The Special Feature for this issue is on the endangered Spotted Handfish, and Marther answers a question about sumps and overflows.

Editorial

So, what do you think? An improvement on what it was? Any idea what I am talking about? Easier to navigate, better appearance? I certainly hope the answers to that is yes ;-), and for those that have no idea what I am talking about ..... OZ REEF Marine Park has a new look. After a couple months of working on it, in time when I am usually adding more content which is why there have not been any changes or additions recentnly, the new look of OZ REEF Marine Park has finally materialised. And what a lot of work that was, taking a lot longer than I thought it would, and I still have not quite finished yet either. There are just so many pages that I had to update and alter the format on, never realised how many. Anyway, I hope now things will be in a much more user friendly and easy to find format. There are still a couple of pages let to change over, such as the Postcard Tour and the Residents Directory (which will be no trival tasks), so these will be missing for another couple of weeks. I was also just itching to get it online ;-) and I hope you continue enjoy it. As a result, this issue of OZ REEF Press is just a little bit rushed, but I still hope you find it enjoyable and informative.

The Marine Aquarium Society of Victoria has just restarted its annual tank competition, just think of it spending an entire Sunday looking at other peoples reef tanks. Does that sound like heaven to you? This is the first time in about 10 years, and it is a great event to get started again. The way it works is there are four judges that travel around Melbourne for one day looking at all the tanks entered, anyone else can tag along for a look, and we stop off at a pub for some lunch on the way. The judges have a list of criteria, divided into sections, with a total mark out of 100. First prize was certainly one worth winning, nothing lame about it at all, a $1000 reef tank donated by an local aquarium store! Of course OZ REEF Marine Park was one of the entrants, enthusiastic one at that.

In the end there were 10 tanks entered, spread all over Melbourne from Coburg right down to Frankston. It was going to be a long day, but hey who can complain about spending an entire day looking at reef tanks? ;-) OZ REEF was the first reef up on the schedule, 8am. Now, how do you get a reef tank into top notch appearance 1 hour before the lights normally come on? If anyone knows, then please tell me so I can do so for next year. To try and get things awake and moving around by 8am I turned the lights on at 7am. But as it worked out, their internal clocks were still hard at work, and only one or two of the fish dragged themselves out of their places to cruise the enclosure. It was also not long enough for any of the corals to fully expand. Oh well, things still looked great. I don't want to go into too much more detail about the entire day, as within the next month or two I will write up a Special Feature on the contest, with pictures of all of the tanks entered and some information about the tanks. I suppose I better tell you, OZ REEF Marine Park came equal 3^rd. Now it is time to start planning for next year ...... ;-)

OZ REEF Marine Park has reached a big, huge milestone. Well it is to me anyway ;-). In just over the last twelve months there have been over 10,000 hits to the Welcome Page, and this number was reached at the end of July. It has now reached over 13,000. Although because of the way the counter works that I am gathering my data from, the actual number of "visits" to the site is about 75% of this. I thought that you might be interested to know where people are from that visit OZ REEF Marine Park. Here is a summary of the most common countries that people come from, in order from most to least visits:

• United States of America, Commercial
• United States of America, Network
• Australia
• United States of America, Educationial
• Canada
• United States of America
• United Kingdom
• United States of America, Non-Profit Organisation
• Spain
• Sweden
• Singapore
• Brazil
• United States of America, Military
• United States of America, Government
• Portugal
• France
• New Zealand
• Germany
• Columbia
• Italy
• Malaysia
• Switzerland

And I think that is quite a wide and varied list there, people from all over the world are dropping in to have a look at OZ REEF Marine Park ;-). There are of course a lot more countries, but those listed above are the most common. The following are were there has only been one or two visits, and it makes a very interesting list of countries:

• Andorra
• United Arab Emirates
• India
• Chile
• Venezuela
• Oman
• Taiwan
• Luxembourg
• Latvia
• Maldives
• Croatia
• Bahrain

Well thats it for this month, til next month. Catch ya,
DBW

Welcome OZ REEF's New Residents

• 1 x Acropora sp., Staghorn Coral. This was a rescue from a store, it was looking very pale and was on the way out. Since moving in it has picked up significanly and has started to gain some brown colouring due to the repopulation of zooxanthellae.
• 1 x Sinularia sp., Green Finger Coral. A really stunning bright green soft coral.

Resident of the Month

Dear Marther ReefKeeper

Dear Marther,

I am building a sump to place a protein skimmer in. I would like to know any information on how to build it. Also, how do I control the flowrate of the water coming from the tank and the water going back to it? Where can I find the right prefilter box for my tank?

From,
Doug I. Yorisof

Dear Doug,

There is actually nothing really to a sump at all, they are very basic. All a sump is is just a container in which water flows into, then out again. It is as simple as that.

Usually the sump is located underneth the main display tank and water comes into the sump via gravity feed (water can be pumped to the sump, with the sump then being located above the main tank). It is then pumped back to the main tank (water can be gravity feed back to the main tank, when the sump is located above the main tank).

The pump used with the sump can either be located inside or outside, i.e. external or submerged. In the case of outside you will need to put a hole in the side of the sump and use a bulkhead to seal it. Be careful what submergible pump you use, that it is powerful enough to pump the water back up to the main display tank. Most powerheads are not designed to handle this kind of back pressure that is generated by having a pipe filled with water elevated to a couple of metres.

What is then located within the sump really depends on what you want the sump for. It can contain a protein skimmer, heaters, float valve, mechanical filtration, chemical filtration media, sand bed, live rock etc. By the sound of it you are going for skimmer, heater and may be some chemical media. Might be also a good idea if you put in a float valve, as it is much easier way to control the salinity of the system. To do this place a baffle in the sump between the inlet and outlet. When some of the system water volume disappears then the water level will fall on the outlet side of the sump (or at the inlet of the pump). This is where you have the float valve. The narrower this compartment is, then the larger height change will occur for a given amount of water evaporated, which then means you can control the salinity much more accurately.

The water flowrate into the tank, from the sump, is controlled by the pumping rate of the return pump. The flowrate out of the tank, down to the sump, is controlled once again by the pumping rate of the return pump. Basically if the overflow system is designed correctly it will remove water from the tank as fast as you put it in (within reason). You then just have to get the correctly sized overflow system to suit the return pump you have.

The overflow can either be built in or via a siphon box. I personally prefer the built in ones, but the tank has to be drilled in order to have this. An internal overflow consists of either a baffle separating a compartment form the rest of the tank, or a stand pipe, see the below diagrams. In the case of the baffle, it is set to a height such that it is below the top of the tank. When the water level reaches the top, it then flows over into the compartment formed by the baffle. Inside this compartment is located a pipe through the tank that then goes to the sump. A stand pipe is just a vertical piece of pipe that is just below the water level required. When the water goes above this level, water then flows down through the pipe. This method is a little more dangerous, because it is easier for the pipe to block and cause the tank to overflow.

A siphon box can be used on any tank, and is normally just hung over the side. It consists of two boxes, one on the inside of the tank and the other on the outside, see the diagram below. Joining the two boxes is a U-tube which is filled with water, and both ends are submerged in water. As water flows out of the outside box water is then siphoned through the U-tube from the internal box to fill it back up. And then water flows into the internal box as it is at a lower level than the rest of the water in the tank. Make sure if you use a siphon box it is large enough and rated to the flowrate you are going to run through it. Also you have to be careful that the flow through the siphon tube is fast enough otherwise bubbles accumlate and the siphon will eventually stop. Then you end up with a wet floor.

You have to first work out what flowrate you want to have through the sump, then you can start determining the pump to purchase and the siphon box, or interanl overflow, that will handle that flowrate.

Best of luck with your project.

From,
Marther ReefKeeper

Special Feature

The Spotted Handfish: Back from the Brink

for more information contact , CSIRO Marine Research

There's an unusual little pear-shaped fish that was once common in the Derwent Estuary in Tasmania that may have the dubious honour of being the first species of marine fish to become extinct! It's called the spotted handfish (Brachionichthys hirsutus) and its population, which is known to occur only in the Derwent Estuary, has collapsed over the past decade. It's now listed as endangered and Barry Bruce, a fish biologist from CSIRO's Division of Fisheries, says it's on the way to becoming the first known species of marine fish to have died in recorded human history.

Named after its strange hand-like fins, the spotted handfish grows to about 10cm, is cream in colour with yellow and black spots, and lives by walking along the bottom of the Derwent Estuary.

The spotted handfish was one of the earliest Australian marine fish collected (in the late 1790s) and was first described in 1804. It grows to 150 millimetres in length and is noted for its superb colouring and its tendency to 'walk' over the sea floor on leg-like fins.

Until the mid 1980s, the handfish was common throughout the lower Derwent Estuary and adjoining bays and channels, but has since declined in distribution and abundance. It was protected under State Fisheries Legislation in 1995, and was listed under the Federal Endangered Species Act in 1996.

Alarmingly, there have only been four confirmed records of it in the past five years!

Concerns over dwindling numbers prompted the formation of a 'handfish recovery team', with representatives from CSIRO, the Tasmanian departments of Primary Industry and Fisheries and Environment and Land Management, the University of Tasmania, Environment Australia, the Hobart Ports Corporation and the Tasmanian Conservation Trust.

Jon Bryan, a marine biologist working with the Tasmanian Conservation Trust, believes the handfish may have been the victim of the recent introduction of the north Pacific seastar. Thought to have arrived in the ballast water of trade ships in the mid-1980s, the seastar has eaten out many local shellfish populations. Handfish lay their eggs in a nest on the sea floor and it's believed that the voracious seastars have being making a meal of them as well.

Research on the spotted handfish began with funding from Environment Australia in early 1996. So far it has involved surveys to locate remnants of former handfish populations in the Derwent Estuary, and monitoring of these colonies to study its biology and habitat. Captive husbandry techniques have also been developed in collaboration with the Tasmanian Department of Primary Industries and Fisheries at Taroona.

The goals of the captive breeding program have been to gather further information on the reproductive biology of spotted handfish, as well as to provide an insurance policy should the species continue to decline in the wild, or should reintroduction be required.

Bruce says the handfish has turned out to be an ideal species to work with. They are small, slow moving, and recognisable individually by their unique spotted patterns. This enables easy monitoring of individual growth rates, movement patterns and estimates of population size and age structure.

It is now known that spotted handfish have a low breeding capacity, the female laying only 80-250 very large eggs which are held together by threads and generally attached to the seafloor. The female guards the egg mass which takes six to seven weeks to hatch and is highly susceptible to disturbance.

Despite these difficulties, Bruce and his colleague Mark Green have produced for the first time the right conditions for spawning and rearing of juveniles in artificial tanks. They have bred 35 juveniles from two adult pairs at the Tasmanian Department of Primary Industry and Fisheries Aquaculture facilities at Taroona.

'Although there are still many gaps in our understanding of the spotted handfish and what affects them, the information we have gathered to date has now been used to develop a recovery plan for them,' Bruce says.

"We believe we now have the techniques to proceed with developing a larger-scale breeding program for this and other related handfish species if required," said Barry Bruce, a biologist at CSIRO's Division of Marine Research in Hobart. "The next step is to develop a plan to guarantee the recovery of this species," he said. Mr Bruce, who leads the Environment Australia (Commonwealth Endangered Species Program) and CSIRO-funded research project, said the breeding results are an especially significant milestone in the International Year of the Ocean.

The plan includes the following strategies:

• establish the biological characteristics affecting the dynamics of handfish colonies and their response to changes in the environment;
• establish a way of assessing population size and stability;
• investigate causes of the species' decline;
• develop a population response model to assess timeframes and the progress of recovery and the implications of population size, and to identify and reduce major uncertainties in the recovery process; and
• take immediate steps to enhance spawning areas, further develop captive breeding techniques and trial reintroductions.

'We hope that with the collaboration of all the groups involved, the handfish will be around for a long time to come,' Bruce says.

You Wouldn't Believe It!

.... cyanobacteria are the most primitive organisms known to have a daily cycle of gene activity. Even without light, they continue to switch on genes for photosynthesis during the day.

.... even though sting rays own skeleton is made of soft cartilage they can crush mussel and snail shells in their jaws. This is due to the presence of mineralised struts that act as reinforcements. Hollow columns of mineralised cartilage run through the jaws of the cownose ray, Rhinoptera bonasus, supporting its tooth plates. The jaw is further stiffened by a coating of calcified cartilage, and as a result can exert a force equivalent to a 25 kilogram weight sitting on your hand.

Bereavement Notices

Thankfully, nothing to mourn this month.

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