Reef Ramblings

The reef aquarium industry comes under threat again as scientists call on the US to stem the ecological impact of trade in coral reef wildlife.

A paper in the journal, Marine Policy, from a team of 18 scientists says that International law has failed to protect coral reefs and tropical fish from being decimated by a growing collectors market, but that U.S. reforms could lead the way in making the trade more responsible, ecologically sustainable, and humane.

Using data from the United Nation’s conservation monitoring program the authors say trade in coral and coral reef species is substantial and growing, removing 30 million fish and 1.5 million live stony corals a year. The aquarium industry targets some 1,500 species of reef fishes. Many die in transit, leading collectors to gather even more animals to compensate for their losses.

“Our actions have a big impact on these coral reef ecosystems, which are already hit hard by global warming, ocean acidification, and over fishing,” said Brian Tissot, lead author and professor of Earth and Environmental Sciences at Washington State University, Vancouver. The result is some species have gone “virtually extinct,” citing as an example the Banggai Cardinalfish, unique to a remote Indonesian archipelago, which has had its numbers reduced and even eliminated through much of its range after it became a popular aquarium fish in the late 1990s.

The paper’s origin goes back to a meeting of more than 40 scientists, NGOs, and policy experts during the 2009 International Marine Conservation Congress. When the Convention on International Trade in Endangered Species (CITES) took no action on key groups of corals this March, concerns grew. Authors include experts from the U.S. Agency for International Development, the National Marine Fisheries Service, Humane Society International, the Pew Environment Group, and the Environmental Defense Fund.

The U.S. accounts for more than half the world trade in live coral, fishes, and invertebrates, the authors recommend using U.S. market power to reduce the trade’s environmental effects. They suggest laws to protect a wider variety of species, enforcement that includes tracking a product’s chain of custody, and reforms in source countries. Also recommended are changes in marketing to promote the sales of species certified as being humane and sustainable. The authors add, “The U.S. should assume its role as an international leader in coral reef conservation and take steps to reform the international trade it drives.”

Tim Hayes

Midland Reefs

2010

The 1^st of June saw the first annual conference of the new coral reef aquarium initiative, the Coral Aquarist Research Network (CARN) take place at the Royal Geographical Society in London.

CARN was formed in October 2009 as a network to foster the exchange of knowledge, expertise, and experience between coral reef researchers and those working in the various fields of aquarium related industries such as suppliers, public aquariums, coral growers, and hobbyists. It is hoped that the creation of this network will provide opportunities for the various coral industries to collaborate with the world class coral and reef biology research community in the UK.

This first conference included presentations that were both research and industry orientated, highlighting the status of knowledge, technology and importantly gaps in our understanding of coral physiology, ecology, transport, growth and sustainable harvesting.

A special issue of the JMBA, one of the UK’s leading marine biology centric journals, will be devoted to the proceedings of the conference.

The day started of with an introduction to the conference by Philippa Mansell from the University of Essex, project manager of CARN.

The conference was split into four sessions of talks, each session based around a theme. Although some of the talks were of a scientific nature the bulk of them were easily accessible to the keen hobbyist. Concluding each session there was a period set aside for questions and answers, enabling conference participants to further exchange information or ask questions clarifying aspects of the presentations.

For the purpose of this article, I’m just going to briefly list the presentations with a few comments on their relevance to the hobbyist.

The session on Coral Eco-physiology was fairly technical, looking at: Mechanisms of thermal induced coral bleaching and the implications for reef community structure ( Dr David Smith, University of Essex), effects of trace metals on reef anthozoan pigmentation (Edward Smith, National Oceanography Centre, Southampton) , and the influence of the light climate on colouration of reef corals (Dr Jörg Wiedenmann, National Oceanography Centre, Southampton). The research being carried out here will have a benefit to hobbyists enabling them to keep bright coloured corals and better maintain their colouration.

The second session, Coral Ecology and Biodiversity, included a fascinating talk on Mushroom corals (Fungiidae) and their associated fauna in the Coral Triangle (Dr Bert Hoeksema, Netherlands Centre for Biodiversity), looking at the various animals that live on or in these popular aquarium corals. The Importance of Symbiodinium diversity: implications for the aquarium trade (Patrick Brading, University of Essex), was about the various species of symbiotic dinoflagellates, the zooxanthellae that live within coral tissue. Environmental influences on coral growth – from Indonesia to the Caribbean (Professor James Crabbe, University of Bedfordshire), gave an insight into how the environment affects the way that corals grow in nature and how this might affect their growth in aquaria.

The session looking at the coral industry and conservation examined issues of conservation, sustainability, and management of resources with presentations on the trade in reef corals (Dr Elizabeth Wood, Marine Conservation Society), the UK trade in ornamental polychaetes or Fan-worms (Joanna Murray, University of Portsmouth), and whether the coral industries can play a role in the future conservation of coral reefs (Philippa Mansell, University of Essex). An important issue, greatly affecting the future of the hobby.

The conference finished of on the subject of aquarium based research and workshops and featured a talk on Coralzoo (Dr Ronald Osinga, Wageningen University), an initiative looking at four years of public aquarium research on stony corals, my own presentation discussing Coral Nutrition in the Captive Environment (Tim Hayes, Midland Reefs), and a report on the 5^th SECORE workshop, a program investigating sexual reproduction in stony corals (Jamie Craggs, Aquarium Curator, Horniman Museum).

CARN is an initiative that welcomes you, the hobbyist, to join in and share your experiences of keeping corals in your reef aquarium. You can do this by going to the CARN website, http://carnuk.org/getinvolved.aspx, there you can share information about the corals and other reef organisms that you’ve kept, with top reef scientists who are very interested in looking at how these fascinating animals fare in the captive environment in comparison to how they live in the wild. For advanced hobbyists it could also offer the opportunity to ask questions of reef scientists based on observations of your reef aquarium.

Together we can take the reef aquarium hobby forward through the exchange of information, perhaps in the process improving long term survivability of reef organisms and the sustainability of the hobby.

Tim Hayes

Midland Reefs

©2010

The Coral Aquarist Research Network (CARN) is holding its 1^st Annual Conference on the 1^st June 2010 at the Royal Geographical Society, London.

CARN, formed in October of last year, was created to facilitate and initiate the exchange of knowledge, expertise and experience between coral reef researchers, coral growers, national and public aquaria, and reef hobbyists. This network is in place to structure opportunities for coral industries such as suppliers and growers to engage with, utilise and collaborate with the world class coral and reef biology research community in the UK.

This first conference will include a number of presentations that are both research and industry orientated highlighting the current status of knowledge, technology and, importantly, gaps in our understanding of coral physiology, ecology, transport, growth and sustainable harvesting.

Indeed, I will be delivering a presentation looking coral nutrition in the captive environment.

This conference provides substantial networking opportunities and a chance to discuss ideas, address queries or simply take interest, and potentially become involved in, impact-led research initiatives from an economic and sustainability perspective as well as from an enhanced coral growth, coral diversity and improved conservation measures viewpoint.

If you think you might have something to contribute (many hobbyists are ahead of educational organizations and public aquaria when it comes to growing corals) or would just like to come along and learn, please get in touch with me ASAP so that I can communicate with the organizers to ensure that name badges are printed, ready for the event.

Oh, and just because it might sound a bit advanced or scientific, please don’t be afraid to come along. I can promise you that there will be accessible content and that it’ll be a great chance to talk with enthusiastic like-minded individuals.

CARN is a Natural Environment Research Council (NERC) funded project, within the the University of Essex’s Coral Reef Research Unit (CRRU).

www.carnuk.org

Tim Hayes

Midland Reefs

©2010

There are reports of extensive warm water coral bleaching in the Andaman Sea.

This is believed to be the worst case of bleaching in Thai waters for 20 years. Coral reefs off Phangnga, Krabi and Phuket, including popular diving sites such as the Similan, Phi Phi and Surin islands have been affected and, according to the Phuket Marine Biological Centre (PMBC), bleaching is likely to extend as far as Satun province, and may worsen if sea temperatures continue to rise. Coral reefs in the Andaman Sea previously suffered severe bleaching in 1991 and 2003.

A bleached coral reef at Koh Aeo in Phuket. PMBC

Bleaching started to occur during April and five percent of the coral reefs so far affected have died. The temperature in the Andaman Sea has been higher than the last two years, staying at around 31-32C, probably because of the late onset of the monsoon over the Bay of Bengal and Andaman Sea. Normally the monsoons arrive during mid-April with the rains bringing a reduction in sea temperature.

The PMBC has been working closely with dive operators, to monitor the coral bleaching situation. The phenomenon is also occurring in the Gulf of Thailand in Rayong province, Somkiat Khokiattiwong, head of the PMBC’s oceanography and environment unit, says Burma and Malaysia could also face the coral bleaching problem in their waters.

The bleached coral reefs may take a long time to recover. The PMBC estimate that coral reefs in shallow waters, depths up to 10m, will take three to four years to recover, whilst deeper reefs will take longer.

The Andaman Sea is one of the Thailand’s most popular diving sites with around 80 sq km of coral reefs. It attracts millions of visitors and divers each year.

For more about the Phuket Marine Biological Center go to the PMBC website.

Tim Hayes

Midland Reefs

May 8, 2010

Over two days, 3 - 4 February 2010, tropical cyclone Oli passed by the west of Tahiti subjecting the islands of Bora Bora, Raiatea-Tahaa, Huahine and Maupiti to waves six to seven meters high accompanied by wind gusting to 170 km/hour. Following this, it was the turn of Tahiti and Moorea followed by the island of Tubuai to undergo the cyclone’s impact, experiencing mean wind speeds of 210 km/hour. This was classed as a severe tropical cyclone, category 4, the second highest storm classification.

Centre National de la Recherché Scientifique, CNRS, the largest governmental research organization in France, has a Coral Observation Department based on Moorea which has been regularly collecting data on coral communities and fish populations in the area. Four days later, after repairing damage to their facilities, they undertook an inventory of the cyclone’s effects after it had passed over two reference sites. Their scientists discovered the extent of the damage to the coral reef, already been made vulnerable by the invasion of a coral predator, was one of almost complete destruction. Their observations revealed that cyclone Oli had flattened the coral population finishing off a reef that was already vulnerable.
The Crown of Thorns Sea Star, Acanthaster planci, notorious for preying on coral, had already nearly wiped out the coral populations on the outer slopes of Moorea. Since the start of an explosion in Acanthaster populations in 2006, the percentages of live coral coverage at 12 meters depth has fallen by around 96 % on the north coast of Moorea, reducing coral cover to roughly 1.0 %. Although this invasion has been a cause for concern, the physical structure of the reefs, particularly the outer slope, the most favourable area for reef growth because of the water’s high level of oxygenation, had been little affected as the skeletons of the dead colonies were still in place, holding out the promise of recovery.

However, once the cyclone had passed, the physical structure of Moorea’s outer slopes, especially the northern side, were found to be seriously and lastingly affected. Comparison of data before and after the cyclone struck reveals a very significant reduction in the relief of the outer slope. The rugosity indices were found to have fallen by 50% at all depths down to 30 meters. Rugosity is an important coral reef parameter that describes the amount of “wrinkling” or roughness of the reef profile. It is an index of substrate complexity. Areas of high complexity are likely to provide more cover for reef fishes and more places of attachment for algae, corals and various sessile invertebrates. A large number of coral colonies previously present were torn off by the wave action and broken up by boulders. The three-dimensional structure of the reef has been badly affected, which may be detrimental to long-term recovery.

Damage to the reef varies with depth:

• From 0 to 6 meters there’s severe destruction. Most of the scattered live colonies being broken off at the base. The area is now totally covered with fine pale yellow algal matting of an algal bloom and there’s no live coral coverage remaining.
• From 6 to 10 meters although many live, branched colonies are damaged their bases are intact, which means recovery may be possible.
• From 10 to 15 meters the flanks of this area are in a critical state of destruction. The large branched colonies, most of which were already dead following Acanthaster predation but intact before the cyclone, are no longer visible, no algal growth is observed.
• From 15 to 30 meters depth there is an abnormal covering of small coral debris, 5 cm on average.
• The populations of fish, molluscs and sea urchins associated with the reefs have also suffered considerably with many shellfish being seen in a state of decomposition between the surface and a depth of 6 meters.

As to the future of the reef, there seem to be two possibilities:

• Either the algae will increase and continue to dominate the system by overgrowing the substrate, leading to the death of the reef, as has happened to many reefs around the world.
• Or the reef will start from scratch recruiting new assemblages of coral from larval settlement resulting in a reef likely to be different from the pre-existing one regards species present, and bio-diversity.

Given that algae are already encroaching on the remains of the reef, I find the second possibility remote, although one can always hope.

Scientists have been monitoring the resilience of these reefs since the1980s. During this period, the reefs have been suffered seven episodes of massive bleaching (1983, 1987, 1991, 1994, 2002, 2003 and 2007), several cyclones, and two outbreaks of Acanthaster planci, the starfish that preys on coral.

Although in the past these reefs have always recovered, this recent series of stresses, coral bleaching, cyclones, local pollution, and predation gives little cause for optimism. It’s too soon to make an accurate assessment of the impact of the cyclone on other species such as fish, and non-coral invertebrates but changes in their numbers and diversity are to be expected. Data about fish populations is being collected, which in time will provide a clearer picture of the extent of the damage caused by the cyclone. It could take up to ten years before the reefs recover, if they are able to, making long-term monitoring of reefs essential in order to take the measure of the resilience of coral reefs in Polynesia today.

It would appear though that cyclone Oli may have been one cyclone too many for the reefs of some of the Polynesian islands, including Moorea, Tahiti, Raiatea, Tahaa, and Bora-Bora.

Afterword.

This incident serves as an example of the plight of many tropical reefs around the world. If a reef is healthy, say in a MPA not subject to manmade pollution and over fishing, it can weather natural disasters such as a cyclone and recover over time. However, where a reef has been constantly affected by stressors such as pollution unbalanced ecosystem owing to over-fishing, damage from shipping etc, there comes a time when it can no longer recover. It becomes added to the statistics as one of the increasing number of reefs lost over the last 50 years, joining the estimated 19% of the world’s coral reefs already lost and the 35% seriously threatened (Wilkinson, 2008), a process which is continuing with little sign of abatement.

Tim Hayes
Midland Reefs
©2010

A significant bleaching event has been reported from the area of Lord Howe Island. Southern Cross University (SCU) researchers, who have been monitoring the coral reefs off of Lord Howe Island since 1993, have mapped the extent of the bleaching and damage to the corals and will be returning later in the year to assess the rate of recovery.

Above average sea temperatures during early 2010 have led to the first recorded major coral bleaching event here, with water temperatures exceeding 26 - 27 ˚C over the last few months, a couple of degrees higher than the usual summer sea temperature.

Lord Howe Island lies within a marine protected area, the Lord Howe Island Marine Park, and was declared a World Heritage site in 1982. This is a reef of particular importance being the southern-most tropical reef in the world. It features an unusual combination of tropical and temperate marine flora and fauna, including many species living at their distributional limits, reflecting the extreme latitude of coral reef ecosystems.

The diversity of marine life here includes:

· At least 500 species marine fish of which 400 are inshore species and 15 are endemic.

· More than 83 species of corals and 65 species of echinoderms of which 70 per cent are tropical, 24 per cent are temperate and 6 per cent are endemic.

· At least 235 marine benthic algae species of which 12 per cent are endemic

This bleaching event was caused by warm seawater carried south on the East Australian Current, coinciding with the hottest, driest, cloudless January on record. It has been far larger than the minor bleaching that took place during the mass coral bleaching of 1998, which severely damaged coral reefs around the world. Lord Howe Island was relatively unscathed in 1998 with few coral species becoming bleached and most recovering.

Although elevated sea surface temperatures are the main factor in coral bleaching this event seems to have been made more severe by there being little ocean swell during the hot weather, leading to poor water mixing resulting in a hotter lagoon with lower levels of water oxygenation.

Unlike the Great Barrier Reef, Lord Howe Island is relatively isolated from other reefs, this reduces the rate with which recruitment of organisms can occur to replace populations damaged by the event, and as a result, the reef may take decades to recover.

Professor Peter Harrison, from SCU’s School of Environmental Science and Management, said that this unusual bleaching event is further evidence that climate change is having a very real impact and that even cooler water, sub-tropical reef systems were not immune to these changes. He also noted that two of the major sites affected by the bleaching were within protected areas of the marine park, and pointed out that research from other tropical reefs showed that areas protected from fishing had better recovery rates from severe coral bleaching episodes.

Marine protected areas are being seen as increasingly important as they can help the recovery of reef systems adversely affected as climate change takes hold and affects the marine environment.

Tim Hayes

Midland Reefs

©2010

The New England Aquarium in Boston, Massachusetts, joined up with Rogers Williams University in Bristol, Rhode Island, in a project to raise the world’s first captive-bred Queen Triggerfish.

The New England Aquarium’s Bahamian coral reef exhibit features a pair of Queen Triggerfish, Balistes vertula, which have been seen to spawn since their early days in the aquarium. Although these fish regularly lay tens of thousands of eggs every 18 to 20 days, the resulting larvae need live food of a small size, making them difficult to feed and keep alive.

Most marine fish larvae are very small and need live food of a correspondingly smaller size. Whereas some species, such as clownfishes, can be successfully raised using rotifers, organisms that grow and reproduce at a fast rate and in high densities, these are too large for many other species or don’t have the correct nutritional profile needed.

In the wild larval marine fish eat copepods, micro-crustaceans found virtually everywhere in the oceans, but raising copepods in large enough quantities is currently difficult. This is one of the reasons why far fewer species of marine aquarium fish are captive bred than are wild caught.

Eggs were collected from the aquarium and taken to the university’s marine laboratory where, at the first attempt, there was a successful hatching.

Although thousands of larvae hatched, work was concentrated on a relatively small number, which were initially fed with a local species of copepod grown by the lab.

Although the majority of the larvae died, four were successfully raised to the point where they could eat dry food and now, at more than four months old, remain alive, three at the university and one at the aquarium, the first triggerfishes to have been successfully bred in captivity.

The success of this project was largely due to Dr. Rhyne’s research into copepods, the critical live food for marine fish larvae.

Dr Andy Rhyne, assistant professor of biology at Roger Williams and a research scientist at New England, was hired in August 2009 in a collaboration between the aquarium and the university to study larval fish production at the aquarium and to start a program in aquarium science and aquaculture at the university.

Today many species of fish are threatened by a combination of overfishing, climate change, and environmental degradation, indeed the Queen Triggerfish is listed on the IUCN red list as being vulnerable. The species is important both as a food fish and for public aquarium displays. It’s a large species; reaching up to 60 cms total length and its bright colours make them a favourite of public aquariums although too large for the majority of home aquaria.

This is an important step in the cultivation of marine species, as researchers such as Andy Rhyne develop new feeding strategies, it increase the chances of being able to raise further species of marine aquarium and food fish in captivity, rather than continuing to take them from the increasingly vulnerable and deteriorating oceans.

To find out more about this wonderful achievement go to MOFIB to see Andy Rhyne’s diary recording the day-by-day progress of the project.

Congratulations, Andy!

Tim Hayes

Midland Reefs

©2010

U.S. Considers Endangered Species Protection for 82 Stony Coral Species.

I’ve included the full NMFS document at the beginning of the article so that you can see the extent of the proposal. This is followed by a discussion about what the proposal may mean for the aquarium industry.

National Marine Fisheries Service Sets Deadline for Public and Expert Input on Petition to List 82 Stony Coral Species Under the Endangered Species Act.

From the Federal Register (Vol. 75, No. 27 / Wednesday, February 10, 2010)

Endangered and Threatened Wildlife; Notice of 90-Day Finding on a Petition to List 83 Species of Corals as Threatened or Endangered Under the Endangered Species Act (ESA)

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Department of Commerce.

ACTION: 90-day petition finding; request for information.

SUMMARY: We (NMFS) announce a 90- day finding on a petition to list 83 species of corals as threatened or endangered under the ESA. We find that the petition presents substantial scientific or commercial information indicating that the petitioned actions may be warranted for 82 species; we find that the petition fails to present substantial scientific or commercial information indicating that the petitioned action may be warranted for Oculina varicosa. Therefore, we initiate status reviews of 82 species of corals to determine if listing under the ESA is warranted. To ensure these status reviews are comprehensive, we solicit scientific and commercial information regarding these coral species.

DATES: Information and comments must be submitted to NMFS by April 12, 2010.

The 83 species included in the petition are: Acanthastrea brevis, Acanthastrea hemprichii, Acanthastrea ishigakiensis, Acanthastrea regularis, Acropora aculeus, Acropora acuminate, Acropora aspera, Acropora dendrum, Acropora donei, Acropora globiceps, Acropora horrida, Acropora jacquelineae, Acropora listeri, Acropora lokani, Acropora microclados, Acropora palmerae, Acropora paniculata, Acropora pharaonis, Acropora polystoma, Acropora retusa, Acropora rudis, Acropora speciosa, Acropora striata, Acropora tenella, Acropora vaughani, Acropora verweyi, Agaricia lamarcki, Alveopora allingi, Alveopora fenestrate, Alveopora verrilliana, Anacropora puertogalerae, Anacropora spinosa, Astreopora cucullata, Barabattoia laddi, Caulastrea echinulata, Cyphastrea agassizi, Cyphastrea ocellina, Dendrogyra cylindrus, Dichocoenia stokesii, Euphyllia cristata, Euphyllia paraancora (ed: sic), Euphyllia paradivisa, Galaxea astreata, Heliopora coerulea, Isopora crateriformis, Isopora cuneata, Leptoseris incrustans, Leptoseris yabei, Millepora foveolata, Millepora tuberosa, Montastraea annularis, Montastraea faveolata, Montastraea franksi, Montipora angulata, Montipora australiensis, Montipora calcarea, Montipora caliculata, Montipora dilatata, Montipora flabellata, Montipora lobulata, Montipora patula, Mycetophyllia ferox, Oculina varicosa, Pachyseris rugosa, Pavona bipartite, Pavona cactus, Pavona decussate, Pavona diffluens, Pavona venosa, Pectinia alcicornis, Physogyra lichtensteini, Pocillopora danae, Pocillopora elegans, Porites horizontalata, Porites napopora, Porites nigrescens, Porites pukoensis, Psammocora stellata, Seriatopora aculeata, Turbinaria mesenterina, Turbinaria peltata, Turbinaria reniformis, and Turbinaria stellula.

Eight of the petitioned species are in the Caribbean and belong to the following families: Agaricidae (1); Faviidae (3); Meandrinidae (2); Mussidae (1); Oculinidae (1).

The petition states that all of these species are classified as vulnerable (76 species), endangered (six species: Acropora rudis, Anacropora spinosa, Montipora dilatata, Montastraea annularis, M. faveolata, Millepora tuberosa), or critically endangered (one species: Porites pukoensis) by the World Conservation Union (IUCN). Montipora dilatata and Oculina varicosa are also on our Species of Concern list.

So what does this mean for the aquarium industry?

This petition came about as result of move by the Center for Biological Diversity, Tucson, Arizona, a not for profit conservation organisation.

The move to include these species on the Endangered Species list may well endanger the aquarium usage of stony corals. Amongst the corals listed are a number of common aquarium species, including the currently popular Acanthastrea species along with Euphyllia species, Galaxea, multiple Pavona and Turbinaria species, plus many Acropora species. Although there are corals listed that are undoubtedly endangered there are also other resilient species mentioned that I wouldn’t have expected to see on such a list. It’s worth noting that Caribbean stony corals are already restricted, hence unavailable to the aquarium trade.

To see the position of the Center for Biological Diversity on this issue:

http://www.biologicaldiversity.org/campaigns/coral_conservation/index.html

If the petition succeeds it would mean the banning of the collection of the listed species of stony coral from U.S. waters along with a ban on the import of these species into the United States. Obviously this would have an enormous affect on the US aquarium hobby.

There would most likely be a knock on affect to the UK and European market as some of our corals are collected from US waters around the world.

I would expect to see opposition to this petition from exporters,  particularly from non-US waters, on economic grounds i.e. the income that the coral trade brings into the local economy, and from the aquarium trade. So far the Pet Industry Joint Advisory Council (PIJAC), a US, not for profit organisation promoting responsible pet ownership and animal welfare, has raised concerns about this issue. In Europe the Sustainable Aquarium Industry Association (SAIA) is also looking at this petition.

It’s interesting to note that some coral reef scientists have also raised concerns about how this would affect their work.

Reef scientist John Bruno, of the University of North Carolina, has started to take a close look at the petition, and, finds some of the assertions made in the petition to be questionable.

To see the views of a respected reef scientist go to: Climate Shifts.org

The NMFS, the NOAA, and the Department of Commerce have opened a 90-day finding period seeking to hear “scientific and commercial information” on whether the list of stony coral species should be given protection under the Endangered Species Act. The consultation process closes 12 April 2010.

To see more go to the NOAA website: http://www.noaa.gov/

Afterword.

Is this the beginning of the end for stony corals in the reef aquarium hobby?

It’s too early to tell how this will turn out but I’ve been predicting this sort of thing happening for a number of years now. As the oceans continue to deteriorate from the effect of climate change and other anthropogenic pressures, the number of Marine Protected Areas and no-take areas will increase in an effort to preserve what’s left; it seems inevitable that this will result in increasing restrictions on collection for the aquarium industry.

Most likely there enough specimens of stony coral in captivity to provide a sustainable captive trade, it’s when it comes to fishes that the hobby will be in real trouble.

Tim Hayes

Midland Reefs

©2010

In my article, “2010, the International Year of Biodiversity - Clownfishes.” under the section entitled, “Can clownfish adapt to climate change?” there was a mention that one species of clownfish had recently been shown to use soft corals as an alternative habitat, something previously only seen in captivity. This is referenced to Arvedlund, M., and Takemura, A. (2005) Long-term observation in situ of the anemonefish Amphiprion clarkii (Bennett) in association with a soft coral. Coral Reefs 24, 698-698.

Having managed to track this paper down I can now expand on the reference.

Between May 2003 to December 2004, during the course of 37 daytime snorkeling surveys between the hours of 11.00 and 18.00, an adult Amphiprion clarkii was observed at a depth of 1 m, living in the same soft coral, a Lobophytum species of around 90 cms in diameter.

This took place in the Ryukyus Archipelago in southern Japan, at the southernmost local reef of Sesoko Island. This area was seriously affected by the global bleaching event of 1998; in the aftermath of this event several species of host anemones disappeared while the surviving anemone species declined. At the time of the paper, 2005, the anemone population had yet to recover.

Although anemonefishes are known to adopt a wide range of soft corals in captivity, this form of behaviour is almost unknown in the wild.

All 28 known species of anemonefishes have an obligate symbiotic relationship with at least one of ten species of anemones belonging to the families: Actiniidae, Stichodactylidae and Thalassianthidae. There tend to be species specific associations which range from Premnas biaculeatus, Maroon Clownfish, associating with a single species of anemone, Entacmea quadricolor, Bubble-tipped Anemone, to Amphiprion clarkii which has been found in association with all ten species of known host anemone.

From personal observation, the main author of the paper, reports that A. clarkii will often take shelter away from its host anemone when pursued by a potential predator whereas most other anemonefishes, take refuge in their host anemone.  The paper ends by speculating whether the ability of A. clarkii to associate with a wide range of anemones and, as has now been observed, with corals might go some way towards explaining why it’s the most widely distributed species of clownfish.

Other than the fact that Lobophytum species soft corals are amongst the most toxic of corals, something that might deter predation by fishes and aid the coral in competition against other corals, this species appears to offer little in the way of protection for a clownfish. This leads me to further speculate whether A. clarkii is evolving away from its obligate association with host anemones or to question if this is just one fish that has been unfortunate enough to lose its host yet been lucky enough to survive for so long in the absence of an anemone.

More reports of clownfishes, particularly A. clarkii, are required before we can come to any conclusions.

Tim Hayes

Midland Reefs

©2010

The United Nations has declared 2010 to be the International Year of Biodiversity. It is a celebration of life on earth and of the value of biodiversity to our lives. The world is invited to take action in 2010 to safeguard the variety of life on earth: biodiversity

As part of the International Year of Biodiversity (IYOB) the IUCN has published a report presenting 10 new climate change flagship species to demonstrate that it’s not just the Polar Bear that’s in trouble.

These 10 species are as follows:

Staghorn corals

Ringed Seal

Leatherback Turtle

Emperor Penguins

Quiver Trees

Clownfish

Arctic Foxes

Salmon

Koalas

Beluga Whales

One thing that is immediately obvious from the list is that 7 of the species are marine animals. The second thing to strike me about this list is that 2 common aquarium animals are included, most worrying of all is the inclusion of the poster animal of the marine aquarium hobby, the clownfish

In this first of two articles I’m going to look at clownfish, the second article will be concerned with Staghorn corals.

Clownfish and Climate Change

Clownfish, or Anemonefish, belong to the Family Pomacentridae, with their vivid orange and white colouration are one of the most familiar species of tropical marine fishes. This familiarity was boosted by the film ‘Finding Nemo’, which featured the Common Clownfish, Amphiprion ocellaris, a mainstay of the marine aquarium hobby.

Clownfish are found in tropical and subtropical areas of the Pacific and Indian Oceans where they are restricted to shallow waters owing to their mutualistic relationship with a small number of specific anemone species. A host anemone can support a colony of several clownfish consisting of one female, one functional male, and a number of subordinate fishes, all non-functional males.

When the female dies the male turns into a female whilst the largest subordinate fish becomes male. Clownfish lay their eggs close by their host anemone, guarding them until they hatch. On hatching the larvae disperse into the water column where they remain for around 8 to 12 days before settling out as juveniles and seeking a host anemone of their own. As larvae develop, chemical signals allow them to detect suitable host anemone.

Research has shown that the larvae that survive to settle out as juveniles tend to return to the reef where they originated so the majority of the survivors do not disperse very far from their parents’ anemone.

There are 28 species of clownfish described to science; all behave in a similar manner, exhibiting reliance on their obligate association with host anemones for survival.

Captive breeding.

Clownfish have been bred in captivity since the early eighties so we have a lot of information about how different environmental conditions such as temperature and pH affect this species. Although it’s interesting to note that the recent studies from the reef, revealing that reduction in ocean pH levels have an affect on clownfish’s ability to detect the chemical signals necessary for locating an anemone host, answer the question of why captive bred clowns are often slow to adopt an anemone in a reef aquarium.

Why are Clownfish vulnerable to the effects of climate change?

Habitat loss: Coral reefs are in decline owing to increased levels of CO2 in the atmosphere. The current level stands at 387 ppm CO2, higher than 350 ppm that many leading scientists say is the safe upper limit for carbon dioxide in our atmosphere, and the level we need to get back to as early as possible to avoid runaway climate change. If CO2 levels reach 450 ppm, predicted to occur by 2030-2040 at the current rates of increase, reefs will be in terminal decline worldwide from mass bleaching, ocean acidification, and other environmental impacts. Clownfish are dependent on anemones for their survival, which most frequently occur on coral reefs.

A couple of examples: the global coral bleaching event of 1998, led to the complete disappearance of several sea-anemone species used by clownfish in the corals reefs around Sesoko Island, Japan, causing local population declines; and take a look at: Reef Ramblings June/July 2008 to see an earlier article about reduction in clownfish numbers on the Great Barrier Reef.

Disruption of navigation: Decrease in ocean pH levels have been shown to affect a clownfish’s ability to detect the chemical signals that allow them to locate a host anemone. This is known to be a particular problem for juveniles as, if they’re unable to locate a host, they’re at greater risk of predation. Juveniles unable to locate a new anemone face the chance of returning to their parental anemone, increasing the likelihood of inbreeding.

Larval development: As ocean temperatures increase we’d expect to see faster development of larval and juvenile clownfishes. This may bring a reduction in dispersal distance with the result of settlement closer to the parental anemone increasing local competition for recruitment to neighboring host anemones. Again increasing the possibility of inbreeding.

Reproductive behavior: Clownfish, along with many other fish species, only reproduce within a narrow temperature range. This presents the possibility that as temperatures increase that there may be a reduction in breeding activity. A secondary problem that we’re familiar with from captive breeding is that high temperatures can have a deleterious affect on egg development.

It’s also worth noting that in the IUCN report, under the heading of “Other threats”, that the marine aquarium industry is singled out for mention, although it does go on to add that the greatest threat is down to human activities, presumably the usual

Can clownfish adapt to climate change?

Currently this is unknown, most species can usually adapt to changes in environmental conditions as long as these change occur slowly over time. As ocean temperatures continue to increase, clownfish and their associated host anemones may be able to shift their ranges southwards to cooler water. However, neither clownfishes, nor their anemones, are particularly mobile so it’s likely that successful relocation to new, more suitable habitats will be limited.

The concern about more rapid larval development, with its resultant limitation on dispersal, raises the question of inbreeding, the consequences of which are unknown.

A further possibility, but one that seems to me unlikely, is whether clownfishes could adapt to seasonal breeding pattern taking advantage of the cooler seasons.

Interestingly, the IUCN report states the one species of clownfish has recently been shown to use soft corals as an alternative habitat, something previously only seen in captivity. This is referenced to Arvedlund, M., and Takemura, A. (2005) Long-term observation in situ of the anemonefish Amphiprion clarkii (Bennett) in association
with a soft coral. Coral Reefs 24, 698-698.

It’s not known if other species of clownfish could adopt other host species, nor whether such associations would have the same value as the present association with anemones.

What can we do?

Whilst climate change does not mean extinction, some species will be able to adapt whilst others will perish. The question is which species will survive and which will perish? Worsening climate change effects are inevitable, even if all CO2 emissions ceased today, because of the lag-effects of the greenhouse gasses already emitted.

It’s up to all of us, along with our governments, to commit to targets to reduce emissions at the earliest opportunity if, we want to slow the pace of climate change and give clownfishes and other species a chance to survive.

If you are a reefkeeper, try to raise awareness of the destructive affects of climate change to the marine environment by using the familiar clownfish as an example of what may be lost.

You can download the IUCN report here: Species and Climate Change

Tim Hayes

Midland Reefs

©2010