Algal-herbivore interactions
Early work focused on algal-herbivore dynamics, investigating the controlling role of molluscan herbivores on the cyanobacteria dominated epilithic biofilm. This work involved quantification of the distribution and behavioural patterns of the grazers and species composition and seasonal variation in the biofilm. Manipulative experiments revealed the role of grazers in controlling algal distribution, but most importantly the interaction of these biotic factors with seasonal changes in the physical environment. Harsh physical stress during the summer had an overall controlling effect, limiting grazer numbers and distribution and therefore severely restricting the importance of grazers on the shore.
Physiological; and behavioural responses to thermal stress
Subsequent work has focused on the role physical stresses on community dynamics, with an emphasis on limpets. Using a variety of field and laboratory approaches we have been measuring physiological responses (body temperatures, heart rate, haemolymph and mantle water osmolality) to a variety of natural (on the shore or simulated in the laboratory) stresses but primarily heat stress and monsoon rains. Some species are amazingly tolerant and exhibit a great variety of behavioural and physiological adaptations to heat stress, whereas others are more susceptible, and cope with heavy mortality during the summer by being very resilient and having short life cycles.
Current research interests
This work has lead to larger scale investigations into species distribution and latitudinal responses to thermal stress. Identifying species distribution ranges across the NW Pacific is difficult as many 'species' are misidentified and actually cryptic species complexes. Currently we are trying to identify these patterns, in order to correctly identify species ranges. To tie in with this we are trying to link this with species' physiological responses, in an attempt to identify which species may be affected by a warming climate. This work, given its scale, involves a variety of collaborators in SE Asia, as well as Europe, S.Africa and the USA. The major goal of this work is to establish a network of collaborators who will be able to work on large scale latitudinal investigations to answer questions of how species respond to environmental stressors and how this may impact future community structure in rocky intertidal systems. |