Coral PropagationWill Ewing

Introduction

Introduction

• This project focused on the growth rates of Nephthea sp., Montipora digitata, and Duncanopsammia axifuga in the 50 gallon tank

• I looked at variables such as salinity, temperature, calcium, and pH

Introduction

• What is Coral Propagation?– It is the process of taking corals, referred to as the mother

colony, and propagating them or making daughter colonies from either fragments, that were broken off from the mother coral, or from polyps that grew out from the mother

• What are some techniques that are used in coral propagation?– It depends on the coral, whether it is an sps (small polyp stony),

lps (large polyp stony), or soft coral– Everything from a scalpel to a saw can be used in cutting the

corals– Everything from epoxy and superglue to rubber bands and zip

ties can be used for fixing the coral to a base– http://www.youtube.com/watch?v=0bc0BsNp3ic

•Ocean Frontiers, “Coral Spawning” 2011 http://www.oceanfrontiers.com/what-to-see/coral-spawning.html •Foster & Smith Educational Staff., “How to Propagate Coral Frags at Home,” http://www.drsfostersmith.com/pic/article.cfm?aid=944

Introduction• Nephthea sp.– Nephthea is a soft coral,

meaning it has no hard skeleton. Instead it has sclerites which are hard calcareous plaques found in the tissue of the animal. This deters other animals from eating it.

– – Because Nephthea sp. Does not need a skeleton, it can grow at a much faster rate than those corals that have a calcium skeleton

• www.Liveaquaria.com

Introduction• Montipora digitata– This coral is a small polyp

stony (sps) coral. This means that there are hundreds of little tiny polyps that line the exterior of the coral. When fully extended these polyps give the coral a velvet look. When retracted the coral looks hard and smooth. These corals are known to grow at a fast rate for stony corals.

• www.Liveaquaria.com

Introduction• Duncanopsammia axifuga– The Duncanopsammia

axifuga or Duncan coral is a large polyp stony (lps) coral. This is similar to the Montipora digitata except that its polyps are much bigger in size. Its polyps rang in anywhere form ½ to 3 ½ inches in diameter and resemble that of a sea anemone

– The Duncan coral is easy to care for and grows at a moderate rate

• www.Liveaquaria.com

Introduction

• Research questions– What corals provide the best profit? (price vs grow

rate)– What, if any, corals help each other grow? What

corals inhibit the growth of other corals?– Do fish in a tank affect coral growth? If so is it

harmful or beneficial? – Does artificial light increase or decrease coral

growth when compared to natural light?– Does the coral to water ratio affect growth, if so

what is the optimal ratio?

Introduction

• Hypothesis– The coral species that grows fastest and produces

more products, or fragments of coral that can be sold, will result in a greater profit than the coral that grows slower and produces fewer products.

Methods

Methods• For this experiment I compared

three different types of coral: sps, lps, and soft coral. I began by collecting my initial specimens and fragging them into roughly equal sizes (about 2”-3”). I then placed them in the 50 gallon tank according to their light and water flow needs and waited.

• I checked the salinity and temperature daily and the calcium and pH levels weekly• The goal was to try and maintain a stable tank environment and observe which corals thrived and which did not. • Harris, Lee E., “Artificial Reefs for Ecosystem Restoration and Coastal Erosion Protection with Aquaculture and Recreational Amenities” 2006, (Paper)

Methods• Initial numbers of corals

– The Nephthea and Montipora digitata were initially around 2 to 3 inches in height each with 3 to 5 branches

– The Duncan coral had initially 12 polyps which I divided into 9 separate frags

– The Montipora digitata slowly bleached over the coarse of about 2 ½ months, and became so weak that they all snapped

– The Nephthea grew very rapidly for the first few months, however I began to notice around February, after reaching 4 ½ inches, the growth rate decreased dramatically. It still grew in girth but very little in height.

– The Duncan coral grew incredibly well, much better then expected. After a month an average of 4 new polyps began to appear on each frag. This number then grew to an average of 8 polyps per frag after another month and a half. Quickly the numbers reached to 10 to 12 new polyps per frag.

Results

Results• Research questions

– What corals provide the best profit? (price vs grow rate)• Out of the three that were observed, the Duncan corals are

predicted to provide the best profit– What, if any, corals help each other grow? What corals inhibit

the growth of other corals?• Corals don’t really work together to help each other grow,

but they can be aggressive in inhibiting the growth of others via external digestion. I had to be careful in my placement of the corals so that they would not harm or be harmed by surrounding coral.

– Do fish in a tank affect coral growth? If so is it harmful or beneficial?• Depends on the kind of fish, but generally fish do not

affect coral growth. The only issue that could arise is an overgrowth of algae due to lack of filtrating waste. I only have one fish, an electric blue damsel fish, and it appears to have no effect on the corals

• www.coralreefsystems.org

Results

– Does artificial light increase or decrease coral growth when compared to natural light?• Corals used in the aquarium trade are able to adjust to

the lower light conditions of an aquarium, around 200 (µE/m2/sec). However in the wild, light intensity reaches as high as 2000 (µE/m2/sec). This suggest that the corals are naturally accustom to a wider range of light intensities and might benefit from being exposed to a more natural light cycle. However this is impractical as it leads to a whole slew of problems such as maintaining temperature and keeping the tank clean.

– Does the coral to water ratio affect growth, if so what is the optimal ratio?• No

• Harker, Richard. Shedding Light on the Reef. http://www.fishchannel.com/saltwater-aquariums/aquarium-frontiers/natural-reef-light.aspx

Results

Coral Nephthea sp. Montipora digitata Duncanopsammia axifuga

Initial 1” – 2” 1” – 4” 12 polyps(1” – 1.5” in diameter)

After two months 3” – 4” 1” – 3” (one specimen broke)

About 40 – 45 polyps

After four months 4” – 5” N/A – all specimens broke by this point

About 95 – 105 polyps(3.5” – 4.5” in diameter)

Table 1. Growth of Coral Over Four Months

Results

Results

Initial Duncan frags

Duncan frags after four months

Results• The numbers show clearly that the most productive species of

coral under the conditions of the 50 gallon tank is the Duncanopsammia axifuga

• Its growth rate has continuously increased where as the growth rate of the other two corals decreased.

• The Duncan has also produced the most “product” of the three corals

• The Nephthea comes in second. Its growth rate decreased, however it still grew rather quickly and constantly where as the Montipora digitata actually declined in growth as it began to bleach.

• It is expected that if everything was to be sold as it is currently … (still need to go to Premier Aquatics to get a quote) (earlier in the year the Nephthea sold for about $15 per frag, and this combined with other corals raked in about $400. It can be assumed that the Duncan coral will sell at a range of $15 - $18 per polyp. This would mean that the estimated value of the coral combined is anywhere from $1000 to $1200… we will probably get around $800)

Discussion

Discussion

• Hypothesis– The coral species that grows fastest and produces more

products, or fragments of coral that can be sold, will result in a greater profit than the coral that grows slower and produces fewer products.

• This turned out to be supported by the data, but not in the way I had originally thought. I had assumed that the faster growing coral would be cheaper and the slower growing coral would be more expensive. In a normal case, this would have applied to the Duncan and Nephthea. However the Duncans began to grow faster and faster where as the Nephthea slowed down. In this case the Duncans, which sell at a higher price, grew faster than the Nephthea. One explanation for this is that the environment of the tank was best suited for the Duncan coral as opposed to the other two species.

Discussion

• The tank was constantly at around 76˚F

• Salinity was always around 1.024 – 1.026

• pH was always around 8.2

• Each of these along with the moderate water flow and light intensity, and the placement of the coral, coincide with the Duncan’s perfect living conditions.

• These conditions created an optimal growing environment for the Duncan coral

Discussion• Some challenges to my project– initially how to compare the Duncan coral (a lps) to the

Nephthea sp. and Montipora digitata, both of which are branching small polyp corals

– The breaking of the Montipora digitata specimens

– Invasion of hair algae

Discussion

• Ways to make the research more complete– Extend the length of time, more time will give

more data and a bigger scope on growth rate of the corals

– Increase the number of specimens used to gain a better representation of the average growth rates

– Repeat experiment and compare new results to the prior

Discussion

• The measurements recorded support the concept that the faster growing corals provide the most money. Interestingly the coral that was predicted to grow fastest did not, and the coral predicted to grow the slowest grew the fastest. As a result the Duncan coral, which grew the fastest, is expected to provide the most money in return

Discussion

• Where can we go from here?– To continue this research I could look into

optimum growing environments

–Maybe look at the idea of having separate tanks which are tailored to maximize the growth of specific coral species

– Look into other species to grow

Bibliography– Ocean Frontiers, “Coral Spawning” 2011 http://www.oceanfrontiers.com/what-to-see/coral-

spawning.html – Foster & Smith Educational Staff., “How to Propagate Coral Frags at Home,”

http://www.drsfostersmith.com/pic/article.cfm?aid=944 – www.Liveaquaria.com – Info on corals, how to grow them, compatibilities, and pricing– www.reefcentral.com – Shipping coral, trading, prices, knowledge from aquarium enthusiast– Stansbery, Matthew., “The allure of Chalice Corals,” 2011

http://www.advancedaquarist.com/blog/chalice-corals – Harris, Lee E., “Artificial Reefs for Ecosystem Restoration and Coastal Erosion Protection with

Aquaculture and Recreational Amenities” 2006, (Paper) – note: this paper has several good examples of photographs used to record fragment growth for Staghorn coral

– www.coralreefsystems.org – Discusses how a reef system works and the role of the coral, discusses different aspects of corals such as reproduction and habitats

– Wallace, C.C., “Reproduction, recruitment and fragmentation in nine sympatric species of the coral genus Acropora,” Marine Biology, Vol. 88, 1985, pp 217- 233.

– Saxby, Tracy. Photosynthetic Response of the Coral Montipora digitata to Cold Temperature Stress (Thesis) – Montipora digitata reacts to cold water stress similar to how it reacts to warm water stress, also pre-treating the coral will not build a tolerance to cold water

– Forsman, Zac H., et al., “Investigating fragment size for culturing reef-building corals (Porites Iobata and P. compressa) in ex situ nurseries,” Aquaculture, Vol. 261, 2006, pp 89 – 97

– Harker, Richard. Shedding Light on the Reef. http://www.fishchannel.com/saltwater-aquariums/aquarium-frontiers/natural-reef-light.aspx