Developing a better understanding of resilience
- Resilience of the intertidal habitat-forming alga Hormosira banksii. This work examines the recovery component of resilience, examining the extent to which severe disturbance causes phase shifts, and looking at recovery rates at a regional scale (along the Victorian coast) and latitudinally (northern New South Wales- Victoria-Tasmania). We are also testing whether harvesting of intertidal snails affects Hormosira recovery rates.
- Resilience and connectivity in the seagrass Zostera nigricaulis in Port Phillip Bay. This collaboration with Craig Sherman, Jeff Ross, Pete Macreadie, Angus Ferguson, Renee Gruber, Tim Smith, and Paul York examines mechanisms of recovery in Zostera, incorporating regional comparisons around a large (2000 km2) embayment and measures of genetic connectivity.
- Responses of sessile invertebrate communities to disturbance. Are heavily invaded communities less resilient? What happens if we remove the invaders – can native species retain space?
- Resilience of the habitat-forming subtidal kelp Ecklonia radiata in Port Phillip Bay. This is a nearly complete PhD project by Paul Carnell
Human impacts on coastal environments
- Better detection tools for pollution in estuaries. We are working to develop quick, cost-effective ways of detecting effects of pollutants in estuaries, using a combination of field mesocosm experiments, biomarkers, genetics, and developing new behavioural and life history assays.. You can find more details of this area through CAPIM and through Allyson O’Brien’s links.
- Water quality targets and seagrasses in Western Port. This is a new collaboration with Perran Cook and Ralph Mac Nally and John Beardall (Monash), Jeff Ross (U. Tas.), Rhys Coleman (Melbourne Water) and Isaac Santos (Southern Cross U.), combining geochemistry, plant physiology, disturbance ecology, and spatial modelling, to understand causes of changes to seagrass cover in Western Port and potential for recovery.
- On rocky shores, humans can exert a direct influence by harvesting particular species for food and bait, and create disturbances by trampling, etc. We have for many years documented these effects, and have a 20 year study following changes in populations of intertidal snails in response to different kinds of coastal management.
Life history and ecology of sessile invertebrates
The two-phase nature of invertebrate life histories create interesting questions about the links between these two life stages. We know now that the condition of larvae at settlement can have far-reaching effects on their success after metamorphosis, influencing growth, survival, and the timing and extent of reproduction. Conversely, we know that larval quality depends on parental, particularly maternal investment, and on larval experiences during dispersal. How tightly linked are these components? To what extent do parents adjust the kind of offspring they produce in response to environmental stresses? What kinds of stresses do they respond to? We are addressing these questions with a number of model species, most notably bryozoans.
Biofouling and mussel farms
As farming contributes an increasing share of the protein we get from the sea, it is important to focus on improving the cost-effectiveness of farming and reducing its environmental footprint. For many aquaculture operations, fouling of structures is a significant economic cost, and this cost increases when the farmed species are themselves fouled. We are working with Victorian mussel farmers to look at the interactions between mussels and fouling species, particularly ascidians, hydroids, and polychaetes. Foulers can influence mussel settlement, influence growth rate and condition, and shell fouling reduces the market value of mussels. In addition to documenting the problem, we are investigating ways of reducing the cost of this fouling.