Of the world’s ecosystems, coral reefs are expected to be the first to experience the repercussions of a changing climate. As images show, coral reefs are already under severe stress by a swiftly heating planet. Corals only thrive in very specific environmental conditions, and when temperature rises by just a little, the coral expels its symbiotic algae partner who provide its nourishment – a process called bleaching. Without its symbiotic algae, the coral turns white and simply starves. Worldwide, mass-bleaching events have been increasingly destructive over the years, hitting an all-time high in the current year, in which high water temperatures killed 67% of corals of the northern part of Australia’s Great Barrier Reef. As climate change continues, oceanic waters across the globe are expected to further warm, suggesting a bleak (and bleach) future for coral reefs.
As a response, a group of coral reef scientists from Hawaii and Australia came up with a controversial plan to save coral reefs from their foredoomed destiny. They aim to create heat-resistant corals that can thrive in warmer water. By steering their evolutionary pathway into a desired direction, these scientists effectively prepare corals for climate change.
Various methods to increase coral’s resistance to climate change – or to enhance adaptation mechanisms – are being developed, denoted as processes of “human-assisted evolution”. The idea is that these heat-resistant corals are then reared in controlled underwater nurseries and out-planted on reefs that are – or expected to be – negatively affected by rising water temperatures. Although the concept of anthropogenically enhanced corals seems controversial, genetic enhancement of favorable traits of commercially valuable animals and plants has been practiced since the dawn of agriculture. In comparison to these former applications of genetic enhancement, the human-assisted evolution of coral seems to differ in two aspects. But is it really all that different?
Diver working in a coral nursery of the Coral Restoration Foundation Bonaire (crfbonaire.org)
The first difference is the switch from a commercial to a non-commercial use of genetic enhancement. In other words, a change from genetic enhancement on the grounds of profit-making, to the purpose of conservation and/or restoration of natural ecosystems. Commercially valuable species, such as for example chicken and agricultural crops, are valuable assets to humans, and – when taking an ecosystem services perspective – have a provisioning function that underpins human well-being. Chickens have been cross-bred to be several times the size of their former ancestors, while certain agricultural crops are resistant to drought and disease, all for the purpose of increased yields and returns. Genetic enhancements of these species increase their value to humans, which can be observed through an increased market-price. Corals are said to be noncommercial species, as they do not have a clear market in which they are traded (except maybe within the aquarium-trade). Yet – again from an ecosystem service approach – coral reefs are known to provide provisioning (fisheries), regulating (flood regulation) as well as cultural (recreational) services to humans, and are undoubtedly of considerable value. Some of these services are marketable, while others less easily. Human-assisted evolution of corals is proposed as a last resort conservation approach for coral reefs, first and foremost such that their value to humans is maintained, or increased. Although genetic enhancement of coral may not be as clearly observed through an increased market-price, human-assisted evolution does increase the value of reefs by enhancing those services that underpin human-wellbeing, in the exact same way value of commercial species is increased through genetic manipulations.
The second difference is that anthropogenically enhanced corals are proposed to be released in the wild, while genetically enhanced commercial stocks are contained within the boundaries of human activities. Some believe this type of human alteration is ecologically too risky and goes too far, arguing that such “farming of the reef” undermines nature in it’s pristine, wild, pre-human state. Considering that humanity has been altering landscapes since prehistory and that anthropogenically induced climate change is affecting even the most remote places on Earth, what are then the boundaries of human activities? Apart from the global repercussions of climate change, another example of world-wide impact of human activities is recent evidence that micro-plastics are ingested by deep-water organisms, living in extremely remote ecosystems that were formerly believed to be unaffected by humanity. Perhaps, releasing human altered corals is not crossing the boundaries of human activity at all, as by now all Earth’s systems fall within the scope of human activity. As Emma Marris argues in her book Rambunctious Garden, maybe it is time to let go of the desire to reinstate a nostalgic, pre-human wilderness and accept that all corners of the planet bear the fingerprints of human societies, intended or unintended.
At first sight, genetically enhancing corals such to conserve the world’s precious reefs seems like a controversial and innovative endeavor. On second thought, however, the approach is arguably not all that different from those methods humans have been using to safely increase or enhance yields. So let’s put aside these presumed differences, learn from the similarities with our past experiences of genetic enhancements and apply this knowledge to the conservation of natural systems of our now post-wild world.