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Geoffrey Bay is Marine National Park Green Zone where all marine life is protected and fishing and collecting is not permitted.


> See the Marine Park Zone Map

2. Geoffrey Bay Marine


Fringing Reef

A large fringing reef platform extends across the bay. Compared to other reefs around Magnetic Island, Geoffrey Bay has a high percentage of subtidal hard coral cover, a high number of Drupella snail scars and a high incidence of other coral damage, mainly intertidal. Geoffrey Bay’s eastern end is a nursery area for several ray species: cowtail, shovelnose and whip. Blacktip shark pups regularly cruise at dusk.

(Photo: Staghorn corals exposed at very low tide, courtesy of Dr Carden Wallace.)


Snorkel Trail

Discover the Geoffrey Bay Self Guided Snorkel Trail from the beach opposite the Arcadia Village Hotel.


The endangered giant clam species Tridacna gigas can be found in the Tourism Magnetic Island trail. You can pick up your Snorkel Guides at a number of local businesses.

> More information is available at:


Coral Spawning Discovered

In 1981 Geoffrey Bay is where scientists discovered that many coral species reproduce on the same few nights each year. The discovery revolutionised coral research.

> READ: Mass Spawning in Tropical Reef Corals
by Harrison, Babcock, Oliver, Wallace and Willis JCU. Published in Science, Vol 223, 1984

> READ: Synchronous Spawnings of 105 Scleractionian Coral Species on The Great Barrier Reef
by Babcok, Bull, Harrions, Heyward, Oliver, Wallace and Willis. Published in Marine Biology 90, 379-394, 1986.

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> WATCH: Mass Coral Spawning Discovery, ABC Quantum 1992. (Video)

These reefs were the site of a momentous discovery in coral reef science – the mass spawning of numerous coral species on just a few nights each year.


This discovery changed forever some of the major concepts in coral reef biology and made possible whole new approaches to field and laboratory research.


Following the discovery (reported in the journal Science in 1984) scientists from around the world have come to Magnetic Island in October-November to study coral spawning and associated topics.

The research has given us greater understanding of how corals respond to damage caused by climate change, coral bleaching, cyclones and predator outbreaks on the Great Barrier Reef, and insights into better care and management of our reefs.

The discovery of mass coral spawning, and 10 years of subsequent research, were awarded the prestigious Eureka Prize for Environmental Science in 1992. Eureka Citation 1992 “Awarded for one of the most exciting discoveries made in coral reef biology, an annually synchronised spawning activity on the Great Barrier Reef of more than 100 species of coral, a sexual synchronisation which is unknown in any other part of the Animal Kingdom”.


Today, Magnetic Island has a place in the history of coral reef research worldwide and its reefs continue to provide inspiration and a training ground for students.


More than 250 scientific papers have been published, stemming from the discovery of mass coral spawning.

Geoffrey Bay Foreshore  |  Geoffrey Bay Marine  | Geoffrey Bay Scrub  |  Alma Bay & Alma Creek
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