Coral Restoration — foolish folly or critical conservation?
Watching the world’s coral reefs suffer under the stewardship of the human species is heart wrenching. Pictures of corals dying or oil spills or algae dominated reefs or bloated turtles seems incomprehensible when compared to our love of the marine world. Those startling pictures of amazing underwater worlds full of corals, sponges, fish, sea cucumbers, sea stars, crabs and so many other creatures of dreamlike shapes and colours have compelled so many people to visit coral reefs around the world. I can recall jumping into the warm tropical waters as a child and simply not believing how amazing all the activity was around me. Moreover, none of the fish seemed to care I was there. While this experience is still possible, the sad truth is the number of gorgeous locations has shrunk enormously. To help deal with the trauma of sitting back and watching the reef suffer from over fishing, land runoff, climate change and plastic pollution, can we simply ramp up restoration efforts?
Diving down with a piece of coral to attach to a metal grid or to stick into a natural crevice to help save the reef is now taking off as the solution for the future. However as much as this sounds attractive there are severe constraints to making this ecologically successful. Here are eight reasons why most restoration activities are a waste of time and potentially even dangerous.
1. Limited species. When you view a healthy reef, you could easily be looking at over 400 coral species in one location and yet most coral restoration efforts focus on a few fast growing branching Acropora species. These are easy to grow since their life cycle includes the process of branch destruction and mobilization to a new location as a way to colonize new locations. Selecting such a small range of species that are most likely already doing pretty well across the reef is almost pointless and potentially disruptive as these ‘weedy’ species are given a helping hand at the expense of the more awkward species.
2. Limited Area. Coral reefs are big, really big. Some individual reefs are so large that conducting a full underwater survey would take a lifetime. Billions of coral polyps collectively growing are required to make the world’s largest living structure. Restoration efforts using individually handpicked branch sections (known as nubbins) is very limited to a tiny area of reef. To even contemplate restoring even a small reef by direct intervention is folly. The only sensible application is in a tourism resort area.
3. Intensive human involvement. To establish even a small coral garden requires a concerted effort by many people over a long time. It’s not easy to be underwater for many hours in a day ‘planting’ the coral, cleaning the silt and removing the algae. The major lesson from the One Billion Trees program in Australia in the ’90s was that forests are very hard to grow and very easy to clear. So stop bulldozing them! The only success at a large scale was the mechanical seeding of large areas with minimal human intervention. This is very difficult to achieve in the marine environment.
4. High input of unnatural material. There is nothing worse than seeing rubbish on a beach or coral reef so why then are we so happy to dump more industrial products on the ocean floor to grow coral? Metal racks, cable ties, polyester glues, concrete blocks, buoys and so much more are commonly used to establish a coral garden. Important to note that some restoration efforts do just seek natural gaps to place the coral fragments but these can be hard to secure properly.
5. Disturbance to diversity changes. Rocks can teach us a lot about our future. As we look back in time to the rocks that were created by ancient reefs we can see how there have been changes in species diversity and abundance of corals. Millions of years have painted a wonderful picture of growth and decay. There is a very strong selection process operating every day in the ocean that picks winners and condemns losers. We might not like that harsh reality but as the environment changes then so too must the biodiversity. With Humans hand picking the winning corals, there is a risk of introducing change at the local area scale which is not resilient to future environmental shocks. Those lovely branching corals growing in the garden will crash at the next bleaching event with little to show long term.
6. Public perception misdirection. The greatest threat to dealing properly with environmental disasters is to pretend that solutions are easily accessible and all is under control. Politicians in particular love the notion of restoration especially with what I call the ‘one photo issue’. With this term, I mean that an engaging photo of a diver planting corals appears to satisfy the public desire for action despite the obvious simplification of a very complex topic. The marketing departments will ensure that the disaster that is climate change appears to be under control. It’s not.
7. Emotional money trap. I am becoming quite irritated by the number of websites and advertisements asking people to donate to a restoration project to save the reef. This money is a waste in every way and much better spent in other environmental activities. Don’t let the emotion of the coral reef destruction over rule your better judgement about coral gardens. Ask the simple questions — Is it scalable? Does the activity use ecology to maximize the impact?
8. Pointless if stress still present. There really is little use planting back the same corals in the same area knowing that a bleaching event will destroy them next summer. The genetics has not been altered to adapt and it might be better to allow other more suitable species to colonise the garden. Not all corals are the same and while we continue to add more carbon dioxide to the atmosphere then we should accept, reluctantly, the changes in the coral diversity.
So all doom and gloom? No! there are a few researchers who understand the ecology and seek to work with the marine environment. Professor Peter Harrison is one who is trying to help maximize the chance that coral spawning is successful and then using the young corals to seed destroyed reefs in a distant location. While much has to be learnt to make this realistic at least the discussions involve scale and biodiversity. Similarly, the Manaco consortium is exploring accelerated evolution of corals through a number of smart mechanisms. This can involve moving corals as seed banks from one location to another or even altering genetic material. Sadly, all these ideas will take many years to perfect and to make an impact. In the meantime, humanity (or at least those that care) need to push as hard as possible to keep that carbon in the ground, reduce fishing pressure and tidy up the land runoff. All the rest is blah blah blah!
