Support IYOR2008. www.iyor.org
Red Acro Bugs in the UK – Prevention is the Best Medicine.
It seems that a few more reefkeepers are putting up their hands and admitting to having problems with these pesky critters. I can’t emphasise strongly enough how important it is for everyone to quarantine new coral purchases prior to placing them in the display aquarium.
In view of this I’ve decided to go over the basics of coral quarantine as the main subject of this month’s Reef Ramblings.
A coral quarantine system is not an expensive luxury. Indeed some of the items needed for your quarantine system can be considered as some of those spare pieces of equipment that every reefkeeper should have on hand for emergencies. Think of it as your spare heater, spare pump, spare lighting, etc.
OK, so what constitutes a quarantine system? It’s just a tank with a heater, a pump for water movement and lighting. I use a 60cm x 30 cm x 30 cm tank (in English that’s 2 foot long, one foot high, one foot wide). The heater needs to be suitable for maintaining a temperature of around 24˚ – 25˚C, in practise usually a 100 watt heater, depending on the ambient temperature where the tank’s positioned, don’t forget to include a thermometer. For water movement say a Koralia 1 or perhaps a Pico 1200 fitted with a Hydor Flo to give a little bit of surge. As any corals being quarantined are not going to be in this system for too long, 2 – 60 cms (2 ft) T8 fluorescent tubes should be adequate (don’t forget the reflectors though!).
Fill the quarantine tank with either 100% water from your main reef or with, say, a fifty-fifty mix of reef water and newly mixed saltwater. As soon as it’s running at correct temperature and salinity it’s ready to use.
Add your newly acquired corals to the tank and then observe for the next 14 to 21 days. The time period is pretty arbitrary, but remember the longer you quarantine for the better chance you have of spotting any undesirable hitchhikers. This isn’t foolproof; you can still find animals such as crabs appearing out of rockwork months after its introduction.
Although I’m writing this in response to Red Acro Bugs, they’re not the only reason for practising quarantine: Red Acro Bugs, Acropora Flatworms, Montipora Nudibranchs, Soft Coral Nudibranchs, Pest Flatworms, Predatory Snails, Aiptasia, Majano Anemones, Mantis Shrimps, Predatory Crabs, the list goes on…
During the quarantine period closely observe your new corals, and look for evidence of any of the above-mentioned pests. Don’t just look during the day, take a look at night using a torch (flashlight if you’re American) some of these animals can be fairly cryptic; others such as pest anemones are obvious. If it is the Red Acro Bugs you’re particularly concerned about I’d also suggest examining your corals under a magnifying glass, not just once but every 3 or 4 days. If any signs of infestation are seen you can then start treating the corals with dips without going in to a state of panic about your entire reef. At this point it would also be appropriate to reach your hand behind your neck and give yourself a congratulatory pat on the back for having the foresight to quarantine your new corals…
By practising quarantine you can deal with any potential pests or predators before the corals are introduced into your display tank, saving yourself lots of heart ache and expense, indeed the cost of setting up your quarantine system is no more than that of a couple of desirable corals yet it could save you the cost of replacing your entire reef.
Quarantine – you know it makes sense!
International Year of the Reef 2008.
I hope you noticed the logo at the top of the page. This year is the International Year of the Reef 2008 (IYOR2008).
The ICRI (International Coral Reef Initiative) International Year of the Reef 2008 is a worldwide campaign to raise awareness about the value and importance of coral reefs and threats to their sustainability, and to motivate people to take action to protect them. All individuals, corporations, schools, governments, and organizations are welcome and actively encouraged to participate in IYOR 2008.
This year Midland Reefs, along with Tim Hayes, is working to promote awareness of IYOR 2008 to the aquarium hobby and industry. Look out for a series of articles in Practical Fishkeeping (PFK) written by Tim, where the emphasis is on The Responsible Reefkeeper, looking at the various ways the hobby and the reefs interact with each other.
To learn more go to: www.iyor.org
Meanwhile you can do your bit by telling non-reefkeepers about these marvellous ecosystems and how they are endangered by human activities. If you want to go one better than that, then how about showing off your reef to non-reefkeepers? Remember most people will never get a chance to see a wild reef, by showing your reef to someone who’s never seen a coral or a reef fish, you’ll be opening their eyes to the beauty that may be lost if action isn’t taken.
If you’d like some promotional material about IYOR2008 for educational purposes or to help promote IYOR, please email me at: email@example.com
Carbon Use in Bleached Corals.
New research indicates that the recovery of bleached corals depends both on how much food the corals can eat and how healthy they can keep the symbiotic zooxanthellae within their tissue.
When corals bleach under aquarium conditions we have a reasonable understanding of how to help them survive. Over time a bleached coral will recover its population of zooxanthellae; it’s possible that not all of the original algae have been expelled and it’s also possible for corals to recruit new zooxanthellae from the water column, a process that may take many months. During this time corals need to be offered a plentiful supply of food as they no longer has access to the nutrition that was formally supplied by the zooxanthellae. Until the corals recover their full quota of algae we treat them as though they’re non-photosynthetic, because, temporarily, that’s what they are.
Recently researchers have come up with an explanation for the mechanism behind the success of this strategy. Andrea Grottoli and her team at Ohio State University have been focusing their research on investigating the key role that carbon plays on the recovery of damaged coral reefs.
Previously they’d discovered that one of the corals they’d tested, Montipora capitata, was able to recover rapidly from bleaching because it increased its rate of feeding five-fold in comparison to how another coral, Porites compressa, fed. This feeding strategy enables Montipora to survive the long-term damage that corals can suffer when sea temperatures climb beyond their natural temperature range, whereas Porites might not.
What wasn’t clear from the earlier experiments was how the corals actually made use of this additional carbon for their survival. Corals get carbon in two ways, either as a product of photosynthesis from the zooxanthellae or directly by feeding on zooplankton. When ocean temperatures rise, corals may eject their algae altogether, or the algal cells themselves lose the pigments needed for photosynthesis. Without their algae corals appear white, the condition referred to as bleaching; extended periods of bleaching can lead to the death of the coral.
To determine exactly how corals obtain carbon and how they use it to survive, samples of both healthy and bleached corals, of the two species, were placed in aquaria replicating ocean conditions. In one set of experiments, seawater containing higher-than-normal levels of a carbon isotope, C-13 was introduced. In the second experiment the corals were fed zooplankton that were also heavily laced with the carbon isotope.
The experiments were designed to track the carbon take up and determine whether it was coming from photosynthesis or from the corals’ feeding, and then to see how it was utilised. This would also show whether the process differed between healthy and bleached corals, or between one species and another.
The experiments showed that healthy corals took up more of the seawater-labeled carbon than the bleached corals.
In the healthy corals carbon was transferred into the algae where it is used for photosynthesis, ultimately ending up in the animals’ skeleton. Showing that the corals are using photosynthetic carbon for calcification and to meet their daily metabolic demands.
The carbon consumed while feeding, however, isn’t ending up in the skeleton. Instead, it’s ending up both in the tissue of the coral polyp or inside the algae. With bleached samples, the coral is apparently feeding carbon to the algae.
It was already known that nutrients such as nitrogen and phosphorus were exchanged in this way but the discovery that this also happens with carbon is a new one, suggesting that there is a great deal more coupling between the coral and the algae than was previously thought. Once the coral gets the carbon from feeding into its system, it locks it in, using it for energy storage and tissue growth, and when bleached, to feed the algae.
This appears to demonstrate that photosynthetic carbon is used for metabolic demands and calcification and that the carbon gained from feeding is used for tissue growth.
Without both forms, corals cannot fully recover. All corals need both photosynthesis and feeding for recovery and the rate of those two processes is the key to whether the coral can actually meet all its metabolic demands and ultimately recover.
So, now we know why our strategy of feeding bleached corals in the aquarium works. I also believe that this information also reinforces why it is important to actively feed your corals rather than the old-fashioned view of just lighting them.
Any questions or comments, or if there are any particular topics you’d like to see covered here, please feel free to get in touch with me: firstname.lastname@example.org