'Symbiont-switching: too optimistic'

Responding to Andrew Baker ('Inoculation: not a cure-all but worth trying') and others, Tom Goreau writes:

I completely agree with Andy Baker that we need to try all we can and hope it works. But I don't share his optimism because almost all corals are really much fussier than he seems to acknowledge about the very precise strain of zooxanthellae they will take up, expel the rest, and don't seem to have much rapid ability to adapt. That has been known for a very long time from the work of Bob Trench and his students. [See also a] recently published great paper by Tamar Goulet. One could be left with only a handful of very unusual corals if Andy is right.

My own view for about 20 years is that it has long been clear from field observations (going back more than 20 years) that susceptibility and resistance to bleaching have genetic components. We therefore need intensive genetic research into understanding exactly which genes and proteins are involved in both thermal stress susceptibility and resistance, and the effects of inducing or repressing their activity. This takes a state of the art laboratory and committed team. The next step is to grow all the variants one can with all the zooxanthellae one can get them to hold on to and all the genetically engineered corals and zooxanthellae in which the variants of the key genes and enzymes are expressed. This needs a huge state-of-the-art coral growing facility.

What is also needed, and which only we can do, is to grow them all on Biorock at faster growth rates, see how they respond to severe bleaching, select the survivors, see how their genes and protein expression may be different, propagate them, and see how they respond to the next bleaching event, etc.

Note: Andrew Baker and Andrienne Romanski commented on Goulet's paper in Multiple symbiotic partnerships are common in scleractinian corals, but not in octocorals (April 2007).

'The living are losing color'

At Maribo, sharp-eyed Simon Donner records the sighting of a rare species: a poem about coral bleaching. The Fever by Kimiko Hahn is in The New Yorker, of all places. I'm not sure what to make of the penultimate verse (if that's the right word for it).

As far as I know, climate change has made it as a topic to what they used to call "high art" such as opera only in the last year or two (unless that's what Götterdämmerung was really about all along!). The Water Diviner's Tale, for example, was premiered at the Proms, a summer series of mostly classical music in London, on 27 August (see here - scroll down). And last autumn may have been the first appearance of the anthropocene at the opera: in a work for mp3 player called And while London burns (my review is here). Can a cantata about vanishing corals be far behind?

Froth

Nothing to do with coral reefs, I think, but Deep Sea News picks up on what may or may not be a classic silly season story in Attack of the giant sea foam. "Scientists explain that the foam is created by impurities in the ocean, such as salts, chemicals, dead plants, decomposed fish and excretions from seaweed", says the source.

John Bruno on the decline of coral reef ecosystems

in a substantial piece at Ove Hoegh-Guldberg's climateshifts.org

ICRS 11

The 'Olympics' of coral reef science is not so far away. Registration and Call for Abstracts is now open. More information here.

Take that, suckers!

Tom Goreau has submitted the following letter to Science regarding attempts to 'vacuum' algae killing coral in Hawaii (noted on Coral Bones at Believe it or not):

"Call the Hose Brigade!" (Random samples, 10 August, p. 729) describes an effort to remove a massive nuisance algae bloom killing corals in Kaneohe Bay, Hawaii, by sucking it up with huge barge-mounted vacuum cleaners. Unfortunately this will give only temporary results and will fail in the long run unless the nutrient excess that fuels the rapid growth is removed. Kaneohe Bay is a classic example of coral reef eutrophication: benthic algal blooms caused by point discharges of sewage killed the reef in the 1970s, and died back when the outfall was removed, allowing the reef to gradually recover (1). With continued suburbanization of the watershed, uncontrolled non-point nutrient discharges to the bay from golf courses, lawn fertilizers, and road runoff have again raised the nutrient concentrations (2,3) above the thresholds for nuisance algae (4-6). Besides the temporary success in Kaneohe Bay, there are very few examples of algae being successfully removed. In one bay in Jamaica where all the land-based nutrients were diverted, nuisance algae that were choking the reef began to die back in weeks, and only a few dying clumps off weedy algae remained two months later (7). If algae are starved of nutrients, they die very quickly, and will not return unless nutrient thresholds are again exceeded. But no amount of sucking them off will work when they grow right back because they are overfertilized. It is the suckers paying for this well intentioned, but ultimately futile effort, who will be hosed unless the underlying causes of eutrophication are removed.
______
1. A Banner, Proc. 2nd Int. Coral Reef Symp., 2, 685 (1974)
2. E Laws, C. Allen, Pac. Sci., 50, 194-210 (1996)
3. S. Larned, J. Stimson, Mar. Ecol. Prog. Ser., 145, 95-108 (1996)
4. P. Bell, Wat. Res., 26, 553-568 (1992)
5. B. Lapointe, N. Littler, D. Littler, Proc. 7th Int. Coral Reef Symp., 1, 323-334 (1992)
6. T. Goreau, K. Thacker, Proc. Carib. Water & Wastewater Assoc., 3, 98-116 (1994)
7. T. Goreau, UN Expert Meeting on Waste Management in Small Island Developing States, 1-28 (2003)

Reject-ski

Ian Popple, at Beautiful Oceans Blog, makes some good observations starting with why jet-skis make great artificial reefs.

'Inoculation: not a cure-all but worth trying'

This blog has hosted a short exchange about 'inoculation' as a way of trying to save coral reefs (posts 1 and 2 are here and here). Here is Andrew Baker's answer to critics:

As I wrote previously, I believe that attempts to boost the natural abundance of heat resistant symbionts by “inoculation” (for want of a better word, this is not a very good one as it comes with a lot of unintended meaning) would indeed be useful and worthwhile if we selectively target the oldest and largest colonies on selected reefs. In some circles this is indeed viewed as naïve, either because prospective algae won’t establish symbioses with these corals (Ove [Hoegh-Guldberg]’s view), or these symbionts will never propagate across reefs to make much of a difference (Charles [Shepard]s’ view). Both of these are valid concerns. I myself avoided this line of research for several years as it’s a bit of a “Go to Jail” card for those of us in the research community (“Do Not Pass Go, Do Not Collect £200”). Ove and Charles comments bear witness to that concern, and I am sure their viewpoints are not unique.

However, in my view, the main justifications for attempting inoculation are that: (1) some of the most important reef builders are already known to be able to host these symbionts (which addresses Ove’s worries regarding “evolutionary switching”); and (2) one doesn’t need to affect entire reefs to potentially make a detectable difference (Charles’ concern), especially if large and/or old colonies are targeted. If we lose these colonies it may take hundreds of years to replace them, so it stands to reason we might want to take extraordinary steps to keep them alive. This might not be a strategy that we can use to save the world’s coral reefs from climate change. However, it might help us keep more corals alive, and preserve reef function in the near-term, while we figure out what other options become available to us (I agree with Charles’ pragmatic view that we never know what the future holds in store).

In the Caribbean, for example, large colonies of the important reef-building star coral Montastraea faveolata are naturally capable of hosting (heat tolerant) Symbiodinium in clade D. The problem is that relatively few of them contain sufficient numbers of these symbionts to prevent mortality in the event of bleaching episode. I have suggested that large scale bleaching and mortality events result in shifts on reefs to favor more Symbiodinium D, and this ends up making these reefs more resistant to future bleaching events. Many mechanisms can account for these shifts in symbionts. However, the problem is that, regardless of mechanism, these shifts are only significant when the bleaching is severe enough to cause dramatic mortality.

These reefs seem to have to pass through the eye of a (hot) needle for their constituent corals to end up being more thermally resistant, and many of them simply don’t make it. I am suggesting that we should attempt to boost the natural abundance of heat tolerant symbionts so that these shifts can be made with less accompanying mortality. Ove and Charles are both correct in identifying problems that will prevent this action from being some kind of miraculous cure-all. It won’t be. However, we should not ignore the fact that an ability to improve the survivorship of corals during a bleaching event is nevertheless an improvement on where we stand now. Currently, we understand the basic cellular physiology of bleaching, but are still unable to make a difference when thermal anomalies pass through and cause widespread bleaching. This is not very satisfactory when all is said and done.

I believe that an attempt to boost the natural abundance of heat resistant symbionts to encourage species-by-species “survivorship networks” on reefs, although ambitious, controversial and high-risk, nevertheless has considerable value as a research activity. This is not just because it might actually work (and increase coral survivorship on critical reefs), but also because the need to demonstrate a willingness to act (to mitigate and alleviate the effects of climate change), as opposed to the need to observe (to predict and understand them) has never been greater. I agree with Ove that blind optimism is no recipe for success. However, reasonable scientific gambles that have half a dozen reasons why they might work are still work attempting, even if there are twice as many reasons they won’t work. It would be a sad state of affairs indeed if, faced with the greatest environmental challenge in history, we excluded activities that might improve survival trajectories because we decided they wouldn’t work in advance of actually trying them.

Thanks to all those who commented.

'Inoculation: naive'

Responding to a comment on inoculation by Andrew Baker, Charles Shepard says:

Inoculation of corals with more heat resistant strains has been talked about for years, and indeed has happened in some experimental aquaria. But what people overlook, in my view, is that there is a bit of a difference between seeing whether it can happen (experimentally) and getting that strain to become dominant over, say, the Seychelles archipelago! [To call it] 'naive' is exactly correct, I am afraid. At least, it is naive for now - if you read science fiction of 50 years ago you will see that we should never say never...

But even if such manipulation is possible one day, my worry is that the decline we see now is too rapid for us to reasonably put much store in some technique which may or may not be developed in 10-20 years time. If we look at the temperature curves, then we don't have more than a couple of decades.

...[Where] Baker [says] that 'we should explore whether there are are any actions we can take [to boost the natural adaptive capacity of corals to survive environmental changes]'... then yes, that I do agree with. Certainly we should explore. Urgently in fact.

Ove Hoegh-Guldberg says:

The biology of symbiosis would suggest that inoculating corals with new strains of zooxanthellae would be a futile waste of money - symbioses don't form easily (analysis suggests switching occurs on a hundred to thousand year time frame). I would wager that even taking the zooxanthellae from the same species in a much warmer sea (assuming that zooxanthellae were the heart of the thermal tolerance and not the coral/zooxanthellae combination!) and trying to inoculate them into colonies of the same species in a colder but rapidly warming sea would simply result in a lack of uptake by the coral. I am afraid focusing solely on ecology without an appreciation of limits of physiology leads people down pathways that essentially involve a lot of wishful thinking.

Not invented here

A press release from the Israeli Ministry of Foreign Affairs describes the creation of what it calls "the world's first artificial coral reef".

The claim is ludicrous, given the long experience with artificial coral reefs in many parts of the world. Still, the project looks quite interesting.

RIP Wolf Hilbertz

Wolf Hilbertz, a good friend of the planet and to many of us, died at about 2:37 this morning, German time. I will remember him for many reasons, including this account from his first journey to Saya de Malha:

We encountered a unique meteorological phenomenon on the North Bank: the sea was flatter than a mirror, a cloudless night sky, and the stars were so brilliantly reflected by the sea surface that one was deceived in thinking one saw the sky there. The horizon had shifted and all the gods were enjoying themselves. This clearly was a once-in-a-lifetime and profound experience. Tom [Goreau] can make the scientific explanation available to you.

Tom Goreau writes:

I'm heartbroken to hear this tragic news. You can be sure that we will do all we can to ensure that the legacy of his pioneering work in the oceans will never be forgotten.

As Wolf would say, "Ja!, Prinzip Hoffnung [the principle of hope]!"

Frequent hurricanes 'decimate sea turtle beaches'

Increasingly frequent and ferocious hurricanes, fuelled by warming oceans, could pose a threat to sea turtles by destroying their nests.

-- from a news report on research by Kyle Van Houten and Oron Bass, and by David Pike here.

Rich and strange

Go to Rick MacPherson's Carvival of the Blue III for a roundup of the rich and fascinating variety of recent posts about ocean conservation from many quarters of ye watery globe. One from Coral Bones slipped in there. Surely shome mishtake.

'Inoculate' coral to save the tough ones?

Commenting on Regional Decline of Coral Cover in the Indo-Pacific (noted on Coral Bones here), Andrew Baker says:

This is an important study that shows that reefs in the Pacific have surprisingly similar levels of coral cover despite being very different in terms of their environment, physical oceanography and level of human impact. It also reveals considerable variability in coral cover from year to year, while also making the case that Indo-Pacific reefs were considerably impacted by the 1970s.

I find it interesting that the impacts of mass bleaching events (such as the 1997-98 El Nino) are quite difficult to detect given the dramatic year-to-year variation in coral cover preceding these events. Instead of suffering dramatic and obvious reductions in coral cover as a result of bleaching, reefs affected by mass bleaching appear to lose their year-to-year variability instead, as if they are being inexorably squashed towards some future minimum level. Instead of the usual, exuberant, boom-and-bust cycles of coral cover you might expect on healthy reefs, we are instead witnessing the whittling away of reefs to their most tenacious component species.

The fact that year-to-year variability in coral cover seems to have disappeared over the last decade might indicate that we are losing the more susceptible coral species from reefs, and we are instead being left with more resistant, hardy species that are able to withstand the relatively poor environmental conditions we are leaving them with. These surviving corals are likely to include varieties that are more resistant to coral bleaching (as documented by Baker et al., Nature 2004).

We should do more to try and understand what makes corals resistant to bleaching, and explore whether there are any actions we can take to boost the natural adaptive capacity of corals to survive environmental changes. This might include attempts to inoculate the largest and oldest colonies on reefs with reserves of heat tolerant symbiotic algae (that are usually lost from corals during bleaching events) that might help them survive bleaching events, and so help perpetuate the essential framework upon which reefs depend.

However, one has to wonder at what point does one draw the line in this decline and ask "When is a reef not a reef"? That is an unanswered question that I fear will become a research focus in coming years.

'Going faster than rainforests'

Some media reports of a paper by John Bruno and Elizabeth Selig of the University of North Carolina at Chapel Hill have not been clear about their estimate of the rate of coral loss, quoting either 1 or 2% per year. Bruno and Selig found that:

Estimated yearly coral cover loss based on annually pooled survey data [on 2,667 Indo-Pacific coral reefs between 1968 and 2004] was approximately 1% over the last twenty years and 2% between 1997 and 2003 (or 3,168 square kilometres per year). The annual loss based on repeated measures regression analysis of a subset of reefs that were monitored for multiple years from 1997 to 2004 was 0.72 %.

They conclude that coral cover declined decades earlier than previously assumed, even on some of the Pacific's most intensely managed reefs. "These results", they note in the kind of language that characterises dispassionate scientific papers, "have significant implications for policy makers and resource managers as they search for successful models to reverse coral loss".

-- Regional Decline of Coral Cover in the Indo-Pacific: Timing, Extent, and Subregional Comparisons. News reports here, here, here etc.

Hot and bothered Okinawa

As Ove Hoegh-Guldberg notes, on 5 August Yomiuri Shimbun reported mass coral bleaching in Okinawa: 'Should the water temperature stay high in August, it is feared that more coral will be destroyed than ever before – surpassing the case that occurred in 1998, when about 40 percent of the coral around Ishigaki island died'.

Islanders adopt their own coral reef rules, Japan Times 2 August, sketches a community-based conservation intiative on Ishigaki island, stresses threats to coral from poorly planned development, but lacks detail.

[P.S. 10 August: Ove Hoegh-Guldberg gathers together further information on the scale of this event, which extends to at least the northern Philippines and Korea as well as southern Japan]

Deep doo-doo

This morning it was reported that the Russians have planted a flag 4,200m (14,000ft) below the North Pole (see also The Arctic is Russian and my post Winners and losers from climate change). It's another reminder of the scale of what's happening in the deep seas, some of which is well summarised in Cindy Lee Van Dover's review of The Silent Deep by Tony Koslow (in Science 20 July 2007) extracted here:

Our dilemma is squarely before us in Koslow's chapter on climate change and the deep sea. As the climate warms, deepwater circulation patterns change, increased carbon dioxide levels acidify the ocean, patterns of primary productivity at the surface reorganize, and methane-hydrate deposits shift to new equilibrium states. There is little doubt that these and other climate-induced changes will affect deep-ocean life, but the manners in which effects will be expressed are nearly impossible to predict or to document because we have scant understanding of how deep-sea ecosystems operate in the first place. While we have all but abandoned the view that deep-sea organisms are exquisitely adapted to a stable and unvarying environment, we have only a modest understanding of physiological tolerances of organisms and ecological responses of populations and ecosystems to changes in basic parameters like temperature, oxygen content, pH, current regimes, and food supply.

We wonder at the strange animals captured in deep-sea trawls, revel in the unsuspected diversity of life dwelling in the cold muds of the seafloor, and celebrate the beauty of deepsea hot springs and cold-water coral reefs. Dramatic deep-sea discoveries unfold year after year, but Koslow reminds us that this "pristine" ocean wilderness is being trampled by the insidious "human footprint across the deep sea": the seabed suffers a nightmarish legacy of tens of thousands of merchant ships sunk and rotting on the seabed, hundreds of thousands of tons of military ordnance scuttled in deep water, millions of curies of radioactive waste and 17 nuclear reactors dumped at depth with no attempt at containment, and residual DDT and PCBs accumulating in deep-sea food chains...

...We are on the cusp of engaging in commercial activities that have the potential of exerting substantial impacts on the quality of deep-ocean ecosystems; there is only a brief window of opportunity for setting policy in place before habitats are compromised. Such policy, internationally sponsored and international in scope, can be holistic and precautionary, rather than a reaction to environmental catastrophe. A forward-thinking approach has immense advantage over negotiating and implementing policy after financial capital is invested, wilderness resources consumed, and habitats destroyed. Koslow provides us with a report on the current status of the ocean depths. Now is the time to chart a path toward rational conservation strategies and sustainable resource uses that acknowledge and accommodate the many gaps in our understanding of the deep ocean.

[For a little context on the Russian mood, see William Pfaff on Putin.]

Believe it or not

"Super Suckers" Slurp Invasive Algae Off Hawaiian Reefs (National Geographic).