Coral reefs: The bustling underwater cities of vibrant colored structures. Bearing a resemblance to Cinque Terre with as much, if not more, drama and passion of animals fleeting around the streets. It wasn’t so long ago that we were sliding into the turquoise waters that blanket these colorful cities, bobbing around like neoprene blimps observing their day to day lives. The voice of Jack Grove booming across the water’s surface to direct our attention towards Chaetodon vagabundus, or as most of us would pretend we know, the Vagabond butterflyfish, only to be distracted by Rich Pagen’s voice heralding the oncoming of a large green sea turtle to pass right below us.
Coral reefs are heavenly oases in the often barren and nutrient-poor waters of the tropical seas. Yes, the beautiful clear waters of the tropics are an indication of low productivity. But the corals make up for that by the truckloads. How, you ask? They’re just colonial filter-feeding polyps that live in a calcium carbonate high-rise and share their gut with symbiotic algae! Can anyone else hear Rich Pagen’s voice pronounce the word zooxanthellae in their heads right about now? Zoo- Xan-Thellae, a photosynthesizing alga that turns light into food and shares it with its host, the coral polyp, in exchange for a safe home. Now, how could these two unlikely characters make up for nutrient-poor waters?
Corals are the foundations required to support biodiversity, and as many of us understand, biodiversity is the secret to healthy, vibrant ecosystems. For those of us unfamiliar with the term, put simply, biodiversity is the variety of living species that can be found in a particular place. Coral reefs are believed by many to have the highest biodiversity of any ecosystem on the planet—even more than a tropical rainforest. Though they occupy less than one percent of the ocean floor, coral reefs are home to more than twenty-five percent of marine life! And scientists continue to find new species in them, keeping the magic and mystery of these incredible ecosystems alive.
In fact, in January of this year, scientists discovered dozens of new coral species on Australia’s Great Barrier Reef. Their findings led the researchers to conclude that the biodiversity of some coral groups could be at least three times greater than initially believed. Now there’s some new material for Brad Climpson’s coral lectures!
Unfortunately, the biodiversity and resilience of coral reefs are under threat. You might be thinking to yourself, “what does it matter if we lose a few species?” Degraded coral reefs spell trouble for animals and humans alike. From a wildlife perspective, if they were to collapse, many animals would go extinct without a home to survive and thrive. From a humanitarian lens, coral reefs provide an estimated 500 million people with food, medicine, protection from storms, and revenue from fishing and tourism - a global economic value of $375 billion a year! With so many reasons to protect these incredible ecosystems, let’s dive into what’s threatening them, and what we can do to reduce our impact.
A recent study published in Science surveyed 159 coral reefs in the Asia-Pacific region and found billions of plastic items were entangled in the reefs. The more spikey the coral species, the more likely they were to snag plastic. Once snagged and wrapped in plastic, the disease likelihood increased 20-fold through light deprivation, toxin release, and anoxia, giving pathogens a foothold for invasion.
But the plastic goes deeper. In 2019, scientists observed wild corals feeding on tiny shreds of plastic trash. Worse than that, the animals seemed to actively select those ‘microplastics’ over their natural food, even when the plastic was coated in bacteria that could kill them.
How to Help
Curbing our single-use plastic consumption is a great way to start a journey towards a zero-waste lifestyle. ZERO-waste! It might sound a fanciful dream to some, but it is becoming more and more doable as businesses create solutions to everyday plastic products.
A simple question to keep in mind on your mission to reduce plastic is: “How can I justify this one-use product knowing this indestructible material will outlive dozens of generations of our descendants?” Only 5% of the world’s plastic production is recycled. So anywhere you can refuse single-use plastic and/or switch to metal, wooden or home compostable packaging/products will help save our coral reefs.
When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH. These chemical reactions are called "ocean acidification". Since the beginning of the Industrial Revolution, ocean acidity has increased by a whopping 30%! Why does this matter? Because calcium carbonate minerals are the building blocks for the skeletons and shells of many marine organisms, and with continued ocean acidification, these minerals are being dissolved, which is likely to affect the ability of some organisms to produce and maintain their shells, including corals.
In a recent paper, coral biologists reported that ocean acidification could compromise the successful fertilization, larval settlement and survivorship of Elkhorn coral, an endangered species. These results suggest that ocean acidification could severely impact the ability of coral reefs to recover from disturbance.
How to Help
~ Support green energy movements, installing solar panels, or riding your bike or walking more than driving the car - 64% of total greenhouse emissions come from the energy sector.
~ Eat less meat - 13-18% of emissions come from animal agriculture.
~ Get behind, either physically or financially, supporting organizations that are reforesting, be it mangroves, rainforests, kelp forests, or alpine regions - 18% of total greenhouse gasses come from deforestation.
~ Remove palm oil products from your purchases also help reduce deforestation. This oil is used in a staggering array of foods, cosmetics, and more — in fact, according to the , around 50% of the items we regularly consume contain ingredients derived from palm oil. Tropical forests around the world are being destroyed (often through burning the trees), to make way for these crops that only grow within 10 degrees of the equator.
Agricultural runoff & sedimentation
Increased runoff of sediment, nutrients, and contaminants from the land ultimately increases sedimentation on coastal reefs, reducing the clarity of coastal waters, and restricting the growth of light-dependent corals and plants. Whilst increased nutrient inputs from agriculture stimulate algal growth on reefs, increasing the occurrence of coral disease. To break it down, runoff and sedimentation:
- Smother coral reef organisms due to the settling of suspended sediment
- Reduce light availability for coral and seagrass photosynthesis due to increased turbidity
- Favor the growth of macroalgae at the expense of corals due to high nutrient availability.
How to Help
Rainwater gardens, wetlands, and planting upriver riparian zones are fundamental in reducing this sort of runoff onto coral reefs. Anyone who has traveled to Easter Island, Rapa Nui with Zegrahm might remember the Cousteau Society’s reef recovery plan to stop runoff by planting trees - whereby restoring the precious reefs of Rapa Nui. Their goal is to plant, 1,400,000 trees in the next 6 years to save the ecosystem.
Overfishing & destructive fishing practices
The impacts from unsustainable fishing on coral reef areas can lead to the depletion of key reef species in many locations. Such losses often have a ripple effect, not just on the coral reef ecosystems themselves, but also on the local economies that depend on them. Additionally, certain types of fishing gear can inflict serious physical damage to coral reefs, seagrass beds, and other important marine habitats.
It is estimated that over 55% of the world’s reefs are threatened by overfishing and/or destructive fishing. Some regions, such as Southeast Asia, are particularly threatened, where nearly 95% of reefs are affected. Fish stocks are increasingly threatened due to numerous factors including increased demand for fish and seafood products; more efficient fishing methods; inadequate management and enforcement; and lack of alternative livelihood options.
How to Help
This can be as simple as asking where your fish comes from and how it was caught. There are several sustainable seafood apps you can download to help you chose your next seafood meal, whilst supporting sustainable fishing practices. Look up the following US-based apps in your app store.
- Seafood Watch
- Safe Seafood
Chemical sunscreen UV blockers
In a 2016 study, a team of international scientists found that a common chemical in many sunscreen lotions and cosmetics is highly toxic to juvenile corals and other marine life. Oxybenzone, or BP-3, is a sunscreen UV blocker found in more than 3,500 skincare products worldwide. The compound has been found entering the environment through wastewater effluent and directly from swimmers wearing sunscreens.
The study showed four major toxic effects in early, developing coral:
- Increased susceptibility to bleaching
- DNA damage (genotoxicity)
- Abnormal skeleton growth (via endocrine disruption)
- Gross deformities of baby coral.
The authors of the study concluded that nontoxic oxybenzone alternatives are critical for protecting reefs and the exacerbating effects posed by climate change and bleaching.
How to Help
Since 2016, the list of toxic sunscreen chemicals has grown to over a dozen. Find it here thanks to the Haereticus Lab and test it out against your sunscreen ingredients!
This is an easy and simple way to help keep our coral reefs healthy, by swapping to a reef-safe sunscreen formulation!
As many of you know, in 2017, still needing to wear sunscreen on the ships and not yet having any alternatives to chemical based sunscreens, Tom and I started hand making SunButter sunscreen. Last year we teamed up with a pharmaceutical partner and launched a 50 SPF, reef-safe, fully approved, and listed sunscreen. Many of you have tried SunButter and have watched the journey unfold from its humble beginnings. Check out how far we’ve come here, we couldn’t have done it without you!
As extremes in temperatures rise, mass coral bleaching events and infectious disease outbreaks are becoming more frequent. Researchers found that bleaching events have increased from one every 25 to 30 years in the early 1980s to an average of one every six years since 2010. While coral reefs can recover from bleaching if given 10 to 15 years for their algae communities to recover, the increasing frequency of bleaching events means that many reefs may never be able to.
According to the Intergovernmental Panel on Climate Change report, if ocean temperatures rise 1.5˚ C, coral reefs are projected to decline 70 to 90% more; at 2˚C, we would largely destroy all our coral reefs. Based on these projections, if we continue with business as usual and don’t slow or stop our global greenhouse emissions, 90% of coral reefs will be in danger by 2030, and nearly all of them by 2050.
There is still a whole lot of pure wilderness out there with so much to explore. Many reefs to snorkel on, atoll lagoons to zodiac through, seabird colonies to visit. Many interpretive dance-like conversations to have with non-English speaking locals, using smiles and laughter whilst bartering for intricately crafted sculptures, as they welcome us with cultural dances to their islands. There is everything to gain by looking after our planet and maintaining healthy ecosystems. And it is important to us to make sure they will still be as beautiful, if not more, on the other side of this global pandemic.
Until then, take care of yourselves, your loved ones, and the coral reefs!