MEGMAR (Molecular Ecology Group for Marine Research) is a
new research initiative from Macquarie University

We are looking for partnerships with governmental and
industry organizations interested in conservation of marine
ecosystems and sustainability of marine-based industries

Overview

Understanding and managing marine biodiversity represents one of the major challenges faced by the scientific community of the 21st century. Maintaining a healthy and biologically diverse marine environment is essential for sustaining economical development. This is particularly true in Australia, an island nation with the world's largest area of ocean territory. For instance, considering only figures for the South-East Australian region, marine -based economy employs more than 270,000 people and generates $19 billion annually. Developing strategies for understanding patterns of biological distribution and diversity in the sea and building conservation into decision making requires cooperation and commitment of a diverse group of governmental and public organizations, including national, regional and local stakeholders.

Systematic discussions about marine biodiversity usually converge on a single topic: the dispersal of marine organisms. Dispersal is the major force shaping species distribution, persistence and evolution and represents a critical factor when developing management strategies for fishery resources, implementing aquaculture initiatives, or designing marine protected areas (MPAs). Data on dispersal of marine organisms has been very difficult to acquire, not least because of the problems of observing direct movements in the sea. However, recent advances in DNA technology and statistical analyses have revolutionized the way we make inferences about the biology of organisms, resulting in the creation of a new research area, Molecular Ecology. Molecular ecology is an expanding and exciting area that includes the large array of questions on ecology, behaviour, evolution, conservation and management that can be addressed with molecular approaches. The impact of molecular ecology is evident in the field of marine biodiversity - researchers are now capable of addressing consequential questions about dispersal in the sea that could not be realistically formulated few years ago.

MEGMAR combines research expertise in marine ecology, conservation, management, and molecular ecology. We represent the first molecular ecology group in Australia with a focus on dispersal of marine organisms. Our initial research strategy is to rapidly describe dispersal patterns (using microsatellite DNA data) in species distributed along the eastern and south-eastern Australian coasts. Through partnerships with the government and industry, we expect that our research will contribute to the conservation of marine ecosystems and sustainability of marine-based industries.

Aim

We are implementing a multi-disciplinary and multi-investigator framework to rapidly and effectively estimate dispersal in groups of marine organisms with contrasting dispersal capabilities: wobbegong sharks, bottlenose and common dolphins, sea-urchins, abalones, ascidians and oysters. By elucidating patterns of connectivity among populations in relation to coastal geomorphology and physical oceanography, we will efficiently describe biological diversity in the sea and contribute to the appropriate manegement of marine resources.

Because we are working on organisms sampled from the same region, we can synergistically combine results from the individual projects. The combined outcomes will be used to address three key topics in marine biodiversity that have enormous implications for public, governmental, and scientific communities: (i) design of marine protected areas (MPAs), (ii) management and conservation of marine resources, and (iii) understanding dispersal in the sea.

Our projects

Sea Urchins
The sea urchin Centrostephanus rodgersii is the basis of a small but developing commercial fishery in NSW. The species is also the dominant benthic herbivore on coastal rocky reefs in NSW and eastern Victoria. Grazing activity by C. rodgersii populations may remove all of the macroalgae within a local area and establish barrens. The impact of this grazing activity has a major influence on the abundance of other invertebrate species such as the blacklip abalone, Haliotis rubra. Recently, C. rodgersii populations have extended south along the eastern coastline of Tasmania, and are thought to be responsible for the decline of Tasmania's unique kelp forests (Prof Craig Johnson, University of Tasmania, unpublished data). Because the planktonic larvae of this species are capable of traversing large distances, the expansion of this species in Tasmania may be due to increased recruitment from the more northerly populations along the coast of the Australian mainland as a result of changing ocean current patterns, or to recruitment from pre-existing, northern Tasmanian populations. Our genetic data will enable us to elucidate the dispersal patterns of this species to contribute to the management of the commercial harvest of the species and understand the origins of the expanding Tasmanian population.

Oysters
Sydney rock oysters (Saccostrea commercialis) are the basis of an important industry along the east Australian coastline. However, oyster production has been locally decimated by outbreaks of the QX disease, caused by the intestinal parasite Marteilia sydneyi. Assoc. Prof. David Raftos recently won an ARC Linkage grant with NSW Department of Primary Industries (DPI) to investigate infectious disease in commercially important molluscs. This work will help DPI to develop management strategies for disease control in aquaculture and may shed light on novel breeding systems in broad spawning marine invertebrates. Our genetic data will enable us to elucidate dispersal patterns and genetic variation between populations of oysters to determine whether genetic population structure affects disease susceptibility and how the translocation of young oysters (spat) by commercial farmers influences patterns of local genetic variation.

Cunjevoi
The cunjevoi (Pyura stolonifera) is a sea squirt that is commonly found along the low tide mark on rocky shores. As with many ascidians, the larval duration of P. stolonifera is very short (several hours) and their dispersal capability is likely to be very restricted. This species may be a better indicator of local population structure than species with greater dispersal capability, such as the sea urchin Centrostephanus rodgersii.

Wobbegong Sharks
Sharks are particularly vulnerable to overfishing and many species are known to have been seriously affected in Australia. The catch rates for wobbegong sharks along the NSW coast have declined over 50% in the last 10 years and preventive measures are urgently needed to prevent further population declines. Fishing of wobbegongs is not adequately managed because commercial fishers do not discriminate among discrete local populations (known as stocks). Field data predict low dispersal for wobbegongs, including high female fidelity to their natal site. These are crucial factors that increase the likelihood of extinction for local populations under intensive fishing pressure. We will: (i) estimate dispersal and the number of discrete populations, (ii) test for differences in the dispersal rates between sexes , and (iii) identify conservation units and propose management strategies .

Our team

Dr Luciano Beheregaray - team coordinator, Senior Lecturer
Dr David Briscoe, Professor
Dr Richard Frankham, Professor
Dr Robert Harcourt, Associate Professor
Dr Neil Holbrook, Associate Professor (University of Tasmania)
Dr David Raftos, Associate Professor
Dr Jane Williamson, Lecturer
Dr Peter Teske, Post-doctoral Fellow
Dr Sam Banks, Post-doctoral Fellow
Dr Luciana Moller, Macquarie University Fellow
Dr Maxine Piggott, Post-doctoral Fellow
Ms Kerstin Bilgmann, PhD Student
Mr Ulysse Bove, PhD Student
Ms Shannon Corrigan, PhD Student
Ms Kathryn Newton, PhD Student
Ms Kim Shaddick, PhD Student
Mr Peter Tung, Marine Fieldwork Manager

Selected publications

- Piggott M, Banks S, Tung P, Beheregaray LB (2008) Genetic eviudence for different scales of connectivity in a marine mollusc. Marine Ecology Progress series. In Press.

- Banks S, Piggott M, Williamson J, Bove U, Holbrook N, Beheregaray LB (2007) Oceanic variability and coastal topography shape local genetic structure in a long-dispersing marine invertebrate. Ecology 88, 3055-3064.

- Möller LM, Wiszniewski J, Allen SJ, Beheregaray LB (2007) Habitat type promotes rapid and localized genetic differentiation in dolphins. Marine and Freshwater Research 58, 640-648.

- Bilgmann K, Moller LM, Harcourt R, Beheregaray LB (2007) Genetic differentiation in bottlenose dolphins from South Australia: an association with local oceanography and coastal geography. Marine Ecology Progress Series 341, 265-276.

- Banks S, Piggott M, Williamson J, Beheregaray LB (2007) Microsatellite markers for the sea-urchin Centrostephanus rodgersii. Molecular Ecology Notes 7, 321-323.

- Piggott M, Banks S, Beheregaray LB (2006) Use of SSCP to improve the efficiency of microsatellite dentification from microsatellite enriched libraries. Molecular Ecology Notes 6, 613-615.

- Banks S, Piggott M, Raftos D, Beheregaray LB (2006) Microsatellite markers for the Sydney rock oyster, Saccostrea glomerata, a commercially important bivalve in south-eastern Australia. Molecular Ecology Notes 6, 856-858.

- Bilgmann K, Griffiths OJ, Allen SJ, Möller LM (2007) A biopsy pole system for bow-riding dolphins: sampling success, behavioral responses, and test for sampling bias. Marine Mammal Science 23, 218–225.

- Möller LM, Beheregaray LB (2004) Genetic evidence of sex-biased dispersal in resident bottlenose dolphins (Tursiops aduncus). Molecular Ecology 13, 1607-1612.