scholarly journals Eutrophication patterns in an eastern Mediterranean coastal lagoon: Vassova, Delta Nestos, Macedonia, Greece

2005 ◽  
Vol 6 (2) ◽  
pp. 17 ◽  
Author(s):  
S. ORFANIDIS ◽  
N. STAMATIS ◽  
V. RAGIAS ◽  
W. SCHRAMM
Keyword(s):  
Coastal Lagoon ◽  
Eastern Mediterranean ◽  
Coastal Lagoons ◽  
Fish Farming ◽  
Basic Knowledge ◽  
Spatiotemporal Variability ◽  
Dissolved Phosphorus ◽  
Salinity Gradients ◽  
High Precipitation ◽  
Water Values

The results of an intensive monitoring study of main eutrophication parameters in relation to fish farming management, climate and hydrography in the Vassova coastal lagoon (Nestos Delta) are presented. The overall aim is to produce basic knowledge in order to contribute to the management of eutrophication of coastal lagoons at local and national levels. Due to extensive spatiotemporal variability of the measured parameters correlation and regression polynomial analysis was used to identify patterns (p<0.05). Freshwater was the main source of nitrate and phosphate in the lagoon. This finding has justified the reduction of freshwater inflow in the past, which, however, has increased mean salinity to 30 PSU and reduced spatial salinity gradients. Maximum nitrate values in winter coincided with adverse climatic and hydrographic conditions (high precipitation, strong NE to E winds and low tide) and fish farming management that hinder water circulation. Dissolved phosphorus variability indicated the combination of the external (freshwaters) and internal (sediment) P-sources. N/P water values indicated nitrogen being the most important nutrient for primary producers throughout the year, except in winter, when phosphorus was the most important nutrient. Practical measures for improving fish farming practices to decrease “eutrophication risk” during winter are suggested. Existing nutrient data from the Vassova and from other Greek lagoons in comparison were also presented and discussed.

scholarly journals Drivers of Macrophyte and Diatom Diversity in a Shallow Hypertrophic Lake

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1569
Author(s):  
Kateřina Šumberová ◽  
Ondřej Vild ◽  
Michal Ducháček ◽  
Martina Fabšičová ◽  
Jan Potužák ◽  
...  
Keyword(s):  
Fish Farming ◽  
Spatial Diversity ◽  
Spatiotemporal Variability ◽  
Water Level Fluctuations ◽  
Nutrient Requirements ◽  
Diatom Assemblages ◽  
Climatic Extremes ◽  
Growing Seasons ◽  
High Species Richness ◽  
Different Parts

We studied macrophyte and diatom assemblages and a range of environmental factors in the large hypertrophic Dehtář fishpond (Southern Bohemia, Czech Republic) over the course of several growing seasons. The spatial diversity of the environment was considered when collecting diatoms and water samples in three distinct parts of the fishpond, where automatic sensor stations continually measuring basic factors were established. Macrophytes were mapped in 30 segments of the fishpond littoral altogether. High species richness and spatiotemporal variability were found in assemblages of these groups of autotrophs. Water level fluctuations, caused by the interaction of fish farming management and climatic extremes, were identified as one of the most important factors shaping the structure and species composition of diatom and macrophyte assemblages. The distance of the sampling sites from large inflows reflected well the spatial variability within the fishpond, with important differences in duration of bottom drainage and exposure to disturbances in different parts of the fishpond. Disturbances caused by intensive wave action are most probably a crucial factor allowing the coexistence of species with different nutrient requirements under the hypertrophic conditions of the Dehtář fishpond. Due to a range of variables tested and climatic extremes encountered, our study may be considered as a basis for predictive model constructions in similar hypertrophic water bodies under a progressing climate change.

GIS in environmental monitoring and assessment of fish farming impacts on nutrients of Pagasitikos Gulf, Eastern Mediterranean

Aquaculture ◽  
2019 ◽  
Vol 501 ◽  
pp. 62-75 ◽  
Author(s):  
Nikos Neofitou ◽  
Kostas Papadimitriou ◽  
Christos Domenikiotis ◽  
Lamprini Tziantziou ◽  
Panagiota Panagiotaki
Keyword(s):  
Environmental Monitoring ◽  
Eastern Mediterranean ◽  
Fish Farming

scholarly journals Multivariate Statistical Analysis Applied to Water Quality of a Tropical Coastal Lagoon, Cartagena, Colombian Caribbean

2019 ◽  
Vol 20 (1) ◽  
pp. 141
Author(s):  
Ildefonso Baldiris-Navarro ◽  
Juan Carlos Acosta-Jimenez ◽  
Angel Dario Gonzalez-Delgado ◽  
Alvaro Realpe-Jimenez ◽  
Juan Gabriel Fajardo-Cuadro
Keyword(s):  
Water Quality ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Coastal Lagoon ◽  
Coastal Lagoons ◽  
Oxygen Demand ◽  
Habitat Destruction ◽  
Environmental Data ◽  
Fecal Coliforms ◽  
Components Analysis

Coastal lagoons are one of the most threatened ecosystems in the world, because of population growth, habitat destruction, pollution, wastewater, overexploitation and invasive species which are the main causes of their degradation. The objective of this paper was to evaluate the water quality behavior in a stressed coastal lagoon in Cartagena, Colombian Caribbean. Environmental data was analyzed using hypothesis testing, confidence intervals, and also Principal components analysis (PCA). The study was focused on water parameters such as dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), salinity, pH, total dissolved solids, total coliforms (TC), Fecal coliforms (FC), ammonium (NH4+) and total phosphorus (TP). The analysis was conducted in line with the Colombian national water standard. Results showed that BOD5, COD, phosphorus, and coliforms are out of the limits for these variables in Colombia and are reaching levels that may be a threat to human health. Principal components analysis detected five components that explained 79.4% of the variance of data and showed that anthropogenic and temporal factors might be affecting the variation of the parameters.

scholarly journals Seagrass of Vasiliko Bay, Eastern Mediterranean: Lost Cause or Priority Conservation Habitat?

2020 ◽  
Vol 8 (9) ◽  
pp. 717
Author(s):  
Demetris Kletou ◽  
Periklis Kleitou ◽  
Ioannis Savva ◽  
Martin J. Attrill ◽  
Stephanos Charalambous ◽  
...  
Keyword(s):  
Surface Area ◽  
Multiple Stressors ◽  
Eastern Mediterranean ◽  
Ecological Status ◽  
Fish Farming ◽  
Posidonia Oceanica ◽  
Shoot Density ◽  
Fish Farms ◽  
Leaf Surface Area ◽  
Marine Fish Farming

Mediterranean coasts are affected by multiple mounting pressures. In Cyprus, marine fish farming has grown rapidly in the past decade and is concentrated in the west side of Vasiliko Bay. The east coast of this bay has ports, a power station, a desalination unit, a cement factory, a major new oil terminal, and gas storage facilities. The bay is earmarked to create the largest hydrocarbon processing, storing, and transport facility in the region. Here, we assess the status of Posidonia oceanica habitat in an understudied region at the upper thermal, and eastern limit, of this Mediterranean endemic seagrass. An extensive ancient seagrass meadow was revealed, covering about 200 ha across 10 km of coastline, over soft substrata at ca 10–30 m depth, and over hard substrata at ca 0–6 m depth. Seagrass shoot density and leaf surface area decreased, both with increasing depth and with proximity to industrial developments; part of the meadow had been destroyed by dredging to build a jetty. Close to fish farms the seagrass had higher epiphytic biomass as well as lower leaf number, mass, and surface area, all of which indicate adverse effects of eutrophication and increased turbidity. Despite these multiple stressors, most of the meadow was in good ecological status, with some of the highest shoot densities ever reported. Furthermore, iconic species like sea turtles, monk seals, and dolphins were seen during sampling. Posidonia oceanica meadows off Cyprus are among the most valuable in the Mediterranean due to their tolerance of high seawater temperatures. Managers of future coastal developments in the region will need to adhere to European legislation and international conventions designed to secure the socioeconomic benefits of seagrass beds.

scholarly journals Lagoon Resident Fish Species of Conservation Interest According to the Habitat Directive (92/43/CEE): A Review on Their Potential Use as Ecological Indicator Species

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2059 ◽  
Author(s):  
Chiara Facca ◽  
Francesco Cavraro ◽  
Piero Franzoi ◽  
Stefano Malavasi
Keyword(s):  
Life Cycle ◽  
Fish Species ◽  
Coastal Lagoon ◽  
Salt Marshes ◽  
Coastal Lagoons ◽  
Conservation Status ◽  
Local Population ◽  
Ecological Indicator ◽  
Habitat Directive ◽  
Population Extinction

Transitional waters are fragile ecosystems with high ecological, social and economic values, that undergo numerous threats. According to the information provided by European Member States in the framework of the European Directive 92/43/EEC (Habitat Directive), the main threat to these ecosystems is represented by morphological and hydrological changes. The present work focuses on six lagoon fish species included in the Habitat Directive annex II (species requiring conservation measures: Aphanius fasciatus, A. iberus, Knipowitschia panizzae, Ninnigobius canestrinii, Valencia hispanica and V. letourneuxi) that spend their entire life cycle in the Mediterranean priority habitat 1150* “Coastal lagoons”. The overview of the current scientific literature allowed us to highlight how the presence and abundance of these species may provide important indications on the conservation status of coastal lagoon habitats. In fact, their occurrence, distribution and biology depend on the presence of peculiar structures, such as salt marshes, small channels, isolated pools and oligohaline areas. Coastal lagoon fragmentation and habitat loss have led to a significant reduction in genetic diversity or local population extinction. Although Aphanius and gobies have been shown to survive in eutrophic environments, it is clear that they cannot complete their life cycle without salt marshes (mainly Aphanius) and wetland areas (mainly gobies).

scholarly journals Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

2006 ◽  
Vol 63 (5) ◽  
pp. 433-438 ◽  
Author(s):  
Gustavo Gonzaga Henry-Silva ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nile Tilapia ◽  
Aquatic Macrophytes ◽  
Fish Farming ◽  
Pistia Stratiotes ◽  
Fish Pond ◽  
Nitrogen And Phosphorus ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen

The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta) to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants). Water samples were collected from the: (i) fish pond source water, (ii) effluent from fish pond and (iii) effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively) and total nitrogen removal (46.1% and 43.9%, respectively) than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen) and the control (50.3% total phosphorus and 22.8% total nitrogen), indicating that the treated effluents may be reused in the aquaculture activity.

Laeonereis watsoni (Annelida, Nereididae), a new species from western Mexico

2017 ◽  
Vol 98 (6) ◽  
pp. 1347-1353 ◽  
Author(s):  
J. A. de León-González ◽  
N. Méndez ◽  
J. G. Navedo
Keyword(s):  
New Species ◽  
Coastal Lagoon ◽  
Anterior Margin ◽  
Pacific Coast ◽  
Coastal Lagoons ◽  
Relative Size ◽  
Mexican Pacific ◽  
Shrimp Farm ◽  
Western Mexico ◽  
A New Species

A new species of Laeonereis from a shrimp farm associated with a subtropical coastal lagoon on the Mexican Pacific coast is described. The new species is characterized by a deep anterior groove on the prostomium, which is shared only with L. culveri. However, longer tentacular cirri extending back to the anterior margin of chaetiger two, the number of papillae of each group on the maxillary ring of the pharynx, and the relative size of the homogomph falcigers in the new species, allow us to separate the two species. Although the species has not been previously detected in the coastal lagoon surrounding the shrimp farm, we postulate that L. watsoni n. sp. is likely to be part of the invertebrate communities of the upper parts of similar coastal lagoons that are common along the tropical coasts of Mexico.

Characterising and predicting algal blooms in a subtropical coastal lagoon

2014 ◽  
Vol 65 (3) ◽  
pp. 191 ◽  
Author(s):  
Kwee Siong Tew ◽  
Pei-Jie Meng ◽  
David C. Glover ◽  
Jih-Terng Wang ◽  
Ming-Yih Leu ◽  
...  
Keyword(s):  
Coastal Lagoon ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Coastal Lagoons ◽  
Inorganic Nitrogen ◽  
Inorganic Phosphorus ◽  
Reliable Measure ◽  
Exponential Relationship ◽  
Outlet Channel ◽  
Chl A

Algal bloom is a major concern worldwide. In this study, we characterised the physical and biochemical parameters during an algal bloom event in a coastal lagoon in an attempt to predict local blooms in the future. Results showed that the highest concentrations of dissolved inorganic phosphorus (DIP), chlorophyll a (chl a) and phytoplankton abundance were found in the inner area, whereas the highest dissolved inorganic nitrogen (DIN) concentration occurred near the inlet-outlet channel. Chl a was correlated with DIP, and there was a significant exponential relationship between chl a and the nitrogen to phosphorus ratio (N/P ratio) across all sampling stations and times. A higher proportion of the variation in chl a was explained by the N/P ratio than either DIP or DIN. We found that a N/P ratio <2.38 will likely trigger an algal bloom (chl a ≥ 10 µgL–1) in the lagoon. Our results suggest that the N/P ratio could be used as an expedient and reliable measure of the potential eutrophic status of coastal lagoons.

scholarly journals Investigation of the Inherent Variability of the Mediterranean Sea Under Contrasting Extreme Climatic Conditions

2021 ◽  
Vol 8 ◽  
Author(s):  
Angeliki Sampatakaki ◽  
Vassilis Zervakis ◽  
Ioannis Mamoutos ◽  
Elina Tragou ◽  
Alexandra Gogou ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Thermohaline Circulation ◽  
Eastern Mediterranean ◽  
Internal Variability ◽  
Climatic Conditions ◽  
Spatiotemporal Variability ◽  
Atmospheric Forcing ◽  
Buoyancy Forcing ◽  
Deep Layers ◽  
The Mediterranean

The internal variability of the thermohaline circulation of the Mediterranean Sea is examined under contrasting extreme thermal and mass atmospheric forcing conditions. Three millennium-long numerical simulation experiments were performed under: (a) the current climatology, (b) a strong buoyancy forcing (SBF) scenario due to cold and dry conditions resembling the Younger Dryas event, and (c) a weak buoyancy forcing (WBF) scenario due to S1a sapropel deposition-like conditions (warm and wet). To isolate the inherent variability of the system, independent of interannual atmospheric forcing variability, the latter was defined as a perpetual year pertinent to each experiment. Self-diagnosed heat and salt fluxes, consistent to sea-surface characteristics of the above periods, forced three millenium-long, relaxation-free numerical experiments. These simulations were preceded by initial spin-up periods. The inherent spatiotemporal variability of the Mediterranean Sea was analyzed using the empirical orthogonal function (EOF) and spectral analysis on the simulated density fields. Our results revealed that the Mediterranean Sea exhibits high sensitivity to climatic conditions, allowing its circulation to change from anti-estuarine (for the SBF scenario, leading to a buoyancy loss to the atmosphere) to estuarine (for the WBF scenario, corresponding to a buoyancy gain from the atmosphere). In all three experiments, the interannual and decennial variabilities dominate in upper layers, and the decennial variability dominates in the Gibraltar and Sicily Straits. Under current climatic conditions the first two EOF modes express only 60% of the density variability in the deep layers. This contribution exceeds 90% under more extreme conditions. Moreover, the first EOF modes correspond to a basin-wide in-phase variability of the deep layers under the reference and WBF conditions. During SBF conditions the first modes reveal a vertical buoyancy exchange between upper and deeper layers. The second EOF mode of deep waters under both extreme scenarios showed that the western and eastern basins exchange buoyancy in decennial (for the cold/dry) and interdecennial (for the warm/humid) timescales. The residence time of the Eastern Mediterranean deep water was diagnosed to be centennial, semicentennial, and intercentennial for the cases of current period, SBF, and WBF, respectively.

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