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A Magic Underwater World with High Power Fluorescence Torches
nice fotos and movies , thats all? By this method it is possible to discriminate between living and dead corals. It could be a valuable tool for reef check activities to estimate the situation of coral reefs worldwide (further explanations see below). The results could help governmental institutions to enforce existing laws for the protection of this sensitive ecosystem.
questions are welcome > contact > horst.grunz@uni-due.de
Reef forming corals are under natural and anthropogenic threats worldwide. We developed HiTec fluorescence torches with strong intensity. We started 3 years ago with OSTAR SMT LEDs to distinguish living from dead corals in large scale scanning approach. In March 2011 we have contructed a new fluorescence lamp with the most powerful blue LEDs worldwide. We delivered the prototype to a marine biology lab in Hawai.
Corals have a vital symbiontic algae (symbiodinium spp.) which is essential for the metabolism of the host coral polyp. When coral lose these algae as a result of increased seawater temperature and other factors (pollution), the corals die - the so called coral bleaching. Vital corals show significant fluorescence, when illuminated with blue light of a controlled wavelength – an attribute that scientist use for distinguishing them from dead ones. Dead corals contain only the skeleton of calciumcarbonat and show therefore no fluorescence. For the detection of fluorescence a blocking filter on the diving mask and the camera is essential. UV (often descibed as black light - Schwarzlicht) is not suitable and even harmful for the corals.
We now developed a HiTec fluorescence lamp with strong intensity which is superior to commercially available lamps. It can distinguish between living and dead corals in large scale scanning. Even small regenerating coral polyps can be detected by this method in night dives. The corals contain species-specific pigments of the GFP (green fluorescent proteins)-family, which are responsible for their specific color. For the isolation of GFP from the jellyfish, Aequorea victoria 3 scientists earned the nobel prize of chemistry in 2008 (for details see my Article "Coral Reefs" (pdf-files in English and German).
The HiTec lamp is based on blue high power OSTAR SMT LEDs in multi-chip technology. For the operation of these LED-modules special boosters and cooling devices are necessary. The high intensity fluorescence lamp cannot only be used for scientific work (reef check etc.), but also during dives of interested professional divers and for fun dives of guests of diving centers. It was first tested in September 2009 with support of Johann Vifian, Director of the SUBEX Diving Centers (Hurghada, Egypt).
With 110 lm from an exceptional compact package (5.8 x 4.7 x 1.5 mm) and a luminance of 9 MegaCd/m², the OSTAR SMT is a small and powerful point light source. The four 1 mm² chips emit blue light with a cleary defined wavelength of 465 nm. As a surface mounted device it combines easily with secondary optics.
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