Experimental setups, college rooms, a handful of aquarists and marine biologists, and a bright Italian sun; last May, the CORALZOO training workshop “Working with Aquarium Corals” was held in Genova, Italy. From May 12^th to 15^th, aquarists from several European zoos and public aquaria gathered at the Acquario di Genova, to learn about the latest coral husbandry techniques. This training was part of the 4-year EU-funded collaborative research project CORALZOO, which aims to optimise the sustainable breeding and husbandry of captive stony corals through scientific research. Now it's up to the aquarists to implement their newfound knowledge of coral husbandry in their aquarium systems, which hopefully will decrease demand for wild-caught coral specimens.

Figure 1: The CORALZOO staff and participants of the CORALZOO workshop at the Acquario di Genova, Italy (photograph: Shai Shafir).

The aquaculture of (stony) corals has been an emerging practice over the last decade, both in private and professional aquaria, and is now becoming increasingly important. Coral reefs worldwide are faced with pollution, overfishing, habitat destruction and climate change pressures such as rising sea temperatures and ocean acidification. Roughly 70% of these delicate ecosystems has disappeared during the last century. These biotopes are of great economical and ecological importance, and many governments have launched projects to counteract their demise.

Another disturbance which is currently aggravating coral reef decline is the overcollection of live corals for the commercial aquarium trade. According to a recent UNEP-WCMC report, only 1% of the currently traded corals originates from aquaculture or mariculture. CORALZOO was launched in 2005, as an attempt to stimulate sustainable coral aquaculture by zoos and public aquaria by providing science-based optimisation tools for coral breeding and husbandry.

Figure 2: Ronald Osinga, CORALZOO project leader, discusses techniques for measuring coral growth rates during a three-day workshop in Genova, Italy (photograph: Tim Wijgerde).

Next to developing breeding and husbandry tools, training of zoo and aquarium staff was one the main goals of CORALZOO. This objective was addressed by organising a workshop of several days, during which scientific results were disseminated by lectures and practicals. This workshop was open to staff from all EAZA (European Association for Zoos and Aquaria) institutions. The participants were all familiar or experienced with coral handling and husbandry, which is why the workshop focused on more advanced topics.

"Next to developing breeding and husbandry tools, training of zoo and aquarium staff was one the main goals of CORALZOO."

The workshop

During three days of training, aquarists were presented with the various aspects of coral husbandry. In the morning, different topics were addressed by lectures, which were followed by hands-on practical training in the afternoon. These topics included general coral biology, colony morphology and fragmentation, sexual reproduction, nutrition, disease diagnostics and treatment, transportation and growth determination.

Figure 3: Participants taking swabs of coral mucus for microbiological analysis. This procedure allows for detection of harmful coral bacteria (photograph: Shai Shafir).

The workshop started with an introduction to coral biology and reef restoration. After this opening session, the participants were shown how coral growth may be simulated by mathematical models, which serve a useful educational purpose. Next, an overview of coral nutrition was presented after which several suggestions for coral feeds were discussed. This included both ecological and economical considerations, as the aquaculture of any species comes with a certain price tag.

"As a participant I found it very informative, well organised and I feel I have acquired new knowledge of coral husbandry" - Jamie Craggs, Horniman Museum and Gardens, London

Lectures about diagnosing coral diseases and parasites followed, after which the afternoon was used to put the acquired knowledge into practice. These practicals focused on determining prey clearance rates by coral polyps, working with a diagnostic kit for detecting harmful coral bacteria and "reading" a coral's health status by careful observation.

Figure 4: Jamie Craggs from Horniman Museum and Gardens determines how long it takes for a stony coral to consume a batch of Artemia nauplii. CORALZOO studies have shown that nutrition is vital for optimal coral growth (photograph: Tim Wijgerde).

On the following day, other important aspects of coral breeding and husbandry were addressed, such as fragmenting and transporting colonies, sexual reproduction (larvae release, collection and settlement) and determining colony size. The last day dealt with important aquarium parameters such as light and water flow. 

"The most important thing this workshop achieved for me is that every time I close my eyes now, I find myself thinking about coral husbandry!" - Pablo Montoto Gaser, Zoo Aquarium de Madrid

As these workshops are quite unique in the field of aquariology, the organising committee was keen to receive feedback from the participants. The first reactions were very positive. Jamie Craggs from Horniman Museum and Gardens, London: 'as a participant I found it very informative, well organised and I feel I have acquired new knowledge of coral husbandry. The team at Acquario di Genova made me feel welcome.'

Figure 5: Larvae of Favia fragum, a brooding coral species, swimming in a drop of water. Participants learned how to handle these larvae for rearing new colonies. Sexual reproduction is a  relatively recent yet important field within coral aquaculture (photograph: Tim Wijgerde).

According to Pablo Montoto Gaser from Zoo Aquarium de Madrid, more basic, practical aspects should be covered as well during a follow-up workshop. 'I found the workshop to be extremely interesting, inspiring and really well organised. I think it would be a good idea to include practical sessions such as aquascaping, because what we do is displaying corals. I guess for myself, the most important thing this workshop achieved is that every time I close my eyes now, I find myself thinking about coral husbandry!' Max Janse, curator of Burgers' Ocean, Arnhem and one of the workshop trainers, agrees with the importance of organising a second workshop in the near future: 'I also found it very interesting, and what I think was powerful in CORALZOO and in the workshop as well is the networking and open communication. We can all learn so much from each other. Topics for a follow-up workshop could be aquascaping, fish health monitoring, fish disease treatment, and water quality monitoring.'

A Book of Protocols

During their training, the aquarists worked with a test version of a protocol book entitled Working with aquarium corals - A Book of Protocols for the Breeding and Husbandry of Scleractinian Corals. This book contains numerous protocols for coral husbandry, and was presented at the start of the workshop as a novel tool for professional aquarists to optimize their coral husbandry practices. This manuscript is a compendium of four years of CORALZOO research, and contains practical guidelines and protocols for the successful aquaculture of stony corals. During the workshop, some of the available protocols in the book were used by the participants to evaluate their practical nature.

The future

Later this year, a final version of the Book of Protocols will be issued under auspices of EAZA (European Association for Zoos and Aquaria), which will be made available to all EAZA-associated zoos and public aquaria. Next to this, a digital version will be made available publicly on the CORALZOO-website (www.coralzoo.org). During the following years, this digital version will be expanded by new protocols, submitted by professional aquarists. The addition of these peer-reviewed protocols will serve to keep the book up-to-date, which will make the website a knowledge repository for the professional marine aquarium field. This updating process will be executed under auspices of the Coral Aquatic Support Group, part of  the Fish and Aquatic Invertebrates Taxon Advisory Group (FAITAG) of EAZA. In conclusion, the CORALZOO-project, including the Training Workshop and Book of Protocols, has contributed significantly to the optimisation of sustainable coral aquaculture and will serve as a blueprint for future collaboration. As Ronald Osinga, CORALZOO project leader states: 'I think we can look back at four successful years, and now it's up to all of us to continue this sustainable approach to coral aquaculture.'

"I think we can look back at four successful years, and now it's up to all of us to continue this sustainable approach to coral aquaculture" - Dr. Ronald Osinga, CORALZOO project leader

Figure 6: Max Janse, curator of Burgers' Ocean, discusses coral parasite treatment. Exchange of knowledge amongst zoos and public aquaria is vital to the establishment of successful breeding programmes, so too for corals (photograph: Shai Shafir).

For more information about CORALZOO, please visit the official website, www.coralzoo.org.

Acknowledgements

The author wishes to thank the CORALZOO and Acquario di Genova staff, and Ronald Osinga and Rachel Jones for critically evaluating and improving the manuscript.