An international consortium has been formed to study the potential effects of adding iron to the ocean to promote the growth of phytoplankton. Phytoplankton use carbon dioxide from the atmosphere and ocean fertilization might therefore be a way of mitigating the effects of global warming. When phytoplankton die, organic carbon sinks to the seafloor where it may remain for decades, centuries or even longer – we still do not now much about the time-line.

Iron fertilization of the ocean is far from uncontroversial, since it is very difficult to foresee the long term effects of such a project. The international consortium, which has been named In-Situ Iron Studies (ISIS) consortium , will carry out iron fertilization experiments in the open ocean in an effort in to answer some of the questions regarding how iron affects the ocean’s capacity for dragging carbon dioxide from the air and into the water. All experiments will adhere to the London Convention/London Protocol regarding ocean iron fertilization research.

“A great deal remains to be learned about ocean iron fertilization and how effective it could be in storing carbon dioxide in the oceans, and the formation of this consortium is an important first step,” says Lewis Rothstein, professor of oceanography at the University of Rhode Island. “This is not a call for climate engineering; on the contrary this is a research consortium. It is premature to advocate for large-scale ocean iron fertilization, but it is time to conduct a focused research experiment that will examine the concept as comprehensively as we can. We want to make sure that it doesn’t generate harmful side effects that might negatively affect the marine ecosystem.”

The twelve ISIS-members are the following:
University of Rhode Island, USA
University of Hawaii, USA
University of Illinois at Urbana-Champaign, USA
University of Maine, USA
University of Massachusetts Boston, USA
University of Plymouth, UK
Xiamen University, Fujian, China
The Antarctic Climate and Ecosystems Cooperative Research Centre, Australia
Netherlands Institute for Sea Research, The Netherlands
The National Oceanography Centre, UK
Moss Landing Marine Laboratories, California, USA
Woods Hole Oceanographic Institution, Massachusetts, USA

walrus

There was a story which was written in the Arizona Daily Star which says “Tens of thousands of walruses have come ashore in northwest Alaska because the sea ice they normally rest on has melted. Federal scientists say this massive move to shore by walruses is unusual in the United States”. The “federal scientists” which the story mentions are supposed to be from the USGS, the U.S. Geological Survey. Since when have they been right about anything?

If you ask the FWS, the U.S. Fish and Wildlife Service, this coming of the walruses is not so far out there, and definitely not unusual.

That walrus of the Pacific makes its home in the shallow waters of the continental shelf of the Chukchi and Bering seas. The actual distribution of the population Pacific walruses actually varies greatly season to season. Almost all of the population makes its home in the pack ice in the Bering sea during the cold winter months. During the winter, they most often stake their claim in two areas, one to the southwest of St. Lawrence Island, and in outer Bristol Bay.

Now, as the Bering Sea pack ice begins to melt down in April, the walruses of course move further north and their population becomes less dense. Some of these walruses inevitably make their way to the shores, perhaps to take in the renowned local hospitality, and this has been the pattern for a long time, and will continue to be in the coming years.

The temperature of the ocean is key in determining just how productive and how much biodiversity there is in the ocean and also where it is.

There have been two separate studies in which researchers discovered that the ocean heating up has caused a massive decline in the amount of plant life in the ocean over the past 100 years. The studies also indicated that there is a link between the ambient temperature of the water of the ocean and the different patterns of marine biodiversity.

“We are just now understanding how deeply temperature affects ocean life,” explained Boris Worm, a biologist of Dalhousie University, and also co-author on both reports published in the July 28 edition of Nature. “It is not necessarily that increased temperature is destroying biodiversity, but we do know that a warmer ocean will look very different.”

In one of the studies performed which took a look at the historical amounts of algae concentrations over the last century, Worm and his associates have discovered that the rising temperatures of the oceans are directly related to the massive decline in marine algae, commonly know in scientific circles as phytoplankton. These phytoplankton also happen to be the base of the food chain for the ocean, and were responsible for creating oxygen on Earth.

The research seems to indicate that the marine algae has declined by about 40 percent since the 1950’s.
“I think that if this study holds up, it will be one of the biggest biological changes in recent times simply because of its scale,” explained Worm. “The ocean is two-thirds of the earth’s surface area, and because of the depth dimension it is probably 80 to 90 percent of the biosphere. Even the deep sea depends on phytoplankton production that rains down. On land, by contrast, there is only a very thin layer of production.”

The study focused on the phytoplankton is the first study to have looked at the changes over the past 100 years, on a global scale and using data from as far back as 1899. Some similar models have been made using the newly available data from satellites, however that data only goes back as far as 1979.

“One of the most important aspects of the new paper is that they’ve come up with the same answer but from a different approach than we saw from space,” explained Michael Behrenfeld, a marine biologist from Oregon State University. “I think that we should be concerned that this convergence of multiple approaches sees a reduction in the phytoplankton pigments as the ocean warms. If we continue to warm the climate we will probably see further reductions.”

So there you have it.. Global warming is having an adverse effect on our oceans.. I guess it’s time somebody stepped up to the plate to do something about it, however the issue has been ignored for so long, it might be very difficult to remedy the situation. Well, at least now there is solid “proof” that there is a problem, and it might finally provide the incentive needed for action to be taken.

Out of the estimated 5.5 gigatonnes of carbon emitted each year by human activities, about 1.8 percent are removed from the air and stored by echinoderms such as starfish, sea urchins, brittle stars and sea lilies. This makes them less important “carbon sinkers” than plankton, but the finding is still significant since no one expected them to catch such a large chunk of our wayward carbon.

The new discovery is the result of a study* led by Mario Lebrato**, PhD student at the Leibniz Institute of Marine Science. The work was done when he was at the National Oceanography Centre, Southampton (NOCS) and affiliated with the University of Southampton’s School of Ocean and Earth Science (SOES).

“I was definitely surprised by the magnitude of the values reported in this study, but [the study’s] approach seems sound, so the reported numbers are probably fairly accurate,” says palaeoceanographer Justin Ries of the University of North Carolina at Chapel Hill.

Ries also points out that these important creatures might be affected by ocean acidification.

“If the echinoderms end up being disproportionately susceptible to ocean acidification then it’s conceivable that the dissolving of echinoderm-derived sediments will be one of the earliest effects of ocean acidification on the global carbon cycle,” he explains. “In fact, maybe it already is.”
The body of an echinoderm consists of up to 80% calcium carbonate and according to the Lebrato study these hard-shelled animals collectively capture 100 billion tons of carbon each year.

“The realisation that these creatures represent such a significant part of the ocean carbon sink needs to be taken into account in computer models of the biological pump and its effect on global climate“, says Lebrato. “Our research highlights the poor understanding of large-scale carbon processes associated with calcifying animals such as echinoderms and tackles some of the uncertainties in the oceanic calcium carbonate budget. The scientific community needs to reconsider the role of benthic processes in the marine calcium carbonate cycle. This is a crucial but understudied compartment of the global marine carbon cycle, which has been of key importance throughout Earth history and it is still at present.”

The study has been published in the journal ESA Ecological Monographs.

* Mario Lebrato, Debora Iglesias-Rodriguez, Richard Feely, Dana Greeley, Daniel Jones, Nadia Suarez-Bosche, Richard Lampitt, Joan Cartes, Darryl Green, Belinda Alker (2009) Global contribution of echinoderms to the marine carbon cycle: a re-assessment of the oceanic CaCO3 budget and the benthic compartments. Ecological Monographs. doi: 10.1890/09-0553.

** mlebrato13 [at]googlemail.com

According to a new UN report, marine plants take 2 billion tonnes of carbon dioxide away from the atmosphere each year as they use the carbon dioxide for photosynthesis. Most of these plants are plankton, but planktons rarely form a permanent carbon store on the seabed. Instead, mangrove forests, salt marshes and seagrass beds are responsible for locking away well over 50 percent of all carbon that is buried in the sea – an amazing feat when you consider that these types of habitat only comprise 1 percent of the world’s seabed.

“The carbon burial capacity of marine vegetated habitats is phenomenal, 180 times greater than the average burial rate in the open ocean,” say the authors of the UN report.

Mangrove forests, salt marshes and seagrass beds are the most intense carbon sinks on our planet and they store away an estimated 1,650 million tonnes of carbon dioxide per year.

Unfortunately, these habitats are being ruined or damaged worldwide and a third of them are believed to have been lost already, although it is difficult to obtain accurate figures regarding the extent of these types of habitats worldwide. What we do know is that half of the world’s population lives within 65 miles of the ocean and that vegetated ocean near habitats are often under severe pressure.

“On current trends they may be all largely lost within a couple of decades”, said Christian Nellemann, the editor of the report.”

To help developing nations protect the remaining marine vegetated habitats the authors of the report suggest that a fund should be launched. They also wish to have a market place created where oceanic carbon sinks are traded in the same fashion as terrestrial forests.

The report, which has been named Blue Carbon, is a collaboration between the United Nations Environment Programme, the Food and Agriculture Organisation and Unesco.

Compared to the record-setting low years of 2007 and 2008, the Arctic Sea ice has made a slight recovery in 2009, according to the University of Colorado at Boulder’s National Snow and Ice Data Center. Despite this positive change, the minimum sea ice extent in 2009 was the third lowest since satellite record-keeping started in 1979.

“It’s nice to see a little recovery over the past couple of years, but there’s no reason to think that we’re headed back to conditions seen in the 1970s,” said NSIDC Director Mark Serreze, also a professor in CU-Boulder’s geography department. “We still expect to see ice-free summers sometime in the next few decades.”

The standard measurement for climate studies is the average ice extent during September. This September, the average Arctic Sea ice extent was 5.36 million square kilometres, which is 1.06 million square kilometres more than September 2007 and 690,000 square kilometres more than September 2008.

According to Mike Steele, Senior Oceanographer at the University of Washington, the decrease in ice loss is probably due to cloudy skies during late summer. Sea surface temperatures in the Arctic were higher than normal this season, but slightly lower than in 2007 and 2008 – most likely due to the presence of clouds this year. Atmospheric patterns in August and September also helped spreading the ice pack over a larger area.

Arctic sea ice follows an annual cycle of melting during the warm season and refreezing in the winter, and the extent of Arctic sea ice has always varied due to changing atmospheric conditions. During the past 30 years, there has however been a dramatic overall decline in Arctic sea ice extent.

“The ‘underwater turbulence’ the jellies create is being debated as a major player in ocean energy budgets,” says marine scientist John Dabiri of the California Institute of Technology.

Jellyfish are often seen to be aimless aquatic drifters, propelled by nothing but haphazard currents and waves, but the truth is that these gooey creatures continuously contract and relax their bells to move in desired directions.

The jellyfish Mastigias papua carries algae-like zooxanthellae within its tissues from which it derives energy and since the zooxanthellae depend on photosynthesis, the jellyfish has to stay in sunny locations. Research carried out in the so called Jellyfish Lake, located in the island nation of Palau 550 miles east of the Philippines, shows that this jellyfish doesn’t rely on currents to bring it to sunny spots – it willingly budges through the lake as the sun moves across the sky.

In Jellyfish Lake, enormous congregations of Mastigias papua can be found in the western half of the lake each morning, eagerly awaiting dawn. As the sun rises in the east, all jellyfish turn towards it and starts swimming towards east. The smarmy creatures will swim for several hours until they draw near the eastern end of the lake. They will however never reach the eastern shore, since the shadows cast by trees growing along the shoreline cause them to stop swimming. They shun the shadows and will therefore come to a halt in the now sundrenched eastern part of the lake. As the solar cycle reverses later in the afternoon, millions of jellyfish will leave the eastern part of the lake and commence their journey back to the western shore.

Together with his research partner, marine scientists Michael Dawson of the University of California at Merced, John Dabiri have investigated how this daily migration of millions of jellyfish affects the ecosystem of the lake.

What the jellies are doing, says Dabiri, is “biomixing”. As they swim, their body motion efficiently churns the waters and nutrients of the lake.

Dabiri and Dawson are exploring whether biomixing could be responsible for an important part of how ocean, sea and lake waters form so called eddies. Eddies are circular currents responsible for bringing nitrogen, carbon and other elements from one part of a water body to another. The two researchers have already shown how Jellyfish like Mastigias papua and the moon jelly Aurelia aurita use body motion to generate water flow that transports small copepods within jellyfish feeding range; now they want to see if jellyfish movements make any impact on a larger scale.

“Biomixing may be a form of ‘ecosystem engineering’ by jellyfish, and a major contributor to carbon sequestration, especially in semi-enclosed coastal waters,” says Dawson.

According to the simplest version of the so called Iron Hypothesis, plankton blooms move atmospheric carbon down to the deep sea and increased carbon dioxide levels in the atmosphere can therefore be counteracted by promoting plankton blooms. The Iron Hypothesis derives its names from the suggestion that global warming can be thwarted by fertilizing plankton with iron in regions that are iron-poor but rich in other nutrients like nitrogen, silicon, and phosphorus, such as the Southern Ocean.

New research from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory is now dealing a powerful blow to this hypothesis by showing that most of the carbon used for plankton blooms never reaches to deep sea.

Using data collected around the clock for over a year by deep-diving Carbon Explorer floats, Oceanographers Jim Bishop* and Todd Wood** have revealed that a lot of the carbon tied up by plankton blooms never sink very far.

“Just adding iron to the ocean hasn’t been demonstrated as a good plan for storing atmospheric carbon,” says Bishop. “What counts is the carbon that reaches the deep sea, and a lot of the carbon tied up in plankton blooms appear not to sink very fast or very far.”

The reasons behind this behaviour are complex, but the seasonal feeding behaviour of planktonic animal life is believed to play major part.

Photoplankton

The Carbon Explorer floats used in the study were launched in January 2002, as a part of the Southern Ocean Iron Experiment (SOFeX)***, and experiment meant to test the Iron Hypothesis in the waters between New Zealand and Antarctica during the Antarctic summer.

SOFeX fertilized and measured two regions of ocean, one in an HNLC (high-nutrient, low-chlorophyl) region at latitude 55 degrees south and another at 66 degrees south. Carbon Explorers were launched at both these sites while a third Carbon Explorer was launched well outside the iron-fertilized region at 55 degrees south as a control.

Bishop and Wood were originally assigned to the project to monitor the iron-fertilization experiment for 60 days, but the Carbon Explorers continued to transmit data throughout the Antarctic fall and winter and on into the following spring.

“We would never have made these surprising observations if the autonomous Carbon Explorer floats hadn’t been recording data 24 hours a day, seven days a week, at depths down to 800 meters or more, for over a year after the experiment’s original iron signature had disappeared,” Bishop explains. “Assumptions about the biological pump – the way ocean life circulates carbon – are mostly based on averaging measurements that have been made from ships, at intervals widely separated in time. Cost, not to mention the environment, would have made continuous ship-based observations impossible in this case. Luckily one Carbon Explorer float costs only about as much as a single day of ship time.”

The scientific hypothesis that iron can be used to stimulate phytoplankton growth in regions low in iron but rich in other nutrients is still intact and experiments show that algal blooms do in fact occur if you add iron to such waters. The study by Bishop and Wood only shows that the carbon bound by the plankton do not end up far down in the depths of the sea.

Jim Bishop’s team. (From left) Christopher Guay,
Phoebe Lam, Jim Bishop, Todd Wood, and David Kaszuba.

During the early stages of the South Sea experiment, the Iron Hypothesis seemed to hold up to scrutiny as the Berkeley researchers could detect not only a vigorous plankton bloom in the fertilized region at 55°N, but also how carbon particles sank beneath the bloom carrying 10-20 percent of the fixed carbon away from the surface layer and down to a dept of at least 100 meters. These results were published in the 2004April issue of Science.

But since the Carbon Explorers continued to submit information even when the 3-month study was officially over, Bishop and Wood could continue their monitoring of South Sea carbon levels throughout fall and winter and well into the following spring; a continued monitoring that would prove invaluable.

The two Carbon Explorers released at 55 degrees south continued to report for over 14 months and almost reached South America before they turned silent. After this, the explorer launched at 66 degrees south continued to transmit for another four months, despite having spent much of the Arctic winter recording at a dept of 800 meters where the pressure is immense. This explorer also had several encounters with the underside of chunky sea ice as it tried to surface to report during the Arctic winter.

All this new data surprisingly showed that there seemed to be much less particulate matter reaching the depth where the biomass was highest, i.e. in plankton blooms. Reports from the 66°S explorer showed how particulate carbon levels decreased sharply as the perpetually dark Arctic winter commenced and ice began to cover previously open waters. As the sun returned in spring and melted the ice the levels made a modest increase, but no sinking (sedimentation) of large amounts of carbon to the deep ocean was observed.

Another even more surprising report came from the control float, dubbed 55 C, which reported higher sedimentation of carbon 800 meters under a region with no plankton bloom than what the other 55°S (dubbed 55A) reported from the fertilized, blooming region.

Researchers are currently pondering several ideas as to explain these unforeseen results but have not reached any conclusion. A higher biomass seems to be linked to a lower export of carbon, but one knows why. One of the most promising hypotheses takes into account how phytoplankton needs sufficient amounts of light to survive and grow. Latitude 55°S is located far enough from the Arctic for light to reach the ocean year round, even though the amount is severely reduced during the winter months. But the notorious winter storms occurring in these waters can cause mixing between near-surface water and underlying water layers all the way down to a dept of 400-500 meters. Phytoplankton are dragged down to depths where it is too dark for them to grow and where hungry zooplankton waits for them.

“Mixing is the dumbwaiter that brings food down,” says Bishop. “The question is whether the dumbwaiter is empty or full.”

If mixing is consistently below the critical light level, phytoplankton can not grow, i.e. the dumbwaiter stays empty and the zooplankton gets no food. As the winter storms stop with the advent of spring, the phytoplankton can quickly rebound, aided by increased levels of sunlight. But since a lot of zooplankton starved to death during the winter, the zooplankton population is not large enough to keep steps with the phytoplankton bloom and intercept carbon loaded material as it sinks between 100 and 800 meters.

In the part of the South Sea where Carbon Explorer 55C spent the winter collecting data, storms where not continuous and the mixing was therefore halted now and then. More zooplankton survived, zooplankton which fed on the phytoplankton in spring, keeping their numbers down and increasing carbon sedimentation.

Bishop says these observations point to an important lesson: “Iron is not the only factor that

determines phytoplankton growth in HNLC regions. Light, mixing, and hungry zooplankton are fundamentally as important as iron.”

You can find more information about Bishop and Wood’s study in the journal Global Biogeochemical Cycles. Preprints of the issue are already available to subscribers at http://www.agu.org/journals/gb/papersinpress.shtml.

* Jim Bishop is a member of Berkeley Lab’s Earth Sciences Division and a professor of Earth and planetary sciences at the University of California at Berkeley.

** Todd Wood is a staff researcher with the U.S. Department of Energy’s Laurence Berkley National Laboratory.

*** The Southern Ocean Iron Experiment (SOFeX) is a collaboration led by scientists from Moss Landing Marine Laboratory and the Monterey Bay Aquarium Research Institute.

In a study announced today by the Wildlife Conservation Society* (WCS) at the International Coral Reef Initiative** (ICRI) meeting in Thailand, researchers show that some coral reefs located off East Africa are unusually resilient to climate change. The high resilience is believed to be caused by geophysical factors in combination with improved fisheries management in these waters.

After studying corals off the coast of Tanzania, researchers found that these coral reefs has made an incredibly speedy recovery from the 1998 bleaching event that wiped out up to 45 percent of the region’s corals. The authors of the study attribute the swift recovery to a combination of reef structure and reef management.

Compared to many other coral reefs around the world, Tanzania’s reefs are used to considerable variations in both current and water temperature which has turned these reefs into an unusually complex web of different coral species. This bio-diverse ecosystem includes several different species known to quickly re-colonize an area after a bleaching incident.

The authors of the study believe that reefs in other parts of the world subjected to similarly diverse environmental conditions might have the same high ability to recover from large-scale climatic and human disturbances. The study provides additional evidence that such “super reefs” can be found in the triangle from Northern Madagascar across to northern Mozambique to southern Kenya and the authors suggest that these reefs should be a high priority for conservation efforts since they may come to play an important global role in the future recovery of coral reefs worldwide.

“Northern Tanzania’s reefs have exhibited considerable resilience and in some cases improvements in reef conditions despite heavy pressure from climate change impacts and overfishing,” says Dr. Tim McClanahan***, the study’s lead author. “This gives cause for considerably more optimism that developing countries, such as Tanzania, can effectively manage their reefs in the face of climate change.”

The study also stresses the impact of direct management measures in Tanzania, including closures to commercial fishing. Algae is known to easily smother corals, but researchers found how areas with fishery closures contained a rich profusion of algae eating fish species that kept the corals clean. The few sites without any management measures remained degraded, and in one of them the population of sea urchins had exploded. Sea urchins feed on corals and can therefore worsen the problem for an already suffering reef.

The study has been published in the online journal Aquatic Conservation: Marine and Freshwater Ecosystems.

Authors of the study include Tim McClanahan and Nyawira Muthiga of the Wildlife Conservation Society, Joseph Maina of the Coral Reef Conservation Project, Albogast Kamukuru of the University of Dar es Salaam’s Department of Fisheries Science and Aquaculture, and Saleh A.S. Yahna of the University of Dar es Salaam’s Institute of Marine Sciences and Stockholm University’s Department of Zoology.

* The Wildlife Conservation Society is an institutional partner to ICRI and is actively conserving tropical coral reef species in priority seascapes in Belize, Indonesia, Papua New Guinea, Fiji, Kenya and Madagascar. Along with monitoring reefs, WCS also trains of park staff in protected areas.

** The International Coral Reef Initiative (ICRI) is a global partnership among governments and organizations working to stop and reverse the degradation of coral reefs and related ecosystems. This ICRI General Meeting was convened by the joint Mexico – United States Secretariat.

*** Dr. McClanahan’s research regarding ecology, fisheries, climate change effects, and management of coral reefs at key sites throughout the world is supported by the Western Indian Ocean Marine Science Association (WIOMSA) and The Tiffany & Co. Foundation.

The oceans of the world absorb a large part of the carbon dioxide released into the atmosphere by us burning fossil fuels, burning forests to make room for fields, etc. This have helped slow down global warming, but new studies shows that it might have a devastating effects on certain fish species such as clown fish. Tests performed on clown fish larvae have shown that increased levels of carbon dioxide can make them disoriented an unable to find a suitable home and avoid predators. The pH level in the ocean has dropped 0.1 since pre-industrial times due to the absorption of carbon dioxide and researchers believe that it will fall another 0.3-0.4 before the end of this century.

This increased acidicy of the water can cause serious problems for clown fish larvae, since clownfish larvae lose the ability to sense vital odours in more acidic waters – probably owing to the damage caused to their olfactory systems. Kjell Døving (Oslo University), co-author of the rapport that was published in US journal Proceedings of the National Academy of Sciences, says “They can’t distinguish between their own parents and other fish, and they become attracted to substances they previously avoided. It means the larvae will have less opportunity to find the right habitat, which could be devastating for their populations.“

The research indicates that other species might be affected in a similar way and might have a hard time finding their way to suitable habitats if carbon dioxide levels raises in the oceans.

About the study

The study was executed in such a way that the researchers checked how well clownfish larvae could detect smells in normal sea water (pH 8.15) and how well they could detect odours in more acidic water (at levels predicted to be a reality around the year 2100 and later). The test showed that at pH 7.8 the larvae stopped following scent trails released by reefs and anemones and started following sent trails they would normally avoid; scents that are associated with environments not suitable for clown fish. The larvae also lost the ability to use smell to distinguish between their parents and other fish. At pH 7.6 the larvae were unable to follow any kind of odour in the water, and instead swam in random directions.