Spatial Ecology of Reef Fishes Justin Welsh and David Bellwood

Roles on reefs: Herbivory Introduction Transport sediment Maintain algal turfs Remove macroalgae Overall, support resilience

Importance of resilience Introduction ?

Who and what... We think we know. But where and why? Introduction

Haremic versus Schooling What is the spatial ecology of roving herbivores and is there an influence of social systems?

Introduction Chlorurus microrhinos Haremic Roving herbivore Active telemetry Case study: the parrotfishes Scarus rivulatus Schooling Roving herbivore Passive telemetry

Algal removal Leave deep, long- lasting grazing scars Haremic Introduction Chlorurus microrhinos

Objectives: Quantify home range size Determine the influence of physical factors Implications for ecosystem role Introduction

Study site: Orpheus Island, Pioneer Bay Methods

Capture Barrier netting Methods

Capture Tagging Anesthetic MS-222 Tag (V9T-2H, Vemco) Suture Methods

Tracking Tracking from Kayak for days (Meyer and Holland 2005) Receiver (VR100, Vemco) Directional hydrophone (VH1110, Vemco) Methods

Home range: 8,100 m 2 Core area: 1,690 m 2 Results Welsh and Bellwood 2012, Coral Reefs Vol: 31

Core vs non-core: Physical characteristics: Results

Results: * * Core area Non-core area * *

Core areas centered on topographic complexity Limited mobility in haremic parrotfish What about schooling species? Summary

Herbivores So far, highly site attached Social species? e.g. schooling? Introduction

Scarus rivulatus Highly abundant Important herbivores Schooling species Roving herbivore? Introduction

Objectives: Evaluate the foraging range of S. rivulatus Understand the foraging range of their schools

Passive acoustic telemetry Introduction Heupel et al 2006 VR2W receivers V9 transmitters 60 m detection range Welsh et al. 2012, Coral Reefs

Orpheus island array Methods

Capture 3 schools captured using barrier nets Methods Tagging Same tagging procedure as per active tracking Monitor individuals for 7 months

Spatial data analysis Maximum potential foraging range Chapter 2 >5% >5% <5% >5% >5% <5%

Spatial range Results Average area occupied: km 2 Welsh and Bellwood 2012, Coral Reefs

Results Average area occupied by the school: km 2 Spatial range

Conclusion Site attached Facultative schooling Limited school fidelity Conclusion

Introduction Chlorurus microrhinos Haremic Site attached Scarus rivulatus Schooling Site attached Herbivores from a different perspective: Regardless of social system, functional role occurs on small spatial scales

Credits David Bellwood, Roberta Bonaldo, Simon Brandl, Rebecca Fox. Chris Goatley, Andy Hoey, Jess Hopf, Charlotte Johansson, Michael Kramer, Susannah Leahy, Carine Lefèvre, Jenn Tanner, OIRS and LIRS staff and Vemco. Photos by Joao Paulo Krajewski Funding provided by: ARC center of excellent for coral reef studies, Australian museum, James Cook University

Schooling and feeding Feeding observations: ‣ 160 individuals, 1 min each, 4 times of the day, 2 sites Results

Significance of schooling Results