The following protocol is intended to respond to the requirements set by the European Union's... more The following protocol is intended to respond to the requirements set by the European Union's Marine Strategy Framework Directives (MSFD) for the D10C3 Criteria reported in the Commission Decision (EU), related to the amount of litter ingested by marine animals. Standardized methodologies for extracting litter items ingested from dead sea turtles along with guidelines on data analysis are provided. The protocol starts with the collection of dead sea turtles and classification of samples according to the decomposition status. Turtle necropsy must be performed in authorized centers and the protocol described here explains the best procedure for gastrointestinal (GI) tract isolation. The three parts of the GI (esophagus, stomach, intestine) should be separated, opened lengthways and contents filtered using a 1 mm mesh sieve. The article describes the classification and quantification of ingested litter, classifying GI contents into seven different categories of marine litter and tw...
Alterations in a number of biochemical parameters in marine organisms represent specific markers ... more Alterations in a number of biochemical parameters in marine organisms represent specific markers of exposure to particular classes of contaminants. They are used as tools for the detection and monitoring of pollution. In this study, two biochemical markers of pollution, metallothionein (MT) content and acetylcholinesterase (AChE) activity were measured in indigenous and transplanted mussels Mytilus galloprovincialis from coastal areas within the Saronikos Gulf subject to high anthropogenic activities. Biannual measurements of the two biomarkers in indigenous mussel populations for two years revealed no significant differences among stations representing a pollution gradient. Limited differences in MT levels were only found between mussel populations transplanted at lesser and more impacted stations. Both biomarkers showed a variation with respect to the season of sampling, whilst during the second year of measurements a concomitant increase in metallothionein content with a decrease...
Dredged sediments derived by the low course and estuary of the metropolitan river of Athens (Kifi... more Dredged sediments derived by the low course and estuary of the metropolitan river of Athens (Kifissos River) were dumped every day for 21 months to an open-sea site in the Saronikos Gulf. The spoil-ground and surrounding area was monitored prior, during and post to dumping for 24 months, over 6-month intervals. Dumping significantly changed the granulometry of the pre-existing superficial sediments to finer-grained only in the spoil ground and increased the sediment contamination load (aliphatic, polycyclic aromatic hydrocarbons and heavy metals) throughout the study area. Microtox® SPT showed that sediment toxicity levels were high at almost all sampling stations. During dumping, burial of natural soft-bottom habitats degraded severely the communities of the spoil-ground resulting in an almost azoic state, as well as significantly declined the species number and abundance of benthic communities in locations up to 3.2 km away from the spoil-ground, due to dispersion of the spoil and...
ABSTRACT Microplastics densities were assessed along the shoreline of Kea Island (Aegean Sea, Eas... more ABSTRACT Microplastics densities were assessed along the shoreline of Kea Island (Aegean Sea, Eastern Mediterranean). Microplastics were categorized according to origin (fragments or pellets), size, colour and polymer type. The majority of microplastics were identified by FT-IR spectroscopy as polyethylene. The keto-carbonyl, ester-carbonyl and vinyl-bond indices of the plastic items showed the degree of the polymers degradation. The microplastics varied among beaches ranging from absence of plastic items at the eastern beaches to more than 300 items per m 2 at the northern beaches, demonstrating a direct relation to beach orientation and wind regime rather than to proximity to land based sources. Our findings underlined the importance of water circulation as the major mechanism of microplastic dispersion which explains their ubiquitous presence in beaches worldwide.
Adult gilthead sea bream Sparus aurata and sea bass Dicentrarchus labrax were exposed for 24 and ... more Adult gilthead sea bream Sparus aurata and sea bass Dicentrarchus labrax were exposed for 24 and 48 h, respectively, to two concentrations of ammonia each (mean values of 3·34 and 13·10 mg l(-1) TA-N in S. aurata; 2·99 and 11·90 mg l(-1) TA-N in D. labrax). Light microscopy and computerized morphometry were used to evaluate ammonia-induced alterations in skin structure during exposure and following recovery in normal water. In S. aurata, ammonia exposure induced a concentration-dependent increase in the number (hyperplasia) of neutral mucous cells (mc), with peak values at 24 h recovery after exposure. An increase in the dispersion of melanosomes in skin melanocytes was also observed in the dermis and occasionally in the epidermis of S. aurata, with peak values at 24 h of ammonia exposure. Exposure of D. labrax to ammonia had, likewise, concentration-dependent effects on mucous secretion. Of the two types of mc in this species, there was an increase in the number of the neutral mc and a reduction in the much more numerous acid mc, with peak values at 24 and 48 h, respectively, of ammonia exposure. The more intense mucous secretion in D. labrax compared to S. aurata could be related to the lower tolerance to ammonia in D. labrax, as reported elsewhere. Finally, the increase in melanosome dispersion was less evident in D. labrax, due to highly variable control values. These morphological alterations to the skin could be useful indicators of non-specific stress in cultured fishes.
Environmental Science and Pollution Research, 2013
A battery of biochemical and immunological biomarkers used for pollution assessment were measured... more A battery of biochemical and immunological biomarkers used for pollution assessment were measured for first time in the clams Venus verrucosa and Callista chione and were compared with those of the mussel Mytilus galloprovincialis, a well-established indicator organism utilized in numerous environmental monitoring programs. Clams and mussel were transplanted at a polluted and a reference site or maintained at the laboratory. Among biochemical biomarkers, acetylcholinesterase did not differ at the polluted site in all species, but there was a significant difference between the mussel and the clams, glutathione S-transferase showed a clear inhibition at the polluted site in all species and a significant difference between the two clams was also indicated, while catalase activities were increased only in V. verrucosa at the polluted site and not in mussel or the other clam. Immunological biomarkers responses were also pronounced at the polluted site. Lysozyme activity was species-dependent whereas respiratory burst activity measured as luminol-dependent chemiluminescence (CL) was site and stimulus dependent, and it was evident in M. galloprovincialis and V. verrucosa and not in C. chione. Further investigation focused on biochemical and immunological biomarkers related with the oxidative mechanisms in clams will strengthen and expand their use as bioindicators for pollution assessment.
The selection of the best site for the placement of dredged sedimentary material (∼7,000 m(3)) fr... more The selection of the best site for the placement of dredged sedimentary material (∼7,000 m(3)) from the Aliveri coastal area in the adjacent South Euboean Gulf (Greece) was accomplished through a screening procedure. The initial stage comprised the determination of physical, chemical, and biological characteristics of the dredged sediment before the commencement of any dredging operation. Grain size measurements, geochemical analyses together with the use of pollution/toxicity indices and empirical sediment quality guidelines, and the conduct of an acute toxicity test showed that the dredged material consisted of "unpolluted to slightly polluted" silty sands and sandy silts. However, the local authorities planned to place this sediment in the neighboring open sea area, i.e., the South Euboean Gulf, due to the absence of any beneficial use or alternative dumping option (i.e., dumping on public lands). Therefore, the next stage of the screening procedure, based on criteria such as the national legislation, seabed and seawater column characteristics, influence of the water mass circulation pattern on the post-placement migration of dredged sediment, impact on living resources and human activities (i.e., aquaculture and fishing), effect on significant marine sites (i.e., sites of scientific, ecological, and historical importance, navigation routes, military zones), and seafloor engineering uses, led to the evaluation of the suitability of the South Euboean Gulf as a potential dumping area. Then, the identification of the appropriate dredged material placement sites in the South Euboean Gulf was based on a cluster analysis, which tested the physicochemical resemblance of the dredged material and the surface sediments of 19 potential placement locations in the gulf. After the statistical process, only four sites situated near the north shoreline of the South Euboean Gulf were qualified as the best dredged material placement locations.
A set of biomarkers was used to assess the impact of heavy metal pollution by a ferro-nickel smel... more A set of biomarkers was used to assess the impact of heavy metal pollution by a ferro-nickel smelting plant in Larymna bay (North Evoikos Gulf, Greece). These included a biomarker reflecting health status of an organism (scope for growth, SFG), a cellular biomarker of heavy metal exposure (composition of metal-containing granules), and two biochemical biomarkers reflecting oxidative stress (glutathione peroxidase, GPX) and neurotoxicity (acetylcholinesterase, AChE) measured in mussels (Mytilus galloprovincialis) both native and transplanted for 1 and 6 months at the coastal area of Larymna. All biomarkers in mussels at Larymna revealed differences from mussels at a reference site, signaling effects of the increased heavy metal levels on the biota. While effects on SFG and GPX in Larymna mussels were obvious on short-term exposure and persistent during chronic exposure, only chronic exposure induced a possibly cumulative effect on AChE. To validate the causal relationship between heavy metal exposure and effects observed in Larymna, SFG, GPX, and ACHE were examined in mussels exposed to a mixture of heavy metals (Ni, Cr, and Fe) under controlled laboratory conditions. The laboratory experiment verified the causal relationship between SFG and GPX responses and heavy metals but this was not demonstrated for AChE. Results from field-collected and laboratory-exposed mussels indicated a potential of GPX as predictive biomarker of population-level effects of heavy metal exposure.
The following protocol is intended to respond to the requirements set by the European Union's... more The following protocol is intended to respond to the requirements set by the European Union's Marine Strategy Framework Directives (MSFD) for the D10C3 Criteria reported in the Commission Decision (EU), related to the amount of litter ingested by marine animals. Standardized methodologies for extracting litter items ingested from dead sea turtles along with guidelines on data analysis are provided. The protocol starts with the collection of dead sea turtles and classification of samples according to the decomposition status. Turtle necropsy must be performed in authorized centers and the protocol described here explains the best procedure for gastrointestinal (GI) tract isolation. The three parts of the GI (esophagus, stomach, intestine) should be separated, opened lengthways and contents filtered using a 1 mm mesh sieve. The article describes the classification and quantification of ingested litter, classifying GI contents into seven different categories of marine litter and tw...
Alterations in a number of biochemical parameters in marine organisms represent specific markers ... more Alterations in a number of biochemical parameters in marine organisms represent specific markers of exposure to particular classes of contaminants. They are used as tools for the detection and monitoring of pollution. In this study, two biochemical markers of pollution, metallothionein (MT) content and acetylcholinesterase (AChE) activity were measured in indigenous and transplanted mussels Mytilus galloprovincialis from coastal areas within the Saronikos Gulf subject to high anthropogenic activities. Biannual measurements of the two biomarkers in indigenous mussel populations for two years revealed no significant differences among stations representing a pollution gradient. Limited differences in MT levels were only found between mussel populations transplanted at lesser and more impacted stations. Both biomarkers showed a variation with respect to the season of sampling, whilst during the second year of measurements a concomitant increase in metallothionein content with a decrease...
Dredged sediments derived by the low course and estuary of the metropolitan river of Athens (Kifi... more Dredged sediments derived by the low course and estuary of the metropolitan river of Athens (Kifissos River) were dumped every day for 21 months to an open-sea site in the Saronikos Gulf. The spoil-ground and surrounding area was monitored prior, during and post to dumping for 24 months, over 6-month intervals. Dumping significantly changed the granulometry of the pre-existing superficial sediments to finer-grained only in the spoil ground and increased the sediment contamination load (aliphatic, polycyclic aromatic hydrocarbons and heavy metals) throughout the study area. Microtox® SPT showed that sediment toxicity levels were high at almost all sampling stations. During dumping, burial of natural soft-bottom habitats degraded severely the communities of the spoil-ground resulting in an almost azoic state, as well as significantly declined the species number and abundance of benthic communities in locations up to 3.2 km away from the spoil-ground, due to dispersion of the spoil and...
ABSTRACT Microplastics densities were assessed along the shoreline of Kea Island (Aegean Sea, Eas... more ABSTRACT Microplastics densities were assessed along the shoreline of Kea Island (Aegean Sea, Eastern Mediterranean). Microplastics were categorized according to origin (fragments or pellets), size, colour and polymer type. The majority of microplastics were identified by FT-IR spectroscopy as polyethylene. The keto-carbonyl, ester-carbonyl and vinyl-bond indices of the plastic items showed the degree of the polymers degradation. The microplastics varied among beaches ranging from absence of plastic items at the eastern beaches to more than 300 items per m 2 at the northern beaches, demonstrating a direct relation to beach orientation and wind regime rather than to proximity to land based sources. Our findings underlined the importance of water circulation as the major mechanism of microplastic dispersion which explains their ubiquitous presence in beaches worldwide.
Adult gilthead sea bream Sparus aurata and sea bass Dicentrarchus labrax were exposed for 24 and ... more Adult gilthead sea bream Sparus aurata and sea bass Dicentrarchus labrax were exposed for 24 and 48 h, respectively, to two concentrations of ammonia each (mean values of 3·34 and 13·10 mg l(-1) TA-N in S. aurata; 2·99 and 11·90 mg l(-1) TA-N in D. labrax). Light microscopy and computerized morphometry were used to evaluate ammonia-induced alterations in skin structure during exposure and following recovery in normal water. In S. aurata, ammonia exposure induced a concentration-dependent increase in the number (hyperplasia) of neutral mucous cells (mc), with peak values at 24 h recovery after exposure. An increase in the dispersion of melanosomes in skin melanocytes was also observed in the dermis and occasionally in the epidermis of S. aurata, with peak values at 24 h of ammonia exposure. Exposure of D. labrax to ammonia had, likewise, concentration-dependent effects on mucous secretion. Of the two types of mc in this species, there was an increase in the number of the neutral mc and a reduction in the much more numerous acid mc, with peak values at 24 and 48 h, respectively, of ammonia exposure. The more intense mucous secretion in D. labrax compared to S. aurata could be related to the lower tolerance to ammonia in D. labrax, as reported elsewhere. Finally, the increase in melanosome dispersion was less evident in D. labrax, due to highly variable control values. These morphological alterations to the skin could be useful indicators of non-specific stress in cultured fishes.
Environmental Science and Pollution Research, 2013
A battery of biochemical and immunological biomarkers used for pollution assessment were measured... more A battery of biochemical and immunological biomarkers used for pollution assessment were measured for first time in the clams Venus verrucosa and Callista chione and were compared with those of the mussel Mytilus galloprovincialis, a well-established indicator organism utilized in numerous environmental monitoring programs. Clams and mussel were transplanted at a polluted and a reference site or maintained at the laboratory. Among biochemical biomarkers, acetylcholinesterase did not differ at the polluted site in all species, but there was a significant difference between the mussel and the clams, glutathione S-transferase showed a clear inhibition at the polluted site in all species and a significant difference between the two clams was also indicated, while catalase activities were increased only in V. verrucosa at the polluted site and not in mussel or the other clam. Immunological biomarkers responses were also pronounced at the polluted site. Lysozyme activity was species-dependent whereas respiratory burst activity measured as luminol-dependent chemiluminescence (CL) was site and stimulus dependent, and it was evident in M. galloprovincialis and V. verrucosa and not in C. chione. Further investigation focused on biochemical and immunological biomarkers related with the oxidative mechanisms in clams will strengthen and expand their use as bioindicators for pollution assessment.
The selection of the best site for the placement of dredged sedimentary material (∼7,000 m(3)) fr... more The selection of the best site for the placement of dredged sedimentary material (∼7,000 m(3)) from the Aliveri coastal area in the adjacent South Euboean Gulf (Greece) was accomplished through a screening procedure. The initial stage comprised the determination of physical, chemical, and biological characteristics of the dredged sediment before the commencement of any dredging operation. Grain size measurements, geochemical analyses together with the use of pollution/toxicity indices and empirical sediment quality guidelines, and the conduct of an acute toxicity test showed that the dredged material consisted of "unpolluted to slightly polluted" silty sands and sandy silts. However, the local authorities planned to place this sediment in the neighboring open sea area, i.e., the South Euboean Gulf, due to the absence of any beneficial use or alternative dumping option (i.e., dumping on public lands). Therefore, the next stage of the screening procedure, based on criteria such as the national legislation, seabed and seawater column characteristics, influence of the water mass circulation pattern on the post-placement migration of dredged sediment, impact on living resources and human activities (i.e., aquaculture and fishing), effect on significant marine sites (i.e., sites of scientific, ecological, and historical importance, navigation routes, military zones), and seafloor engineering uses, led to the evaluation of the suitability of the South Euboean Gulf as a potential dumping area. Then, the identification of the appropriate dredged material placement sites in the South Euboean Gulf was based on a cluster analysis, which tested the physicochemical resemblance of the dredged material and the surface sediments of 19 potential placement locations in the gulf. After the statistical process, only four sites situated near the north shoreline of the South Euboean Gulf were qualified as the best dredged material placement locations.
A set of biomarkers was used to assess the impact of heavy metal pollution by a ferro-nickel smel... more A set of biomarkers was used to assess the impact of heavy metal pollution by a ferro-nickel smelting plant in Larymna bay (North Evoikos Gulf, Greece). These included a biomarker reflecting health status of an organism (scope for growth, SFG), a cellular biomarker of heavy metal exposure (composition of metal-containing granules), and two biochemical biomarkers reflecting oxidative stress (glutathione peroxidase, GPX) and neurotoxicity (acetylcholinesterase, AChE) measured in mussels (Mytilus galloprovincialis) both native and transplanted for 1 and 6 months at the coastal area of Larymna. All biomarkers in mussels at Larymna revealed differences from mussels at a reference site, signaling effects of the increased heavy metal levels on the biota. While effects on SFG and GPX in Larymna mussels were obvious on short-term exposure and persistent during chronic exposure, only chronic exposure induced a possibly cumulative effect on AChE. To validate the causal relationship between heavy metal exposure and effects observed in Larymna, SFG, GPX, and ACHE were examined in mussels exposed to a mixture of heavy metals (Ni, Cr, and Fe) under controlled laboratory conditions. The laboratory experiment verified the causal relationship between SFG and GPX responses and heavy metals but this was not demonstrated for AChE. Results from field-collected and laboratory-exposed mussels indicated a potential of GPX as predictive biomarker of population-level effects of heavy metal exposure.
Uploads