Detritivorous fish contamination in the Río de la Plata estuary: a critical accumulation pathway in the cycle of anthropogenic compounds

Abstract

Aliphatic hydrocarbons, chlorinated pesticides, polychlorinated biphenyls (PCBs), dioxins, furans, and trace metals have been quantified in fishes collected at four stations in Río de la Plata to determine contaminant sources, elucidate interstation and interspecies differences, and assess the health risks associated with fish consumption. Río de la Plata fish present low trace metal concentrations and moderate to high levels of organic pollutants, particularly aliphatic hydrocarbons and PCBs. The highest concentrations were recorded in Prochilodus lineatus, a dominant and remarkably specialized fatty detritivore that feeds on contaminated organic-rich flocculent matter. Lower levels were registered in Cyprinus carpio and especially in Mugil cephalus, reflecting different feeding preferences. A geographical pattern of higher contaminant concentrations close to the Buenos Aires urban center and lower levels in distant stations was also observed. The multivariate analysis of contaminant signatures indicated that most contaminated Prochilodus had fresh petrogenic and PCB traces, similar to fossil fuels and Aroclor 1254-1260, whereas Mugil and fish from distant sites presented a higher proportion of biogenic hydrocarbons and of more chlorinated PCBs. Toxicity equivalents ranged from 11 to 39 pg·g fresh weight-1 in Prochilodus, exceeding the guideline of 25 pg·g-1 for human consumption, with allowable consumption rates as low as 1 g fish·day-1.

Fatty acid alterations in the detritivorous Prochilodus lineatus promoted by opportunistic feeding on sewage discharges in the Río de la Plata estuary

“…liver hypertrophy, fish production increase and community structure alterations), as well as a prevailing contamination pathway for detritus feeding organisms (deBruyn et al ., ; Porter & Janz, ). These effects are amplified further when highly specialized detritivorous fishes feed directly on anthropogenic organic matter (Colombo et al ., ). Prochilodus lineatus (Valenciennes 1837) has several morpho‐physiological adaptations to selectively feed on organic detritus (sucker‐like mouth, gillraker filtering grid, cardiac and muscularized pyloric stomach with pyloric caeca and intestinal mucosal folds; Bowen, ).…”

Biomarker responses in caged carp (Cyprinuscarpio)and native collected fish (Leporinus obtusidens) in the Río de la Plata Estuary, Argentina

“…The persistent organic compounds may bioaccumulate in aquatic organisms through the ingestion of suspended particles and through the diet (biomagnification) (van der Oost et al, 2003). Studies performed in the Río de la Plata estuary, Argentina, have revealed bioaccumulation of pollutants in many species, including C. carpio and L. obtusidens (Colombo et al, 2000). These authors observed that the most representative pollutants in these fish were certain organic compounds, among which the most abundant were hydrocarbons and PCBs, suggesting a continuous input of these potentially bioaccumulable compounds.…”

“…The coastal locality of Punta Lara is located between two important urban centers (Buenos Aires and La Plata) which together have a population of about 12 million people and is situated near a large-scale petroleum refinery and several petrochemical plants (Colombo et al, 2006). The presence of different xenobiotics in Punta Lara include aliphatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dioxins, benzofurans, and heavy metals has been shown to be mainly associated with sediment, suspended particulate matter (SPM) and biota (Colombo et al, 2000(Colombo et al, , 2005(Colombo et al, , 2006. The composition of the hydrocarbon mixtures in the sediments reflects the relative contributions of different natural and anthropogenic sources: biogenic, diagenic, petrogenic, and pyrogenic.…”

Degradation of linear alkylbenzene sulfonate by a bacterial consortium isolated from the aquatic environment of Argentina

“…The site is characterized by a high contamination level attributable to the intensive industrial and urban activities which drastically affect the biological productivity of this estuary and adjacent marine waters (Mianzan et al 2001). Moreover, LAS represents one of the main xenobiotics discharged directly into this aquatic environment, resulting in physical and physiological alterations in aquatic organisms (Colombo et al 2000). Understanding LAS biodegradation by autochthonous bacteria isolated from this polluted ecosystem can provide a useful tool for applied microbiology.…”