Refine search
Results 2301-2310 of 7,292
Coastal gradients of small microplastics and associated pollutants influenced by estuarine sources Full text
2022
González-Ortegón, Enrique | Sendra, Marta | Sparaventi, Erica | F. Sánchez Leal, Ricardo | de los Ríos, Isaac | Baldó, Francisco | González-Fernández, Daniel | Yeste, María Pilar
Small microplastics (SMPs) in the gulf of Cadiz was sampled at 5 m depth by pumping it through the ship's pipe system and filtered through a 45 μm mesh size net. Our study reveals that higher densities have been found (130 mg·m⁻³) compared to other regions worldwide and these densities decreased from the coastline to the outer stations, showing a general coastal gradient influenced by estuarine outflows. SMPs with a size range between 45 and 193 μm were predominant and most of them composed by polyethylene and polypropylene. The metals associated with the MPs were mainly Na (21.1%), K (11.3%), Fe (8.5%), Ca (2.1%), Cr (1.8%), Zr (13.3%) and Hf (0.7%). The high proportion of Zr compared to Fe, which is different from what can be found in the environment, suggests that this metal is intrinsic to the materials used in catalytic processes during plastic production.
Show more [+] Less [-]Remote sensing provides new insights on phytoplankton biomass dynamics and black pearl oyster life-history traits in a Pacific Ocean deep atoll Full text
2022
Lefebvre, Sébastien | Verpoorter, Charles | Rodier, Martine | Sangare, Nathanaël | Andréfouët, Serge
Thus far, no long-term in situ observation of planktonic biomass have been undertaken to optimize the black-lip pearl oyster aquaculture in the remote Tuamotu atolls. The feasibility of using data from the OLI sensor onboard Landsat-8 satellite to determine chlorophyll a concentrations (Chla) in a deep atoll, Ahe, was then assessed over the 2013–2021 period using 153 images. Validations with in situ observations were satisfactory, while seasonal and spatial patterns in Chla were evidenced within the lagoon. Then, a bioenergetic modelling exercise was undertaken to estimate oyster life-history traits when exposed to the retrieved Chla. The outputs provide spatio-temporal variations in pelagic larval duration (11.1 to 30.6 days), time to reach commercial size (18.8 to 45.3 months) and reproductive outputs (0.5 to 1.7 event year⁻¹). This first study shows the potential of using remote sensing to monitor the trophic status of deep pearl farming lagoons and help aquaculture management.
Show more [+] Less [-]Quantitative assessment of two oil-in-ice surface drift algorithms Full text
2022
de Aguiar, Victor | Dagestad, Knut-Frode | Hole, Lars Robert | Barthel, Knut
The ongoing reduction in extent and thickness of sea ice in the Arctic might result in an increase of oil spill risk due to the expansion of shipping activity and oil exploration shift towards higher latitudes. This work assessed the response of two oil-in-ice surface drift models implemented in an open-source Lagrangian framework. By considering two numerical modeling experiments, our main finding indicates that the drift models provide fairly similar outputs when forced by the same input. It was also found that using higher resolution ice-ocean model does not imply better results. We highlight the role of sea ice in the spread, direction and distance traveled by the oil. The skill metric seems to be sensitive to the drift location, and drift model re-initialization is required to avoid forecast deterioration and ensure the accurate tracking of oil slicks in real operations.
Show more [+] Less [-]From rivers to marine environments: A constantly evolving microbial community within the plastisphere Full text
2022
Delacuvellerie, Alice | Ballerini, Tosca | Frère, Laura | Matallana-Surget, Sabine | Dumontet, Bruno | Wattiez, Ruddy
Plastics accumulate in the environment and the Mediterranean Sea is one of the most polluted sea in the world. The plastic surface is rapidly colonized by microorganisms, forming the plastisphere. Our unique sampling supplied 107 plastic pieces from 22 geographical sites from four aquatic ecosystems (river, estuary, harbor and inshore) in the south of France in order to better understand the parameters which influence biofilm composition. In parallel, 48 enrichment cultures were performed to investigate the presence of plastic degrading-bacteria in the plastisphere. In this context, we showed that the most important drivers of microbial community structure were the sampling site followed by the polymer chemical composition. The study of pathogenic genus distribution highlighted that only 11% of our plastic samples contained higher proportions of Vibrio compared to the natural environment. Finally, results of the enrichment cultures showed a selection of hydrocarbon-degrading microorganisms suggesting their potential role in the plastic degradation.
Show more [+] Less [-]Mediterranean seagrass Posidonia oceanica accumulates sunscreen UV filters Full text
2022
Agawin, Nona S.R. | Sunyer-Caldú, Adrià | Díaz-Cruz, M. Silvia | Frank-Comas, Aida | García-Márquez, Manuela Gertrudis | Tovar-Sánchez, Antonio
Certain ultra-violet filter (UVF) components of solar creams have negative impacts on coral reefs and have been prohibited in international tourism destinations (i.e., Hawaii, Florida, and Palau) to protect coral reefs. In the Mediterranean coasts which are also hotspots of international tourism and where endemic seagrass Posidonia oceanica forms extensive meadows, the accumulation of UVF components have not been studied. We report for the first time, that the rhizomes of P. oceanica internally accumulated UVFs BP3, BP4, AVO, 4MBC and MeBZT and the paraben preservative MePB. The components BP4 and MePB occurred in higher concentrations reaching up to 129 ng g⁻¹ dw and 512 ng g⁻¹ dw, respectively. This work emphasizes the need for more experimental studies on the effects of UVFs on seagrasses and check if we should follow suit to prohibit certain UVFs to protect this species as what has been done in other regions to protect corals.
Show more [+] Less [-]The fate of conventional and potentially degradable gillnets in a seawater-sediment system Full text
2022
Abandoned gillnets in the marine environment represent a global environmental risk due to the ghost fishing caused by the nets. Degradation of conventional nylon gillnets was compared to that of nets made of polybutylene succinate co-adipate-co-terephthalate (PBSAT) that are designed to degrade more readily in the environment. Gillnet filaments were incubated in microcosms of natural seawater (SW) and marine sediments at 20 °C over a period of 36 months. Tensile strength tests and scanning electron microscopy analyses showed weakening and degradation of the PBSAT filaments over time, while nylon filaments remained unchanged. Pyrolysis-gas chromatography/mass spectrometry revealed potential PBSAT degradation products associated with the filament surfaces, while nylon degradation products were not detected by these analyses. Microbial communities differed significantly between the biofilms on the nylon and PBSAT filaments. The slow deterioration of the PBSAT gillnet filaments shown here may be beneficial and reduce the ghost fishing periods of these gillnets.
Show more [+] Less [-]Severe, rapid and widespread impacts of an Atlantic blue crab invasion Full text
2022
Clavero, Miguel | Franch, Nati | Bernardo-Madrid, Rubén | López, Verónica | Abelló, Pere | Queral, Josep Maria | Mancinelli, Giorgio
The Atlantic blue crab (Callinectes sapidus) has rapidly invaded coastal environments in the western Mediterranean, but there is no consistent assessment of its impacts yet. We use interviews and long-term data series in the Ebro Delta (NE Spain) to: i) characterise the evolution of the blue crab invasion; and ii) identify its impacts. The blue crab was first recorded in 2012, but its expansion started around 2016, with an exponential increase in abundance between 2017 and 2018. Aquatic communities have tended to be dominated by the blue crab, coinciding with the steep and consistent declines of several species, including threatened and commercially exploited ones. Blue crab impacts seem to be exerted even at low abundances, arguably hindering the recovery of declining species. The blue crab is becoming a keystone species in invaded systems and efforts should be made to understand its many-folds impacts in order to prevent or mitigate them.
Show more [+] Less [-]First long-term assessment of metals and associated ecological risk in subtidal sediments of a human-impacted SW Atlantic estuary Full text
2022
Truchet, D.M. | Buzzi, N.S. | Negrin, V.L. | Botté, S.E. | Marcovecchio, J.E.
The main objective of this article was to profile the metal accumulation, sources, pollution levels and trends during 6 years in a SW Atlantic coastal system (Bahía Blanca estuary). Subtidal sediment samples were taken from six stations with different human impacts, and chemical element analyses were performed using ICP-OES. As a result, metals tended to increase in time and differences were observed between a site profoundly impacted by sewage waters and the rest of the sampling stations. Values range from background levels to those considered toxic for the marine biota, as in the case of Cd and Cu. Besides, the geochemical analyses exhibited low to moderate pollution with probable adverse biological effects. Finally, the physicochemical parameters of the water column like pH and DO significantly decreased in time in all stations and temperature correlated with some metals, indicating a potential interaction.
Show more [+] Less [-]Predictions of sardine and the Portuguese continental shelf ecosystem dynamics under future fishing, forced-biomass and SST scenarios Full text
2022
Szalaj, D. | Silva, Adailton da | Ré, P. | Cabral, H.
We used the Ecopath with Ecosim ecosystem model to assess the future effects of multiple stressors on sardine and the Portuguese continental shelf ecosystem. We assessed individual and combined impacts of changes in sardine fishing pressure, biomass of sardine competitors and predators and sea surface temperature (SST). This study demonstrated that the greatest impact on sardine stock is caused by projected SST rise whose effect is dominant and detrimental to sardine stock regardless of other conditions, including sardine fishing at maximum sustainable yield (FMSY). The largest impact on ecosystem stability, maturity and diversity of flows was observed under the forced-biomass scenarios that simulate changes in biomass of sardine predators and competitors. Moreover, these stressors alongside FMSY are projected to play an important role in the future evolution of the sardine stock. Results presented in this study can assist long-term and strategic management of the Iberian sardine stock.
Show more [+] Less [-]Future microplastics in the Black Sea : River exports and reduction options for zero pollution Full text
2022
Strokal, Vita | Kuiper, Eke J. | Bak, Mirjam P. | Vriend, Paul | Wang, Mengru | van Wijnen, Jikke | Strokal, Maryna
Future microplastics in the Black Sea : River exports and reduction options for zero pollution Full text
2022
Strokal, Vita | Kuiper, Eke J. | Bak, Mirjam P. | Vriend, Paul | Wang, Mengru | van Wijnen, Jikke | Strokal, Maryna
The Black Sea receives increasing amounts of microplastics from rivers. In this study, we explore options to reduce future river export of microplastics to the Black Sea. We develop five scenarios with different reduction options and implement them to a Model to Assess River Inputs of pollutaNts to seA (MARINA-Global) for 107 sub-basins. Today, European rivers draining into the Black Sea export over half of the total microplastics. In 2050, Asian rivers draining into the sea will be responsible for 34–46% of microplastic pollution. Implemented advanced treatment will reduce point-source pollution. Reduced consumption or more collection of plastics will reduce 40% of microplastics in the sea by 2050. In the optimistic future, sea pollution is 84% lower than today when the abovementioned reduction options are combined. Reduction options affect the share of pollution sources. Our insights could support environmental policies for a zero pollution future of the Black Sea.
Show more [+] Less [-]Future microplastics in the Black Sea: River exports and reduction options for zero pollution Full text
2022
Strokal, Vita | Kuiper, Eke J. | Bak, Mirjam P. | Vriend, Paul | Wang, Mengru | van Wijnen, Jikke | Strokal, Maryna
The Black Sea receives increasing amounts of microplastics from rivers. In this study, we explore options to reduce future river export of microplastics to the Black Sea. We develop five scenarios with different reduction options and implement them to a Model to Assess River Inputs of pollutaNts to seA (MARINA-Global) for 107 sub-basins. Today, European rivers draining into the Black Sea export over half of the total microplastics. In 2050, Asian rivers draining into the sea will be responsible for 34–46% of microplastic pollution. Implemented advanced treatment will reduce point-source pollution. Reduced consumption or more collection of plastics will reduce 40% of microplastics in the sea by 2050. In the optimistic future, sea pollution is 84% lower than today when the abovementioned reduction options are combined. Reduction options affect the share of pollution sources. Our insights could support environmental policies for a zero pollution future of the Black Sea.
Show more [+] Less [-]