I’m here at St. John’s Island attending a 10-day workshop to learn how to rear coral larvae. This workshop is organised be SECORE which stands for SExual COral REproduction. YES. Corals do reproduce sexually (and yes, they are animals). Corals can reproduce both sexually and asexually. When we say “sexual reproduction” we refer to reproduction by fusion of gametes (sperm and eggs). “Asexual reproduction” on the other hand, means reproduction (increase in numbers) by other means (no fusion of gametes) such as fragmentation and budding. Asexual reproduction generates progeny that are identical to their parent while sexual reproduction produces diversity in the offspring. There are pros and cos to both reproductive strategies, can you think of some of them?
What is SECORE, you might ask. The main focus of the organisation is establish sexual reproduction methods for captive coral colonies (in laboratories). Aiding the sexual reproduction corals yields a higher success rate than allowing nature to take its course, probably due to the increasing the chances of survival (not bring swept away by the current, lowering predation rate) and increasing the chances of fertilisation (since eggs and sperm are confined to an area) by allowing fertilisation and rearing the larvae in a controlled environment. Although original intention was to create a sustainable source of corals for aquariums, it’s now quite clear that there are many implications for coral conservation and restoration efforts as well.
This is the first time SECORE is having a workshop here in Singapore (or South East Asia for that matter) and I’m glad to have a chance to attend it. Every year around this time, many species of corals will release their eggs and sperm in a synchronised event which takes place over a few days. This mass-synchronous event is cued by the full moon, increased temperatures and nightfall. This isn’t my first time observing the mass spawning event, I’ve participated in the survey dives organised by the Marine bio lab at NUS a few times before since Dr James Guest (one of the organisers of this year’s workshop) did his PhD there and we would help him out. But still! The spawning is something out of this world! I love diving because underwater, it’s like being in a different realm altogether. Everything seems to defy gravity (even myself sometimes) and fish swim above you, under you, and sometimes even upside down. The creatures you see underwater come in different shapes and sizes it really blows my mind. And then spawning… it’s amazing. In my own words, it’s like reverse snow. The little bundles of pink eggs and sperm are released from different colonies of coral roughly around the same time and before you know it, you’re caught in a blizzard, except it’s coming from below you and floating to the surface.
If I manage to take a video of it I’ll upload it for you guys to see. You’ll be amazed.
Anyway, today is the first day of the workshop and we’ve had a few lectures. I’ve already learnt quite a bit. Here are some snippets:
Ocean acidification is possibly one of the biggest threats to our coral reefs. Although the oceans are a carbon sink for our carbon emissions, if photosynthetic organisms (algae, plants etc) are unable to take in as much CO2 as is being dissolved in it (due to increased atmospheric CO2), our reefs will die.
Current atmospheric CO2 concentration is something like 380ppm (parts per million) at the moment (and increasing). If it reaches 450ppm, corals will not be able to incorporate the calcium into their skeletons and reefbuilding processes will be halted. IF (and there is a high chance it will) it reaches 550ppm, the calcification process will reverse and our corals reefs will start to dissolve (and acidification levels will skyrocket i.e. pH will be lowered by alot alot).
Dr Mary Hagedorn (from the Smithsonian Institute and based in Hawaii) is currently doing some research into cryopreservation of coral fragments as well as coral sperm. Did you know that there are 3 cryogenic coral banks in the world? That’s amazing.
I’m a bit tired of typing for now, so I’ll leave you with that thought. Think about all the implications of having cryogenically frozen coral sperm. :) More updates tomorrow!
More about the workshop: http://tinyurl.com/secoreworkshop