Metal pollution as a potential threat to shell strength and survival in marine bivalves

TY - JOUR

T1 - Metal pollution as a potential threat to shell strength and survival in marine bivalves

AU - Stewart, Bryce Donald

AU - Boig, Charlotte

AU - Jenkins, Stuart

AU - Sinfield, Catherine

AU - Kennington, Kevin

AU - Lart, William

AU - Brand, Andrew

AU - Kröger, Roland

N1 - © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.

PY - 2021/2

Y1 - 2021/2

N2 - Marine bivalve molluscs, such as scallops, mussels and oysters, are crucial components of coastal ecosystems, providing a range of ecosystem services, including a quarter of the world’s seafood. Unfortunately, due to human activity, coastal marine areas often suffer from metal contamination. We establish that increased levels of metal pollution (zinc, copper and lead) in sediments near the Isle of Man, resulting from historical mining, strongly correlate with significant weakening of shell strength in king scallops, Pecten maximus. This weakness increases mortality during fishing and leaves individuals more exposed to predation. Comparative structural analysis revealed that shells from the contaminated area were thinner and exhibited a pronounced mineralisation disruption parallel to the shell surface within the foliated region of both the top and bottom valves. Our data suggest that these disruptions caused reduced fracture strength and hence increased mortality, even at subcritical contamination levels with respect to current international standards. This hitherto unreported effect is important since such non-apical responses rarely feed into environmental quality assessments, with significant implications for population survival. Hence, our findings highlight the impact of metal pollution on shell mineralisation in bivalves, and urge a reappraisal of currently accepted critical contamination levels.

AB - Marine bivalve molluscs, such as scallops, mussels and oysters, are crucial components of coastal ecosystems, providing a range of ecosystem services, including a quarter of the world’s seafood. Unfortunately, due to human activity, coastal marine areas often suffer from metal contamination. We establish that increased levels of metal pollution (zinc, copper and lead) in sediments near the Isle of Man, resulting from historical mining, strongly correlate with significant weakening of shell strength in king scallops, Pecten maximus. This weakness increases mortality during fishing and leaves individuals more exposed to predation. Comparative structural analysis revealed that shells from the contaminated area were thinner and exhibited a pronounced mineralisation disruption parallel to the shell surface within the foliated region of both the top and bottom valves. Our data suggest that these disruptions caused reduced fracture strength and hence increased mortality, even at subcritical contamination levels with respect to current international standards. This hitherto unreported effect is important since such non-apical responses rarely feed into environmental quality assessments, with significant implications for population survival. Hence, our findings highlight the impact of metal pollution on shell mineralisation in bivalves, and urge a reappraisal of currently accepted critical contamination levels.

KW - scallops

KW - fisheries

KW - Seafood

KW - pollution

KW - Ecotoxicology

KW - Heavy metals

U2 - 10.1016/j.scitotenv.2020.143019

DO - 10.1016/j.scitotenv.2020.143019

M3 - Article

SN - 0048-9697

VL - 755

JO - Science of the Total Environment

JF - Science of the Total Environment

IS - part 1

M1 - 143019

ER -