Beach and sunscreen equals no coral?
Oh dear, now another thing is assaulting coral - sunscreen! Since late May, various news sources have been picking up on a study done by the European Commission on sunscreen and tourists. With 78 million people visiting areas of coral reefs each year (according to the World Trade Organisation), about 4,000-6,000 tons of sunscreen gets washed off the bathing tourists.
Blimey! What is a tourist to do? For those from the northern climes, heading down to tropical locations is almost synonymous with sunscreen - whether it is to try and age the skin by turning it browner or prevent any UV rays ever darkening their skin…
And now if we swim around corals, we will add to all the other ways we, the human race, are contributing to them bleaching. Coral bleaching is the process by which the coral expels all the symbiotic algae because of a stress related event such as pesticides from farming, dramatic changes in temperatures and now… sunscreen particles.
Vexingly, the earlier reports quoted the scientists as saying the solution was to wear sunscreen which didn’t contain certain chemicals? Ok. What chemicals? Fortunately waiting a few weeks has meant some journalists have done their homework and we can all now grab a very large pad of paper and write down UV inhibitors known as 4-methylbenzylidene camphor, or 4-MBC, and octocrylene, or OC - although that’s not to say other chemicals won’t effect coral - they just haven’t been tested for. The San Francisco Chronicle gives you some ’safe’ sunscreens - for the US anyway…
Now before we start carefully weighing up whether it is better to give ourselves first degree sunburn in an effort to save the coral, consider this… Coral can thrive at depths as deep as 3000m and as far north as Alaska and as far south as Antarctica. Yes… you could consider heading to the polar regions to swim amongs the coral - although snorkelling might not be an option in the sub-zero water…
And another thing - coral has been around for a good 450 million years or so! Over that 450 odd million years, the world has been 10 degrees warmer as well 10 degrees cooler than it is now. Life in the ocean was nearly wiped out 250 million years ago when warming combined with slowing currents met oxygen wasn’t being distributed to all depths of the ocean. But before you panic and think warming today will cause that - bear in mind the continents were distributed very differently 250 million years ago - in fact, there was only one continent, Pangea. There was no frozen polar icecap causing the temperature, density and salinity differences that drive today’s ocean conveyor belt. In short, it is IMPOSSIBLE to shut down the ocean conveyor belt today, even with 2 or 5 degrees of warming unless ALL the land masses merge as one and all the ice on Antarctica melted.
So what does this mean so far? Coral has survived climate changes far harsher than anything we can even predict today.
If we start to delve into literature and exciting papers published with science-friendly, public-unfriendly names like “Changes in Zooxanthellar Densities and Cholorophyll Concentration in Corals during and after a bleaching event” (R.J. Jones et al, 1997, Marine Ecology Progress Series 158, pp51-59) that coral of the Great Barrier reef bleached rapidly over a period 8 days when tempertatures rose abruptly (and locally) by 2.5C over 8 days.
Contrast that with the equally science-friendly and public unfriendly titled paper, “Ring bleaching in Southern Carribean Agaricia Agaricites during Rapid water cooling” (D.R. Kobluk and M.A. Lysenko, 1994, Bulletin of Marine Science 54, pp. 142-150) that coral bleached severely when water temperatures dropped by 3C in 18 hours!
In fact, it has been known for well over a decade that coral bleaches in response to changing environmental conditions. It’s a survival mechanism. If the water temperatures suddenly gets warmer or colder or the prevailing chemical conditions change, the coral let go of all their symbiotic aglae that was favourable in the odd environment to allow new and more favourable algae floating in the vast algal and bacterial soup of the ocean to move in and protect the coral in its new environment.
There’s no doubt the chemicals man is dumping into the water are not helpful to the coral, and maybe, there aren’t symbiotic algae floating out there which will assist the coral in adapting to dealing with 6000 tons of sunscreen (spread around the tropical zones of the world one might add) and adding stress to the coral as it is constantly evicting algae to strike up new relations that deal with localised warming, cooling, seasonal pesticide runoff and natural predators.
But it should not go unnoticed that coral have survived a lot worse and the oceans of the world are a vast natural resource to find new algal comrades. And 6000 tons of sunscreen spread around the globe but locally focused on beaches where the coral grows close to white sand beaches is probably not creating quite as much stress as several million tons of pesticide draining into the ocean from farming….
So what do you think you will do now you realise you won’t kill the coral? We at The Dappled Planet will do our best to wear sunscreen which doesn’t contain the most known agents to exacerbate coral bleaching, but we are also not ready to sacrifice our skins for contributing a few grams of sunscreen to the ocean waters. We have faith the coral will continue to adapt and survive the natural irritants - but we are concerned about pesticides stressing their system!
