Feeling the heat in Hawaii – climate change and the pacific decadal oscillation

Posted on September 9, 2009 by ovehblog

A new paper published in Geophysical Research Letters sheds some interesting light on the impacts of climate change and regional shifts in temperature. Whilst it’s generally accepted that the instrumental temperature record shows an upward trend (see here for a graph), the regional patterns of climate change are less well known. Through analysis of an 85 year dataset of 21 base stations across the Hawaiian Islands, Giambelluca and his team from the University of Hawai’i show a dramatic increase in temperature trends over the past 30 years, with a stronger trend in the high altitude regions. According to their data, most of this warming is attributed to increases in minimum temperatures rather than the maxima, resulting in a decrease in the diurnal range of temperatures:

Hawaii_-Temperature-gradient

At a glance, it’s easy to ‘eyeball’ this graph and consider it a skeptical field day. After all, according to the data the temperature was warmer in the 1940’s than throughout the last two decades, right? Even more alarming: for the majority of the dataset, the temperature cycles have followed the pacific decadal oscillation (PDO, a natural pattern of climate variability in the pacific on a 20-30 year cycle). The long-term trends of the PDO look like follow a trend as follows:

800px-Reconstructed_PDO_since_1660

The recent Hawaii data set suggests that although the PDO is currently in a ‘cool’ phase, climate change has effectively ‘derailed’ the PDO cycle, as evident in the increase in linear trends of temperatures from 1975 onwards. Such changes on a regional scale are a huge cause for concern, particularly in the high altitude areas of Hawaii such as Mauna Kea (the worlds tallest mountain when measured from the base of the Pacific Ocean), which has a high rate of endangered endemic flora and fauna.

Japan aims for 25% reduction in CO2 emissions by 2020

Posted on September 7, 2009 by ovehblog

Japan vows big climate change cut” (BBC News, 7th September 2009)

Japan’s next leader has promised a big cut in greenhouse gas emissions, saying he will aim for a 25% reduction by 2020 compared with 1990 levels.

Democratic Party leader Yukio Hatoyama is due to take over as prime minister on 16 September, after a resounding election victory in August.

His predecessor, Taro Aso, had pledged cuts of only 8%.

Mr Hatoyama said the plan was dependent on other nations agreeing targets at December’s climate talks in Copenhagen. (Read More)

“Armed forces may be the agents of climate change” (The Age, 5th September 2009)

THE oceans are getting warmer, coral reefs are increasingly under threat, Arctic ice is dropping into the sea. July was the warmest month in 130 years of testing ocean temperatures. Who are we going to call?

The admirals and the generals. It appears that the US military is as concerned about the fate of the Earth as the man and woman on Civvy Street. And, as history has shown, what troubles the US generals troubles the rest of the world. (Read More)

“One minute to midnight for Maldives’ corals” (Minivan News, 6th September 2009)

If the experts are right, however, the Maldives’ coral reefs are in terminal decline. A UN report entitled The Economics of Ecosystems and Biodiversity released last week in Berlin, stated the world’s coral infrastructure and accompanying biodiversity would be the first ecosystem to go due to climbing greenhouse gases.

The message is critical; the reality is grim. “Corals are the foundation of the whole ecosystem, the building blocks of the reef itself,” said Guy Stevens, a British marine biologist at Four Seasons resort. “If the reef went, the Maldives would cease to exist, the islands themselves would be eroded and washed away. Without them, there’s nothing.” (Read More)

More evidence of the old switcheroo in the seafood industry

Posted on September 6, 2009 by ovehblog

By Michael Vasquez, Miami Herald

Genetics professor Mahmood Shivji didn’t get into DNA research to strike fear in the hearts of restaurant owners and chefs. But the Guy Harvey Research Institute, which he heads, is a virtual CSI: Seafood lab these days. The widespread — and illegal — practice of fish substitution at restaurants has placed Shivji’s marine life genetics expertise in high demand.

In the last two years, Shivji has analyzed upward of 100 restaurant plates from across the country, more than half the time proclaiming that the dish was not the grouper or snapper specimen that diners thought they were eating. Instead, restaurants secretly served up cheaper fish such as catfish or tilapia.

“It’s consumer fraud,” said Shivji, who teaches at Nova Southeastern University. “You’re paying for item X and usually grouper and red snapper are on the higher end of the price list.”

With domestic grouper costing restaurants $11 or $12 a pound — and imported catfish available for a mere $2.50 a pound — unsavory chefs can profit handsomely from this unethical bait-and-switch.

Shivji has picked apart breaded fillets, fillets doused in sauce, even charred fillets left on the grill a little too long.

“We can tell with 100 percent certainty” whether restaurants are scamming, Shivji said. The professor’s initial interest in identifying fish through DNA came from his passion for conservation. The federal government was having a hard time enforcing protections for endangered shark species, for example, because rogue fishermen would chop up their illegal shark catches in ways that hid any identifying features.

But chopping up a fish can’t hide the DNA, Shivji reasoned. Shivji went on to pioneer a new way of testing shark DNA that has been instrumental in cracking down on the shark fin trade.

SCOPE OF PROBLEM

Enter CBS4’s Al Sunshine. Sunshine approached Shivji in 2007 with the idea to use the power of DNA to expose fish-swapping restaurants. Sunshine had to do a bit of arm-twisting to convince Shivji to run the first test, but Shivji’s skepticism melted as the evidence of rampant seafood fraud poured in.

“It just validates the argument that this is a national, if not international, problem,” Sunshine said.

Shivji’s phone was soon deluged with calls from TV reporters in other towns. Shivji dutifully accepted and tested their frozen fish samples — mailed in from places that included Los Angeles, New York and Charlotte, N.C.

Shivji has also fielded inquiries from an unidentified local fish wholesaler (who wanted to make sure his inventory was legit) and the Missouri attorney general’s office (which was investigating restaurants in Kansas City).

Fish mislabeling persists in part because it is virtually impossible for federal and state regulators to police all of the nearly five billion pounds of seafood consumed by Americans each year — more than 80 percent of which is imported.

Many restaurant patrons are also unfamiliar with the differences between species — they might order grouper simply because it’s a name they’ve heard before. “Most consumers can’t really tell the difference between a grouper and a catfish,” said Carlos Sanguily, vice president of Doral-based fish importer JC Seafood.

Aside from not getting what you pay for, fish mislabeling is a serious obstacle to ocean conservation efforts, Shivji said.

Read the full story here

And related stories here and here, a great story in the NYT about how sushi and seafood restaurants sell farm-raised salmon as wild (and got busted for doing so) and about the study that started it all, performed by by my former colleague Peter Mark and a team of UNC students! here

Global warming warps marine food webs

Posted on September 5, 2009 by ovehblog

Dina Leech and Virginia Schutte collect zooplankton from Bogue Sound using a plankton tow net. Plankton from the net were rinsed into a sieve and then added to the experimental microcosms. Photo: M. O'Connor

Humans rely on marine ecosystems for economic and nutritional sustenance—including about 16% of animal protein consumed by humans—making it especially important for natural scientists, economists, conservationists and long-term policy planners to understand how climate change is likely to affect oceanic food webs. Yet the general effects of warming on food web productivity are completely unknown. The productivity of consumers (such as zooplankton), in food webs is determined in large part by their metabolic rates and the availability and productivity of their limiting metabolic resources. A general theory relating food web dynamics to temperature suggests that fundamental differences between consumers and primary producers (such as phytoplankton) may lead to predictable shifts in their relative abundance and productivity with warming. A team of UNC scientists led by my former PhD student Mary O’Connor experimentally tested the effects of warming on food web structure and productivity under two resource supply scenarios. Our results show that warming alone can strengthen the role of consumers in the food web, increasing consumer biomass relative to producer biomass, and reducing the total biomass of the food web despite increases in primary productivity. In contrast, when resources were less available, food web production was constrained at all temperatures. These results demonstrate that small changes in water temperature could drive dramatic shifts in marine food web structure and productivity, and potentially provide a general, species-independent mechanism of ecological response to climate change.

Mary O’Connor checks temperatures in the food web experiment. Eight water tables each contain five microcosms, which are shielded from UV and full sunlight by plexiglass and window screen. The water bath maintains the temperature, and air tubes going into each microcosm deliver oxygen. Photo: A. Anton

From an article about the paper in Science Now:

By Erik Stokstad, 26 August 2009

Teasing apart the complex ways in which global warming will affect ocean life has been tough. But new research suggests that a simple ecological theory may explain at least one piece of the puzzle: the effect on marine food webs. And the news may not be all bad.

New experiments confirm that phytoplankton, which form a bottom rung of oceanic food chains, will become less productive in warmer, nutrient-rich water. However, the results also show that zooplankton should boom in these warmer areas, which could benefit certain fisheries.

The food-web theory hinges on the assumption that temperature affects the metabolism of organisms that rely on other creatures for food, like zooplankton, while not having much of an impact on photosynthetic organisms like phytoplankton. That suggests that in warmer waters, zooplankton should generally grow faster and start reproducing sooner than they do in cooler waters. As zooplankton become more abundant and eat more phytoplankton, the population of phytoplankton should shrink.

Mary O’Connor, now a postdoc at the National Center for Ecological Analysis and Synthesis in Santa Barbara, California, and her colleagues set up an experiment to test the theory. They put zooplankton and phytoplankton into 4-liter tubs and let them sit for 8 days. Some were kept at the ambient temperature; others were heated by 2°, 4°, or 6°C. Recognizing that nutrient levels vary in the ocean, they added extra nitrogen and phosphorous to half the tubs in each group.

As temperatures rose, the productivity of the communities without extra nutrients hardly changed. Nor did the food web. This suggests to O’Connor and her colleagues that nutrient-poor food webs may be relatively resilient to global warming. The tubs that got additional nutrients were another story: The zooplankton in warmer water became more abundant while the numbers of phytoplankton fell. In fact, the ratio of zooplankton to phytoplankton rose 10-fold, the team reports in a paper posted online on 25 August in PloS Biology. “It matched our predictions really well,” O’Connor says. She adds that even though overall biological productivity declined as temperature rose, the increase in zooplankton could benefit fish that eat them in nutrient-rich waters.

Concentrated phytoplankton at the end of the experiment. Phytoplankton from 50 mls (1/60) of each microcosm are filtered onto a white filter before the concentration of chlorophyll is measured. Higher density of phytoplankton results in deeper green color.

There is a great synopsis of the article in PLoS which starts out with a pretty politically charged perspective:

While politicians like United States Representative Michele Bachmann (RMinn.) rail against efforts to curb human contributions to global warming—she thinks carbon dioxide, a ‘‘natural byproduct of nature,’’ could not possibly be harmful—scientists are documenting the damage. Numerous studies describe how climate change is threatening the persistence of a broad range of plant and animal species across diverse taxa, geographic regions, and trophic levels, from the polar bear at the top of the food chain to the shrimp-like krill at the bottom. As they catalog the ecological casualties.

Mary also published the study-related haiku in the New Yorker, which originally appeared at the website Dissertation Haiku.

Hungry herbivores,

It’s warm; feel your tummies growl?

Graze down hot seaweed.

See the related story in Scientific American here

Reference

O’Connor MI, Piehler MF, Leech DM, Anton A, Bruno JF (2009) Warming and Resource Availability Shift Food Web Structure and Metabolism. PLoS Biol 7(8): e1000178. doi:10.1371/journal.pbio.1000178

Download the PDF: http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.1000178

Download the PLoS Synopsis: http://www.plos.org/press/plbi-07-08-OConnorSynopsis.pdf

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

Posted on September 5, 2009 by ovehblog

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

Posted on September 4, 2009 by ovehblog

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’

Posted on September 3, 2009 by ovehblog

_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

Posted on September 2, 2009 by ovehblog

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?

Posted on September 2, 2009 by ovehblog

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

Posted on September 1, 2009 by ovehblog

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.