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International Coral Reef Symposium Day 2 - My highlights

21 June 2016, Honolulu Hawaii

Note that I write this as speakers talk, so let me know if you think I have missed something, see mistakes or want me to remove something.

See also my blog on ICRS: Key insights that will be updated daily.

Key themes emerging today (in the sessions I attended) included:

Plenary from Charles Birkeland

Birkeland spoke about the success of fishery management in Palau and other Pacific Island nations.

Success comes from making decisions on a rapid time-scale. Examples of management success come from places where fishers and regulators (often the same people!) don’t wait to confirm impacts, they act first, then establish impacts later.

How some of the #ICRS2016 followers on twitter feel about eating seafood. Source:

Birkeland said we often don’t need precautionary management, we need data-less management.

An example was night-time scuba spear fishing in Solomon Islands. Fishers came to the Governor and expressed concern that fish stocks were declining because of the spear fishing. Overnight, the Governor banned night time spear fishing.

Rapid management decisions in Palau and other nations are in contrast to fishers managed under western laws. For instance, in Guam action to reduce overfishing was a long and slow process, because the scientists pushing for changes had to work their way through the courts and have laws changed. In the meantime several fisheries were severely overexploited.

Birkeland then explored the role of humans in coral reef food-webs. He argued that reef food-webs have relatively low productivity compared to other ecosystems. Therefore, fishing on reefs should be subsistence only.

He argued that coral reef food-webs are not exporting energy, they in fact use more energy than they can produce through benthic production. On reefs you often observe inverted biomass pyramids at any one instant in time. For instance, coral polyps are inverted biomass triangles - more biomass in animal cells than in algae - 5% is producers, 95% is animal.

Importantly, reef food-webs must be importing energy and cannot sustain fishery exports

Why we shouldn't eat reef fish - from Birkeland's talk. Source:

Because reef food-webs are importing energy they cannot sustain much fishing pressure. Palau can sustainably support local subsistence fishing, which is limited. Now the problem is feeding the tourists. E.g. Palau has about ~21 000 locals vs ~161 000 tourists annually. Birkeland argued therefore that we should feed the tourists pelagic fish.

Pelagic fish are faster growing and have higher reproductive potential at an early age than reef fish. For instance, yellow fin tuna are extremely fast growing and reach 30 pounds in their first year.

The experience in Palau was also that buying fish was also inefficient economically because they had to sell 5kg of locally caught fish to buy one small can of tuna. Therefore, the government banned export of reef fish.

Birkeland moved on to explain how Palau is a world leader on reef management. For instance, they were the first nation to specify their EEZ to be a shark haven (in 2009). Many other Pacific Island countries have now followed suit.

Order of priorities for when we should eat tropical fish - from Birkeland's talk. Source:

We have seen some reef fish management successes in other nations. For instance, in West Hawaii they have a very successful fishery management council that has increased the total value of fishery value 4x over the last ~20 years. The success comes from good leadership (from Bill Walsh) and that the government backed up the formation of the fishery council.

Further, the fishers avoid taking the biggest fish - they primarily want intermediate sized fish for aquariums. Bigger fish produce exponentially more eggs, so this helps keep the fishery productive.

Birkeland said we should ‘work with, not against coral reef fisheries’. Doing so requires (in a nutshell) village level management, saving the big fish, avoid exporting reef fish, keep the biggest slowest growing fish (e.g. humphead wrasse) for special events, encourage pelagic fish as food for tourists and put a cap on tourists, focus on high value tourism.

Some of Birkeland's take home messages. Source:

Birkeland’s talk was inspiring for its mix of lessons learned from Palau and the important role of reef ecology in understanding management success and failures. Let’s hope that other nations can follow Palau’s example in implementing more successful reef fishery management for the future.

Watershed impacts on coral reefs

Quantifying the impacts of land-based stresses to coral reefs is challenging reef scientists to get out of the water and head up onto the land. One of the key challenges is just figuring out where pollutants come from. In the watershed impacts session we saw a number of innovative techniques presented for tracing pollutants to its sources.

Tracing pollutants will help management identify locations where action is needed, such as improving waste water treatment.

Most from The Nature Conservancy is tracing sewage pollutants to a reef in Hawaii. Corals on the reef have been in decline over several years. They used a technique that is new to marine systems - Microbial source tracking. They took water samples and grew the bacteria. They then used genetic techniques to detect the presence of human gut bacteria.

By combining the microbial source tracking with other tracing techniques, they were able to show that groundwater is transporting sewage onto coral reefs, resulting in coral disease and growth deformities. They then developed maps of their water quality indicators to create a map to communicate the results to the community.

Pait spoke about numerous pollutants in the Virgin Islands that are occurring at levels above those recommended for human consumption. These include metals from boat yards and chemicals like PCBs. This information fed directly into the local watershed management plan.

Lewis will be reconstructing land-use change in Palau using evidence from coral skeletons. She is also using novel evidence sources too, like the number of permits for annually allocated for heavy machinery. She is starting her dissertation, so we look forwards to hearing more as her work progresses.

Informing management decisions

Coral reef scientists are increasingly branching out to use decision science to help communicate the actions we need to take to conserve reefs to managers.

This session was packed, standing room only, indicating the interest in the science of managing reefs.

A key insight from this session was developing science to provide direct advice to managers. We need to do more than document declines, we need to show how we can reverse them.

But a challenge to achieving effective decision science is obtaining sufficient data to evaluate the effectiveness of management actions. For instance, we need monitoring that is designed to establish whether management actions are slowing or reverse declines (see Ahmadia’s talk from yesterday)

Ken Anthony on managing the Great Barrier Reef Marine Park. Source:

Another key emphasis was on managing local stressors (e.g. nutrients) in the face of climate change, which can’t be managed locally. (A problem Cote, Darling and I explain in more detail here).

In fact, Global vs local stressors was the theme of the morning’s session.

Ken Anthony from Australian Institute of Marine Sciences spoke about the importance of acting to save reefs, even with imperfect scientific information. He spoke about how uncertainty can paralyse decision makers into not taking any action. We need to recognise that not taking acting is a decision in itself.

Hoegh-Guldberg spoke about the global risk of climate change to coral reefs. He said we need to limit global warming to 1.5 degrees to avoid massive degradation of coral reefs - less than the current policy target of 2 degrees. In the meantime we need to do what we can to sustain ecosystems through local management while the climate stablises.

Mcleod from The Nature Conservancy started with a quote: ‘insanity is doing the same thing over and over again and expecting the same result’. We keep telling ourselves that if we design protected areas well enough, we will ensure reef resilience to climate change. But reefs continue to decline.

Hoegh-Guldberg on global warming. Source:

Mcleod was asked by a journalist if it is true that incorporating resilience into management is making a difference to the health of reefs. She admitted that she stumbled. We don’t yet have the data to evaluate if resilience management is working, even though we have been working on these issues for over a decade.

She argued that to justify our efforts we need to establish whether ‘resilience management’ is working, or not.

The written word can’t communicate what how compelling a speaker Mcleod is. She had no slides but the audience was enwrap. Anthony joked at the completion of her talk that he would vote for her if she ran for president.

Mcleod finished early and there were numerous questions. Someone (Maria Beger?) asked what is the difference between resilience management and normal management. Mcleod answered that resilience management has a specific focus on ecosystem function, not just the stresses, including actions like protecting herbivorous fish on coral reefs.

Salm from The Nature Conservancy started by emphasising that we often don’t have the time to do the science to support decisions when working with local governance. He asked how much science is enough and how much is too much?

Quote from Salm. Source:

Salm said we need science to be designed to be nimble so it can feed into governance structures. One way to do this is to involve local people and tourists in data collection. This can help us get the data we need to evaluate whether management is working.

He gave an example of how very straightforward science - involving community monitoring of species recovering in protected areas - had convinced the community that they need more protected areas to aid recovery of overfished species.

Jill Harris from WWF started with a great summary of how conservation prioritisation works. Managers have limited resources, so we need to target management efforts for protection at areas where the management actions will have the greatest benefits.

To prioritise management actions to maximise their effectiveness, we will often want to target areas with the greatest local threats (that can be managed) and avoid areas threatened by climate change (which can’t be managed locally).

Harris looked at level of threat across protected areas in Indonesia and showed protection is biased towards reefs that have lower potential for management benefits.

Harris also highlighted the importance of considering the local situation. They identified priority areas for protection, but also considered what type of management was most likely to work given local context.

Nick Wolff (University of Queensland and recently moved to The Nature Conservancy) started by describing how science is portraying a very bad story for decline of the Great Barrier Reef. In contrast, Australian Government policy documents are very optimistic that management of fisheries and catchments can secure the future health of the reef.

Wolff is using novel methods to establish the degree that local management can influence the future health of the reef. Stay tuned for his upcoming publications.

Approaches to decision problems

A key theme emerging in the afternoon was how to communicate more nuanced messages about coral reef conservation to the public and policy-makers. There is wide-spread concern that the key points of science may often be lost once it is communicated outside the scientific community.

Kareiva (current chief scientist of The Nature Conservancy) started his talk with the message box, a tool to help scientists communicate their science. He said that it was a good start, but that it may miss key points that scientists often want to communicate: thresholds, impact and uncertainty.

As an example of why thresholds and uncertainty are important, he recommended you read about this experiment. The experiment shows that if the threshold for a disaster is uncertain, multiple players fail to come to a collective agreement.

He hypothesised that unfortunately, science often gets boiled down into one of three stories that are then communicated to the public:

If we want to communicate more sophisticated messages, we need to understand how public, media, policy-makers read our papers an interpret them. Kareiva said this will be the focus on ongoing work.


Pandolfi led his talk by asking how can we communicate a more nuanced message of science to the public?

For instance, as a good example, Pandolfi gives the media communication of the 2016 coral bleaching of the Great Barrier Reef. There has been widespread bleaching and coral mortality, but the pattern is spatially variable, with some areas hit harder than others. However, even in those areas that had been spared severe bleaching mortality, coral health is poor. Pandolfi contended that the nuances in this event were well represented in the media.

He wants us to think more about how to communicate uncertainty to the public.

Crow White from CalPoly wants us to use ‘trade-off analysis’ to understand how to balance multiple objectives for ocean management. He gives four steps to developing a trade-off analysis:

  1. Develop models of ocean uses
  2. Estimate sector responses to alternate forms of management
  3. Compare outcomes of management in relation to management
  4. Identify management strategy that maximises positive benefits to all sectors.

Trade-offs analysis can help us find compromise solutions for management of multiple sectors that are often better than the status-quo. They can thus be useful for communicating science to decision makers and stakeholders.

Kirstin Oleson and Megan Barnes and from the University of Hawaii are using trade-off analysis to identify optimal actions for managing sediment impacts on coral reefs. Importantly, unsealed roads in the tropics are a key source of sediments to coral reefs. There are too many roads to seal them all, so managers need to identify priorities to seal to avoid sediment impacts.

Trade-off analysis let them identify the optimal strategy for road repair across a range of budgets for road repair. They are now applying this approach to a broader range of land-use management activities.

Abdulla talked about resilience management in the Maldives. Growing tourism is increasing pressure on reef fisheries to feed tourists. People are also switching to fishing herbivorous fish because other species are depleted.

The Maldives are remote, but unprotected, with 0.04% reserve coverage. They are looking at marine managed areas as an approach to management, rather than no-take areas, which are unlikely to be effective in the region. Due to the spatial spread of communities and reefs the effective management requires a decentralized approach.

Laurance McCook talked about how to operationalize the precautionary principle for management of coral reefs. He presented a convincing case for an approach that better communicates and uncertainty for decision-makers, especially when there are divergent scientific views.

He gave an example of dredging impacts on the Great Barrier Reef. A key step was to convene a panel of experts that represented the range of views on impacts of a new development. This meant they could clarify what the panel agreed and did not agree on and make more rapid progress in the debate. It also enabled them to prioritise future research efforts on the unknown impacts.

I have learned some important lessons on communicating my science to decision makers from this session. I hope I can carry these through to my own work.

That’s all from me today. Tomorrow I will be co-chairing a symposium on Ridge to Reef management approaches, so hope to see you there.

Mistakes in this blog, thoughts on this blog, want me to add or remove something? If you have anything to say, feel free to email me.

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