Monthly Archives: September 2009

Where would you want to live under sea level rise? Interactive floods maps

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Ever wondered where the wise investment in the property market is going to be under the IPCC projected scenarios? Check out the Sea Level Rise Explorer over at Global Warming Art:

During the twentieth century, sea level rose 20 cm. It is predicted that sea level rise will accelerate during the twenty-first century, but many model predictions still foresee a sea level rise of less than 1 additional meter by 2100.

Regardless of the time scale involved, an analogy to the previous interglacial suggests that a few degrees Celsius of sustained warming can cause enough melting to raise sea level 4-6 m before the ice sheets reach equilibrium. This level of warming is likely to be achieved or even exceeded by 2100 in the absence of intervention to combat climate change, though as above, it would take far longer to realize the full sea level change.

Belize passes a law to limit fishing of herbivores

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This past May, my lab surveyed 20 reefs in Belize from Bacalar Chico in the north, down to the Sapodilla Keys in the south.  It was a fantastic expedition.  We had great weather and very calm seas.  I was amazed at how wild much of coastal Belize still is.  We saw manatees in mangrove creeks and red footed boobies on offshore keys.  On some islands you can’t snorkel at night due to the hungry crocs.  But I have to admit, the reefs were in pretty bad shape.  Mainly from Hurricane Mitch, which struck Belize in 1998, but also from coral disease, bleaching (also in 98) and possibly local stressors.

Glovers_fisher

We were also struck by the intensity of spear fishing, especially on reefs in the central  Belizean Barrier Reef, even inside MPAS (but outside of the no-take zones) where fishing is allowed.  One morning we surveyed a reef just of the southeastern tip of Glovers Atoll, inside a no-take zone.  There was lots of macroalgae and few herbivores, despite the fully protected status.  After pulling away from the site, just a few tens of meters outside the no-take zone, we encountered a young spearfisherman in a simple canoe.  He was on the forereef, in the open ocean!  The mother ship – an equally sketchy looking sailboat – was behind the reef crest.   He was very friendly and came over to our boat to show off his catch; nearly 70 kilos of fish by 11 AM!  Mostly parrotfish, triggerfish, angelfish and barracuda.  The fish are filleted at sea and sold in the fish markets and to local restaurants as “fillet”, i.e., mystery meat.

Pretty depressing.  The no-take zones are so small I imagine many fish wander out of them, unknowingly into the line of fire.  But the Belizean government just passed a new law designed to protect parrotfish and other key grazers.  From a post on the WCS website:

Belize is giving its beleaguered parrotfish, Nassau grouper, and other reef fish a chance to recover from years of overfishing. The national government and minister of agriculture and fisheries signed a sweeping set of new laws to protect the country’s extensive coral reefs…

The first of the new laws will protect parrotfish and other grazers, such as doctor and surgeonfish. These herbivores keep algae growth in check, enabling corals to flourish. In the past, fisherman did not target the grazing fish; rather, they caught mainly snappers and groupers. It was only when these species declined that they turned to the next tier of the food web, and parrotfish began to disappear.

WCS research from Glover’s Reef show that parrotfish are now the most commonly caught fish on this part of the Belize Barrier Reef Reserve System. As a consequence, coral cover has declined. Marine researchers expect that the new laws protecting parrotfish and other grazers will help the corals recover.

The second set of regulations will protect Nassau grouper, which is listed as an endangered species by IUCN’s Red List. The new rules set a minimum and maximum size limit, and require that all Nassau groupers be brought back to the dock whole. Until now, fishermen have generally brought in their catch as fillets, making it difficult to monitor catch rates. All other fish can still be brought in as fillets but must retain a patch of skin so authorities can confirm that they aren’t Nassau grouper.

The third regulation bans spearfishing within marine reserves. Spearfishing is the main method used to catch grazing fish, Nassau grouper, and other groupers and has caused severe declines of these species.

Other aspects of the new laws create “no-take” zones in protected areas. South Water Caye and Sapodilla Cayes marine reserves are now closed to fishing, and the Pelican Cayes—a hotspot for rare sponges and sea squirts—are also off-limits. Though these marine reserves were declared in 1996 and form part of the Belize Barrier Reef Reserve System World Heritage Site, prior to this law, fishing had been permitted there.

We will be tracking the 20 sites to monitor how parrotfish populations change and whether this has cascading effects on corals, algae, etc. Interestingly, the   when Melanie McField, a leading coral reef scientist in Belize and the director of the Healthy Reefs for Healthy People initiative showed a video of parrotfish grazing (which you can see here) to the minister of the environment, this is what it took to convince him of the role of these grazers in reef ecosystems.  All the science in the world isn’t as powerful as a good You Tube video.

[youtube=http://www.youtube.com/watch?v=4n6pJLC2c0A&w=425&h=344]

Arctic ‘warmest in 2,000 years’

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_46316580_arctic_temperatures_466gr

New research from the journal Science shows that arctic temperatures are higher now than they have been for the past 2000 years. Using ice cores, tree rings and lake sediments, Kaufmann et al were able to establish a comprehensive record of decadal change within the region, revealing that four of the five warmest decades occured between 1950 – 2000. One of the most striking factors is the rate of this change  – a gradual cooling is evident throughout the time series (0.2°C up untill 1900), yet the subsequent rate of warming in the last century is substantial (1.2°C – see the hockey-stick curve above). Click below to read more from the BBC News, or here for the article summary from Science.

“The most pervasive signal in the reconstruction, the most prominent trend, is the overall cooling that took place for the first 1,900 years [of the record],” said study leader Darrell Kaufman from Northern Arizona University in Flagstaff, US.

“The 20th Century stands out in strong contrast to the cooling that should have continued. The last half-century was the warmest of the 2,000-year temperature record, and the last 10 years have been especially dramatic,” he told BBC News. (Read More)

Coral reef gloom and doom in the news

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The GBRMPA report Ove covered yesterday and several related reports about the threats to and economic value of coral reefs made international headlines today.

from Reuters:

CANBERRA (Reuters) – Australia’s Great Barrier Reef, the world’s largest living organism, is under grave threat from climate warming and coastal development, and its prospects of survival are “poor,” a major new report found on Wednesday.

“We know that a failure to act on dangerous climate change puts at risk significant places like the Great Barrier Reef and this report confirms the scale of the challenge ahead,” Australia’s Environment Minister Peter Garrett said.

read the full story here

from the BBC:

Current climate targets are not enough to save the world’s coral reefs – and policymakers urgently need to consider the economic benefits they bring.

Those are two of the conclusions from a UN-backed project aiming to quantify the financial costs of damaging nature.  Studies suggest that reefs are worth more than $100bn (£60bn) annually, but are already being damaged by rising temperatures and more acidic oceans. The study puts the cost of forest loss at $2-5 trillion annually.

Looking ahead to December’s UN climate conference in Copenhagen, study leader Pavan Sukhdev said it was vital that policymakers realised that safeguarding the natural world was a cost-effective way of protecting societies against the impacts of rising greenhouse gas levels.

There are a number of somewhat notional targets on the table in the run-up to Copenhagen.  One, an EU initiative that now has much wider support, is to keep the global average temperature rise since the pre-industrial age within 2C – which according to some analyses means carbon dioxide concentrations in the atmosphere cannot rise above 450 parts per million (ppm). The current level is about 387ppm, and it is rising at about 2ppm each year, although this year’s global recession may bring a blip.

Mr Sukhdev’s team heard evidence from coral scientists that these targets would not be enough to prevent damage to coral reefs around the tropics.

read the full story here

Increasingly bleak future for the Great Barrier Reef?

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Screen shot 2009-09-02 at 10.12.30 PM

The Great Barrier Reef Marine Park Authority released it’s Outlook Report 2009 today (direct link to PDF’s here). The report is a independently peer reviewed assessement of the impacts of climate change, catchment runoff, fishing, coastal development and an array of other impacts on the reef. Alongside the report comes the signing of a new State and Federal Government plan to protect the GBR, tightening regulations for farmers and improving water quality in the GBR lagoon:

“This is about a renewed plan that is underpinned by new and ambitious targets,” Ms Bligh told Parliament today.

“… Through the measures identified in the renewed reef plan we aim by 2013 to halve the runoff of harmful nutrients and pesticides and ensure at least 80 per cent of agricultural enterprises and 50 per cent of grazing enterprises have adopted land management practices that will reduce runoff.”

Ms Bligh said the reef’s resilience had to be built up so it could cope with the effects of climate change, predicted to cause more frequent coral bleaching among other things.

“The poor quality of water running into the reef from catchments has been identified in report after report as a major threat,” she said.

Ms Bligh said two million people visited the coast between Bundaberg and Cairns each year, spending more than $5 million and underpinning 50,000 jobs in the tourism industry alone.

Fisheries contribute a further $290 million annually to the economy, she said.

“We must strike a delicate balance – a balance between making the most of this natural asset and affording it every protection possible,” she said. (Read More)

The sharpnose puffer explosion of 2009

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Many people have observed the striking increases in sharpnose pufferfish on Caribbean reefs this year.   You can read accounts of the explosion here and here (hint: click “next message” to scroll through them).  The sharpnose puffer is a small (3-4 cm), goofy (or cute depending on your perspective) fish that hovers around the bottom of reefs like little helicopters.  My lab surveyed 20 reefs in Belize in May and we were struck by their densities.  At several sites, they were literally the most common fish!  Their antics kept us all entertained as we performed our surveys.

Such regional population explosions are not uncommon.  I worked on a massive explosion of subtidal mussels with Jon Witman in the Gulf of Maine when I was a PhD student in the mid 1990s.  We surveyed dozens of sites off Rhode Island, New Hampshire and up into Maine, many miles offshore.  Everywhere we went, the coverage by tiny mussel recruits was near 100%.  But within months, their predators responded and sea star populations, having gone through their own explosion, gobbled them up (Witman et al 2003).

Regarding the sharpnose pufferfish phenom, our otherside video of the month prize goes to Drew Wohl who documented the plight of the sharpnose puffer in a short film that includes dire warnings and sad music to accompany the puffer-death-spiral.

[youtube=http://www.youtube.com/watch?v=MrCDe6vfsaU&w=560&h=340]

Canary in a coal mine?  Caused by coastal development? Personally, I really doubt it.   In Belize, the puffers where everywhere, including inside fully-protected reserves and on reefs tens of miles from shore and people.  In fact the highest densities (64 individuals per 100m2) were on Glovers Reef, just east of the WCS research station in a no-take reserve.


Reference

Witman, J.D., et al. (2003) Massive prey recruitment and the control of rocky subtidal communities on large spatial scales. Ecological Monographs 73, 441-462