(Featured image – The author diving on the Great Barrier Reef in 2011)
Professor James Crabbe graduated from Hull in 1971 with a 2:1 BSc degree in Biochemistry. His career journey has taken him to a range of institutions including Manchester, Oxford and Reading. Whilst at Reading, Professor Crabbe began to apply his knowledge of computational biology to the study of coral reefs. Today, he is Emeritus Professor of Biochemistry at the University of Bedfordshire and a Supernumerary Fellow of Wolfson College Oxford and his research has yielded over 180 publications in peer-reviewed international journals, 67 books, book chapters and reviews, and 14 items of commercial software. In recent years, his work has modelled the effects of injecting sulphur dioxide into the atmosphere and has highlighted a real potential to reduce solar radiation, cool sea temperatures and reverse the bleaching of coral reefs. This work has recently featured in New Scientist, bringing Professor Crabbe’s vital research to the attention of new audiences. In this article he talks about his career, his current research and his hopes for the recovery of these fragile eco-systems upon which, at least 500 million people depend for food, coastal protection, and livelihoods.
Why coral reefs are important to us all in 2018 – the third
International Year of the Reef
Professor James Crabbe
In 1858, Robert M Ballantyne published his most famous story, The Coral Island, describing how three young men survived on a Pacific atoll after their ship was wrecked on the reef during a tropical storm, and rest of the crew perished. The popularity of the book owed much to its exotic location and dangerous situations. Coral reefs were hazardous places, causing loss of life, and to be avoided at all costs. As a young boy, I was excited by this story when it was presented to me as a prize at school, but it was to be a long and fascinating journey before I came to work on coral reefs in exotic locations, and understand how important living reefs are to us all.
That journey took me to Hull University, where I read Biochemistry (1968-1971). After I found a new enzyme as part of my undergraduate project working with Dr. Peter Large, I was committed to research and moved to Manchester and then to Oxford, where I became a Governing Body Fellow (and Wine Steward!) at Wolfson College. I worked for many years on diabetes and diabetic complications, including cataract, the largest cause of blindness in the world. In collaboration with industry I was able to develop an early molecular modelling program, Desktop Molecular Modeller, which was produced by Oxford University Press and sold worldwide. After 10 years at Oxford I moved to Reading University, where after a Readership I was appointed to a Personal Chair. Management and leadership beckoned, and I became Head of a large and successful School of Animal and Microbial Sciences, followed by Executive Dean of Creative Arts, Science & Technology at the University of Bedfordshire. Serendipity took a hand in my research. A chance conversation with our marine biologist at Reading led to him asking me ‘You’re a computational biologist, why don’t you look at coral reefs?’ So I did, as I felt this would also enable me to collect and analyse data myself, a concept which originally attracted me into science.
The majority of reef building corals are found within tropical and subtropical waters, and typically occur between 300 north and 300 south latitudes. Around the globe, over 275 million people live in the direct vicinity of coral reefs, and approximately 850 million people live within 100 km of coral reefs. At least 500 million people rely on coral reefs for food, coastal protection, and livelihoods. In developing countries, coral reefs contribute about one-quarter of the total fish catch, providing food to an estimated one billion people in Asia alone.
Recent estimates suggest coral reefs provide over US$30 billion each year in goods and services, including:
- Fisheries: Coral reefs form the thriving nurseries for about a quarter of the ocean’s fish, and thus provide revenue for local communities as well as national and international fishing fleets. Coral reefs are also linked to seagrass and mangrove ecosystems, which themselves act as nurseries for many coral reef fish and invertebrates.
- Tourism: Tourism revenues generated by coral reefs are also significant. For example Australia’s Great Barrier Reef generates well over US$1 billion per year.
- Coastal protection: Massive – brain-like- corals on coral reefs break the power of the waves during storms, hurricanes, cyclones, and tsumanis. More than 150,000 km of shoreline in 100 countries and territories receive some protection from reefs.
- Source of medical advances: Many medicines have been derived from coral reef organisms, including antiviral drugs Ara-A (Vidarabine, active against herpes simplex and varicella zoster viruses), AZT (Zidovudine, active against HIV-AIDS) and the life-saving anticancer agent Ara-C (Cytarabine, active against leukaemia). Thousands of other useful compounds may still be undiscovered; however, their discovery depends on the survival of reefs.
- Intrinsic value: For many coastal societies around the world, coral reefs and their inhabitants are intricately woven into cultural traditions. For these people – as well as for those who snorkel or SCUBA dive, or experience these habitats through media and books – a world without coral reefs would be an infinitely poorer place.
Coral reefs throughout the world are under severe challenges from a variety of anthropogenic and environmental factors including overfishing, destructive fishing practices, coral bleaching, ocean acidification, sea-level rise, crown-of-thorns starfish outbreaks in the Indo-Pacific regions, algal blooms, agricultural run-off, coastal and resort development, marine pollution, increasing prevalence of coral diseases, invasive species such as lionfish in the Caribbean, and hurricane/cyclone damage.
Atmospheric carbon dioxide concentration is expected to exceed 500 parts per million and global temperatures to rise by at least 2°C by 2050 to 2100, values that significantly exceed those of at least the past 420,000 years during which most extant marine organisms evolved. Even if pledges made following the 2015 Paris Climate Change Conference (COP21) become a reality, these pledges do little to provide reefs with more time to adapt and acclimate prior to severe bleaching conditions occurring annually.
However, there are pockets of hope. In 2005, there was a massive Caribbean-wide bleaching event causing the mortality of many coral species, owing to the high and prolonged SSTs. On one of the Jamaican reefs I was studying, there was an almost 95% loss of Acropora cervicornis – staghorn coral – a species crucial to the ecosystem vitality for fish and invertebrates, and on which much of the human population depends. When I returned in 2006, about 50% of the branching corals at that site had returned. Unfortunately that was not mirrored at all the sites I was studying. So why should some sites be more resilient to climate change than others? Local conditions are important, for example hydrodynamics (a cool upwelling can mitigate temperature rise), light, and a mixed species community structure. Also a complex three-dimensional shape may help, acting as a refuge for genetic material and developing embryonic corals.
An exciting declaration announced in 2016 by the International Coral Reef Initiative (ICRI) is that 2018 will be the third International Year of the Reef, to:
- strengthen awareness globally about the value of, and threats to, coral reefs and associated ecosystems;
- promote partnerships between governments, the private sector, academia and civil society on the management of coral reefs;
- identify and implement effective management strategies for conservation, increased resiliency and sustainable use of these ecosystems and promoting best practices; and
- share information on best practices in relation to sustainable coral reef management.
In the future, geo-engineering could be a novel way to help mitigate against the deleterious effects of greenhouse gases. There are broadly two types of geoengineering: Carbon dioxide removal (CDR) and Solar radiation management (SRM). With colleagues in Beijing Normal University and with the UK Met Office, we showed that stratospheric aerosol geoengineering, a type of SRM, could significantly mitigate future coral bleaching throughout the Caribbean Sea. In addition, although geoengineering would prolong the return period of future severe hurricanes, this may still be too short to ensure coral recruitment and survival after hurricane damage. Our study was picked up in several media outlets, including the New Scientist.
My latest research, in collaboration with Fudan University in Shanghai and Tibet University in Lhasa, describes new cyanobacterial and plant ecotypes that have evolved and thrive in the harsh conditions of the Qinghai-Tibet plateau over 4000m above sea level. It is such inter-disciplinary research, linking the latest genetics and computational biology with experimental physiology and metabolic studies that may help us understand how organisms adapt and evolve in extreme environments, and how we might mitigate some of the worst effects of climate change in the future, both in aquatic and terrestrial environments.