar Menor were detected, suggesting that these habitats may have the potential to be essential reservoirs for this nutrient. However, the major role of belowground tissues of the seagrasses in nitrogen accumulation may determine important differences between the two species in temporary N storage and sequestration. The data on N demands for the meadows of both macrophytes in the Mar Menor suggest an important contribution of these habitats in controlling the inputs of this nutrient into the lagoon. We conclude that C. nodosa and C. prolifera meadows can play a key role as a sink for dissolved inorganic nitrogen in temperate coastal lagoons, being an important mechanism of resistance to eutrophication.

Seasonal and Spatial Variability of Phytoplankton Primary Production in a Shallow Temperate Coastal Lagoon (Ria Formosa, Portugal).

Coastal lagoons are among the most productive ecosystems in the world, and they provide a wide range of ecosystem services and resources. In the Ria Formosa (southern Portugal), phytoplankton production has rarely been addressed. The main goal of this study is thus to evaluate the variability of phytoplankton production and photosynthetic characteristics over the seasonal cycle and in different locations (landward, urban, intermediate, and seaward boundaries) of the Ria Formosa coastal lagoon, subjected to distinct natural and anthropogenic stressors. Primary production was evaluated using the 14C incorporation technique, and photosynthetic parameters were estimated by fitting photosynthesis-irradiance curves. Primary production showed significant seasonal variations, with higher values in the summer associated with lower euphotic depths, higher water temperatures, and higher nutrient concentrations. No spatial differences were found for primary production or photosynthetic parameters. Primary production values were lower than previous estimates, which reflects an improvement in water quality in the Ria Formosa, but values are higher than primary production estimates for other temperate coastal ecosystems, which reflects the highly productive nature of this coastal lagoon.

Influence of seagrass meadows on nursery and fish provisioning ecosystem services delivered by Ria Formosa, a coastal lagoon in Portugal

This study is the first to evaluate the fish provisioning services of a whole transitional landscape (Ria Formosa lagoon, Portugal), in parallel with the enhancement of growth, survival and production of single cohorts of the most important commercial fish species by vegetated and unvegetated sub-tidal habitats. Based on monthly beach seine samples, total density and biomass of 96 species of fishes were 1.89 and 3.03 times greater in vegetated habitats than unvegetated habitats, respectively. Vegetated habitat enhanced survival in six of eight commercial species for which survival could be estimated in both habitats. The total production of all 12 commercially important species within vegetated habitat was approximately double that of unvegetated habitat, with production enhancement in 7 of 12 species ranging from 1.8 to 169-fold for the vegetated habitats. Within the lagoon, vegetated sub-tidal habitat covers an area 5-fold smaller than unvegetated habitat, yet it accounts for 27.1 % of fish production. Estimated total lifetime economic values of the single cohorts of the 12 commercial species were between 30 million and 59 million EUR. An exceptionally strong year class of the European seabass (Dicentrarchus labrax), a species with higher density and biomass in unvegetated habitat, accounts for the higher overall values per hectare for unvegetated habitat (Low natural mortality (M): EUR 32,844 ha−1; High M: EUR 16,751 ha−1) than for vegetated habitat (Low M: EUR 22,028 ha−1; High M: EUR 10,700 ha−1). These results highlight the enormous importance of temperate coastal lagoons as a nursery and source of recruits for coastal fisheries. Our evaluation of fish provisioning services based on data for individual cohorts of fish for a whole transitional landscape is a stronger and more valid approach for estimating future biomass and value than previous studies based on mean densities and biomasses of fish that did not distinguish between cohorts.

Seasonal variations in biochemical and stable isotope compositions of particulate organic matter in two contrasting temperate coastal lagoons of Korea

The geomorphology of coastal lagoons has an important effect on the hydrological balance between fresh water and seawater, which exhibit a wide range of salinity from nearly fresh water to hypersaline water. The present study aimed to characterize seasonal biogeochemical properties of suspended particulate organic matter (POM) in response to environmental variability driven by hydrological dynamics in contrasting coastal lagoon systems. We selected two lagoons distinguished by their geomorphological features, a permanently open artificial lagoon (Gyeongpoho) and an intermittently open natural lagoon (Hyangho), analyzed environmental characteristics, and compared the seasonal differences in the biochemical compositions of POM. Variations in temperature and precipitation in both lagoons showed the characteristics of a typical monsoon climate but variation in salinity differed 6.5−35.0 in Gyeongpoho and 1.1−10.8 in Hyangho. A self-organizing map analysis using the environmental data revealed that the spatiotemporal variations in salinity and nutrient concentrations differed significantly between the two lagoon systems, indicating a difference in hydrologic connectivity between lagoons and marine systems. Furthermore, a canonical correlation analysis highlighted that the POM properties differed according to physicochemical factors. The differing environmental conditions may affect the spatial and temporal variations in organic matter composition, resulting in significant differences in the biochemical composition of POM between two lagoon systems. Overall, this information provides insight into the origin and transport process of POM under changing coastal lagoon environments caused by climatic and human activities.

Seasonal, Diurnal, and Tidal Variations of Dissolved Inorganic Carbon and pCO2 in Surface Waters of a Temperate Coastal Lagoon (Arcachon, SW France)

We report on diurnal, tidal, and seasonal variations of dissolved inorganic carbon (DIC), water partial pressure of CO2 (pCO2), and associated water–air CO2 fluxes in a tidal creek of a temperate coastal lagoon with 70% of intertidal flats, during eight tidal/diurnal cycles and two consecutive years covering all seasons. Surface waters of the lagoon were always slightly oversaturated in CO2 with respect to the atmosphere with an average pCO2 value of 496 ± 36 ppmv. Seasonally, subsurface water pCO2 values were controlled by both temperature and biological/tidal advection effects that compensated each other and resulted in weak annual variations. High-resolution temporal pCO2 records reveal that the highest fluctuations (192 ppmv) occurred at the tidal/diurnal scale as a result of biological activity, advection from the tidal flat, and porewater pumping that all contributed to water pCO2 and carbonate chemistry variations. Total alkalinity (TA) versus salinity plots suggest a net production of alkalinity in the lagoon attributed to benthic carbonate dissolution and/or anaerobic degradation of organic matter. We specifically highlighted that for the same salinity range, during flooding, daytime pCO2 were generally lower than nighttime pCO2 values because of photosynthesis, whereas during ebbing, daytime pCO2 were higher than nighttime pCO2 values because of heating. Waters in the lagoon were a relatively weak CO2 source to the atmosphere over the year compared to other estuarine and lagoon waters elsewhere, and to sediment-air fluxes measured simultaneously by atmospheric Eddy Covariance (EC) in the Arcachon lagoon. Because of low values and small variations of the air-sea pCO2 gradient, the variability of fluxes calculated using the piston velocity parameterization was greatly controlled by the wind speed at the diurnal and, to a lesser extent, seasonal time scales. During the emersion, the comparison of these pCO2 data in the tidal creek with EC fluxes measured 1.8 km away on the tidal flat suggests high heterogeneity in air-sea CO2 fluxes, both spatially and at short time scales according to the inundation cycle and the wind speed. In addition to tidal pumping when the flat becomes emerged, our data suggest that lateral water movement during the emersion of the flat generates strong spatial heterogeneity in water–air CO2 flux.

Carbon accumulation and storage in a temperate coastal lagoon under the influence of recent climate change (Northwestern Adriatic Sea)

Pialassa Baiona is a shallow temperate coastal lagoon influenced by a variety of factors, including regional climate change and local anthropogenic disturbances. To better understand how these factors influenced modern organic carbon (OC) sources and accumulation rates, we measured OC as well as stable carbon isotopes (δ13C) in 210Pb-dated sediments within a vegetated saltmarsh habitat and a human impacted habitat. Relative Sea Level (RSL) at the nearby tide gauge station data and four different Sea Surface Temperature (SST) data sets were analyzed starting from 1900 to assess the potential effect of sea ingression and warming on the coastal lagoon sedimentary processes. The source contribution calculated from the MixSIAR Bayesian model revealed a mixed composition of sedimentary OC, dominated by an increase in marine-derived OC after the 1950s, matching with a decrease from autochthonous saltmarsh vegetation (Juncus spp.) in the saltmarsh habitat, and from riverine/estuarine-derived OC in the impacted habitat. RSL rise in the area (8.7 ± 0.5 mm yr−1 in the period 1900–2014) has been mainly driven by the land subsidence, especially during the central decades of the last century, enhancing the sea ingression into the lagoon. RSL rise influenced changes in sedimentary OC sources and accumulation at different level within the two habitats from the 1950s onward; conversely, no direct effect of SST was detected.

Short-term effects of winter warming and acidification on phytoplankton growth and mortality: more losers than winners in a temperate coastal lagoon

Short-term effects of winter warming and acidification on phytoplankton growth and mortality: more losers than winners in a temperate coastal lagoon

Evaluating connections between nitrogen cycling and the macrofauna in native oyster beds in a New England estuary.

Recent efforts to quantify biogeochemical and ecological processes in oyster habitats have focused on provision of habitat and regulation of the nitrogen cycle. However, it is unclear how these two processes may interact. In this study, seasonal patterns of habitat use and nitrogen removal from natural oyster beds were quantified for comparison with nearby bare sediment in Green Hill Pond, a temperate coastal lagoon in Rhode Island USA. Relationships were tested between benthic macrofaunal abundance and nitrogen removal via denitrification and burial in sediments. Nitrogen removal by oyster bio-assimilation was quantified and compared with nearby oyster aquaculture. Despite limited differences in habitat use by macrofauna, there were fewer non-oyster benthic organisms (e.g., filter-feeders, detritivores) where oysters were present, possibly due to competition for resources. Additionally, low rugosity of the native oyster beds provided little refuge value for prey. There was a shift from net N removal via denitrification in bare sediments to nitrogen fixation beneath oysters, though this change was not statistically significant (t(96) = 1.201; p = 0.233). Sediments contained low concentrations of N, however sediments beneath oysters contained almost twice as much N (0.07%) as bare sediments (0.04%; p < 0.001). There was no difference in tissue N content between wild oysters and those raised in aquaculture nearby, though caged oysters had more tissue per shell mass and length, and therefore removed more N on a shell length basis. These oyster beds lacked the complex structure of 3-dimensional oyster reefs which may have diminished their ability to provide habitat for refugia, foraging sites for macrofauna, and conditions known to stimulate denitrification.

Shifting resource utilization of the lacustrine shrimp Palaemon paucidens in temperate coastal lagoons of Korea as revealed by stable isotopes

The spatial and seasonal variations in resource use of the lacustrine shrimp Palaemon paucidens were investigated in three different Korean lagoon systems in June and October 2018 by measuring their carbon and nitrogen stable isotope ratios. P. paucidens had much higher δ13C values at the permanently open lagoon (PL) as compared to the intermittently open lagoons (ILs), revealing a disparity in resource utilization. Isotopic niches of the shrimp were relatively wider at the PL than at the ILs, suggesting a greater diversity of carbon pathways in the PL system. These results indicate that the degree of water exchange with the sea, associated with lagoon geomorphology, may be a major factor influencing resource availability for P. paucidens. Our findings suggest that the duration and degree of inlet opening may affect dietary variation at the population level, and may be one of the key components of sustainable management for coastal lagoon ecosystems.

Mercury forms in the benthic food web of a temperate coastal lagoon (southern Baltic Sea)

The study was conducted in the coastal zone of the southern Baltic. The research material consisted of macrozoobenthos and elements of its diet. The samples were analysed for Hg and its labile and stable forms, using the thermodesorption method. The results showed that the level of total Hg in zoobenthos was associated with dietary preferences and the share of bioavailable Hg in its food. The Hg fractionation in the macrofauna was conditioned by biological features (morphological structure) and environmental parameters (oxygenation, pH) which shape the mobility and assimilation of Hg. The absorption of the most toxic organic Hg in macrofauna was more effective in aerobic conditions, at low primary production and with the limited inflow of organic matter. The trophic transfer of Hg was favoured by the limited biomass of primary producers, and consequently of zoobenthos. An important factor influencing the biomagnification was also the share of labile Hg in macrozoobenthos.

Plankton community and copepod production in a temperate coastal lagoon: What is changing in a short temporal scale?

Coastal lagoons are often exposed to intense short-term environmental changes and strong anthropogenic pressures influencing zooplanktonic communities and production. However, most works focus on long-term temporal scales using monthly or seasonal sampling strategies. The present study analysed the structure of the mesozooplanktonic assemblages, the production (egg production rates) and physiological condition (RNA:DNA ratio) of the copepod Acartia clausi in a temperate coastal lagoon (Ria Formosa) during the summer, using an intensive sampling approach. Salinity was the main factor affecting the short-term variability of mesozooplankton composition, followed by tidal phase (ebb tides) and semilunar cycle (spring tides). There was a positive relationship between the abundance of Appendicularia and the cladoceran Penilia avirostris with the toxic dinoflagellate Gymnodinium catenatum, suggesting no deleterious effects. The egg production rate of A. clausi was influenced by salinity and ammonia concentration, with a positive correlation between the egg productivity and the macronutrient, showing a possible adaptation of this calanoid species. The RNA:DNA index was positively related to egg production rate, suggesting that it is a good proxy for the reproductive output of copepods, even in short-term periods. This study shows that different timescales need to be included in regular monitoring of planktonic assemblages in coastal lagoons in order to understand the influence of environmental and anthropogenic variables on marine organisms.

Diel variation of ichthyoplankton recruitment in a wind-dominated temperate coastal lagoon (Argentina)

This study aimed to assess the diel changes of ichthyoplankton occurrence, during a known recruitment period, to a wind-dominated coastal lagoon (Argentina). We collected plankton samples at three sites of the lagoon's inlet area every 3 h during four 24 h cycles in mid austral summer. For each early-life history stage (eggs, yolk sac, preflexion larvae, postflexion larvae and early juveniles), the relationship between the abundance and possible combinations of the time of sampling, the wind effect, the wave period and the tidal state was evaluated by fitting generalized linear mix-effects models (GLMM). The wind effects depending on the time of sampling mainly affected fish abundance in all developmental stages. Overall, the highest abundances were collected at nocturnal hours when low-speed offshore winds blew. In addition, higher abundances of eggs, yolk sac and preflexion larvae were related to the incoming flood tide; whereas higher abundances of postflexion larvae and early juveniles were related to longer wave periods. We argued that the daily variation in the abundance of early-life history stages of fishes is related to the sea-land breeze cycle. Therefore, a conceptual framework of the recruitment process of eggs, larvae and early juveniles of fishes into this estuarine system considering the daily effect of winds is proposed.

A review of the influence of biogeography, riverine linkages, and marine connectivity on fish assemblages in evolving lagoons and lakes of coastal southern Africa.

The Holocene evolution of eight South African coastal lakes and lagoons is examined and related to changes in fish composition over that period. Historical and current connectivity with riverine and marine environments are the primary determinants of present‐day fish assemblages in these systems. A small and remarkably consistent group of relict estuarine species have persisted in these coastal lakes and lagoons. The loss or reduction of connectivity with the sea has impacted on the diversity of marine fishes in all eight study systems, with no marine fishes occurring in those water bodies where connectivity has been completely broken (e.g. Sibaya, Groenvlei). In systems that have retained tenuous linkages with the sea (e.g., Verlorenvlei, Wilderness lakes), elements of the marine fish assemblage have persisted, especially the presence of facultative catadromous species. Freshwater fish diversity in coastal lakes and lagoons is a function of historical and present biogeography and salinity. From a freshwater biogeography perspective, the inflowing rivers of the four temperate systems reviewed here contain three or fewer native freshwater fishes, while the subtropical lakes that are fed by river systems contain up to 40 freshwater fish species. Thus, the significantly higher fish species diversity in subtropical versus temperate coastal lakes and lagoons comes as no surprise. Fish species diversity has been increased further in some systems (e.g., Groenvlei) by alien fish introductions. However, the impacts of fish introductions and translocations have not been studied in the coastal lakes and lagoons of South Africa. In these closed systems, it is probable that predation impacts on small estuarine fishes are significant. The recent alien fish introductions is an example of the growing threats to these systems during the Anthropocene, a period when human activities have had significant negative impacts and show potential to match the changes recorded during the entire Holocene.

Effect of spatio-temporal shifts in salinity combined with other environmental variables on the ecological processes provided by Zostera noltei meadows

The present study aims to assess the plastic response of Zostera noltei meadows traits under spatio-temporal shifts in salinity combined with sediment environmental variables (temperature; pH; loss-on-ignition (LOI); carbon (C) and nitrogen (N) pools (top 5 cm)). Z. noltei biomass, C and N pools, leaf photosynthetic performance and esterified fatty acid (FA) profile were assessed within a temperate coastal lagoon during winter and late spring, along sites spatially distributed. None of the surveyed traits for Z. noltei displayed a clear spatial trend. Z. noltei proved to be euryhaline, whose biology was only slightly affected within this salinity range, in each season (14–39 in winter; 33–41 in late spring). Seasonal differences in salinity and environmental parameters explain the differences recorded in Z. noltei traits (aboveground biomass, N and C pools; photosynthetic performance). Spatio-temporal salinity shifts did not significantly affect the pool of FA present in Z. noltei. Overall, within the salinity range surveyed, the ecological processes studied and regulating Z. noltei meadows do not appear to be at risk. This work reinforces the plasticity of Z. noltei to salinity shifts within the studied range, with this finding being particularly relevant in the context of extreme weather events (e.g., winter freshwater floods, summer droughts).

Topological and biomass balance approaches to analyzing food webs of Bahía Magdalena, Baja California Sur, Mexico

In this paper, we used two methodological approaches to analyze the structure and function of a trophic web in the temperate coastal lagoon of Bahia Magdalena, Baja California Sur, Mexico, which represents the largest wetland ecosystem along the west coast of the Baja California peninsula. Ecosystem structure was studied using a topological approach, while ecosystem functioning was analyzed using a biomass balance model. Connectance values indicated a low number of functional group interactions, consistent with the range proposed for similar marine trophic webs. This pattern may reflect incorporation of a few functional groups clustered along the trophic web. Results would vary if the model included more functional groups or different levels of aggregation, since aggregation and diversity strongly influence the base of the food web. Topological results suggest that trophic web structure depends primarily on lower and intermediate trophic level organisms like macrobenthic invertebrates, penaeid shrimp and marine turtles. Balance biomass model results suggest that trophic groups positioned on the first level most strongly support Bahia Magdalena trophic web functioning. In particular, the pelagic red crab (Pleurocondes planipes) transfers energy between basal and upper levels of the food web (a wasp-waist energy control). When compared to ecosystems at different latitudes, the results indicate that the Bahia Magdalena ecosystem is still in a developmental phase, wherein trophic web functioning depends largely on the balance between energy flows originating from primary producers and those originating from detrital pathways. While these results are preliminary, they demonstrate the potential of combined topological and biomass approaches in analyzing highly organized ecosystems. The combined approach can make both theoretical and empirical predictions about the functional response of real systems to structural changes, thus enhancing evidence-based methods for ecosystem management.

Effect of historical contamination in the fish community structure of a recovering temperate coastal lagoon

This study aimed to assess the impact of trace element concentrations in fish assemblages of a recovering coastal lagoon. Fish, water and sediment were sampled in winter and summer in the Ria de Aveiro (Portugal). Multivariate analyses were used to examine the relationship between fish assemblages and environmental variables (physical-chemical parameters, contaminants and sediment grain size). In winter, fish density and biomass were mainly affected by the water turbidity, while Li concentration in the water column was found to be significant for fish biomass. During summer, a significant relationship was found between fish density and temperature, Hg, Li and Zn concentration in the sediment. These contaminants were mainly associated with the historically contaminated area, were Liza spp. and Dicentrarchus labrax appeared as dominant species. Environmental variables were not significant for fish biomass. The historical contamination in the Ria de Aveiro still seems to exert some influence on fish community structure.

Pollution by endocrine disruptors in a southwest European temperate coastal lagoon (Ria de Aveiro, Portugal).

Ria de Aveiro is a Portuguese lagoon renowned for its ecological and economic importance. Nonetheless, in literature, few data exist about its organic pollution. Accordingly, this study chemically monitored for the first time a series of 17 endocrine disruptor compounds (EDCs). The target EDCs include natural (17β-oestradiol, oestrone) and pharmaceutical (17α-ethynylestradiol) oestrogens, industrial/household xenoestrogenic pollutants (octylphenols, nonylphenols and their mono and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein) and the phytosterol sitosterol (SITO). For the investigation of these EDCs, water samples were taken from eight sampling sites widely spread along the lagoon, at three different occasions in 2011, and analysed by gas chromatography-mass spectrometry. Results not only proved the ubiquitous distribution of all analysed EDCs but revealed that their amounts were extremely high at all sampling sites. The annual average concentrations were ≈ 46 ng/L for oestrogens, ≈ 3962 ng/L for industrial/household chemicals, ≈ 1740 ng/L for phytoestrogens and ≈ 908 ng/L for SITO. Normalising these values in ethynylestradiol equivalents (EE2eq), the oestrogenic load in this lagoon attained ≈ 50 ng/L EE2eq, which is a value well above that known to produce oestrogenic-induced disorders in aquatic fauna. Additionally, phosphate concentrations were also above the legal limits (>1 mg/L). Overall, data show EDCs at toxic relevant levels in the Ria de Aveiro and stress the need to enforce depollution measures in this habitat.