RESUMO
This study summarizes the concentration in dry weight (dw) of several metal(oid)s (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn), as well as the abundance and characteristics of microplastics (MP) in wet weight (ww) of the soft tissues of clam Corbicula fluminea from Chubut River (Patagonia, Argentina). The contents of essential elements were in the following decreasing order: Zn > Mn > Cu > Ni; meanwhile, non-essential elements Cd, Cr and Pb were below the detection limit (<0.5 µg/g dw). A high mean concentration of As (6.1 ± 0.3 µg/g dw) was found, surpassing the maximum allowable limit established by the Argentine Food Code for bivalve molluscs. The number of MP ranged from 0.07 to 1.27 items/ind. and from 0.2 to 2.9 items/g ww. Fibers were the most common shape, mainly transparent. The size of MP ranged from 42 to 1917 µm, accounting for 62 % of MP between 50 and 450 µm. The dominant polymer was PET based on the results of Raman spectroscopy. Based on the widespread distribution of MP in the environment and the wide range of effects on organisms, it is necessary to develop long-term monitoring programs for MP contamination in different environmental matrices. Understanding the bioaccumulation of MP in bivalves is crucial to assess the potential risk to human health through consumption and to the ecosystem. We propose that the widespread Asian clam could serve as a useful biomonitor for MP and As pollution in freshwater and estuarine environments such as the Chubut River.
Assuntos
Corbicula , Monitoramento Ambiental , Metais , Microplásticos , Rios , Poluentes Químicos da Água , Animais , Poluentes Químicos da Água/análise , Corbicula/efeitos dos fármacos , Corbicula/metabolismo , Rios/química , Argentina , Microplásticos/análise , Metais/análise , Metais/metabolismoRESUMO
This is the first report of anthropogenic particles (APs), including microplastics and synthetic, semi-synthetic and anthropogenically-altered natural fibers, in water and sediment of the Chubut River estuary. This river is the main source of freshwater in Chubut Province (Patagonia, Argentina), where wastes and pollutants are poured and finally end in the Atlantic Ocean. The average concentration in surface and bottom water samples was 5.5 items/L, while in sediment was 175.4 items/kg dw. Raman's analysis identified particles dominated by polyethylene terephthalate (PET) (35.5 %), dye signature only (18.5) and anthropogenic cellulose (10 %). Fibers were the prevalent shape (83 %), and the chemical identification evidenced a textile origin. The highest APs concentration was found in sediments from the site with the finest grain size and the greatest amount of organic matter. Present results will provide a baseline for future studies and raise public and governmental awareness.
Assuntos
Microplásticos , Poluentes Químicos da Água , Rios , Estuários , Plásticos/análise , Sedimentos Geológicos , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Oceano Atlântico , Água/análiseRESUMO
The dynamics of phytoplankton across a seasonal frontal system formed in San José Gulf (SJG, Patagonia Argentina) and in neighbouring shelf waters was assessed based on bio-optical satellite data (2003-2018) and spring and summer in situ samplings. Bio-optical properties of the water masses on the eastern (ED) and western (WD) domains of the seasonal frontal system of SJG showed clear differences: the year-round-vertically-mixed waters from the WD, strongly connected with the adjacent shelf waters, evidenced a brief and strong single phytoplankton bloom, while those from the ED, showing lower exchange with shelf waters and a strong vertical stratification during the warm season, displayed an earlier and long-lasting spring phytoplankton bloom, followed by a late-summer and autumn bloom, both associated with the development and erosion of the seasonal thermocline. Waters from the entire system are optically influenced by the absorption of coloured dissolved organic matter and detritus (cdom + detritus), suggesting a strong sediment load contribution from the continent and the seabed. To remark, a strong correlation between satellite chlorophyll-a (Chla-sat) and absorption by phytoplankton (aphy443) in the outer shelf waters differs from the weak correlation of those variables in the gulf's water masses, whose optical parameters are more complex. In situ Chla records may indicate wind-driven upwelling and downwelling areas in the northern and southern coasts of the ED. Dissolved nitrogen was identified as the limiting macronutrient for phytoplankton growth in the ED during summer. This work contributes relevant ecological information that may support management actions on the SJG shellfish artisanal fishery.
Assuntos
Matéria Orgânica Dissolvida , Fitoplâncton , Clorofila , Clorofila A , Nitrogênio/análise , Estações do AnoRESUMO
Plastic pollution in the oceans has become a global problem, but its documentation is disparate around the world. We assess the abundance and type of microplastics in three benthic matrices: mussels, small fishes, and bottom water; in three sites nearby Puerto Madryn city (Patagonia, Argentina). Microplastics were present in the three matrices for all sites sampled. The average amounts of items observed were 1.6 and 0.3 per total wet weight in fishes and mussels, respectively, and 10.5 per liter in bottom water. Mussels and fishes presented a difference of microplastics size comparing with the surrounding bottoms waters; fishes also presented color discrimination, suggesting the necessity of more than one bioindicator to perform microplastic pollution monitoring. Moreover, small fishes had more MPs in their gastrointestinal tracts than bigger ones. The present study is the first one about the interaction between MPs and small aquatic organisms in coastal marine environments from Patagonia.
Assuntos
Plásticos , Poluentes Químicos da Água/análise , Animais , Argentina , Ecossistema , Monitoramento Ambiental , Microplásticos , Oceanos e MaresRESUMO
The aim of our study was to assess the combined impact of UVR (280-400 nm) and temperature on the first larval stage (Zoea I) of three crab species from the Patagonian coast: Cyrtograpsus altimanus, C. angulatus, and Leucippa pentagona. We determined the survival response of newly hatched Zoea I after being exposed for 8-10 h under a solar simulator (Hönle SOL 1200) at 15 and 20 degrees C. There was no mortality due to Photosynthetic Active Radiation (PAR, 400-700 nm) or ultraviolet-A radiation (UV-A, 315-400 nm), and all the observed mortality was due to ultraviolet-B radiation (UV-B, 280-315 nm). The data of larval mortality relative to exposure time was best fit using a sigmoid curve. Based on this curve, a threshold (Th) and the lethal dose for 50% mortality (LD(50)) were determined for each species. Based on the Th and LD(50), C. altimanus was found to be the most resistant species, while L. pentagona was found to be the most sensitive to UV-B. For both species of Cyrtograpsus, mortality was significantly lower at 20 degrees C than at 15 degrees C; however, no significant differences between the two temperature treatments were found in L. pentagona. Bioaccumulation of UV-absorbing compounds in the gonads and larvae of C. altimanus, and to a lesser extent in C. angulatus, might have contributed for counteracting the impact of UV-B. However, most of the resilience to UV-B observed with the increase in temperature might be due to an increase in metabolic activity caused by a repair mechanism mediated by enzymes.