Seasonal effects to metallothionein responses to metal exposure in a naturalised population of Ruditapes philippinarum in a semi-enclosed estuarine environment

Abstract

The Manila clam (Ruditapes philippinarum), an invasive species in Northern Europe, can be used as a bioindicator of metal pollution. Seasonal effects on metallothionein (MT) production have not been considered in this species at the northernmost extent of its European distribution. This study assesses the annual seasonal effects on MT and metal concentrations in R. philippinarum from Poole Harbour, UK. R. philippinarum were collected in winter, spring, summer, and autumn throughout 2015, and MT and metal concentrations, as well as biotic and abiotic variables, were quantified. During winter, linear regression analysis showed significant positive relationships between tissue metal and MT concentrations. However, during spring and summer, these relationships were mostly insignificant. MT concentrations during spring had significant positive relationships with tissue and whole weight. Significant positive relationships were also observed between MT and condition index, during summer. During spring and summer, biotic factors seem to override the role of MT as a detoxification mechanism for metal exposure in this species. This is probably due to an increase in MT concentration in spring caused by gametogenesis, associated with increased tissue weight as the gonads expand. A depletion of energy resources, or physical stressors such as heat, may be attributed to the reduced MT production in clams of poor body condition in summer. The evidence from this study suggests that MT may only be a useful biomarker of metal pollution during winter in R. philippinarum in the UK. This verifies the natural variability of MT in this species at high latitudes, and highlights the potential and limits to a widely available bioindicator of metal pollution.

Metal Accumulation and Metallothionein Response in Fucus spiralis

“…This is in agreement with previous literature on metal pollution in Poole Harbour by Langston et al [30], Aly et al [31], and Oaten et al [32], which reported generally higher metal concentrations within Holes Bay in sediment and seawater, as well as biota. F. spiralis metal concentrations at Sandbanks were also relatively high.…”

Metals and As content in sediments and Manila clam Ruditapes philippinarum in the Tagus estuary (Portugal): Impacts and risk for human consumption

“…The use of Manila clam as a bioindicator for metals and As contamination in transitional environment has been debated, since some authors suggested its possible use (Oaten et al, 2017), whilst others (Moschino et al, 2012), demonstrated a weak responsiveness and sensitivity to anthropogenic pollutants, and a lack of biochemical response in field studies (Velez et al, 2015b). The present work demonstrated that condition index (C.I.…”

“…These authors showed that MTs synthesis in the Venice lagoon is influenced by gonadal development, reflecting seasonal metallothionein trends. Also Oaten et al (2017) proved that MTs synthesis in Manila clam can change depending on seasonality. R. philippinarum from the Tagus estuary are generally in mature phase of reproduction (phase III) or immediately after gametes release (phase IV) during spring months (Moura et al, in press), however they showed an increased synthesis with respect to clams and sediment metals and As content.…”

Analysis Metallothionein of Carp fish in The Brantas River, Indonesia

“…The heavy metal elements (Pb, Cu, Cr, and Cd) that found in the upstream and downstream of the Brantas River are fluctuative [2], usually dependent on the seasons. In the dry season, level of heavy metal is higher than the rainy season due to heavy metals will tend to settle in sediment [3]. Related The effect of this heavy metals are so dangerous, especially for fish that live on the river.…”