Reef Ramblings

Introduction.

Yet again we’ve had a couple of busy months at Midland Reefs leaving me little time to prepare monthly Reef Ramblings, so it’s another omnibus edition, this time combining June and July.

News.

You might ask why Midland Reefs has been so busy of late; well the big news is that we’ve recently moved into our own new warehouse, closer to home. As you could expect, this has meant something of a chaotic disruption of life for all at Midland Reefs. So, it’s thanks to Jon, Rob, Ruth, and Sue for all the hard work everyone’s put in to make the move a successful one. We’re still not quite as organised as I’d like but given a little more time to get into the swing of things I hope that we’ll soon be offering an improved service to all our customers.

“Clownfishes in Danger of Extinction!” or “Losing Nemo!”

At least that was the way some online newspapers presented a report from Dr Billy Sinclair of the university of Cumbria. It’s fortunate that none of the print papers really ran with this story in its lazy, online form. I contacted Dr Sinclair to find more about his report and he was good enough to forward me a copy of his paper.

It turns out to be a both interesting and disturbing report, detailing a dramatic drop in the numbers of clownfish on the Great Barrier Reef, outside of the no take zone. An example was given of one coral reef that was studied in Keppel Bay, where the size of clownfish populations, that’s the number of fishes living together in a family group in association with an anemone, had dropped from twenty five to just six, in two years.

Studies of the catch data from commercial boats operating in this area seem to back up these findings as they show large drops in the numbers of clownfishes caught over the last five years.

Studying the report, it would appear that the fall in clownfish numbers has been caused by a combination of factors, collection for the aquarium industry at a time when anemones are being lost to bleaching, with a resultant reduction in the number of anemones and their accompanying population of clownfishes.

It’s very worrying to see the reef aquarium hobby’s signature fish apparently under threat. This also reinforces my belief that there’s no excuse for taking clownfishes from the wild when they can be readily bred in captivity.

The manner of collection on the GBR is reasonably responsible, with usually only the Alpha and Beta clowns being collected with the rest of the group being left. This means the female and male are taken leaving the remaining fishes to establish a new hierarchy; the largest or most dominant fish becoming female while the second in the pecking order becomes male.
This sort of collection practice ensures that there’s a group of clowns left to associate with, and protect, their anemone.
In areas where less scrupulous practices are observed all the clowns associating with the anemone can be collected at once, leaving the anemone vulnerable to predation by Butterflyfishes unless it’s fortunate to have new clowns move in within a very short period of time. As clownfishes are not the best of swimmers they rarely travel far from their host anemone as their style of swimming makes them easy pickings for predators. The chances of fresh clowns moving to a new anemone must be rare except where anemones are grouped close together.

A Cautionary Tale.

The other Saturday I was reminded of the importance of hygiene when dealing with aquarium foods. On a Saturday evening I tend to have an aperitif before settling down to a nice meal and a movie. Whilst savouring my pre-meal drink I like to go round my tanks at a leisurely pace, feeding the inhabitants. I take my time when doing this so I can really study each animal to assess their health and condition, I find slowly sipping my drink adds to my enjoyment of the exercise. It’s important to take a little time out and really look at your animals, I feel that far too often people just throw some food into the tank, give the fishes and corals a cursory glance and then go off to do something else, perhaps only paying full attention to the tank when carrying out maintenance.

I guess I should have been paying full attention when preparing the food, my usual mix of PE Mysis, Cyclop-Eeze FreezerBar, and DT’s Oyster eggs. Imagine my surprise when I took a sip of my drink and encountered something slightly chewy and fishy … Yep, you guessed it, I left my drink right next to the jug where I was mixing the frozen foods, agitating them with a baster until they’d separated out. My previously tasty aperitif, I now realised, contained rather too much Mysis for my taste!

Product News.

We’ve added some great new products to our range of late.

There’re the new fantastically efficient Hydor Koralia Magnum circulation pumps, see last week’s online article for more on these.

We now have the second generation of the Hydor Performer skimmers in stock. These have been upgraded and improved to produce a drier skimmate and come with the fitting kit and feed pump included in the price. With each of the larger skimmer pumps drawing 26 watts or less, it makes them the skimmer of choice for the Cost Conscious Reefkeeper. Interestingly we’ve been seeing quite a few shop staff purchasing these for their own use after seeing how well they perform on shop systems.

If you use Poly Filters on a regular basis you might like to take a look at our new PURA pads, these are about twice the area of a regular Poly Filter for around the same price. The manufacturer has had these filter pads independently tested against others on the market and the results indicate that the PURA pad out competes the others, both in quantity of pollutant removed and the speed with which pollutants are removed. Another one for the Cost Conscious Reefkeeper! We’re getting these into the shops at the moment but won’t be adding them to our online shop until next month when we’ll also post the details of the independent testing.

Hints ‘n’ Tips.

Although at the time of writing the weather seems to have deteriorated I’d like to remind you about the perils of warm weather. At this time of year reef aquaria can often reach potentially dangerous temperatures. This brings with it two distinct problems: heat induced coral bleaching and depleted oxygen levels.

Saltwater has a lower capacity for carrying dissolved oxygen than freshwater, as temperatures increase this carrying capacity reduces, in a reef with poor gas exchange the level of oxygen in the water can easily drop low enough for animals such as fishes and mobile invertebrates to asphyxiate.

I’d suggest checking that all pumps are working properly and efficiently and making provision for increasing your water movement in case of a prolonged period of hot weather. Making sure that the surface of the water is sufficiently agitated will both enhance gas exchange and aid temperature control via evaporative cooling. I’m currently recommending around a centimetre of “wave height” on the surface of the water, you’ll find that this will also enhance the effect of glitter lines, especially in an aquarium lit with fluorescent lamps.

Although you can mitigate the effects of high temperature induced oxygen depletion by increasing gas exchange, this will only go part way to helping corals to survive. This additional water movement can greatly enhance your corals chances of survival at higher temperatures and may be all that’s needed in some reefs, but ultimately you need to control the upper temperature reached in your aquarium.
It’s unfortunate that the cost of cooling a reef can often be as great, if not greater, than the cost of lighting it. Some reefs may need some form of cooling for the best part of the year owing to the way they’re lit. Your choice of methods of temperature control includes: refrigerant based chillers, evaporative cooling chillers, fans, air conditioners, and extractor fans.

Refrigerant based chillers and evaporative cooling chillers are the most expensive options.

Air conditioners are also expensive but they do have the bonus of controlling room temperature, which you and your family may well appreciate (it may also be a selling point to ”the significant other”, who may well have objected to the purchase of that expensive aquarium chiller!).

Extractor fans are useful to a degree but may make little difference once the room temperature is the same as outside.

Fans can be usefully employed to blow along the surface of the water to promote evaporative cooling, they’re cheap but do remember to take care in their placement as the last thing you want is a mains fan ending up in the aquarium! If possible choose a low voltage fan for safety.

Fans can also be extremely useful with enclosed aquariums and may improve how the tank runs on a daily basis, rather than just at times of high temperature, by improving gas exchange at the surface.

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Next week I hope to be bringing you another article in the ongoing series: The Cost Conscious Reefkeeper.

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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: tim@midlandreefs.co.uk

Tim Hayes
Midland Reefs
©2004 - 2008

Coral Magazine Volume 3: No.5 £5.25

The Porifera (Living Sponges) by Steve Tyree £24.35

MarinePure Coral Plugs. £16.99

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