Thesis Research
Supervisor: Dr. Frédéric Guichard
Many organisms have two distinct phases of movement: a sedentary or slow-moving adult stage (such as trees or mussel beds) and a generally short-lived and fast-moving juvenile stage (e.g. seeds or pelagic larvae). While each organism may spend the bulk of its life in its adult stage, the mechanisms that drive movement of the juvenile stage play a vital role in the survival of the organism, as the juvenile's movement determines the conditions the adult will face.
One particular mechanism that may play an important role in population dynamics is packet-driven (or clustered) dispersal; this is where individuals (of one or more species) move together in a spatially discrete group, and settle simultaneously in some location. This may be driven by physical forces, such as large marine eddies driving larvae together, biological factors such as seeds in a single seed head moving together or seeds being eaten and defecated by an animal, or by organism behaviour, as with schooling or herding animals. The result is that individuals end up arriving at their final habitat in clusters, which means individuals will typically face stronger density-dependent interactions with one another than they would under un-clustered settlement.
My research focuses on understanding packet-driven dispersal in marine invertebrates. There's several questions Iım trying to answer: 1) How can we detect packet-transport in larval settlement, and determine what mechanisms are causing it? 2) How does clustering in the water column affect the behaviour of dispersing larvae? 3) What long-term impact does packet-driven transport have on population dynamics, and how should this impact vary with the spatial scale of the packets and the spatial scale a given species interacts at? To understand these questions, I work with theoretical population and behaviour models, behavioural experiments and statistical analysis of larval distribution and settlement data.
