March 31, 2014
The IPCC’s new report on climate change puts coral reefs front and center. Is there still time to save them? The Nature Conservancy’s Mark Spalding walks us through the science.
January 30, 2014
If no one uses an ecosystem service, is it still a service? Marine scientist Mark Spalding examines the different ways we value nature.
December 5, 2013
Marine scientist Stephanie Wear is on a conservation mission: to save coral reefs and, at the same time, improve the lives of the people living in coastal areas.
May 20, 2013
As if the long list of threats to coral reefs weren’t enough, we can now add ocean acidification to the list.
Perhaps you’ve seen the gloomy headlines like “Ocean Acidification: ‘Evil Twin’ Threatens World’s Oceans, Scientists Warn.”
Perhaps it is no wonder that folks think coral reef scientists are never finished “crying wolf” about the next global challenge threatening to wipe out coral reef ecosystems.
How serious is this threat and what can we do to address it? To answer these questions, we decided to enlist the help of some global acidification experts. But first, we have to understand the problem.
April 15, 2013
I never expected to be so intrigued and excited about poop, until a paper in PloS ONE came out in 2011 that demonstrated that a common human pathogen found in human wastewater, Serratia marcescens strain PDR60, caused white pox disease in elkhorn coral (Acropora palmata), the foundation species in Caribbean coral reefs.
Caribbean reefs have been plagued by disease in recent years and figuring out the source of the pathogens has been a challenge. Human sewage has long been a suspect, but the science behind this suspicion was always tenuous. I think most people would assume that exposing reefs to partially treated or untreated sewage couldn’t be a good thing, but there were no clear data that made the connection of human sewage to the degradation of corals so clearly until this paper.
Unfortunately, there is plenty of untreated sewage making its way into tropical seas.
In the Caribbean, most sewage isn’t actually treated, rather it is put into containers that sit in the ground — the ground being comprised of porous calcium carbonate rock (limestone) that is characteristically leaky.
In many places in the Pacific, the ocean is the toilet.
March 22, 2013
It’s a little hard to get your head around what Australia did last November. I live in a country, the United Kingdom, that covers 250,000 km² – not a huge country for sure, but not tiny. Australia declared new marine protected areas that cover almost ten times that area – some 2.3 million km².
Well, as you might imagine, there have been some pretty big celebrations about this, certainly among conservationists, but also among a public that widely supported the declaration.
I’m delighted that Australia has upped the ante for marine conservation everywhere in this way. This sort of move should excite and inspire, in much the same way that Australia’s Great Barrier Reef has already done.
They have shown us that large-scale conservation can be done, and can be done with full participation and broad support, and that it can be income-generating – good for people as well as nature.
But not everyone’s happy. Some – including Bob Pressey, a highly regarded conservation scientist in Australia – has called these new sites “residual protected areas.”
He suggests that these sites are not in the best places either for averting threats or protecting diversity. He also says that they don’t really have teeth, and it’s true that, on declaration, the new parks required no immediate changes “in the water” – that ongoing activities such as fishing, and even mineral extraction can carry on.
That’s worrying of course, and might lead to a sense that they aren’t going to do as much good as might be hoped. But it’s an important first step.
February 1, 2013
Coral bleaching, increasing storms, the loss of polar bears: many impacts of climate change are already vivid in our minds. We naturally worry about the things we can see. Huge waves and the loss of big fish and colorful corals get our attention.
But what about things we can’t see, like the tiny creatures called plankton? They are also poised for dramatic changes.
A recent dive in the sapphire waters of the Caribbean offers a close encounter with plankton. While most of my dive buddies hurry to reach the bottom, I linger as I usually do, pondering the “blue” and looking out for the visible and the invisible.
Suddenly, clouds of tiny filaments come sharply into focus. It’s blue-green algae–Trichodesmium–a type of phytoplankton that plays an important role in these nutrient-poor waters. They essentially break gaseous nitrogen’s tough triple bond and convert it into a form other phytoplankton can feed on.
What would these waters look like without them?
January 31, 2013
In July, I introduced via The Nature Conservancy’s photo of the month what may then have been the world’s largest living table coral (pictured above).
I found it on a reef in Nusa Laut, Indonesia. I also indicated that the coral felt like an old friend to me and that I would develop a knot in my stomach on visiting the reef in anticipation of finding my “old friend” dead or damaged.
Table corals are not as long lived as some of their massive boulder forming community members.
The reason is that table corals grow by dividing horizontally away from the center after reaching a certain thickness.
The central polyps stop dividing vertically and eventually get old and die from natural senescence. The center of any very large table coral colony usually is dead.
Massive corals on the other hand, like some we’ve seen in our Indo-Pacific seas, may be hundreds to over a thousand years old.
These corals grow by dividing vertically and thus are constantly renewing themselves as they grow upwards and outwards.
Table corals are also vulnerable to toppling by storm surges and breakage of their narrow pedestals when shaken by earthquakes and tremors in seismically active areas like those in the West Pacific and Coral Triangle.
How these corals respond to the stress of being shaken and toppled is a great indicator of their resilience. Some simply give up and die. Other more resilient ones seem to shrug off the stress and reorient their plane of growth, contributing dramatic new architecture to the reef community.
I exhorted friends who visited the Nusa Laut reef in November last year to measure the majestic table coral precisely and report on its well-being.
The news wasn’t good.