Biological responses to contaminants in the Humber Estuary: Disentangling complex relationships

Abstract

Due to the ecological importance of estuaries, it is necessary to understand the biological effects that potentially toxic contaminants induce in bioindicator species. A key aspect is whether effects at lower levels of biological organisation transfer through the system to higher levels. In understanding such processes, characterising multivariate relationships between contaminants, sediment toxicities and detoxification processes are important. Worms (Hediste diversicolor) and sediments were collected along the Humber Estuary, England, and inorganic and organic contaminants were quantified. Sediment toxicities and glutathione S-transferases (GSTs) activity in the ragworm were analysed. Concentrations of metals were highest near urban and industrial areas, whereas organic contaminants appeared at upstream locations. GST activity correlated with heavy metals. The genotoxicity, estrogenicity, dioxin and dioxin-like activity were higher at upstream locations. Estrogenicity correlated with alkylphenols and some organochlorines, whilst genotoxicity correlated with organochlorines and heavy metals. Despite this, higher level biological responses could not be predicted, indicating that homeostasis is operating.

Habitat quality of estuarine nursery grounds: Integrating non-biological indicators and multilevel biological responses in Solea senegalensis

“…Arguably, the system complexity enabled the absorption of these changes which did not follow through to higher levels of biological organization (i.e. environmental homeostasis; Elliott and Quintino, 2007;García-Alonso et al, 2011). Nonetheless, higher juvenile densities were not concordant with higher contribution to coastal adult populations.…”

Integrated assessment of contaminants and monitoring of an urbanized temperate harbor (Montevideo, Uruguay): a 12-year comparison

“…All these chemicals can affect the natural condition of the faunal community. In estuaries, their presence has been associated with high sediment toxicities (GARCÍA-ALONSO et al, 2011). PCBs have been used as a flame retardant in plastics, while organochlorine pesticides are widely disseminated in natural environments after use for pest control (COMBI et al, 2013).…”

Bacterial diversity patterns of the intertidal biofilm in urban beaches of Río de la Plata

“…Hence, these areas would be stressful only for marine or freshwater-adapted organisms, while for estuarine organisms the naturally occurring stress would be a positive state. It has been shown that natural stress in estuaries gives similar conditions to those found in anthropogenic stress, therefore the assessment of ecosystem structural features when looking for quality indicators makes the detection of the anthropogenic stress more difficult (Elliott and Quintino, 2007;García-Alonso et al 2011). Sun et al (2012) analyzed sediments from estuarine sites heavily modified and relatively unmodified and found shifts in both bacterial community composition and diversity by ARISA, a technique that allows analyzing bacterial communities to species level (Ramette, 2009).…”