2010 in review

RECENT POSTS

January 14, 2011 | 10:32 AM | By

Phytoplankton decline or not? Four points to consider

NASA Earth Observatory

A phytoplankton bloom near Norway, as observed by NASA's Aqua-MODIS satellite on July 27, 2004.

One of the most notable scientific findings of 2010 came from a group of scientists at Dalhousie University in the form of evidence of a 40% decline in phytoplankton (the microscopic marine plants that generate half of the oxygen on Earth) since 1950, coinciding with rising ocean temperatures. Even more interesting than the results (if that’s possible), were the methods the researchers used to arrive at this conclusion – not high-tech satellite measurements, but data collected with a device called a Secchi disk – essentially, a plate-sized white disk on a rope that is used to gauge the transparency (or conversely, the turbidity) of the ocean by measuring the depth at which it becomes invisible. The scientists used mathematical models to infer phytoplankton concentrations from hundreds of thousands of turbidity measurements. As I wrote, the approach was not embraced by everyone:

this study sparked some debate among experts in the field. A lot of data from a lot of different sources went through a lot of blending, filtering, and modeling, leaving some with doubts about the reliability of the results.

If you were left unsatisfied by that vague description of the concerns about this study, you’re not alone. Tracking down more specifics took a little bit of, well, tracking. Eventually, a local ocean color researcher suggested I get in touch with Mark Ohman, an oceanographer at Scripps Institution of Oceanography whose critiques, she said, were the most concrete and mature she’d seen. After a few emails back and forth, Mark posted his critique as a comment on the Nature website. Here are some of the highlights:

Continue reading →

FILED UNDER: Ocean Change, 2010 in review, phytoplankton, sea surface temperature
January 11, 2011 | 8:49 PM | By

Listen up

On Monday morning, I was on The Point – WCAI’s public interest call-in show – talking about the biggest ocean discoveries and news stories of 2010. A fun time was had by all. You can listen here.

Joel called in with a question about the undersea electricity transmission lines I mentioned, specifically whether they would be high-voltage DC (more efficient for long distance transmission) or AC (what’s generated by wind turbines and used in our homes). I’ve confirmed that, in the cases of both the Deepwater Wind Energy Center and Google’s proposed project, the transmission lines will, indeed, be high-voltage DC with AC/DC conversion stations at the sites of power generation (i.e. wind farms) and landfall.

FILED UNDER: Mitigation, 2010 in review, wind energy
January 11, 2011 | 1:21 PM | By

Looking back, looking forward

The Yale Forum on Climate Change and the Media has two great pieces up right now – one looking back on the most notable climate-related stories of 2010:

The year now just behind us flew by with record warm temperatures, severe droughts, and numerous other weather anomalies; policy action and inaction; evolving attitudes on geoengineering and adaptation; and evolving attitudes and action by American voters on climate change.
And one peering into the future of the climate policy:

The Environmental Protection Agency, buttressed by the Supreme Court’s 2007 decision in Massachusetts v. EPA, is rolling out new regulations in 2011 designed to curb carbon emissions from vehicles, power plants, refineries, and other major sources. (See Yale Forum article.)

In Congress, where Republicans are emboldened by the November mid-term elections, efforts to strip the EPA of its regulatory power are under way. Some lawmakers have said they also may review mainstream climate science and question the credibility of prominent climate scientists.

In the federal appeals courts, legal challenges to the EPA’s regulatory moves are being heard.

In the U.S. Supreme Court, a review of a Second Circuit ruling could determine whether states can use nuisance lawsuits as common law instruments to force reductions in carbon emissions.

Some states, such as California and Massachusetts, continue to affirm their own paths toward low-carbon futures, while others, such as Texas, resist new regulations to cut carbon emissions.

FILED UNDER: Straight talk, 2010 in review
January 7, 2011 | 10:37 PM | By

5 ocean discoveries you should know about

flickr/Pieter Pieterse

The diversity of marine life and the structure of the ocean food web were at the heart of some of the top discoveries of 2010.

2010 was a big year for ocean science. Here are my (and your) picks for the most important advances of the year. There’s one for each of the greatest threats facing the ocean (pollution, overfishing, and the two arms of climate change – warming and acidification), plus an overall winner. Enjoy!

1. First Census of Marine Life completed

October 2010 marked the end of a decade-long, international effort to catalogue the diversity of life in the ocean. The work of some 2,700 scientists from 80 nations resulted in thousands of new species being described, upping the total number of known marine species to almost 250,000. Scientists estimate that there may be over a million kinds of marine life that earn the rank of species, plus tens or even hundreds of millions of microbes. A number of scientists involved in the Census told me that one of the most shocking discoveries was the frequency and rate at which species are being driven into decline, even extinction. Ensuring that we have the information necessary to know when species disappear was a major motivation for the gargantuan effort.

2. Dramatic phytoplankton decline linked to warming seas

Pioneering work combining over a century of low-tech observations with modern modeling and mapping resulted in a dramatic (if somewhat controversial) finding – evidence of a 40% decline in phytoplankton (the microscopic marine plants that generate half of the oxygen on Earth) since 1950, strongly linked to rising ocean temperatures. Phytoplankton are the foundation of the marine food web, draw down atmospheric carbon dioxide, and produce half the oxygen on Earth. Their decline has ramifications for all life on Earth. That’s why ClimateCentral, Wonk Room’s Brad Johnson, and several Climatide commenters voted this the hands-down discovery of the year.

3. Ocean acidification is happening NOW

Over the course of the past 200 years, the ocean has absorbed nearly a third of carbon dioxide emissions, resulting in a 30% increase in ocean acidity – a phenomenon known as ocean acidification. Acidic water conditions impair the ability of animals like oysters and corals to extract the calcium carbonate they need to build their skeletons or shells. Scientists have generally considered such impacts of ocean acidification to be a problem of the (near) future. But in September 2010, two marine scientists from Stony Brook University published a study that forced a revision of that thinking by demonstrating that modern carbon dioxide levels produce shellfish with thinner shells, slower growth, and death rates almost double those of shellfish grown in pre-industrial water conditions.

4. We are NOT fishing down the food chain (or Why we need a new indicator of fisheries sustainability)

For years, prevailing wisdom has held that we are “fishing down the food chain” – over-harvesting the top-level predators, then moving on to fish lower and lower on the chain. But a new research showing that catches of fish (and other marine life) at all levels of the food chain have generally increased since the 1970s has upended this theory, leaving scientists and managers fishing for a new measure of ecosystem health (sorry, subscriptions needed for both articles). When this story hit, I overheard people talking about it in the local coffee shop. Granted, that’s in Woods Hole, where the vast majority of people in the coffee shop are likely to be ocean scientists. Still, this was big news.

5. There’s plastic in the Atlantic, too

Scientists have long known that plastic debris accumulates in parts of the northern Pacific Ocean bounded by circular ocean currents, or gyres; these regions have been called The Great Pacific Garbage Patches. This year, scientists from Sea Education Association and Woods Hole Oceanographic Institution confirmed what many have suspected for years: that there is a similar accumulation of plastic debris in the Atlantic Ocean. One of the most interesting findings in the landmark study was the fact that, while plastic use and disposal has skyrocketed in recent years, the amount of floating plastic debris hasn’t changed much. That begs the question – where is all the extra plastic going? Answering that question should keep scientists busy for years to come.

FILED UNDER: Ocean Change, 2010 in review
January 7, 2011 | 4:27 PM | By

Discovery of the year: phytoplankton decline linked to warming seas

NASA image created by Norman Kuring, Ocean Color Web

NASA’s Aqua satellite captured this image of a massive phytoplankton bloom off of the Atlantic coast of Patagonia on December 21, 2010.

Today’s “Discovery of the Year” goes to a study that several Climatide commenters, ClimateCentral, and Wonk Room’s Brad Johnson voted the hands-down discovery of the year – evidence of a 40% decline in phytoplankton (the microscopic marine plants that generate half of the oxygen on Earth) coinciding with rising ocean temperatures. It’s big news, but not without controversy.

WHAT WE KNOW (and HOW WE KNOW IT)

Since 1979, scientists have used satellite images (like the one above) to track the color of the ocean’s surface and infer the amount of chlorophyll – a green pigment produced by phytoplankton and other plants for use in photosynthesis (the production of biological energy from sunlight). Such studies have revealed variation that might be related to climate change, but a few decades of data isn’t enough to really see long-term trends. So a group of scientists at Dalhousie University used data collected with a much older and lower-tech device called a Secchi disk – essentially, a plate-sized white disk on a rope that is used to gauge the transparency of the ocean by measuring the depth at which it becomes invisible. Standardized Secchi disks have been used to measure ocean transparency for over a century. The authors of the new study used “established models” to convert hundreds of thousands of publicly available transparency measurements into chlorophyll counts.

The results were striking: eight out of ten major ocean regions have seen dramatic declines in phytoplankton abundance since 1950. Globally, the rate of decline was estimated at 0.6% per year (compared to the global median, or most commonly measured level) – a total drop of almost 40% in 60 years. The decline was most notable in open-ocean regions where phytoplankton productivity is highest. Sea surface temperature was the single factor most tightly linked to the phytoplankton decline; water temperatures could affect phytoplankton growth in a number of direct and indirect ways, including altering the mixing and flow of nutrients.

The results were striking: a total global drop of almost 40% in 60 years.
As I mentioned before, this study sparked some debate among experts in the field. A lot of data from a lot of different sources went through a lot of blending, filtering, and modeling, leaving some with doubts about the reliability of the results. The study may also have suffered from guilt by association; one of the authors – Boris Worm – has drawn criticism for past dire predictions about marine ecosystems. An accompanying commentary in the same issue of Nature compared the strengths and weaknesses of Secchi disk and satellite measurements; the two authors (both scientists in this field) conclude that satellite data present their own challenges and that the study is “a sorely needed contribution to our knowledge of historical changes in the ocean biosphere.”

WHAT IT MEANS

Phytoplankton are the foundation of the oceanic food web, draw down carbon dioxide from the atmosphere, and produce half the oxygen we need to survive. In other words, they’re important – really important. In the words of lead author Daniel Boyce, “Phytoplankton is the fuel on which marine ecosystems run. A decline of phytoplankton affects everything up the food chain, including humans.”

WHAT WE DON’T KNOW

Aside from lingering questions about methodology (which are considerable), the single biggest question left hanging is whether phytoplankton abundance will continue to decline as temperatures continue to rise. The ocean’s response to climate change is anything but simple. Rising carbon dioxide could spur phytoplankton growth. Ocean circulation could change dramatically, throwing current trends (no pun intended) out the window. This is certainly not the last word on the subject, but it was a major development.

FILED UNDER: Ocean Change, 2010 in review, phytoplankton, sea surface temperature
January 5, 2011 | 2:33 PM | By

Discovery of the year: ocean acidification is happening NOW

The greatest threat facing the ocean, namely rising levels of carbon dioxide in the atmosphere, actually poses two distinct threats – warming and acidification. Each will get its day in the “Discovery of the Year” spotlight. Today, it’s ocean acidification’s turn.

As you may recall, ocean acidification is the phenomenon in which carbon dioxide from the atmosphere dissolves in the surface waters of the ocean, producing carbonic acid that (in sufficient quantities) shifts the pH balance of the ocean toward acidity and impairs the ability of animals like oysters and corals to extract the calcium carbonate they need to build their skeletons or shells. In the past 200 years, the ocean has absorbed nearly a third of carbon dioxide emissions, resulting in a 30% increase in ocean acidity.

Stony Brook University

The impacts of ocean acidification - slowed growth and thinner shells - are strikingly visible in a side-by-side comparison of quahogs raised in water simulating past (250ppm), present (390ppm) and future (750ppm and 1500ppm) levels of atmospheric carbon dioxide.

Scientists have generally considered the impacts of ocean acidification to be a problem of the (near) future. But in September 2010, two marine scientists from Stony Brook University – Stephanie Talmage and Christopher Gobler – published a paper in the Proceedings of the National Academy of Sciences that forced a revision of that thinking, suggesting that ocean acidification may already be (and have been for some time) taking a toll on shellfish.

WHAT WE KNOW (and HOW WE KNOW IT)

Talmage and Gobler reared quahogs (Mercenaria mercenaria) and bay scallops (Argopecten irradia) under conditions simulating past, present, and likely future carbon dioxide levels. Not surprisingly (because numerous previous studies have documented similar findings), the shellfish of the future had severe shell defects, higher death rates, and slower growth than their modern-CO2 counterparts. What was less expected was the observation that modern conditions produced shellfish with thinner shells, slower growth, and death rates almost double those of shellfish grown in pre-industrial water conditions.

WHAT IT MEANS

Talmage and Gobler conclude that ocean acidification “may [already] be inhibiting the development and survival of larval shellfish and contributing to global declines of some bivalve populations.” In fact, since shellfish grown in the laboratory are granted a relatively luxurious life with abundant food and no predators or competitors, the authors say their data represent conservative estimates of the impacts of acidification. In the wild, slow-growing, thin-shelled animals would likely be vulnerable to any number of untimely ends – predation, over-crowding, incidental crushing. Stressed animals may also be more susceptible to diseases, like those that have ravaged east coast oyster populations in recent decades.

WHAT WE DON’T KNOW

With ocean acidity reaching levels not seen in over twenty million years, perhaps the biggest question on many scientists’ minds is whether evolutionary adaptation will be able to keep pace with rising acidity.

FILED UNDER: Ocean Change, 2010 in review, ocean acidification
January 4, 2011 | 9:36 AM | By

Discovery of the year: new indicator of fisheries health needed

flickr/Pieter Pieterse

Selecting the overfishing-related discovery of the year was a no-brainer. When this story hit, I overheard people talking about it in the local coffee shop. Granted, that’s in Woods Hole, where the vast majority of people in the coffee shop are likely to be ocean scientists. Still, this was big news. Here’s a lightly edited version of my original post:

“Trophic level” is a fancy term for whether you’re more likely to eat or be eaten. In the ocean, microscopic algae sit at the bottom of the food chain – a trophic level of one – while large predators such as sharks and tuna are on the top of the world, around trophic level four or so. Currently, many fisheries managers use the average trophic level of fish harvests as a leading indicator of ecological health. The system is based on a 1998 study of over four decades of data that indicated the average trophic level of catches was declining as we “fished down the food web” by overharvesting the highest trophic levels, then moving on to fish lower and lower on the chain. It’s a familiar storyline here on Cape Cod – when the cod dried up, fishermen moved on to dogfish and herring. But a high-profile study published in the journal Nature upended this theory and left scientists and managers fishing for a new measure of ecosystem health (sorry, subscriptions needed for both articles).

Continue reading →

FILED UNDER: Ocean Change, 2010 in review, overfishing
January 3, 2011 | 11:55 AM | By

Discovery of the year: plastic in the Atlantic

SEA/Skye Moret

Plastic debris collected by Sea Education Association scientists and students as part of their study of plastic pollution in the Atlantic Ocean.

This week, I’m highlighting my (and your) picks for the most important ocean science discoveries of 2010 with a special series of “What We Know” posts – one for each of the greatest threats facing the ocean – starting with plastic pollution.

WHAT WE KNOW

Scientists have long known that plastic debris accumulates in parts of the northern Pacific Ocean bounded by circular ocean currents, or gyres; these regions have been called The Great Pacific Garbage Patches.

This year, scientists from Sea Education Association and Woods Hole Oceanographic Institution confirmed what many have suspected for years: that there is a similar accumulation of plastic debris in the Atlantic Ocean. In the Subtropical Gyre, plastic debris – most of it less than half an inch in diameter – reached concentrations of 20,000 pieces per square kilometer. To put that in perspective, imagine walking down a sidewalk (about 4ft wide). You’d encounter a piece of plastic debris every 100-150ft.

Continue reading →

FILED UNDER: Ocean Change, 2010 in review, plastic pollution
January 3, 2011 | 8:17 AM | By

Top ocean stories of 2010

U.S. Coast Guard

The Deepwater Horizon oil rig exploded on April 20, 2010 - killing eleven workers and causing the largest oil spill in U.S. history. It tops Discover Magazine's list of the 100 biggest science stories of 2010.

#1. Deepwater Horizon blowout – the largest oil spill in American history

On April 20th, 2010 BP’s Deepwater Horizon oil rig exploded and (two days later) sank, killing 11 workers and starting the largest oil spill in US history. Oil gushed into the Gulf of Mexico for more than three months before the well was capped on July 15th, and then permanently sealed with cement on September 19th. All told, more than 4 million barrels of oil entered the Gulf of Mexico (an estimate reached after months of heated discussion between BP officials, government scientists, and academic researchers). Read more …

#2. Record heat and extreme weather

From record-breaking East Coast blizzards and devastating flooding in Pakistan to heat waves that gripped Russia and the eastern half of the U.S. much of the summer, 2010 was a year of extremes. The question that’s been on everyone’s mind is: Was it global warming? The standard answer – one that has made the rounds this year – is that it’s impossible to attribute any one storm, season, or year to climate change. But that’s not always the case. Maybe the more accurate, if equally unsatisfying, answer is: It depends. Read more …

#3. EPA policy for addressing ocean acidification through the Clean Water Act

Carbon dioxide emissions don’t just build up in the atmosphere; nearly a third of atmospheric carbon dioxide gets absorbed by the ocean. As carbon dioxide dissolves in water, it produces carbonic acid, shifting the pH balance of the ocean toward acidity – a phenomenon known as ocean acidification. In mid-November, the Environmental Protection Agency published a memo that put ocean acidification on the federal regulatory map. The memo elucidated the Agency’s stance that changes in the acidity of coastal waters caused (or presumed to be caused) by rising atmospheric carbon dioxide levels could be listed under the Clean Water Act. Read more …

#4. Major developments in offshore wind energy development

2010 was an historic year for offshore wind power in the United States. On October 6th, after almost ten years of permitting reviews and amidst ongoing controversy, Cape Wind – a 130-turbine wind farm proposed for Nantucket Sound – was granted the first federal lease for offshore wind power generation.

Other historic landmarks for the industry include a new “smart permitting process” for siting and permitting offshore wind energy projects along the Atlantic seaboard, plans for the largest offshore wind farm in the U.S. – 200 turbines in Rhode Island Sound, and two major undersea transmission lines to connect offshore suppliers and onshore grids. Read more …

#5: New climate science communication initiatives

This fall saw the launch of two new efforts by groups of scientists aimed at narrowing the gap between scientific consensus and public understanding of climate science. These initiatives are indicative of a larger (and very important) shift taking place in the scientific community – a growing realization by scientists that sitting passively on the sidelines of the public debate over climate change is not enough, that the public (and the journalists on the front lines of communicating scientists’ understanding of climate science) need scientists to be actively, openly, and enthusiastically sharing their knowledge. Read more …

FILED UNDER: Human Impacts, Ocean Change, Straight talk, 2010 in review
December 31, 2010 | 9:21 AM | By

Top stories of the year: #1 – Gulf oil spill

U.S. Coast Guard

The Deepwater Horizon oil rig exploded on April 20, 2010 – killing eleven workers and causing the largest oil spill in U.S. history.

#1. Deepwater Horizon blowout – the largest oil spill in American history

This story began months before Climatide existed and the aftermath (ecological, economic, political) may be felt for years to come. One of the most interesting stories – the debate about the fate and impacts of the spilled oil – was just heating up as Climatide launched in August. But back to the beginning …

On April 20th, 2010 BP’s Deepwater Horizon oil rig exploded and (two days later) sank, killing 11 workers and starting the largest oil spill in US history. Oil gushed into the Gulf of Mexico for more than three months before the well was capped on July 15th, and then permanently sealed with cement on September 19th. All told, more than 4 million barrels of oil entered the Gulf of Mexico (an estimate reached after months of heated discussion between BP officials, government scientists, and academic researchers).

The Deepwater Horizon spill is distinguished by more than just its sheer enormity. A large quantity of oil – just how much nobody knows – never saw the light of day (literally); scientists have found deep underwater oil plumes and layers of oil on the sea floor. Of the oil that did reach the ocean surface, it is estimated that a third or more dispersed (broke into tiny droplets) or dissolved back into the water – thanks in large part to the use of chemical dispersants on an unprecedented scale. As a result, less oil has washed up on Gulf coast beaches, and the impacts of the oil spill on coastal wetlands have been less than anticipated. But the Gulf’s exotic deep-sea ecosystems may end up paying the toll; scientists have found evidence of deep-sea coral die-offs and are continuing to monitor the impacts of the oil spill on life at the bottom of the Gulf.

Looked at in a certain light, the Gulf oil spill is an ecological experiment of unprecedented proportions. The resultant public spotlight and research funding provide rare opportunities to explore and gain new insights into the workings of life in the Gulf of Mexico. With luck, some lasting good may yet come of this unnatural disaster.

FILED UNDER: Ocean Change, 2010 in review, Gulf oil spill