Dispersal energetics of fishes with different lifestyles

Dispersal energetics of fishes with different lifestyles: An assessment of the relative ability of fishes to 'bounce back' following disturbance.

One of the things animal ecologists seek to understand is how environmental change will interact with species traits to affect the long-term persistence of biodiversity. This isn't easy, and to make the problem simpler, we often break population persistence into two parts: 'resistance' and 'resilience.'

In the context of riverine fishes, the resistance of a population to a stressor is positively proportional to the magnitude of that stressor required to drive a population locally extinct. Resilience of the same population to the same stressor is negatively proportional to the speed with which that population repopulates a river reach following localised extinction. Species with high dispersal capacity may be seen to be more resilient than those with lower dispersal capacity, as they might be able to recolonise reaches quicker than species with inferior dispersal capacity.

The objective of this summer cadetship is to study the swimming energetics of two fishes with contrasting lifestyles: unspecked hardyhead (pelagic species) and flathead gudegon (benthic species). Building on recent work, we will test the hypothesis that hardyhead have a (a) higher critical swimming velocity, and (b) lower energetic cost of transport, than gudgeons.

This study will improve our understanding of the resistance and resilience of fishes to drought. We are currently publishing papers on the physiological resistance and resilience of fishes to drought, and this study will build on that foundation, and fill a critical gap in our data-set

Location Wodonga
Supervisors Rick Stoffels and Kyle Weatherman
Student Bettina Grieve
Duration 10 weeks (commencing 1 Dec 2014)
Expected outcome Final Report and Seminar