Snorkellers discover rare, giant 400-year-old coral – one of the oldest on the Great Barrier Reef


Richard Woodgett

Adam Smith, James Cook University; Nathan Cook, James Cook University, and Vicki Saylor, Indigenous KnowledgeSnorkellers on the Great Barrier Reef have discovered a huge coral more than 400 years old which is thought to have survived 80 major cyclones, numerous coral bleaching events and centuries of exposure to other threats. We describe the discovery in research published today.

Our team surveyed the hemispherical structure, which comprises small marine animals and calcium carbonate, and found it’s the Great Barrier Reef’s widest coral, and one of the oldest.

It was discovered off the coast of Goolboodi (Orpheus Island), part of Queensland’s Palm Island Group. Traditional custodians of the region, the Manbarra people, have called the structure Muga dhambi, meaning “big coral”.

For now, Muga dhambi is in relatively good health. But climate change, declining water quality and other threats are taking a toll on the Great Barrier Reef. Scientists, Traditional Owners and others must keep a close eye on this remarkable, resilient structure to ensure it is preserved for future generations.

coral and snorkellers
Muga dhambi is the widest coral structure recorded on the Great Barrier Reef.
Richard Woodgett

Far older than European settlement

Muga dhambi is located in a relatively remote, rarely visited and highly protected marine area. It was found during citizen science research in March this year, on a reef slope not far from shore.

We conducted a literature review and consulted other scientists to compare the size, age and health of the structure with others in the Great Barrier Reef and internationally.

We measured the structure at 5.3 metres tall and 10.4 metres wide. This makes it 2.4 metres wider than the widest Great Barrier Reef coral previously measured by scientists.

Muga dhambi is of the coral genus Porites and is one of a large group of corals known as “massive Porites”. It’s brown to cream in colour and made of small, stony polyps.

These polyps secrete layers of calcium carbonate beneath their bodies as they grow, forming the foundations upon which reefs are built.

Muga dhambi’s height suggests it is aged between 421 and 438 years old – far pre-dating European exploration and settlement of Australia. We made this calculation based on rock coral growth rates and annual sea surface temperatures.

The Australian Institute of Marine Science has investigated more than 328 colonies of massive Porites corals along the Great Barrier Reef and has aged the oldest at 436 years. The institute has not investigated the age of Muga dhambi, however the structure is probably one of the oldest on the Great Barrier Reef.

Other comparatively large massive Porites have previously been found throughout the Pacific. One exceptionally large colony in American Samoa measured 17m × 12m. Large Porites have also been found near Taiwan and Japan.

Mountainous island and blue sea
Muga dhambi was discovered in waters off Goolboodi (Orpheus Island).
Shutterstock

Resilient, but under threat

We reviewed environmental events over the past 450 years and found Muga dhambi is unusually resilient. It has survived up to 80 major cyclones, numerous coral bleaching events and centuries of exposure to invasive species, low tides and human activity.

About 70% of Muga dhambi consisted of live coral, but the remaining 30% was dead. This section, at the top of the structure, was covered with green boring sponge, turf algae and green algae.

Coral tissue can die from exposure to sun at low tides or warm water. Dead coral can be quickly colonised by opportunistic, fast growing organisms, as is the case with Muga dhambi.

Green boring sponge invades and excavates corals. The sponge’s advances will likely continue to compromise the structure’s size and health.

We found marine debris at the base of Muga dhambi, comprising rope and three concrete blocks. Such debris is a threat to the marine environment and species such as corals.

We found no evidence of disease or coral bleaching.




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to come
The structure may be compromised by the advance of a sponge species across Muga dhambi (sponge is the darker half in this image).
Richard Woodgett

‘Old man’ of the sea

A Traditional Owner from outside the region took part in our citizen science training which included surveys of corals, invertebrates and fish. We also consulted the Manbarra Traditional Owners about and an appropriate cultural name for the structure.

Before recommending Muga dhambi, the names the Traditional Owners considered included:

  • Muga (big)
  • Wanga (home)
  • Muugar (coral reef)
  • Dhambi (coral)
  • Anki/Gurgu (old)
  • Gulula (old man)
  • Gurgurbu (old person).

Indigenous languages are an integral part of Indigenous culture, spirituality, and connection to country. Traditional Owners suggested calling the structure Muga dhambi would communicate traditional knowledge, language and culture to other Indigenous people, tourists, scientists and students.




Read more:
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coral rock under water with sky
It’s hoped the name Muga dhambi will encourage recognition of the connection Indigenous people have to the coral structure.
Richard Woodgett

A wonder for all generations

No database exists for significant corals in Australia or globally. Cataloguing the location of massive and long-lived corals can be benefits.

For example from a scientific perspective, it can allow analyses which can help understand century-scale changes in ocean events and can be used to verify climate models. Social and economic benefits can include diving tourism and citizen science, as well as engaging with Indigenous culture and stewardship.

However, cataloguing the location of massive corals could lead to them being damaged by anchoring, research and pollution from visiting boats.

Looking to the future, there is real concern for all corals in the Great Barrier Reef due to threats such as climate change, declining water quality, overfishing and coastal development. We recommend monitoring of Muga dhambi in case restoration is needed in future.

We hope our research will mean current and future generations care for this wonder of nature, and respect the connections of Manbarra Traditional Owners to their Sea Country.




Read more:
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The Conversation


Adam Smith, Adjunct Associate Professor, James Cook University; Nathan Cook, Marine Scientist , James Cook University, and Vicki Saylor, Manbarra Traditional Owner, Indigenous Knowledge

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Europe’s oldest forest is threatened by a beetle infestation – let nature take its course


Lucinda Kirkpatrick, University of Stirling

Białowieza Forest is the kind of place you imagine from the Grimm fairy tales. Huge firs, oaks and ashes tower over you, woodpeckers and other birds call all around you and the guides who work there know the intimate history, and names, of many individual trees.

For anyone, it is a magical place – and, as a forest ecologist, visiting it was a dream come true. However, the features that make it so unique may be under threat thanks to new plans for large-scale logging.

Straddling the border between Poland and Belarus, Białowieza is the last remainder of the vast primeval forest that once covered most of Europe. It is a hotbed of biodiversity, home to nearly 20,000 plant and animal species including wolves, lynx and the largest remaining population of European bison. Rare birds, including several woodpecker species, provide a glimpse of the bird life that used to exist in European forests before humans transformed the continent.

The forest is home to around 800 bison.
Francesco Carrani, CC BY

Unfortunately, on the Polish side of the border, only one third of Białowieza Forest is protected. Outside of this area as much as 35% has been earmarked for felling and the fear is that this will result in an increasingly isolated small “island” of protected forest surrounded by fragmented and poorer quality woodland, which has already been shown to support lower bird populations than the protected park area.

Felling around Białowieza has been controlled in the past; quotas were set in 2012 to limit how much wood could be removed. However by 2015, 90% of that quota had already been logged – and the new proposals will triple the permitted volume of logging.

The proposal for further logging is controversial. Poland’s state forest department, Lasy Panstwowe, views the felling as necessary to combat outbreaks of spruce bark beetle, the larvae of which burrow under the bark of living spruce trees to lay its eggs. The developing larvae feed on inner woody layers and can eventually kill the tree.

Spruce bark beetles were here…and it didn’t end well for the tree.
Tõnu Pani, CC BY-SA

However, both local scientists and NGOs, such as Greenpeace Polska, argue that removing damaged trees will cause more harm than good and that further logging is driven by economic rather than management interests. Professor Tomasz Wesołowski, who has studied Białowieza’s birds for more than 30 years, told me it would be a disaster, as logging and replanting would completely change the quality of the forest habitat and threaten its UNESCO heritage site status. There is even a suggestion that this violates Poland’s environmental commitments under the EU’s Natura 2000 program.

The newly proposed logging areas cover 20% of the old-growth forest, as well as areas overgrown by endangered bog woodland habitat. Mass logging would dramatically alter the character of both the areas in question and the surrounding habitat – even more than the bark beetles.

In fact, across the world this form of “salvage logging” to recover economic value from damaged forests often causes more damage to ecosystems than the initial natural disturbance. After a bark beetle invasion hit Sumava National Park, that stretches across the border between Bavaria and the Czech Republic, evidence showed that salvage logging delayed forest recovery.

There’s life in dead wood

The proposed increased logging in Białowieza includes removing quantities of dead wood, yet this dead wood plays an important role in the functioning of a healthy forest. Forests are often built from the bottom up, with dead wood as the foundation.

While aesthetically they may not be that pleasing for us, dead trees are a vital habitat for saproxylic insects which feed on dead and decaying matter. Białowieza supports large populations of endangered saproxylic beetles and invertebrates which rely on dead wood and, in turn, these provide food for birds, small rodents such as shrews and voles, and bats including the rare barbastelle. In turn these animals are eaten by larger predators such as owls, wolves and lynx.

The forest food web starts here.
Aleksander Bolbot / shutterstock

Dead and dying spruce stumps are almost exclusively used by some woodpecker species as nests and also act as great hosts for lichens and mosses, some of which are facing extinction in Europe. If the dead wood is removed, the entire forest ecosystem will suffer.

Logging is unnecessary

Logging is not the only solution to the spruce bark beetle problem. Pheromone traps, for instance, effectively attract large numbers of beetles while outbreaks in the UK are controlled by unleashing a specific predator beetle, Rhizophagus grandis, that targets the spruce beetle. Due to its widespread use in commercial forestry, R. grandis is relatively cheap and readily available, and Forestry Commission research showed it was more effective at controlling outbreaks than salvage logging.

In any case, a beetle infestation might be disastrous for individual trees but it won’t necessarily harm the forest itself. Like many ecosystems, Białowieza is vulnerable to climate change. As species such as Norway spruce are weakened by changing climatic conditions, the bark beetle is able to take hold. This is an invaluable part of the forest regeneration process, allowing deciduous trees that are better able to cope with changing climatic conditions to grow in the gaps left by dying spruces. In the long run it may be better for Białowieza Forest to let nature, and regeneration, take its course.

The Conversation

Lucinda Kirkpatrick, PhD Researcher in Forest Ecology, University of Stirling

This article was originally published on The Conversation. Read the original article.