Today we want to talk to you about a matter of life and death: the state of health of the Great Barrier Reef.
Recently we have been a little uneasy with some comments from followers that the Reef looks in pretty good nick. In an attempt to focus on the riches of the Reef and highlight what is at stake, we have shown and written about more of the positives than the negatives. We worry that based on some of our posts you might think the Reef is just fine. This is not the case. After spending several months at the Great Barrier Reef this year, and on our fourth year of reef exploration, it is time to reflect on what we have seen – warts and all – as you know us for.
So how do we really see the state of the Reef? B L E A K
Overall, we have noticed a marked deterioration. We see less colour in the corals, less density, more algae, less fish variety and quantity. We have also witnessed extremes in reef health: significant destruction along the inner and fringing reefs, vigorous growth on the outer reefs. Of course with any coral destruction you also lose habitat and food source for the fish populations that dwell in those reefs.
Four elements are damaging to the reef:
- Increased ocean temperature creating bleaching or heat stress.
- Coastal runoff which increases turbidity, adds nitrogen in the water, both resulting in algal growth that suffocates the coral.
- Increasingly violent and frequent storms that uproot corals and smash reef platforms.
- Crown of Thorn Starfish infestations that devour corals.
Big differences between fringing, inner and outer reefs
We have observed a significant difference between the inner and outer reefs. The satellite image below shows a section of the Great Barrier Reef. Within the dark blue stretch you can see two distinct lines of reefs which run along its entire length, an inner line, closest to the coast, and an outer line, furthest offshore on the edge of the Continental Shelf. There is also a string of continental islands between the mainland and the reef.
Fringing and Inner Reefs
The fringing reefs edging the continental islands located 8 to 10nm off the coast are in the worst state. This includes areas like the Keppels, the Whitsundays, the islands off Townsville and Cairns. The water is turbid with increased sediment, pollutants and contaminants. You dangle your feet at the back of your boat and they disappear into a milky opaque water with poor visibility. With little light penetrating under the surface, hardly any coral is left and there is low fish population.
The whole line of reefs running about 30nm from the Queensland coast is also very damaged. Here is what many of the inner reefs look like:
When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. We have not seen the totally bleached white coral expanses that are often shown on TV. We have seen patches of this, but typically what follows after bleaching is algal growth… and that we have seen… a lot!
Bleached corals are weaker and more susceptible to a microbial takeover fuelled by algae. Once fleshy algae gain foothold in a reef, it encourages the growth of disease-causing micro-organisms that can kill coral. It is not uncommon for lagoons to heat up too much in summer and consequently we are seeing less and less live corals inside these shallow inlets on the inner reefs.
Why is it so bad at both the fringing and inner reefs? Because they are affected by multiple stressors, the big one being agricultural runoff. In addition, some of these reefs have also suffered the effect of storms a few years ago and most of them have been affected by marine heat waves repeatedly over the past five years. With multiple devastating assaults, can they survive and recover? We worry they won’t.
A little further offshore, things are less dire, but not good. Some reefs positioned a bit more centrally on the GBR are in reasonably good condition, however it is dependent on where you go and where you look. You will see live coral colonies, often on the more exposed slopes rather than in the lee of the reef platform, but there are areas of dead coral covered in algae. Generally 40% cover is what you can expect.
The healthiest reefs we have seen are the ones on the very outer edge of the Great Barrier Reef where marine life is thriving thanks to their position along the Continental Shelf with its upwelling of clean, cool and nutrient rich ocean waters.
The offshore reefs in the central and northern region (offshore of Mackay, Townsville and Cairns) have been damaged by large scale coral bleaching events but they are fighting back. The Reef is incredibly resilient and despite the onslaughts it is recovering in places far from the coast, 50 to 90nm offshore, where there are areas thriving with life and vigorous coral growth again. It gives us some hope, as long as another bleaching event does not cook the new growth this summer.
Crown of Thorn Starfish – it can hit anywhere
As if storms and rising temperatures aren’t enough, there is the impact of the Crown of Thorns Starfish (COTS). These can invade an area and obliterate the corals at lightening speed. They feed on branching and table corals such as Acropora species rather than more rounded corals with less exposed surface area, such as Porites. Like other starfish, they exude their stomach and start the process of digestion outside their body. They settle on a piece of hard coral, release chemicals which attract additional COTS to healthy reef sections. They then begin their destructive feeding frenzies, releasing digestive enzymes onto the reef, and liquefying the coral tissue. You will notice the white coral skeleton – the scar – where they have digested the polyps as they move around and eat their way through an area. The coral skeleton is then rapidly infested with filamentous algae. An older scar will look brown or grey. During a severe outbreak, there can be many crown-of-thorns starfish per square metre, even piling on top of each other. They can eat so much that they can kill most of the living coral in that part of the reef, reducing hard coral cover from the usual 25 – 40% of the reef surface to less than 1%. Such a reef can take 10 years or more to recover its coral cover.
Last year we saw and reported a COTS outbreak at Walker Reef. It got dealt with swiftly. We returned to that reef this year and it is showing some signs of recovery, but very patchy. We are told by marine biologists at the Australian Institute of Marine Science (AIMS) that the Swain Reefs have been badly damaged by COTS. These are the furthest offshore reefs on the GBR, some 150 nm from the coast. We are yet to go there at this stage. The GBR Marine Parks Authority is quick to react to reports of outbreaks and send teams to cull the COTS. We have seen Crown of Thorns but not at outbreak level anywhere again and we have seen the scars they leave behind on most reefs.
Thank God for Green Zones
One thing is encouraging: the effect of the Marine National Park Green Protection zones which forbid fishing or take of any kind and in so doing limit the activities of people using and abusing those fragile places. Reefs in green zones are in noticeably better condition with many more fish. But they represent only 33% of the Great Barrier Reef Marine Park. We need more of these protected areas to help preserve and restore habitat. The Marine Park people are patrolling these reefs by air and sea and severe fines are imposed on those breaking the rules. We have little pity for those getting caught.
The Reef is a sensational and delicate ecosystem. We have shown this in our series of Outer Reef posts. We have been incredibly lucky to spend so much time exploring and witnessing what is there, good and bad.
But there is no denying that the Great Barrier Reef is being ravaged by climate change. Should it be listed as an endangered world heritage site? Yes, because it is, and we are running out of time to halt the devastation. How long have we got? We don’t know, marine biologists we met on our journey don’t know either. We fear we are talking a few years rather than several decades.
What we do know is this… If we stay on the current destructive trajectory, burning fossil fuels, letting agricultural run off flow carelessly into our rivers and inshore waters, if we keep over populating and overfishing, if we keep showing an insatiable desire for stuff, if we keep getting rid of waste recklessly, we will surely kill what is left of the Reef, and not in the distant future, but very, very soon.
It is sad to see that while everyone has been distracted with the global pandemic and focused on saving people, the real issue of protecting, nurturing and safeguarding the environment and the very ecosystems that keep us and every living thing alive have been neglected.
When will our local and global priorities change? When will we shift our focus to the real crisis of our time?
We need climate action now, but our Australian politicians don’t really get it. Rather than taking energetic and urgent action, Australia’s so-called Plan lazily falls back on projections that emissions will fall by up to 35% by 2030, “exceeding” the federal target of 26 to 28% that was set some 6 years ago by just “momentum”. This is half of what we need to do! While some countries in the rest of the world try, with targets and properly costed and mandated strategies, we have no plan for 2030, having been dragged kicking and screaming to reach even a woolly, irrelevant 2050 net-zero promise. Our leaders worry about their re-election rather than the climate crisis with its dyeing reefs, rising seas, catastrophic bushfires, cyclones and floods. Our prime minister is embarrassing, lacks leadership, vision and diplomacy, and certainly doesn’t represent us. We can’t wait for the next federal election… to show our current leaders what we think of their Plan and vote them out! We hope many other Australians do likewise.
Only with bold, ambitious 2030 targets, and new, concrete policies will we reverse this global emergency. Let’s hope the COP26 Summit achieves the shake up that is so desperately needed.
Rant over! We look forward to your comments.
24 thoughts on “A matter of life and death”
I’m glad that you have said this – but sad that you had to – it confirms the many scientific findings on coral reefs globally.
Professor Terry Hughes, from the ARC Centre of Excellence for Coral Reef Studies, has been a party to annual aerial surveys of the GBR.
In 2016 he tweeted “I showed the results of aerial surveys of #bleaching on the #GreatBarrierReef to my students, And then we wept”
Hi Roger, and that was in 2016… 5 years later and after 3 mass bleaching events you can imagine what it is like now. We too have shed many tears.
Wow, the photos clearly show what a healthy reef looks like, opposed to the dead zones where they look like a war zone. Very sad indeed. I’m glad that people are getting rid of the terrible starfish, nasty critters! Thank you for clarifying what a healthy reef and dead or damaged reef actually look like, I really wish that I could do something to help the reef, and get rid of the rotten politicians. We have those rotten politicians here too.
Hi John, other than minimise our own footprint and take part in citizen science projects, I suspect the only power we have is who we vote for.
Your vote may get lost here, even dead people and illegal aliens have voted. Our system is so broken.
Fortunately ours is not!
thank you for this invaluable post. Let’s not minimize the impact individuals can have by changing their behaviors – what we eat, whether we fly, what we drive, what we do with our food waste, what we buy (no plastic – another ocean tragedy) and more. Individuals making changes and entrepreneurs creating solutions are our greatest hopes in the absence of political will. Aloha, Mary
PS. You should look for a documentarian to help tell your story to more people.
Thank you Mary for your input.
I agree the reef needs to hopefully recover .
I was saddened to hear recently that a Company on their vessels have divers to collect live corals and aquarium fish from healthy reefs I understand they are able to remove 600 tonnes a year One of these vessels has been working from Mackay around the southern GBR.Taking healthy specimens has to affect reef health.
I also witnessed a dory fishing vessel unload over 3 hours their live catch of reef fish. Large live specimens of Coral trout were put into tanks on the back of a Ute on the wharf at Mackay under the watchful eye of 2 fisheries officers.
Taking mature live fish from a reef system at such a rate leaving only juveniles has to affect the whole ecosystem.
It is almost impossible to find quotas that Government (Qld?) has set for live reef fish and aquarium collection.
People talk about issues in the blog that are an issue but we need to try to protect the whole ecosystem.
A reef with no large fish and biodiversity is doomed.
Yes absolutely, Diane, we have seen those dories along the inner reefs which unless protected get abused and overfished.
Good on you, I like yourselves struggle with telling of a positive story and showing the best of our country while passing over the clear felling of old growth forests, the huge scars on the landscape left by mining and the erosion and soil degradation from poor farming practices. Its not just the barrier reef. There were many parts of Ningaloo I visited that were dead and dying. Locals say the long term degradation of Ningaloo is very significant. Once again a great post.
Thanks Mick – very sad we had to write this and realise the GBR is but one ecosystem suffering.
A very sobering post, and I fear that governments will remain tardy in tackling climate change
Yes, I don’t know what it takes to raise their sense of urgency.
I’m really glad to see you posting about this, more people need to know.
Thanks Leanne, trying to get more exposure in the media too for greater coverage.
A well written article Chris. Our underwater photos tend to be the ‘best’ ones. Colour, clarity and happy stories under the water. But, they are often found amongst coral damage.
Yes it is really where you choose to focus, but it can and does tell the wrong story. I needed to rectify that. The more people are aware of the sad reality, the more chance we have of people in demanding and getting involved in climate action.
On you Chris, well said and thank you for doing so. We need more people to say what you did, because it was good coming from the long experience you have in sailing in the GBR areas. I agree, vote the Libs out, they are not only useless in saving the reef and waters in and around Australia but also the land and our wonderful animals as well. And they appear to act corruptly on multiple fronts which they refer to as giving grants etc. A morally corrupt group of politicians who think only of the next election and not the country and the people they are supposed to serve.
Just wished we could do more individually. We feel so powerless and have so much to lose.
Your posting was really informative, Chris, and deeply disturbing. It helps me to understand much better now the nature of the problem. You have mentioned the reef situation in other postings in the past, but I don’t think I truly understood its scope until now. It seems that we have to rely on politicians to do the right things and that is a scary proposition, no matter where in the world you live.
Hi Mike, a few enlightened industrialists are taking their businesses in the right direction for their own survival as well as in response to climate change, without waiting for the politicians. But there is a lot of short term thinking and an inability to see past “the way things have always been done”. It keeps us stuck in a destructive cycle. There is also much denial that things are dire, on the Reef and on land. It feels like we are signing our own death warrant.
Thanks Chris for highlighting the reef degradation through your own observations. I reckon most Aussies who read are aware of this calamity, but like us, feel quite powerless to be able to change things. Sadly it is clear that our world is getting more broken year by year. To list but a few ‘breakages’; micro plastic in the environment, chemicals of all sorts building up in land and sea, the constant extinction of animals and of course the numerous events leading to global warming. We (man/ woman/ other) are in effect so stupid! So many of us embrace the selfish ‘me’ philosophy, greed and that wonderful macro-economic driver called ‘economic growth’! I’m not sure we (humankind) will be able to turn the clock back, it’s like we’re on this giant treadmill of ‘progress’ and the the hand brake is broken.
Sorry, I’ll get off my high sea-horse now, but I have to say that you guys are giving us joy and beauty and taking us away from the brokenness. Keep it going guys, seeing the beauty of this creation in your regular blog is simply uplifting! Happy wet seasoning!
We are glad you added your views, Elgar. Too many people just stay quiet. We have a lot to answer for.
Thanks also for your feedback. We try to find something positive to share in our posts even if increasingly it means pointing the camera selectively at our surroundings.