Heavy Metals in the Marine Environment

Introduction

The aim of this volume is to draw together state-of-the-art reviews of knowledge on levels of heavy metals in marine environments (particularly in marine animals), the dynamic processes in these systems, toxic effects, and threats presented by heavy metals in foods of marine origin.

All heavy metals, whether biologically essential or not, have the potential to be toxic to organisms at a threshold bioavailability. Such threshold concentrations vary between metals, between species and with the physicochemical characteristics of the medium, so like copper being particularly toxic even though essential in trace amounts.

Animal Responses and Metal Regulation

Responses of animals to metals in their medium or food depend to a large extent on the ability of species to regulate levels attained in their tissues. Higher animals have the capacity to regulate levels of many metals, while marine invertebrates can regulate some within certain limits.

Where animals cannot regulate physiological levels of metals, an alternative strategy is to detoxify and store metals in relatively harmless forms.

Importance of Metal Handling

Knowledge of the manner in which animals deal with potentially toxic concentrations of heavy metals is of fundamental importance in the assessment of metal pollution by analysis of metal levels in biological samples.

Biological Interactions and Effects

The interaction of heavy metals with biological materials is a key theme running through this volume. Toxic effects may be reflected at the individual, population, or ecosystem level, affecting species composition and production levels, or may be of direct dietary significance to man.

Global Metal Cycling

The global cycling of metals through the marine environment is crucially affected by biological processes.