Owen Burnell

A changing climate within marine ecosystems is inevitable, however the understanding of its effects on individual, local and global scales are still in infancy. Currently I am working to investigate the effect of ocean acidification, in the form of a lowered level of pH, combined with temperature increases predicted over the next century. These two changing oceanic climatic variables are inherently linked to one another through increasing atmospheric carbon dioxide, and are predicted to create a synergistic interaction, where their combined effect may be larger then the individual effects added together.

My current study is focused on how rapidly carbon dioxide will reduce pH levels in oceans, and how this in conjunction with temperature changes will effect calcium carbonate shell building organisms. Acidification reduces the level of carbonates in seawater. This reduction lowers the availability of carbonates for shell builders, and can also dissolve pre-existing shells. My experimental work will involve the southern Australian species of abalone Haliotis laevigata. This species is of great economic importance and may be at an early risk due to a combination of ecological and environmental factors. However the risks predicted as a result of acidification and temperature are not isolated to this species but extend to multiple calcifying organisms including corals, calcifying algae, molluscs, echinoderms and bryzoans, as well as many planktonic calcifiers. 

Laura Falkenberg

Human activities are causing the earth’s environment to change at an increasingly rapid rate. In response to this change ecosystems will not gradually alter but abruptly shift to alternative, generally simplified, states. Shifts between states have been observed in numerous ecosystems. My honours project will consider a shift which is occurring in marine ecosystems, that from kelp canopies, and the associated encrusting coralline understorey, to turf-forming algae.

The factors which will facilitate the switch from kelp forests to turf-forming algae remain unclear. Even the most recent studies into human impacts in these systems only consider combinations of local factors such as nutrients and grazers, yet increased carbon dioxide concentrations may alter interactions between the factors. My honours project will work to identify the effect of carbon dioxide on the interaction between nutrients and grazers, enabling better-informed environmental management and possibly the retention of desired ecosystem states on which human societies rely.

Ingrid Bunker

Climate change is a result of human actions which our economy currently depends on, and these changes are predicted to have damaging consequences on our natural systems.

The focus of my project is on the effect of temperature and ocean acidification associated to climate change and how this will affect the ecology of our temperate marine systems. My particular focus will be on the ecology of algae and algal grazers, which play a crucial role on the establishment and persistence of certain habitats, such as kelp forests, which support a large diversity of species. If biodiversity loss due to climate change occurs in these systems there are likely to be economic and social losses, such as a decline in the fishing industry.

To be able to predict the consequences of climate change is important for the adaptation to these changes and also to make us aware of the need for the mitigation of further climatic impacts.

Claire Passarelli

Kelp forests are widespread and highly productive ecosystems in temperate and polar oceans, and yet they are in decline. Local modifications of the environment by humans, like increases in nutrient concentrations, reduce their ability to regenerate following disturbance. Global changes probably affect kelp forests as well.
My internship project investigates the combined effects of increases in carbon dioxide (CO2) concentration and ultraviolet (UV) intensity on the ecology of two types of algae. One of them (encrusting coralline algae) facilitates kelp regeneration; the other one (turf-forming algae) hinders it. The experiments will allow predictions on the future of kelp forests under global change, and assess the possibility of depth as a refuge for kelp, as UV radiation does not penetrate very deep in the water.