Travellers’ impact on coral reefs
Non-biodegradable sunscreen could be harming the algae that keeps the world’s coral healthy. (Bob Halstead/LPI)
Travellers who want to swim with migrating whale sharks near Cancun are often told by tour operators that only biodegradable sunscreen is permitted.
And those visiting the nearby Mayan-themed nature parks Xcaret and Xel-Ha face similar rules, lest travellers leave behind an oily trail when they snorkel or swim with dolphins. In its 2011 annual report, Xcaret said that its parks handed out 152,506 samples of “chemical-free” sunscreen and invested 354,238 pesos in the program.
So should ocean-bound vacationers pack only the biodegradable stuff? Travellers certainly can do that, but experts say sunscreen is not a big contributor to the destruction of reefs worldwide.
A 2008 study published in the US-based Environmental Health Perspectives journal in the US found that the ultraviolet filters in sunscreens bleach hard corals by causing a viral infection in the algae that keep coral healthy. The authors concluded that sunscreens “potentially play an important role in coral bleaching in areas prone to high levels of recreational use by humans”. And they estimated that about one quarter of the sunscreen tourists apply washes off when they swim or bathe, “accounting for a potential release of 4,000 to 6,000 tons per year in reef areas”.
In the June issue of Vancouver-based Diver magazine, Jean-Michel Cousteau, son of Jacques Cousteau and founder of the marine conservation group Ocean Futures Society, promoted the use of biodegradable products, saying that ingredients including zinc oxide and titanium dioxide “will never biodegrade and have the potential to harm corals and sea life”. Cousteau wrote that he “would not suggest that sunscreen products are the primary reason our reefs are collapsing”, but “everything is connected”.
Choice of sun block, however, doesn’t register as an issue with Carl Safina, founding president of the conservation group Blue Ocean Institute at Stony Brook University in New York. “I think that it would be a trivial thing compared to other things, such as the overfishing that afflicts almost all of the reefs of the world, the pollution from nearby towns, the warming of the water which certainly triggers bleaching over very large areas, and the acidification of the ocean that is also resulting from the same carbon dioxide that is causing [the water’s] warming.”
Kiho Kim, professor of environmental science at Washington DC’s American University, specialises in coral reef ecology. He, too, said that while it’s good to use products that are biodegradable, the issue with sunscreen is “probably not even on the radar of things people ought to be thinking about”. According to Kim, pollution is one of the primary concerns on the local level. Many places in the tropics, he said, “don’t have the level of water treatment that would relieve the coral reefs from much of the pressure from water pollution”.
The Coral Reef Alliance, based in San Francisco, lists several things people can do to help protect coral reefs: choosing sustainably-harvested seafood and not buying coral jewellery are a few. But using biodegradable sunscreen isn’t one of them. "It’s not the thing that we feel is really going to be the turning point," said conservation programs director Rick MacPherson. If the topic of sunscreen launches a conversation on other threats and action people can take, he said, that’s great. But “when we focus too much on something like the sunscreen, that makes it feel like it’s one and done”.
Kim said concerned travellers should ask what steps their hotels are taking to treat wastewater and think about how much carbon they’re emitting by flying to their holiday destination. Both Kim and Cousteau cautioned against “green washing” -- whether it’s tour operators promoting biodegradable sunscreen but doing little else environmentally, or sunscreen companies falsely touting products as eco-friendly.
“Travelling is not particularly sustainable,” Kim noted. And there’s only so much people can do to lessen that impact. “If biodegradable sunscreen is part of the mix”, he said, “that’s fine.” But travellers “shouldn’t have the illusion that [they’re] protecting the destruction of the coral”.
Lori Robertson writes the Ethical Traveller column for BBC Travel. You can send ethical dilemmas to firstname.lastname@example.org.