Response of invertebrates to metal pollution
My research has two inter-related strands. The first is an examination of the impact of trace metals at the individual and ecosystem level. We have recently shown that aluminium present in polluted waters modifies behaviour in the pond snail Lymnaea. Future work will look for neurophysiological changes and be extended to other sub-lethal measures of potential damage such as a decrease in immuno-competence. My studies at the ecosystem level have centred on an examination of the impact of pollution from mining and mine wastes. In collaboration with geochemists and hydrologists I am looking at changes in community structure in relation to shifts in metal concentrations arising from hydrometeorlogical events. This work is focusing on a catchment in Anglesey whose small size lends itself to intensive study. These investigations have been extended to sites on the Isle of Man and Greece.
The second theme in my work examines how organisms accumulate trace metals and the role of certain organs in detoxifying the absorbed metals. Studies with aluminium are particularly interesting, as we have shown that the metal is accumulated to a high degree by aquatic gastropods and crustacea at pH values where it was thought to be relatively unavailable. I have continued my interest in the response of invertebrates to pollution by metals with an examination of intrinsic and extrinsic influences on metal uptake in relation to their use as monitors.
More recently I have also become interested in the hydrography and ecology of waterbodies recovering from pollution. Redeveloped docks and canals, in particular, provide ideal sites to examine the process of ecological change and recovery. The need to manage such systems also provides opportunities to assess the impact of habitat manipulation and hydrographic changes on the ecology. Of particular interest is the control of phytoplankton by filter-feeding bivalves and exudates from barley straw. My work in this area centres around an examination of estuarine and freshwater docks and waterways.