It may seem to the hobbyist today, that keeping marine aquariums is a relatively new hobby. Although it is true that the keeping of reef systems which are heavily dominated by colourful sps corals as we see them now is fairly new, the keeping of marine systems dates back further than you might think. The history of humans keeping fish dates back over 4,000 years to the time of the Sumarians who around 2,500BC kept fish in ponds for food, the Egyptians also kept and bred species of ornamental fish for their aesthetic value, but it was not until the 1800′s that aquariums really first started to appear.
In 1842 Dr Johnson reported the first keeping of marine aquaria with various species of Caulerpa and annelid worms, then in 1852 a Mr Goose successfully set up the first public marine aquarium at the Zoological Society of London. This aquarium measured 24 inches in length, 18 inches in width and consisted of a slate floor and Birch corner pillars which had grooves cut in to hold the glass in place. This aquarium was stuffed with countless animals and algae including fish, molluscs, crabs, shrimp, tube worms, anemones, pipefish, starfish, sea urchins and more, over 100 different species of animal and seaweed! This display caused massive interest from the public and huge crowds would gather to marvel at the wonders of the animals that lived at the bottom of the sea. Often these crowds were reportedly so big that it was impossible to actually see the small two foot display. Initially this aquarium was a success but it fell foul to Mr Goose’s enthusiasm to add more and more creatures to it and soon pollution became a problem resulting in a reported ‘foul smell’ emitting from the aquarium. There was no filtration on this aquarium, simply sand on the bottom, rocks and later a pump to push air into the water.
Following the huge interest caused by this aquarium in 1852, aquarium manufacturers quickly sprang up to feed the public interest and so did information on how to keep marine aquaria. In 1857 a book by H. Noel Humphries was published entitled “Ocean Gardens”. This impressive book covered the setting up of an aquarium, detailed sections on various different groups of animals that could be kept and even detailed instructions on how to mix up your own synthetic sea water. In those days filtration equipment simply did not exist but they did try to obtain a balance between the number of animals that they kept and the amount of seaweed to have. The focus was on the level of oxygen that was in the water which they knew was produced by the seaweeds. Water testing was also much simpler in those days, there were no ammonia tests, no electronic probes or monitoring system, their test was simple – the water was either ‘sweet smelling’ or ‘foul smelling’, fortunately for the animals we keep things have progressed since then.
In the 1950′s and 60′s Lee Chinn Eng performed some ground breaking work on what was to be known as the ‘Natural System’ for aquarium filtration. This natural system relied on a sand bed and live rock for biological filtration and it was from this pioneering work that the Jaubert, deep sand bed and Berlin style systems were developed.
In the 1970′s Bruce Carlson reportedly kept and grew the first species of Acropora at the WKK Aquarium in Honolulu, by 1972 there were numerous species of coral that were kept there in open systems that had water pumped from the sea. Some of the first Acropora’s reportedly kept there are still alive at the aquarium today.
The early closed marine aquariums were often a sorry affair, the decoration in them usually consisted of dead, bleached coral skeletons and inappropriate lumps of rock or empty shells, hardly a natural environment for the aquarium inhabitants. Filtration and water quality was also rather less than the high standard that we expect today. Filtration usually consisted of undergravel systems or external canister filters – neither of which catered for the reduction of nitrates. In the late 1970s to early 80′s the vast majority of marine aquariums still used tap water for the mixing of synthetic seawater. Although the first synthetic RO membrane was made in 1959, the portable RO units for the marine hobbyist were not readily available until the late 1980′s. By the 1980′s marine aquariums had long been around in the UK and true reef aquariums had started to appear as well. In 1983 I set up my first marine aquarium which was adapted from a fresh water aquarium and run on undergravel filters, this was not too successful but I quickly progressed! By 1985 I had set up my first true reef aquarium which consisted of Tufa rock, a sump and masses of Caulerpa which enabled me to keep several species of coral including various LPS species.
By the mid to late 1980′s there were several books that had been published on how to keep what were then termed ‘advanced’ reef aquaria including a book by Martin Moe entitled ‘The Marine Aquarium Reference, Systems and Invertebrates’ and was a book that quickly became a bible for many aquarists. By this time we were well on the way to keeping successful closed reef systems. In the late 1980′s and 1990′s much of the talk for aquarium filtration was around wet and dry filters and trickle towers. These were great pieces of kit as they were far more effective at dealing with ammonia and nitrites than their predecessors the undergravel filter and canister filters. What made them much more effective was that oxygen was not a limiting factor. In undergravel filters you could only get so many bacteria colonising the substrate as there was oxygen available to support them. The wet and dry and trickle filters solved this by keeping the filtration media above the water and passing water over a open media such as bioballs. This created an environment for the bacteria where oxygen was not a limiting factor and various manufacturers and ‘scientists’ shouted forth claims of how many more millions of bacteria you could keep per square micrometer than you could with undergravel filters. There was only one problem, these filters did nothing for the conversion of nitrate to free nitrogen gas so there was a surge in the combining of these filters with large Caulerpa beds which would consume the nitrates produced.
Following on from the work of Lee Chinn Eng, in the late 1980′s Dr Jean Jaubert of Nice University developed the plenum system. The plenum system consists of a deep sand bed above a plate which was raised one inch above the base of the aquarium. The plate is made of an open plastic that the water can flow through to the cavity below. The idea behind the plenum system is that areas of low oxygen form in the lower regions of the sand bed and within the cavity under the plate. These areas of low oxygen are the perfect environment for the anaerobic bacteria that reduce nitrate. Combined with a protein skimmer this technique was very effective at maintaining low nutrient conditions in the reef aquarium and was very popular around the world from the 1990′s through to the 21st century.
In the early 1990′s the Berlin System was developed and is probably still the most popular method of maintaining reef aquaria today. The Berlin system relies on live rock and protein skimming as the main methods for maintaining water quality. The use of live rock also introduces to the aquarium a huge variety of flora and fauna which greatly increases the diversity of life and create a more natural environment. This huge diversity of life that comes into our aquariums from the live rock play a large role in maintaining the health of the corals and keeping a healthy balanced system. With an increased understanding of the needs of corals in captivity there has been some great advances in the technology produced especially for reef aquariums. Specialised lighting, filtration equipment, computerised monitoring and dosing systems, in fact just about every device that you could think of for maintaining corals in captivity.
This development of the technology used today has been driven by an ever growing number of people keeping aquaria and the customers demand for better and more advanced equipment for maintaining the perfect reef environment. The growth of the reefkeeping hobby has been dramatic over the last thirty years. The graph in figure 1 shows the increase from 1986 to 1999 in the global trade in live corals. A weight of 0.2kg per piece of coral was given to convert number of pieces traded into tonnes traded.
It is quite clear to see that the increase in the numbers of people keeping reef aquariums has dramatically increased the number of live corals exported around the world. However it is not until you look at the global picture of all corals traded, both live and dead from 1985 to 1997 that you can see a different picture. The graph in figure 2 shows the number of tonnes of live corals traded as well at the total number of tonnes traded incorporating both live and dead corals.
We can see that in previous years the export of live corals for the aquarium industry only made up a tiny fraction of the corals that were exported dead around the world. However since the early 1990′s the global trade in dead corals has dropped dramatically but the trade in live corals has increased rapidly so that by the end of the 1990′s the trade in live corals made up half of all the corals exported.
This increase in the number of corals traded has been mirrored by the increase in the number of people keeping reef aquariums. Advances in equipment, knowledge of corals care requirements and the shortening of transit times for shipping have led to a massive increase in the number of marine aquariums across America and Europe. It was estimated that by around the year 2,000 there were between 1.5 and 2 million marine aquaria kept globally with 600,000 of those being in America. Recent figures indicate that both the number of people keeping marine aquaria and the number of corals being exported is still increasing although not at it’s previous rates. In 2003 it was estimated that the global marine aquarium trade in live animals was worth up to US$330 million with 1,500 tonnes (7.5 million pieces) of hard coral being traded and 18 million pieces of soft coral. It is likely that these figures have increased further still in the last few years.
With the improvements in coral husbandry techniques and the lowering of the prices for setting up and maintaining reef aquaria, more and more people are taking up the hobby. This has been considerably helped along by the rise in popularity of nanoreefs. In previous years it was thought that healthy reef systems could only be achieved by the use of fairly large aquariums and it was recommended that the minimum size for a reef aquarium be around 200 litres or more and that this was needed to ensure a stable environment. Nowadays reef aquariums are getting smaller and smaller and far less expensive. Stunning nanoreef aquariums brimming with colourful sps corals can be set up and maintained in as little as thirty litres of water with a little knowledge and care.
Not only has there been an increase in the number and health of aquariums kept but we have reached a point where we are able to manipulate corals to our benefit. Coral farms are now becoming more common place in the tropics with small cuttings taken from the reefs and being grown up on farms for exporting to the aquarium market. This benefits both the local communities and puts a greater incentive on local communities protecting coral reefs. Aquarists throughout the world are propagating and selling coral cuttings from their own aquariums further reducing the numbers of corals removed from the wild. There has been progress on the captive breeding of fish as well. Although most species are still collected from the wild there is an ever growing list of hundreds of species which have successfully been bred in captivity, and as improvements in live food culture occur, more and more of these species will be bred commercially.
Corals are being further manipulated in aquaria by filtration techniques. Over the last few years the Ultra Low Nutrient System has become popular among some hobbyists. In it’s purest form this filtration and maintenance method results in super low nutrient levels and results in a massive reduction in a corals ability to maintain zooxanthellae, as a result of this the coral grows more slowly and shows more of the underlying colours and less of the brown zooxanthellae.
In the future it is likely that we will see further improvements in the equipment available, greater links with the scientific community will improve our knowledge of the biology of corals and hence their optimal environmental conditions. Further developments in captive fish breeding and coral propagation techniques will lead to more and more species that have not been taken from the wild being available and the industries expertise in many of these fields may in turn, become a great resource for the conservation of the worlds natural reefs.
The burgeoning of this hobby has led us to a place where many of the private individuals have become experts in the husbandry of delicate reef animals. Such is the dedication of the hobbyist that there is now a vast global network of reef keepers who’s knowledge and ability in the husbandry of reef aquaria often surpasses that of public aquaria and academics. However much is still to be learnt, the scientific community and private hobbyists would both benefit by sharing the information that they each hold and hence improve the overall knowledge of coral reefs, both in aquaria and the wild.