Recent experiments conducted at the Australian Institute of Marine Science (AIMS) produced striking results, showing for the first time that corals hosting a single type of zooxanthellae can have different levels of thermal tolerance – a feature that was only known previously for corals with a mix of zooxanthellae.

Zooxanthellae are single-celled plants that live in the tissues of animals. They are dinoflagellates, a group of microscopic plants which are usually found swimming and floating in the sea. Organisms which live like this are called plankton, and those that are plants are called phytoplankton. Like most plants, phytoplankton are able to convert the sun’s energy into food through a process called photosythesis, so to survive they are only found in the upper layers of the sea and lakes where sunlight can penetrate.

Zooxanthellae are best known for their role in the life of reef-forming corals. In tropical waters almost all coral animals contain a colony of zooxanthellae. Without these symbiotic plants, the coral animals would be unable to obtain enough nutrients to build their calcium carbonate skeletons, which accumulate to form the vast coral reefs of the tropics.

Cnidarians (corals, soft-corals, sea anemones, gorgonians etc) are the most well-known animals containing symbiotic zooxanthellae, but they are also found in other invertebrates such as the Giant Clams (Tridacna) and many nudibranchs. Just as in their free-living relatives, zooxanthellae need to live in the sunlight, so they are usually found in those parts of animals, such as the skin, which are in the sunlight.
Rising ocean temperatures can lead to the loss of zooxanthellae from the coral host, as a consequence the coral loses its tissue colour and its primary source of energy, a process known as ‘coral bleaching’. Globally, coral bleaching has led to significant loss of coral, and with rising ocean temperatures, poses a major threat to coral reefs.

It was previously known that corals hosting more than one type of zooxanthellae could better cope with temperature changes by favouring types of zooxanthellae that have greater thermal tolerance. However, until now it was not known if corals hosting a single type of zooxanthellae could have different levels of thermal tolerance.

Results recently published in the scientific journal, Nature Climate Change, showed corals that only host a single type of zooxanthellae may in fact differ in their thermal tolerance. This finding is important because many species of coral are dominated by a single type of zooxanthellae.

PhD student, Ms Emily Howells from the Australian Research Council Centre of Excellence for Coral Reef Studies (CoECRS) at James Cook University, Townsville, together with scientists from AIMS and CoECRS, collected two populations of a single type of zooxanthellae (known as C1) from two locations on the Great Barrier Reef. The population collected from Magnetic Island near Townsville experiences average ocean temperatures 2°C higher than the population collected from the Whitsunday Islands. In experiments at AIMS, young corals were treated with one or other of the two different populations of zooxanthellae, and exposed to elevated water temperatures, as might occur during bleaching events.

The results were striking. Corals with zooxanthellae from the warmer region coped well with higher temperatures, staying healthy and growing rapidly, whilst corals with zooxanthellae from the cooler region suffered severe bleaching (loss of the zooxanthellae) and actually reduced in size as they partly died off.

Madeleine van Oppen, ARC Future Fellow at AIMS, says the research results will likely have a major impact on the field, as until now corals associating with the same type of zooxanthellae have been viewed as physiologically similar, irrespective of their geographical location.

“Our research suggests that populations of a single type of zooxanthellae have adapted to local conditions as can be seen from the remarkably different results of the two populations used in this study. If zooxanthellae populations are able to further adapt to increases in temperature at the pace at which oceans warm, they may assist corals to increase their thermal tolerance and survive into the future.” says Emily Howells.

“However, we do not yet know how fast zooxanthellae can adapt, highlighting an important area of future research,” says Bette Willis, Professor from the CoECRS at James Cook University.

Research at AIMS is therefore currently assessing whether zooxanthellae can continue to adapt to increasing temperatures and at what rate. This work in progress will provide insights into the capacity of zooxanthellae to adapt to future climate change.

Acropora Eating Flatworms or AEFW are flatworms who live as parasites on Acropora corals. In my experiences at least two different types of flatworm seem to affect our Acroporids although others probably exist. I’m not sure if the two types I have dealt with are two different species, or the same species exhibiting two different types of behavior. Of these two types, one seems to be a rather benign species that seems to do harm only when present in large numbers. This flatworm acts as an irritant and the corals hosting it keep their polyps withdrawn a majority of the time. I have never observed any tissue recession, bite marks or egg masses with this particular flatworm. On the other hand there are the larger, more aggressive AEFW that produce a lot of egg clusters and tend to consume the Acropora until it starts to STN at the base caused by stress.
To my knowledge, no in-tank treatment exists that positively eliminates these flatworms and harms nothing else.

The first thing is to find out if your corals are infected and to what scale. Are the colonies full of AEFW, or are there just a few on some colonies. That’s why you have to start with observing the corals closely. Important things to look at are the following;
Does the colonies still have good colors? Infected colonies have a pale color most of the time, without a rich color on base and tips. Most of the time growth is lacking so the tips stop growing and the often distinctive color of the growth-tips disappear. This brings me to the next question.
Does the colony still show growth? Infected colonies often show no growth because they need a lot of energy to repair themselves from the damage that has been done by the Flatworms.
Does the colony show necroses from the bottom up (STN)? This is also one of the signs of AEFW.

If you notice one of these issues and you are sure other factors can’t be an issue (flow, water parameters, fish) the best thing to be absolutely sure you have AEFW in your tank is to dip the corals in TLF Revive Coral Cleaner. I prefer revive over Lugol based products like Tropic Marin Pro Coral Cure or other substances like Levamisole because it is far less harsh on corals.

If you performing a dip following the instructions of the product you will or will not notice “flakes” coming of the colony. These are stunned AEFW, curling up and losing grip on the coral tissue.
Sometimes you will also notice beige-brown egg-clusters on the (dead) base of the colonies. These are the eggs of the AEFW and have to be scraped of completely before treatment. On the base you sometimes notice small “bite-marks”, caused by AEFW eating away coral tissue.

The treatment procedure:

This procedure is based on an out of tank treatment with TLF Coral Clean Revive.

Set up a quarantine tank with decent flow, light and heating. Other equipment isn’t necessary because water changes (with tankwater!) can be done twice a week to keep the parameters in check. This have to be repeated every week for four weeks.

1. Calculate the amount of Coral Clean Revive you need for the bucket you dip the corals in.
2. Regularly check the corals for their condition during the treatment.
3. After 10-15 minutes, gently blow off the corals to remove any possible attached AEFW. Use a small powerhead for this.
4. Inspect all the corals very well for egg clusters, and scrape them off.
5. Empty the quarantine tank between every (weekly) dip and clean it out very well.
6. Fill the quarantine tank with aquarium water, to prevent further stress, and place the corals back.
7. Repeat weekly, four times until no AEFW or eggs are found anymore.

Quarantine during process of dipping and cleaning the Quarantine tank

Next question, how to prevent future infections and how to keep population in control in case I miss just one of these buggers? There are a few answers to these questions. The first one may be simple, but is is the most important; quarantine! It is useless to dip, treat and quarantine the whole tank following with introducing new corals without giving them the same treatment. Sooner or later you will reintroduce AEFW back into your tank.
Many aquarists have the mistaken idea that you have to spend a lot of money on an elaborate quarantine system. A quarantine system can be a simple 20-gallon tank with a powerhead and a dual PC bulb or T5 bulb. Use water from your display tank for initial setup and water changes. Keep the coral in quarantine for at least one or two weeks. During this quarantine period do a couple of investigative dips with your dip of choice. I would suggest to use Coral Clean Revive because in my experience it is a lot less aggressive towards the corals then Iodine-based dips (like TMPCC). A close inspection with a magnifying glass can also expose some unwanted guests.

Corals just after treatment in Quarantine tank

In case you want to prevent a large outbreak in the future or just for peace of mind; Introduce natural predators of AEFW. There is a lot of debate if Wrasses really can prevent a (large) outbreak, but there are numerous observations known that they really can make a change. Of course (over)fed fish will always choose for “fast-food” (the food we give them). Here’s a list of wrasses you can introduce in your reef to control an outbreak.

Halichoeres Leucoxanthus

Halichoeres Melanurus

Pseudocheilinus Octotaenia

Halichoeres Radiatus, Terminal Phase

Pseudocheilinus Hexataenia

Halichoeres Garnoti, Juvenile

]]> http://www.leonardosreef.com/2012/01/aefw-treatment-how-to-get-rid-of-them/feed/ 0 http://www.leonardosreef.com/2012/01/semporna-borneo-malaysia-may-have-the-worlds-highest-marine-biodiversity/ http://www.leonardosreef.com/2012/01/semporna-borneo-malaysia-may-have-the-worlds-highest-marine-biodiversity/#comments Mon, 16 Jan 2012 12:04:47 +0000 Leonardo http://www.leonardosreef.com/?p=1702

The preliminary results of the Semporna Marine Ecological Expedition (December 2010) indicate that Semporna may have the world’s highest marine biodiversity. The expedition yielded a record number of 43 species of mushroom corals. Furthermore, some new species were discovered, among which at least two shrimps and possibly a number of gall crabs.

The health of the reefs was judged to be relatively poor: 36% of the transects had fair, another 36% had poor live coral cover. Eighteen scientists from Malaysia, the Netherlands and the USA spent three weeks examining the reefs of Semporna, Sabah, Malaysia, situated at the apex of the Coral Triangle. A biodiversity team documented the species richness for mushroom corals, reef fish, shrimps, gall crabs, ovulid snails, and algae. A reef status team documented the health of the coral reefs.

Mushroom corals are a family of corals of which most species live freely on the sea bed, from the shallow reef flat down to the sandy reef base. The expedition documented a record number of 43 species of mushroom corals in Semporna. The previous highest recorded richness of this family was 40 species at several sites in Indonesia and Papua New Guinea. “Mushroom corals can be used as a proxy for other coral richness. Where we find high richness of mushroom corals, we usually find extremely high richness of other corals,” says Dr Bert Hoeksema, Head of Department of Marine Zoology, NCB Naturalis. Hoeksema was leader of the biodiversity team. Team member Dr Charles Fransen discovered two new shrimp species and PhD student Sancia van der Meij found at least one gall crab species new to science.

The count of fish species clearly demonstrates that Semporna is one of the richest areas within the Coral Triangle. Dr Kent Carpenter, Professor at Department of Biological Sciences, Old Dominion University states, “At some of the more diverse reefs, fish species counts rivalled the highest counts that the fish team found in the Philippines and were greater than what they have encountered in Indonesia.” The fish team encountered 844 species of fish in Semporna.

The coral reef status team used a modified ReefCheck methodology to assess the health of the reefs. 12 kilometres of transects were laid in the course of 60 dives. The preliminary results show that the reef status ranged from poor to excellent condition. 5% of the transects had “excellent” live coral cover, 23% had “good,” 36% had “fair,” and another 36% had “poor” live coral cover. Signs of coral bleaching and suspected coral disease were observed at various sites. While Semporna has several sites with good coral cover, nearly all sites showed significant human impacts including fish bombs, discarded fishing gear, and solid waste.

With the expedition’s conclusions that the coral reef diversity is extremely high, while the health of the reefs is relatively poor, a good basis can be provided for sustainable management of the reefs of Semporna. Not only is Semporna a world class diving destination, it may well be one of the Coral Triangle’s top hotspots for marine biodiversity, and hence, the world’s. Many thousands of local people also rely on these rich reefs for their livelihoods and income.

Source: NCB Naturalis. “Semporna area on island of Borneo, Malaysia, may have richest marine biodiversity in the world.” ScienceDaily, 23 Feb. 2011. Web. 16 Jan. 2012.

Related posts:

1. Strong Links Between Corals Reefs Key to Preserving Fish and Marine Resources
2. Reefs have been Successful in Surviving Large Environmental Disturbances
3. Coral Reefs Create Clouds to Control the Climate

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An international scientific team has shown that strong links between the corals reefs of the south China sea, West Pacific and Coral Triangle hold the key to preserving fish and marine resources in the Asia-Pacific region.

Research by Dr Johnathan Kool of the ARC Centre of Excellence for Coral Reef Studies and James Cook University, and his colleagues, has established that the richest marine region on Earth — the Coral Triangle between Indonesia, Malaysia and the Philippines — depends vitally for its diversity and resilience on coral and fish larvae swept in from the South China Sea and Solomon Islands.

“The currents go in various directions, but the prevailing direction is from east to west, and this carries coral spawn and fish larvae from areas such as round the Spratly Islands in the South China Sea and the Solomons/Papua New Guinea,” he explains.

“Maintaining the network of links between reefs allowing larvae to flow between them and re-stock depleted areas, is key to saving coral ecosystems threatened by human pressure and climate change.

“The Coral Triangle is home to more than one third of all the world’s coral reefs, including over 600 different species of reef-building coral and 3,000 species of reef fish. These coral ecosystems provide food and income for more than 100 million people working in marine based industries throughout the region,” Dr Kool explains.

“Knowing where coral spawn comes from is vital to managing our reefs successfully. Even though coral reef communities may not be connected directly to one another, reefs on the edge of the Coral Triangle have the potential to contribute significant amounts of genetic diversity throughout the region,” says Dr Kool.

He argues that recent evidence showing the region’s biology is closely inter-connected suggests it is in the interests of all Asia-Pacific littoral countries to work together more closely to protect it: “The science shows the region’s natural resources are closely interconnected. Nations need to co-operate to look after them — and that begins with recognising the resources are at risk and that collective action is needed to protect them.

Six nations within the Coral Triangle, (Indonesia, the Philippines, Malaysia, Papua New Guinea, The Solomon Islands and Timor L’Este) are now working together to strengthen coral reef governance and management, under an arrangement known as the Coral Triangle Initiative.

The paper “Connectivity and the development of population genetic structure in Indo-West Pacific coral reef communities” by Johnathan T. Kool, Claire B. Paris, Paul H. Barber and Robert K. Cowen appears in a recent issue of the journal Global Ecology and Biogeography.

Source: ARC Centre of Excellence in Coral Reef Studies. “Coral ‘network’ can protect Asia-Pacific fish stocks, study suggests.” ScienceDaily, 22 Feb. 2011. Web. 16 Jan. 2012.

Related posts:

1. Semporna (Borneo, Malaysia) May Have the World’s Highest Marine Biodiversity
2. Reefs have been Successful in Surviving Large Environmental Disturbances
3. Warmer Seas may Prevent Coral Reefs from Producing Clouds

Coral reefs are extremely diverse ecosystems that support enormous biodiversity. But they are at risk. Carbon dioxide emissions are acidifying the ocean, threatening reefs and other marine organisms. New research led by Carnegie’s Kenneth Schneider analyzed the role of sea cucumbers in portions of the Great Barrier Reef and determined that their dietary process of dissolving calcium carbonate (CaCO₃) from the surrounding reef accounts for about half of at the total nighttime dissolution for the reef.

Coral reefs are among the most diverse ecosystems on the planet, second only to tropical rain forests. Bird’s nest coral (Seriatopora hystrix) is common throughout the Indo-Pacific and is able to live across a range of depths. However, there is little gene flow between the coral populations at each depth and even the algal endosymbionts (Symbiodinium), which provide energy for the corals to survive, are genetically different across habitats.

New research published in BioMed Central’s open access journal BMC Evolutionary Biology used genetic and photosynthetic analyses to demonstrate that these genetic differences reflect adaptations to the different environmental conditions encountered at different depths.
A team of researchers from the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland looked at coral populations from three habitats on coral reefs: the sheltered back reef (Back Reef), the wave-exposed top of the reef slope (Upper Slope) and the dimly lit deeps (Deep Slope). Despite the fact that corals in the Deep Slope habitat only receive a fraction of the light available in shallow habitats (about 10 times less), the coral S. hystrix was found to be far more abundant at these depths and was also observed to grow faster. Transplantation of coral fragments to different habitats did not alter the algae-host symbiosis. Dr. Sophie Dove explained, “The corals we looked at exhibited distinct physiological strategies — while normally corals are dependent on light for their energy requirements, the deep corals, appeared to have adapted to low light conditions by having an increased capacity to exploit nutrients and plankton.”
Dr Pim Bongaerts, lead author of the paper, continued, “The different selective pressures across reef environments pose an ecological barrier to migration and further promote genetic divergence of these coral populations by limiting the extent of interbreeding. This case study of S. hystrix clearly shows how ecological processes of selection can play an important role in the diversification of corals.”

Related posts:

1. Coral Reefs Create Clouds to Control the Climate
2. Warmer Seas may Prevent Coral Reefs from Producing Clouds
3. Great Barrier Reef Dissolved by Sea Cucumbers?

After months of planning, the new tank has been delivered in my new apartment! I will give a short introduction of the idea behind this tank.

The new tank -Apogon Reef- will be Apogon dominated. That means +75 Apogon, several species.
Not too many, large Acropora will provide shelter for the very high flow (2x 6301 and Tunze Wavebox).
The Apogons (and the corals indirectly) will be fed from dusk till dawn, many automated feedings in small amounts, to mimic their natural feeding pattern.

A BB setup allows me to use high flow and heavy feeding.

Livestock:

60 Apogon Leptacanthus
20 Apogon margaritophorus
1 Pseudocheilinus hexataenia
1 Salarias Fasciatus
1 Acanthurus Triostegus

Some other fish may be added later on. For example some Wrasse species.

Info about the tank and equipment:

The dimensions of the tank are: 43″ x 34″ x 22″ high. The tank alone, without sump, is 135 Gallon. There is an external overflow on the right side, so the tank can sit flush to the back wall. All edges are polished.

Hardware:

14 x 39 watt T5 using ATI Sunpower Pendants and ATI bulbs
LED Supplement (CREE XP-E Royal Blue, Blue and Cool White)
2x Tunze 6205 on multicontroller 2x Tunze 6301 on multicontroller
Tunze Wavebox
Eheim 1262 Return Pump
Grotech TEC III Controller for Balling+ Trace Elements

And the first pictures of the tank! The Tempex under the tank will be hidden with a decorative strip. Suggestions and comments are well appreciated!

Please check back soon for more updates!

I will use some hardware from the previous setup, plus some new equipment:

14 x T5 ATI Sunpower Pendants
LED Supplement (CREE XP-E Royal Blue, Blue and Cool White)
2x Tunze 6205 on multicontroller
Tunze Wavebox
Eheim 1262 Return Pump
Grotech TEC III Controller for Balling+ Trace Elements

The tank will be SPS dominated with some mixed LPS. Dominant fish will be Apogon Species.

60 Apogon Leptacanthus
20 Apogon margaritophorus

1 Pseudocheilinus hexataenia
1 Salarias Fasciatus

According to the builder the tank will be ready next week, I will have photo’s when it’s delivered!

Part two of the trip to China and Hong Kong, with some more photo’s of the fish I saw in HK. Like I said before, all the fish were disease-free and in good condition. The equipment was well taken care of. Maybe some of you think the tanks these fish are in are too small, and I tend to agree with that. But take into account the turnover rate of the stores are quite high, and these fish aren’t in these tanks for a long time, only for display when the stores are open.

Pygoplites Diacanthus

Pomacanthus Imperator Juv and Adult

Paracanthurus Hepatus with Zanclus Comutus and Forcipiger Flavissimus

Acanthurus Japonicus and Zebrasoma Flavescens together with a
Pomacanthus Imperator

Related posts:

1. The not so Local Fish Store in Hong Kong SAR

The most striking for me was the excellent condition of the fish and coral, in 通菜街 and everywhere else. Everything looked very well taken care of and healthy. The aquariums were clean, well equiped with sufficient flow, cooling  and light. Nothing close to the small fish in bags that you hear of, at least not in the saltwater stores.

These photo’s are taken in Fish-Street and in stores in other parts of Hong Kong. Most of the corals are wildcap Australian corals in pristine condition. Especially the larger Acropora Millepora Tables and the deepwater species were really breathtaking.

Please come back soon for part 2, with more fish and equipment photos.

Related posts:

1. Hong Kong 通菜街, part 2