Fluorescent Corals

Many species of coral produce fluorescent pigments that light up in a dazzling display of neon colours when exposed to UV light.

Fluorescence is the phenomenon whereby a substance absorbs electromagnetic radiation (such as light) and emits it at a lower energy level. In this case, the corals’ fluorescent proteins absorb invisible high energy UV light and emits visible light, which has longer wavelengths and lower energy.

Scientists have hypothesised several reasons for fluorescence in corals.

Corals form symbiotic relationships with algae called zooxanthellae, which they house in their polyps. The algae photosynthesise and provide nutrients for the coral. However, the algae are not able to process UV light. Through fluorescence, the corals may be able to turn the UV light into wavelengths that are useful to the algae for photosynthesis, especially in darker environments. 

It has also been suggested that the fluorescence provides protection against UV rays, notably in shallow water. UV rays are mutagenic and are capable of damaging cells in both the coral and symbiotic algae. Fluorescence may be a means to convert UV light into harmless lower energy wavelengths in order to protect both the coral and algal cells.

Studies have shown that corals with higher concentrations of fluorescent proteins are more resistant to bleaching.

Check out more photos of fluorescent corals on flickr

© via Flickr

Coral Gardening - South Pacific - BBC

Local fisheries have largely damaged fragile reef ecosystems, which are important habitats for fish. Fish numbers are falling due to a loss of habitat, affecting the livelihoods of fishermen.

In Fiji, biologists are working with local fishermen to repair the reefs, raising corals in ‘gardens’. The gardeners collect wild specimens that are crowded and break them into smaller live fragments. They then place the fragments onto tables located in areas perfect for coral growth.

Within two years, the corals are ready to be transplanted back into the reef. Some new fragments are taken to restart the process.

Scorpionfish
Scorpionfish often have colourations that disguise them as coral rocks. This allows for unsuspecting prey to approach the waiting scorpionfish, which is a poor swimmer.
dachalan on Flickr

Scorpionfish

Scorpionfish often have colourations that disguise them as coral rocks. This allows for unsuspecting prey to approach the waiting scorpionfish, which is a poor swimmer.

dachalan on Flickr

Reefscape
Tony Shih on Flickr

Reefscape

Tony Shih on Flickr

rhamphotheca:

NY TIMES - Scientist at Work: To Save a Coral Reef Enabler

by LUIZ ROCHA

Rocha, the curator of ichthyology at the California Academy of Sciences, writes from Belize, where he conducts research on one of the world’s most endangered fish.

There’s a lion on the loose, and it’s hunting endangered prey. I’m on my way to Belize to see what I can do about it.

Belize is home to a portion of the largest barrier reef in the Caribbean, the Meso-american Barrier Reef System. Hundreds of species of fish inhabit this diverse coral reef system, many of them unique to the region. This week I will conduct field work there, joining forces with a team from the Smithsonian Institution led by fish curator Carole Baldwin.

Our team will look specifically at the population status and habitat conditions of the social wrasse, Halichoeres socialis, ut why pick this one species from the hundreds to be found there? The social wrasse is currently listed as “critically endangered”

(read more: NY Times)            (photos: Luiz Rocha)

Purple Anthias (Pseudanthias tuka)
Nick Hobgood on Flickr

Purple Anthias (Pseudanthias tuka)

Nick Hobgood on Flickr

rhamphotheca:

Tracking Oceanic Fishes
Scientists have long been able to tag animals on land and follow their movements and habits. But tagging and tracking fish, like this  spinecheek anemonefish, through vast oceans is a Herculean task. Tagging fish larvae less than an inch in length had proved almost impossible.
Biologist Simon Thorrold, director of the Ocean Life Institute, is among an international team using TRansgenerational Isotope Labeling (TRAIL) and DNA fingerprinting to determine how fish populations disperse and connect to one another in the reefs of Kimbe Bay, Papua New Guinea. Such information is essential for identifying critical marine habitats that should be set aside to protect fish populations that are coming under increasing pressure from fishing and habitat destruction.
(Visit Website)           (Image: Simon Thorrold, WHOI)

rhamphotheca:

Tracking Oceanic Fishes

Scientists have long been able to tag animals on land and follow their movements and habits. But tagging and tracking fish, like this spinecheek anemonefish, through vast oceans is a Herculean task. Tagging fish larvae less than an inch in length had proved almost impossible.

Biologist Simon Thorrold, director of the Ocean Life Institute, is among an international team using TRansgenerational Isotope Labeling (TRAIL) and DNA fingerprinting to determine how fish populations disperse and connect to one another in the reefs of Kimbe Bay, Papua New Guinea. Such information is essential for identifying critical marine habitats that should be set aside to protect fish populations that are coming under increasing pressure from fishing and habitat destruction.

(Visit Website)           (Image: Simon Thorrold, WHOI)