Salmon begin their life in rivers and streams, move out to sea and then return to their natal streams to spawn as adults. The transition from the freshwater environment to the ocean is critical for these fish with high and variable mortality during this period. I seek to understand the role that size and growth during this critical period plays in survival.

I use a combination of physiological measures (insulin like growth factor) and otolith based metrics to reconstruct growth patterns in fish during this difficult transition. I then put this in the context of environmental conditions to see when, where, and how growth may provide a survival advantage. To date I have shown that when overall survival is lower, fish which are growing faster, but aren't necessarily larger, prior to ocean entry are more likely to survive.

Human driven carbon dioxide emissions are causing the worlds oceans to become warmer and more acidic (ocean acidification). These two dual stressors are likely to place stresses on marine species making it difficult to survive, grow and reproduce. I try to understand how these two climate change stressors may work synergistically or antagonistically to affect the growth and survival of adults and larvae.

Currently I am investigating how these stressors impact pacific staghorn sculpin, a common coastal fish in the northern California current ecosystem. Using tightly controlled laboratory experiments I investigate how these dual stressors may impact the growth and survival of adults. I also investigate the transgenerational impacts of these stressors by examining the impact that parental exposure to stress has on the growth and survival of larvae.

Knowledge of population connectivity driven by larval dispersal is a key aspect for understanding of population dynamics. I use both trace elemental fingerprinting techniques and biophysical modelling to estimate dispersal patterns of marine larvae.

Using a combination of these techniques, I estimated the potential for larvae from green lipped mussel aquaculture to spillover to locations at which efforts to restore degraded natural populations may occur. This research showed that the larval pool in the area of interest was likely well mixed. Larvae originating from large aquaculture populations had the potential to settle throughout the area, and provide a population subsidy to restoration efforts.

The chemical composition of calcified structures such as shell or otolith can be used to reconstruct the conditions at their time of formation. Therefore, I seek to understand how environmental and biological factors may impact these structures.

Using laboratory experiments I investigated the impacts of ocean acidification on shell chemistry of green lipped mussels (Perna canaliculus). This research demonstrated consistent differences in the composition of some trace elements across pH treatments while others remained consistent. This research highlighted the potential for shell chemistry to be used to reconstruct pH conditions at the time of formation.

Secondly, using a combination of laboratory experiments and field studies I investigated the impact that genetic differences between families of green lipped mussels on their shell composition. While laboratory experiments showed that different families exhibited differing elemental shell composition, in the field environmental differences between individuals growing at different locations exerted a stronger influence on shell chemistry.