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 29, 2013
If a community protects a portion of its fishing grounds, will it actually benefit them?
Or will the young fish produced in protected areas just move hundreds of miles away and benefit communities that played no role in protecting the resource?
These questions were the focus of researchers working in Manus, Papua New Guinea who investigated whether community protection efforts for the squaretail coral grouper (Plectropomus areolatus) actually benefited the community by providing more fish.
Their results, published today in the journal Current Biology, clearly show that local management of this species provides local benefits.
“For years, we’ve been preaching that community-based conservation is a key component to protecting reef fisheries,” says Rick Hamilton, senior scientist for the Conservancy’s Melanesia program and one of the coauthors of the paper. “The idea has been that if we protect some areas, large female fishes will be left undisturbed. They would then produce millions of larvae that spill over into nearby areas open to fishing. But until now that assumption has largely been faith based.”
In Manus, as in many parts of the world, people essentially own the coral reefs near their village. They decide when, where and who can fish in these areas. Some of these areas have no formal designation, but fishers know these customary boundaries. Local communities can thus enact and enforce management and protection efforts.
One of the most important fishes for commercial and subsistence harvest for Manus communities is the squaretail coral grouper. It is also highly susceptible to overfishing. This is in part due to the fact that they form spawning aggregations, where huge numbers of fish congregate in one spot to spawn at predictable times. This makes it easy to overharvest the reproductive population. At night, the aggregating coral grouper sleep in shallow water, making them easy targets for spear fishers.
March 28, 2013
I have a confession to make: I’m a marine scientist who thinks marine protected areas (MPAs) aren’t going to be nearly enough to save our oceans, and that fishing needs to be part of the solution too.
Here’s why: As a conservationist, I’ve seen how MPAs can protect habitat and allow fish populations to flourish, but I’ve also seen how effective fisheries management can balance economic needs with those of a healthy ocean. Within the next generation the global population will reach 9 billion, and it’s our shared challenge to implement the next generation of ocean management techniques to allow us to restore and maintain our oceans against this ever-rising wall of pressure.
That means working together.
March 27, 2013
For a marine scientist, there is nothing like being on a boat. Your senses become alive, your creativity peaks. As you gaze over the side of a boat, the ocean mysteries you have been trying to solve suddenly come into focus.
But being on a boat is expensive. A recent article in the journal Science, “A Sea Change for Oceanography” by Eli Kintisch, clearly spells this out. Kintisch tells us that shrinking budgets and increasing costs are driving a change in how people study our oceans. A growing array of high tech devices that remotely collect information are being deployed and less days on sophisticated boats are spent at sea. The article suggests that this shift from field data collection programs to remote data collection programs is a change from “small” to “big” oceanography.
But what should “big” oceanography really be? Should the ability to connect to society’s needs be a part of “big” oceanography? If the answer is yes, I would say oceanography is failing. The good news is: there is still opportunity to redirect course.
Why has a field critical in describing the fabric of anything that has do to with oceans (how we use them, how we depend on them) failed in demonstrating its relevance beyond primary science? Perhaps it’s because oceans are still viewed—by oceanographers and the public—as one of the last great frontiers. Kintisch calls attention this in the Science article, concluding with a call for support of ocean studies “…comparable to [funding for] research in outer space…”
Indeed oceanic exploration has always generated tremendous media attention and public interest. But the ocean is much more than a last frontier. Our decisions around assigning priorities and allocating resources, the stories we share about the ocean should reflect this.
When the field started the ocean was mostly un-explored (and large sections of the ocean still are). The last frontier should and will continue to provide inspiration for years to come. But what about all the people that we now know live and depend on the ocean? Who solves their mysteries and the integral part that the ocean plays in solving their riddles?
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.
March 13, 2013
I was just revising the “marine chapter” for a textbook I have coauthored, and looking at reviews from professors who had taught a conservation course using our first edition. We were criticized for making marine conservation too much about fishing and marine protected areas, while neglecting ocean pollution as a big deal, and probably the greatest threat to our oceans.
It turns out these critics were right.
For much of human history the ocean has been viewed as a place to dispose of waste where it would be so diluted that it does no harm. We now know better.
Dead zones, floating mats of plastics, and toxic chemical residues in marine fish tissue are striking evidence that human waste and by-products could be every bit as much of a threat to our oceans as over-fishing.
Dead zones now affect more than 400 systems, and cover vast areas of the ocean — more than 475,000 square kilometers. Plastic debris in the oceans is now so common it is hard to find a beach without washed up plastics. This plastic is much more than a matter of aesthetics; all sea turtles, 45% of marine mammals, and 21% of seabird species are harmed by plastic.
The sheer volume of human waste products and the fact that most people live along coasts means that there will be no simple, single measure that can address marine pollution.
Take something as specific as cigarette butts — over 4.5 trillion cigarette butts are discarded annually, and researchers have observed a 96-hour mortality effect (measured as LC-50) in larval topsmelt (a Pacific ocean silverside) at a dilution of one cigarette butt per liter of water. Latte-drinking enthusiasts in my hometown of Seattle have given rise to elevated caffeine concentrations in Puget Sound, which are known to cause chemical stress in mussels and other marine invertebrates.
So what are we to do?
March 7, 2013
This week has without a doubt been the highlight of my career as a marine conservationist. And, as someone who has had a long-term love affair with the world’s oceans, it’s been a life highlight as well.
On 20 February 2013, the Raja Ampat government officially announced that it has declared its entire 4 million hectares of coastal and marine waters a shark sanctuary.
This means that all harvesting of sharks is now prohibited in its waters. In addition, the sanctuary also gives full protection to a number ecologically and economically important ocean species, such as manta rays, dugongs, whales, turtles, dolphins and ornamental fish species.
Why is this important and why should we care?
Well, sharks have a really hard time in our oceans. Beyond the often over-amplified fear people have of sharks, they are also targeted for their high-priced fins or are caught accidently in fishing nets.
It is estimated that at least 26-73 million sharks are killed each year globally, mostly for their fins. Shark finning is one of the cruelest practices around—it involves throwing a still-breathing shark overboard with its fins cut off and its body bleeding into the water.
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.