Mechanistic understanding of climate driven range shifts: using thermal tolerances of rock lobster to predict future range shifts
Samantha Twiname (1*), Quinn Fitzgibbon (1), Alistair Hobday (2), Gretta Pecl(1)
1 Institiute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS 7001
2 CSIRO Oceans and Atmosphere, Castray Esplanade, Hobart, TAS 7001
Ocean warming is affecting marine species worldwide, with one of the most visible changes being alterations to species geographical distributions. Understanding what drives these range shifts is key to predicting what may happen with future warming. This study takes a mechanistic approach to understanding climate-driven range shifts, looking at the metabolic and escape responses of puerulus stage spiny rock lobster and how they may change under different temperature scenarios as an indicator of future change. The puerulus stage of the spiny rock lobster life cycle is an important transitional stage between the larval and juvenile stages and understanding how ocean warming may affect their aerobic and swimming capacity allows us to better predict future scenarios of population dynamics. We examined the metabolic physiology and escape response of the puerulus stage of Jasus edwardsii, a common Tasmanian species of spiny rock lobster, and Sagmariasus verreauxi, a species of spiny rock lobster extending its range into and further south in Tasmania. Jasus edwardsii puerulus were tested at 14, 16, 18, 20, 22 and 24°C, and S. verreauxi puerulus were tested at 18, 20, 22, 24, 26 and 28°C. Intermittent flow respirometry was used to determine ae robic scope (AS), excess post-exercise oxygen consumption (EPOC) and recovery times. Escape velocities were determined from high speed stereo-video footage. The comparison between the physiologies of the two species indicates that future ocean warming may allow S. verreauxi to further expand their population in Tasmanian waters.