New Genus of Crustacean and Five New Species

Feb. 15, 2013 — On recent expeditions to Madagascar and the French Polynesia, two Spanish researchers have discovered five new species of crustacean and a new genus named Triodonthea .

Experts from the Centre for Advanced Studies of Blanes and the University of Barcelona (UB) collected and studied different crustacean specimens during recent expeditions to Madagascar, New Caledonia, Vanuatu, the Philippines and French Polynesia.

Enrique Marcpherson

Using morphological and molecular data they have discovered five new species of crustaceans in the waters of these regions. They are genetically different but morphologically very similar and they also found a new genus, named Triodonthea. The five new species documented in the study belong to the Lauriea genus of the Galatheidae family, which is differentiated easily from other species of the group as it has very long setae and their legs end in a double spine.

"The Triodonthea is a new genus that it genetically very different from the Lauriea species despite being very morphologically similar. The morphological differences are small to our eyes but reflect great inequalities on a species level," as explained  by Enrique Macpherson, researcher at the Centre for Advanced Studies of Blanes and co-author of the study along with Aymee Robainas-Barcia from the UB.

Continued:  http://www.sciencedaily.com/releases/2013/02/130217083604.htm

Reef devastation caused Crown-of-thorns outbreaks still a mystery to researchers

Researchers tackle the coral-killing starfish

February 2013. Crown-of-thorns Acanthaster planci is the principle natural enemy of reef-building corals. Outbreaks of this coral-feeding starfish occur periodically, due to reasons that remain unclear. It decimates entire reefs in the space of just a few years, as has been the case in French Polynesia since 2004. A new study conducted by IRD researchers and their partners describes this population explosion around Moorea, the "sister island of Tahiti". The rate of living coral cover in ocean depths and lagoons alike dropped from 50% (healthy reef) to under 5% in 2009. The ecosystem will need at least a decade to be restored to its original state.

Photo:  Kurt Domingo 

The starfish has spread from island to island
The archipelago has been suffering from a new population explosion of the predatory starfish since 2004. It is one of the most intense and devastating outbreaks ever recorded. The outbreak of Acanthaster began in a very specific location in the Austral and Leeward Islands, then in 2006, the starfish colony spread to Tahiti and Moorea. Thanks to a dozen stations around the island of Moorea, scientists were able to make spatio-temporal observations of the dynamics of the infestation of coral populations. Thus, in a new study published in PLoS One, they described the spread of the coral reef invasion.

Ocean depths and lagoons alike
The starfish first settled in the deeper areas along the outer slopes of the reef, around 20 to 30 metres below the ocean surface. It then rose to a depth of approximately 6 metres, and even colonised certain parts of the lagoon. The damage was gradually observed: from 47% of living coral cover at one of the stations in 2006, for example, this rate dropped to 21% in 2007, 6% in 2008 and 2% in 2009: a disastrous state of affairs that disrupts the structure and functioning of all reef communities (including other coral-feeding species, such as butterflyfish, etc.).

http://www.wildlifeextra.com/go/news/crown-thorns-cause.html

Cook Islands' shark sanctuary creates world's largest

As shark numbers fall, other species further down the food chain are put at risk

The Cook Islands has approved a shark sanctuary in its waters, making for the largest such sanctuary in the world.

The South Pacific island chain declared a 1.9 million-sq-km sanctuary, contiguous with one established last week by neighbouring French Polynesia.

That sees a ban on shark fishing and possession or sale of shark products in an area now totalling 6.7 million sq km - nearly the size of Australia.

As top predators, overfishing of sharks disrupts complex oceanic food webs.

And about a third of ocean-going sharks appear on the internationally-recognised Red List of Threatened Species.

"We are proud as Cook Islanders to provide our entire exclusive economic zone... as a shark sanctuary," said Teina Bishop, Cook Islands minister of marine resources.

"We join our Pacific neighbours to protect this animal, which is very vital to the health of our oceans, and our culture."

Other island nations with sanctuaries also include Palau, the Maldives, Tokelau, Honduras and the Bahamas.

Continued:  http://www.bbc.co.uk/news/science-environment-20709853

Warmer seas to hit reef fish badly

Warmer seas triggered by the 1997-98 El Niño led to a dramatic drop in the number of reef fish around French Polynesia, scientists have found.

The fish may have starved, because higher water temperatures killed off tiny marine creatures called plankton, which the fish feed on when they're young.

During the El Niño – the second strongest on record – ocean temperatures shot up to 3.5°C above average. El Niño is the name given to the change in the temperature of the eastern Pacific Ocean which can bring huge changes in the world climate.

Scientists are predicting that warmer waters like those typified by an El Niño event will be the norm under climate change. If they're right, this could spell disaster for around 500 million people who rely on coral reef fish either for their food or for tourism.

'This is the same event that wiped out more than half of the Seychelles reefs. It was a substantial El Niño,' says Dr Steve Simpson from the University of Bristol, one of the authors of the study, published in Global Change Biology.

Although climate change is predicted to bring much warmer seas, it's difficult to be sure how this will affect ecosystems.

In this latest study, Simpson and an international team of experts managed to get hold of data on the numbers of coral reef fish in French Polynesia spanning four years – with the 1997-98 El Niño bang in the middle.

'This meant we could look at the effects of the warming and compare that to fish numbers before El Niño warmed the seas,' says Simpson.

Not just that, but the effects of an El Niño are far-reaching, with higher water temperatures happening over thousands of kilometres, and over relatively long periods. So the team realised that combined with the fish data, this was probably the best opportunity they were going to get to find out how reef fish cope with warmer-than-average water.

Simpson and his colleagues analysed satellite data on water temperatures, ocean currents and the amount of chlorophyll in the water from January 1996 to March 2000. Many plankton use chlorophyll to photosynthesize in the same way that plants do, so chlorophyll tells scientists how much plankton is in the water.

They found during the 1997-98 El Niño, water temperatures rose, concentrations of chlorophyll dropped and the direction in which the ocean currents flowed changed around French Polynesia.

But warmer waters didn't just hit young fish badly; lack of plankton may have meant adult fish couldn't produce as many offspring as usual. The team found that once plankton had recovered, it took three to four months before the numbers of young fish started to climb.

'Even after the current switched with El Niño, we still saw young fish on the reef, so the current didn't seem to be the problem. We're fairly sure this is all down to food availability,' says Simpson.

Young reef fish don't grow up on the reef. Instead, after the adults have laid eggs, they drift out to sea, where they feed on plankton until they're developed enough to come back to the reef. The numbers of predators around coral reefs are much higher than out at sea, so the young fish can grow up in relative safety.

Fisheries managers often monitor the numbers of young fish returning to the reef to get some idea of the likely numbers of fish the following season. It was this data that Simpson and his colleagues analysed.

While reef fish could be badly hit by climate change, Simpson is finding that other species, in the northern Atlantic for example, aren't doing quite as badly.

'There's bound to be winners and losers. Some species will find it easy to move north or south as temperatures rise; those that are more mobile. But reef fish are tied to the reef, so they won't be able to move so easily,' adds Simpson. 'It's not a simple story.'

by Tamera Jones

http://planetearth.nerc.ac.uk/news/story.aspx?id=896