Wild Ocean Blue

As I mentioned in my last post, 2010 is the International Year of Biodiversity. And what better way to start things off than with a neat study from Florida telling us why some fish species are especially important.

This is the story of the red grouper.

Red grouper. by NOAA.

As their name suggest, these chaps are usually red. They can grow to over a metre from head to tail although 50cm (or nearly 2 feet) is more common. They can apparently live for up to 25 years, which is quite a lot for a fish. And like many other fish, red groupers are sex shifters: they are all born as females and after between 7 and 14 years they reajust their sexual organs, transforming into fully-functioning males.

The warm waters of the Caribbean Sea and central west Atlantic, between North Carolina and Brazil, are where the red groupers call home. And it now turns out these fish help to build and maintain their complex reefy  habitats.

“Red groupers are the Frank Lloyd Wrights of the sea floor” said the study co-author Susan Williams, from University California-Davis.

Red grouper. Photo by tiswango.

Felicia C. Coleman from Florida State University’s Coastal and Marine Laboratory led the study in the West Florida Shelf, sending both scuba divers and mini-subs down to spy on the red groupers. The researchers watched on as the fish got busy, digging great holes in the seabed to live in – up to a few metres wide and deep. The fastidious fish then keep their homes neat and tidy, ejecting mouthfuls of sand and sweeping the rocks clean with their tail.

In a series of experiments, the research team temporarily kept groupers away from their excavated abodes (by putting a cage around them), showing just how well they maintain their burrows.

And it turns out that this meticulous housekeeping creates important three-dimensional habitat that many other species rely on, giving a boost to biodiversity wherever red groupers are present; it clears areas of hard rock for corals and sponges to settle on and provides hiding places for spiny lobsters and dozens of other fish species including many that we like to eat such as snappers.

No-one has yet experimented with taking away red groupers permanently to test out this theory; somehow that doesn’t seem like a very good idea, these days.  But this study from Felicia Coleman and colleagues gives us a strong hint that all would not be well if red groupers were to disappear. In their own habitat-building way, they could well be what ecologists call “key-stone species”.

So, without the red groupers it seems likely that a whole host of other species would suffer.

And in the end that’s why red groupers really matter.

In detail:

• Red groupers – Epinephelus morio – are listed as Near Threatened on the IUCN Red List, which is a fairly low threat category but means they are certainly not safe. Many populations are considered to be overfished, especially parts of the Gulf of Mexico, and despite a few recoveries declines have been particularly bad in some areas.
• They are ambush predators, sneaking up on their prey and swallowing it whole, including shrimp, octopus, squid, fish and crabs.
• Other key-stone species include sea otters and starfish. They exert a disproportionate influence (for their size and abundance) on the rest of the ecosystem mainly because of their voracious appetites.

A pair of sea otters holding hands. Just too cute. Photo by joemess

• The red grouper paper can be downloaded for free from the Open Fish Science Journal.

I welcomed in the new decade under a stunning blue moon here in Cambridge, and it’s got me to wondering whether the brand new year, and decade, that lie ahead of us might also be full of other rare and beautiful things.

2009 was undoubtedly the year when more people than ever before began paying attention to the problems of climate change. It was incredible to see these issues climb so high in the international agenda, even if the outcome might not yet be what most of us were hoping for.

But has all the talk about climate change distracted us from many of the other threats to the natural world?

Biodiversity – the wonderful diversity of wild species and the threats they face from human actions – is an issue that has been patiently waiting in the wings, waiting for the UN to push in out onto centre stage in 2010. Because this year is the UN International year of biodiversity.

The question is, will the dwindling populations of so many important, breathtaking, extraordinary species command as much global attention in 2010 as the climate change debate did in 2009.

Perhaps, if we’re lucky.

Coming up in the following months are a few major international meetings that could decide the fate of some of the world’s wildlife.

The international trade in bluefin tuna – highly prized for Japanese sushi – could be banned in March at the latest conference of CITES – the Convention on International Trade in Endangered Species. Following the failure last November of management bodies to take bold steps to help stop these magnificent fish being hunted to extinction, CITES could be the bluefin tuna’s last hope. But will countries with a vested interest in the trade be prepared to vote for a ban? The pessimist in me says, not likely.

Bluefin tuna on sale in Tsukiji Market, Tokyo. Photo by Sanctu

Also on the agenda at the CITES meeting will be a group of sharks that conservationists fear are being driven towards extinction by demand for their meat and most notably their fins, to be made into the Asian delicacy sharks fin soup. I’ve been working for the last 6 weeks assessing the proposals to have hammerheads, oceanic whitetips, spiny dogfish and porbeagle sharks join a trio of awesome sharks that already have trade restrictions – the basking sharks, whale sharks and great white sharks.

Hammerhead shark. Photo by gnuru

I’ll be blogging more about sharks and tuna this year, so watch this space.

Then, November will see another landmark UN meeting and with it another opportunity to make global deals that could help secure the future of the planet, this time at the UN Convention on Biological Diversity.

Back at the Rio Earth summit in 1992 nations pledged to put a halt to the loss of biodiversity. And they were going to do it by 2010.

Everyone knows that this has not happened – no where near it. We are barely even starting to understand how human actions are affecting biodiversity, let alone figure out ways of stopping extinction.

So this meeting will be a tricky one, but could be vital if a way forward for global action against extinction is to be found.

But ultimately what I hope this coming year will do is help people appreciate why biodiversity matters, just like many people in 2009 began to realise why climate change matters.

The link between biodiversity loss and our own lives may not be as obvious as the threats from climate change, but there are so many ways in which we depend on healthy, diverse, functioning ecosystems. And that’s something else I’ll be writing about more this year.

For now, Happy New Year to you all. May 2010 be full of rare and beautiful things for us all.