ABSTRACT
This chapter reviews some of the ways in which metals may exert their toxic effects, together with the methods used to establish threshold levels. Metals occur naturally in seawater and many, such as Cu, Co, Fe, Mn, Ni, Se, V, and Zn, are used for essential purposes by marine organisms. Toxic effects occur when excretory, metabolic, storage, and detoxification mechanisms are no longer capable of matching uptake rates. Techniques used to assess the effects of metals are varied and range across many levels of biological organization from cells to whole communities. Lower-order biochemical responses may be intimately linked with disturbances in essential life processes, such as growth and reproduction, which in turn may influence the health and survival of individuals, populations, and ultimately communities. The chapter describes the incidents of metal pollution merely serve to highlight the types of change which can occur at contaminated sites.
