Stories tagged oceanography

Okay, California's weird enough as it is usually. But they've been finding some very weird stuff along the California coast this week, including an 18-foot oarfish and a 15-foot saber-toothed-whale.

Dec
20
2012

C-MORE Group Blog Post

On October 2, 2012, the Center for Microbial Oceanography: Research and Education (C-MORE) hosted the Virtual Workshop on Science Writing as part of the Science Communication module for the Professional Development Training Program for graduate students and post-doctoral researchers. One of the activities for the workshop was to write a 350(+/-)-word blurb about their own research for a broader audience. We are excited to share some of these blog posts. Thanks for reading!
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Life is tough: we live in a dog-eat-dog world, where it is every man for himself and those that prosper seem to be the smartest and the sneakiest. Life in the deep blue sea is similarly challenging: food is scarce, hiding places are few, and predators are always lurking in dark waters in search of a quick meal. However, all marine organisms are connected to one another through a network of feeding interactions called a food web. Marine food webs are whale-eat-plankton, squid-eat-shrimp, shark-eat-tuna kinds of places. All of these diverse organisms are engaged in an on-going arms race for survival.

So how do scientists know the structure of the marine food web? Who eats whom? Which organisms are the most important players in the web? What happens if human activity like large-scale fishing or trawling interrupts some of the links in the web? Anela Choy, a Ph.D. student studying Oceanography at the University of Hawaii, is trying to answer some of these very questions in Hawaiian waters. Traditional techniques like looking in the stomachs of marine organisms can be time-consuming, sample-intensive, and downright smelly. However, new biochemical tracers (e.g., stable isotopes, fatty acids and trace metals) are being used by Anela to elucidate food web connectivity. Ultimately, Anela hopes to shed new light in the dark ocean on understudied predator-prey relationships between deeper ocean animals and large marine fishes, many of which are commercially harvested at unsustainable levels.

Predator-prey interactions make up the backbone of a food web. While complex and confusing at times, the transfer of energy through these interactions allows for life to persist in the ocean. For example, without microscopic plankton there would be no large sharks – not because sharks dine regularly at the plankton salad bar but because plankton is food for small crustaceans called zooplankton, which are in turn food for small fishes, which then feed larger fishes that sharks eventually eat themselves. A change or break in any link of the food web ultimately means changes in the other links. A better understanding of marine food webs will provide a basis for ensuring that in an ever-changing ocean, people will still have access to fresh and delicious Hawaiian-caught fish for dinner!

Anela Choy is a Ph.D. graduate student at the University of Hawaii at Manoa. You can read more about her research here.
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On a November morning in Hawai’i, the ocean stretches out like a rippling sheet of glass before me – the surfers are surely disappointed, but it’s a perfect day for SCUBA diving. One hundred feet beneath the boat, colonies of “cauliflower” coral are clearly visible. As the name implies, they bear a striking resemblance to a certain hated vegetable. Once at depth, I’m amazed by the diversity of animals hiding in the reef – a startled octopus that immediately releases a cloud of ink, a moray eel defending his crevice, and even a pair of whitetip reef sharks resting in a shallow cave. But what about the corals themselves? They are as animated as rocks or trees. So, are corals animal, vegetable, or mineral?

The answer is that although corals are technically animals (so props to you if you guessed correctly!), they also have aspects that are “vegetable,” “mineral,” and perhaps most surprisingly, “microbial”. It has long been recognized that the coral harbors symbiotic algae (the “vegetable” part) that perform photosynthesis and pass most of the sugar products to the coral. Likewise, anyone who’s ever cut herself on a reef realizes that corals produce a hard skeleton (the “mineral” part). The “microbial” part of coral, invisible to the naked eye, has only received serious attention within the last decade.

But what a decade it’s been! Microbes on corals, including bacteria, viruses, fungi, and a domain of life known as the Archaea, have been found to play essential roles in both coral health and disease. For instance, certain bacteria are now known to provide nutrients to the coral host. However, other microbial species cause the deadly White Band Disease, which has decimated the elkhorn and staghorn coral populations in the Caribbean. These are only a couple of examples of microbial activities on coral reefs – the fact is, there are hundreds of millions of microbes on each square centimeter of coral and we know next to nothing about them. Scientists have their work cut out for them – so stay tuned for updates from the world of corals and microbes!

Dr. Christine Shulse is a postdoctoral scholar with C-MORE at the University of Hawaii where she studies coral symbioses with marine bacteria. Read more about her research here.
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How did life start on Earth? One idea is that organic molecules, the basic building blocks of life, were delivered to Earth by comet impacts. However, recent research at the University of Hawai’i suggests that organic molecules could be produced much closer to home, in craters at the Moon’s poles, as a natural result of exposing simple ices like water and CO2 to radiation from space.

The craters at the Moon’s poles are never exposed to sunlight, so temperatures in these craters can reach as low as 25 Kelvin (about -248 degrees Celsius), as measured by the Diviner instrument on the Lunar Reconnaissance Orbiter spacecraft. These permanently shadowed regions are cold enough to trap volatile compounds like water, carbon dioxide, ammonia, and more from comets, asteroids, and the solar wind. These simple ices can combine to form complex organic molecules when they’re exposed to radiation—in fact, this is one process used to explain the presence of organic molecules on comets.

The Moon is constantly exposed to radiation from galactic cosmic rays, or energetic charged particles from outside the solar system. The only question is whether the trapped ices at the Moon’s poles are present long enough to acquire the high radiation doses that stimulate organic synthesis on comets, since the Moon’s tilt changes with time and today’s permanently shadowed regions probably weren’t cold enough to trap ices two billion years ago.

Researchers at the University of Hawaii used particle physics modeling to calculate the radiation dose received by ices at the lunar poles. In results submitted to the scientific journal Icarus, they discovered that the Moon’s cold traps could accumulate 36 eV per molecule of radiation over their two billion history—compared to only 10 eV per molecule required by chemists to stimulate organic synthesis in experiments.

These results suggest that organic molecules are not a rare resource in the inner solar system, delivered only by wayward comets. Instead, they could be continuously produced in craters on the Moon, Mercury, and asteroids, providing a wealth of ingredients from which life could have formed billions of years ago. If organics really are being produced at the Moon’s poles, it means that, as the closest place to Earth where we can study this process, the Moon would be a great natural laboratory for future robotic and human astrobiology missions to visit!

Sarah T. Crites is a Ph. D. student at the Hawaii Institute for Geophysics and Planetology at the University of Hawaii at Manoa.
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Similar to the way that a meteorologist predicts the weather, I predict the activity of phytoplankton (plant-like micro-organisms, or algae) in the ocean; I like to figure out where, when and how these cell-sized plants grow. I do this using numerical models. Some of these models are statistical (e.g., regression, correlation) or more mechanistic (e.g., fitting data to a specially shaped curve), while others are complex and deterministic (i.e., using fancy partial differential equations calculated over 3-dimensional domains).

Most recently, I have been able to investigate how phytoplankton interact and complement one another using a complex “trait-based model”. With this type of model, I first prescribe simple rules (or parameters) to each phytoplankton type: some types prefer lots of nutrients; some prefer low light conditions, etc. I put all of these different phytoplankton types into a model that simulates the tides and sloshing around of the ocean’s waters, watch the different phytoplankton types interact and compete for resources, and see where they end up (or “emerge”).

It turns out that the types that prefer nutrient-poor waters offshore may ultimately depend on those types that prefer growing in high nutrient coastal waters! All of these phytoplankton types together are called a community. Even though they are single-celled plant-like organisms, they grow and interact with one another in ways that parallel that of human communities. And like people, phytoplankton are complicated, their behaviors vary quite a bit, they come in all shapes and sizes, and sometimes they can be very unpredictable! Despite the challenges of measuring and predicting phytoplankton populations in the ocean, our ecosystem model of the California Coastal System does a great job at capturing seasonal changes in the low productive offshore waters and high productive coastal waters, as shown in this video:

See video

Dr. Nicole Goebel is a post-doctoral researcher at the University of California, Santa Cruz.
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Food webs are all around us: ant caravans carrying food, deer nibbling leaves, bats snapping insects, and squirrels crunching nuts. Open ocean food webs are harder to spot, because in the oceans, all the action is microscopic! Whales, sharks, tuna, and anchovy alike are all ultimately fed by phytoplankton, plants that are too small to see.

Land plants grow by adding leaves or thickening trunks. Phytoplankton have less storage space and can’t just keep growing bigger, so they behave differently. Consider a teabag in water; inside the bag are particles like phytoplankton cells. The tea itself is water and various dissolved compounds, like sugars, proteins, caffeine, and amino acids. During phytoplankton photosynthesis, some of the new organic carbon material they produce from carbon dioxide, using sunlight energy, stays within their cells (growth of particulate stuff, basically making more stuff in the teabag); some of the new material becomes dissolved compounds like sugars, proteins, fats, and amino acids. Just like terrestrial plants, phytoplankton are eaten by other organisms called zooplankton. These zooplankton don’t eat neatly and so some of each cell they try to eat is spilled and adds to the amount of dissolved compounds; we call this “sloppy feeding”. Think of a baby first learning to eat, sometimes as much gets on baby and parent as goes into the child!

We can certainly drink tea and use the dissolved compounds it contains (caffeine!), but many ocean organisms can’t use dissolved material, because they swim in water. If they drank the water to get the compounds dissolved in it, they would be trying to drink the ocean. So, the dissolved stuff from phytoplankton is available only to bacteria, because bacteria are small enough to get the dissolved amino acids, and proteins, and so on without taking in the water as well. The bacteria then turn some of those dissolved compounds back into carbon dioxide as they respire, and some of it they use to build new cell material. That cell material now in the bacteria is then big enough to attract the attention of the zooplankton, and so that dissolved stuff can be recycled back into the food web.

How much new organic material is usually produced? Is it mostly inside cells or outside the cells? As part of my work with the Hawaii Ocean Time-series program, I try to measure how much dissolved material is produced by phytoplankton photosynthesis, what percent of the total photosynthetic production that is, and also how fast the bacteria are growing. I want to know if these production rates change with seasons, or the amount of light, or the amount of nutrients present. I am also interested in how ocean acidification affects the amount of dissolved material produced. As we add more CO2 to the atmosphere and it finds its way into the oceans, does increased CO2 make the phytoplankton produce more organic matter, and if so, will that new material be in the tea or in the teabag?

Donn Viviani is a Ph.D. graduate student at the University of Hawaii at Manoa. You can read more about his research here.
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Leaning over the railing of our 40’ research vessel, I notice a tug on the thick blue rope serving as our fishing line. “I think we’ve got one!” I yell to the crew, "Get the tagging gear ready!” From over 1000 feet below the surface of the ocean, we haul a live, 10-foot sixgill shark onto the boat.

Sixgill sharks live on deep slopes of islands and continents, where divers cannot venture and light hardly penetrates. So, how can we find out anything about them? Well, Kevin Weng and his team at the University of Hawaii tag them with small sensors, which collect data such as depth, temperature, and light. The tags pop off at a preset date, so we don’t have to catch the shark twice to find out where it's been.

Using these tags, we’ve discovered that sixgill sharks cover a lot of "ground"! They are amazing divers, diving over 1000' each day. Horizontally, they can cross hundreds of miles of open ocean. Sixgills could be moving all around the Pacific, or even beyond! This could mean that distant populations of sixgills may be connected by movements and breeding, which might make them less susceptible to local fishing impacts. But even with large-scale geographic movements, sixgill sharks could still be in trouble. Some studies indicate rapid declines in sixgill shark populations over short time scales, potentially associated with fishing pressure. Deep sharks often grow and mature quite slowly, so it might take a long time to replenish a population. Learning where sharks go and how they use their habitat can help us locate important nursery areas, which need to be protected to ensure continued survival of the species.

Returning to the deck of our research vessel, it’s time to tag a shark. On the count of three, we insert the sensor under the tough layer of skin and set the shark free. She points her snout downwards and with two tail beats, is diving back to her dark, cold home far beneath the surface.

Christina Comfort recently completed her M.S. degree in Biological Oceanography this semester at the University of Hawaii at Manoa.
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Each summer in the dark bottom waters off Louisiana, fish and crabs scatter to avoid suffocating in a 20,000 square kilometer dead zone. The Dead Zone is neither adjacent to the Twilight Zone nor crawling with zombies, but it does sit 70 miles southeast of New Orleans in the Gulf of Mexico. Hundreds of kilotons of nitrogen and phosphorous rich fertilizer runoff from the breadbasket of America drain in to the Gulf of Mexico via the Mississippi River, stimulating the growth of tiny aquatic plants (phytoplankton). These plants die and sink to the sea floor where bacteria devour the remains using oxygen in the process. It is this hypoxic (oxygen lacking) area that mobile animals flee from, searching for healthier waters.

What happens when there is no escape? What makes this low-oxygen layer a long-term threat? Don’t all those tiny plants make more than enough oxygen?

The answer to that is stratification: the sun-warmed, freshwater from the river sits on top of the salty, cold ocean water, due to density differences. The physical differences between the two water bodies prohibit movement of gases by creating a physical barrier called a pycnocline that prohibits oxygen from passing from the surface to the bottom. Beneath the pycnocline any oxygen produced is devoured rapidly with every microbial bite.

Yet, something in the dark survives, because the Dead Zone isn’t really “dead.” The Mississippi River’s persistent plunge to the sea has gone on for a thousand years and a hardy community of invertebrates has learned to thrive under these harsh conditions. In 2005, the passage of Hurricane Katrina threw the entire ecosystem for a loop. The physical havoc wreaked on the seafloor opened the door for a whole new set of invertebrates to move in and take over, but they could not adapt to the low oxygen levels ensuring a summer massacre on the sea floor. They just didn’t have the decades of adaptations to sit calmly in the dark and wait out the long rain of dead plants and wait for fall storms to mix oxygen back into the bottom layer.

Climate change is going to impact coastal ecosystems in many unexpected ways. Systems that function admirably under environmental stress can be devastated by the unexpected. The Dead Zone might soon resemble the horrifying corpse-ridden wasteland that its name suggests.

Dr. Clifton Nunnally is a post-doctoral research fellow at the University of Hawaii.
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The wind blowing over the ocean does not only produce surface waves that are enjoyed by surfers, but it also generates waves that propagate from the surface towards the deep ocean. For that reason, this type of wave is called “internal wave” or “internal swell” in an analogy to the surface waves people see on the beach.

The ocean can be thought of as composed of an infinite amount of thin layers of same density or temperature (“stratified”). Internal waves displace these layers up and down as they move from the surface to the deep. Because of this, researchers have long recognized breaking internal waves as key factors in controlling the amount of mixing between warmer near-surface waters and colder deeper waters.

The amount of mixing occurring in the interior of the ocean, which depends strongly on the energy of the internal waves, has important implications to Earth’s climate and its understanding remains as one of the biggest conundrums in climate science. For instance, it is still unclear how much of the wind energy is converted to internal waves, let alone how much of the wave’s energy is used for mixing in the deep ocean. Therefore it is important to map and quantify the sources of internal swells.

Similar to surf waves, most of the internal swell energy in the ocean has been known to originate from winter storms near the Westerlies region. However, researchers at the University of Hawaii suggest that powerful internal swells may be regularly generated in the tropics, more specifically off the coast of Central America.

In this region, an atmospheric phenomenon called the Easterly Wave is responsible for blowing strong winds over the ocean, repeating itself every 3 to 7 days with such perfect timing as to generate energetic, near-inertial (because their frequency is close to that of the Earth’s rotation) internal waves. Because of the particularly strong stratification of this part of the ocean, most of this energy inputted by the wind is carried away downward as big internal swells. Thus, the Easterly Wave can be a viable source of energy for mixing in the deep ocean, or for surfers to find the biggest waves yet, if only they could catch internal waves!

Saulo Soares is a Ph.D. graduate student at the University of Hawaii at Manoa.
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With our bodies bent at the waist, leaning dangerously over the rail, we watch in anticipation as the Secchi disk twirls in the purplish blue waters near Easter Island. The round, black-and-white plastic disk has been providing measurements of water clarity since its invention in 1865. The white sections of the disk flicker as sunlight penetrates to an astounding depth of 236 ft. Who lives down below, and how do they live?

Since phytoplankton use sunlight, carbon dioxide, and water to make their cells, one might think that the phytoplankton in this region would be happy campers. But phytoplankton, much like land plants, also need nutrients to make proteins, nucleic acids, and other cell parts for reproduction. Even though the South Pacific Gyre is full of light, it is one of the most “oligotrophic” (low nutrient) waters in the world. My goal during this expedition was to investigate the identities of a group of really small phytoplankton that have adapted to low-nutrient conditions, and to determine whether some species prefer to live in specific light levels at different depths in the ocean.

To obtain a census of the photosynthetic inhabitants of this region, I collect and filter about half a gallon of seawater from different depths onto a small filter membrane. Each filter is barely an inch wide, but contains ~3 million cells of my study organisms. When I'm back on land, the cells on the filter are extracted for DNA, molecules comprising genetic instructions for cell development. A specific gene (18S ribosomal RNA) in this extracted DNA is isolated using coding markers, and is compared to genes from other cells collected around the world. If I find matches, I will know that either the same, or related, phytoplankton species are living in certain regions of the world ocean. I can then piece together a larger picture, linking the types of phytoplankton to their environmental characteristics such as light intensity and nutrient concentrations.

With every expedition, one gene at a time, I am able to zoom into the life of the phytoplankton that make their home in the clearest ocean water on Earth.

Shimi Rii is a Ph.D. graduate student at the University of Hawaii at Manoa. She hosted the C-MORE Virtual Workshop on Science Writing.

Nov
16
2011

If you look at the U.S. Nuclear Regulatory Commission’s interactive map of nuclear power plants in the United States, you will see several in states bordering the Atlantic Ocean. This prompted the Nuclear Regulatory Commission to request the U.S. Geological Survey (USGS), along with other governmental and academic partners, to research the potential for tsunamis to strike the U.S. Atlantic and Gulf of Mexico coasts, and prepare maps using sonar (originally an acronym for SOund Navigation And Ranging). Note that the March 11, 2011 earthquake near Honshu, Japan, created a tsunami that resulted in a nuclear disaster that is still being remediated.

NOAA Research Ship Nancy Foster: Nancy Foster supports applied research primarily for NOAA's National Ocean Service and Office of Oceanic and Atmospheric Research.
NOAA Research Ship Nancy Foster: Nancy Foster supports applied research primarily for NOAA's National Ocean Service and Office of Oceanic and Atmospheric Research.Courtesy National Oceanic and Atmospheric Administration
Through this research, initiated about five years ago, the leading potential source of dangerous tsunamis to the East Coast was identified as landslides, either originating in submarine canyons or on the continental slope of the submerged margin of the continent of North America.

According to USGS marine geologist Jason Chaytor, many years of data collection and integration of existing data sets was needed in order to produce seafloor maps with the resolution needed to identify all of the relevant features for this study. The first field effort of this project was a multibeam bathymetric mapping cruise conducted aboard the National Oceanic and Atmospheric Administration (NOAA) Ship Nancy Foster from June 4 to June 16, 2011. Using echosounders installed on the hull of Nancy Foster, the science team mapped canyons and shelf regions at high resolution over more than 380 square miles (1,000 square kilometers) of seafloor from south of Cape Hatteras, located offshore of North Carolina, to the eastern tip of Long Island in New York.
Bathymetric Map of Continental Slope 150 km Southeast of New Jersey: High-resolution multibeam bathymetry collected in and between Baltimore and Accomac Canyons during the June 2011 cruise. Color key at left shows depths (in meters).
Bathymetric Map of Continental Slope 150 km Southeast of New Jersey: High-resolution multibeam bathymetry collected in and between Baltimore and Accomac Canyons during the June 2011 cruise. Color key at left shows depths (in meters).Courtesy United States Geological Survey


A number of submarine landslides, some previously unknown, were either partly or completely mapped. Characteristics collected include the size and number of landslides, soil and rock properties, the water depth they occur in, and the style in which they fail. This information is often used in numerical modeling of tsunamis generated by landslides.

The scientists detailed their findings in the September/October issue of the USGS newsletter Sound Waves.

RV Melville
RV MelvilleCourtesy WHOI
Being on a ship exploring the oceans: how cool is that?! If you can't be on the ship, or maybe you get seasick and don't want to be, check out videos from a real oceanography expedition.

An entire series is now on Science 360: The Knowledge Network. YouTube videos are filtered from some classrooms. Since Science 360 is sponsored by the National Science Foundation, their videos have passed a high academic standard and are not filtered.

Marine Microbes: Come see videos about us!
Marine Microbes: Come see videos about us!Courtesy C-MORE
The Center for Microbial Oceanography (C-MORE), headquartered at the University of Hawai`i, conducted the BiG RAPA oceanographic expedition. The C-MORE scientists sailed from Chile to Easter Island, making discoveries about micro-life in one of the least explored areas of the world's ocean.

Welcome aboard!

May
18
2011

R/V Hespérides, docked at Aloha Tower in Honolulu, Hawai`i
R/V Hespérides, docked at Aloha Tower in Honolulu, Hawai`iCourtesy C-MORE
How would you like to be aboard a ship, circumnavigating the globe, collecting samples from the world’s ocean?

That’s exactly what Spanish oceanographers are doing on their Malaspina Expedition aboard the Research Vessel, R/V Hespérides. Scientists and crew left southern Spain in December, reached New Zealand in mid-April, and recently arrived in Hawai`i. The expedition's primary goals are to:

  • build upon the historic 1789-1794 Malaspina expedition to promote interest in marine sciences among the Spanish public, particularly the nation’s youth
  • collect oceanographic and atmospheric data -- chemical, physical and biological – that will help evaluate the impact of global change
  • explore the variety of marine life, including microbes, especially those living in the deep sea
  • CTD: As this oceanographic instrument is lowered over the side of a ship, each gray Niskin “bottle” can be electronically triggered to collect a seawater sample from a different ocean depth.
    CTD: As this oceanographic instrument is lowered over the side of a ship, each gray Niskin “bottle” can be electronically triggered to collect a seawater sample from a different ocean depth.Courtesy C-MORE
    In connection with the latter two goals, the Malaspina scientists met with their colleagues at the Center for Microbial Oceanography: Research and Education (C-MORE). The two groups of scientists are working together. "We can exchange data on the local effects, what's happening around the Hawaiian Islands, and they can tell us what's happening in the middle of the Pacific," said Dr. Dave Karl, University of Hawai`i oceanography professor and Director of C-MORE.

    The Malaspina-C-MORE partnership is the kind of cooperation that can help solve environmental problems which stretch beyond an individual nation’s borders. The R/V Hespérides has now left Honolulu on its way to Panama and Colombia. From there, the scientists expect to complete their ocean sampling through the Atlantic Ocean and return to Spain by July. Buen viaje!

May
02
2011

the ocean's 5 major gyres
the ocean's 5 major gyresCourtesy NOAA
We often talk about the ocean ecosystem. And, indeed, there is really just one, world-wide ocean, since all oceans are connected. An Indian Ocean earthquake sends tsunami waves to distant coasts. Whitecaps look as white anywhere in the world. The ocean swirls in similar patterns.

However, oceanographers do find differences from place to place. For example, let’s take a closer look at the chemistry of two swirls, or gyres as they’re more properly called. Scientists have found a micro difference between the North Atlantic Gyre and the North Pacific Gyre. The Atlantic generally has really low levels of phosphorus, measurably lower than the North Pacific Gyre.

the element phosphorus among its neighbors in the Periodic Table of the Elements
the element phosphorus among its neighbors in the Periodic Table of the ElementsCourtesy modified from Wikipedia
Phosphorus is a very important element in living things. For example, it’s a necessary ingredient in ATP (adenosine tri-phosphate), the energy molecule used by all forms of life. Phosphorus is picked up from seawater by bacteria. All other marine life depends upon these bacteria, either directly or indirectly, for P. Therefore, if you’re bacteria living in the impoverished North Atlantic Gyre, you’d better be really good at getting phosphorus.

And they are!

Oceanographers at the Center for Microbial Oceanography: Research and Education (C-MORE) at the University of Hawai`i have made an important discovery. C-MORE scientists Sallie Chisholm, based at the Massachusetts Institute of Technology and her former graduate student Maureen Coleman, now a scientist at the California Institute of Technology, have been studying two species of oceanic bacteria. Prochlorococcus is an autotrophic bacterium that photosynthesizes its own food; Pelagibacter, is a heterotrophic bacterium that consumes food molecules made by others.

Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.
Pacific HOT and Atlantic BATS Stations: Microbial samples were collected at each location.Courtesy C-MORE
Drs. Chisholm and Coleman took samples of these two kinds of bacteria from both the Atlantic and Pacific Ocean. The Atlantic samples were collected by the Bermuda Atlantic Time-Series (BATS) program. The Pacific samples were collected in the North Pacific Gyre (about 90 miles north of Honolulu) by the Hawai`i Ocean Time-Series (HOT) program. The scientists discovered surprising differences in the genetic code of the bacteria between the two locations:

  • First of all, the Atlantic populations of both bacterial species have more phosphorus-related genes compared to their Pacific cousins. (Picture Atlantic microbes in Superman outfits with a big "P" on their chests!)
  • Secondly, in the Atlantic, Prochlorococcus has different kinds of P-related genes compared to Pelagibacter. Perhaps this means the two microbial species have evolved over time to use different phosphorus sources, to avoid competing with one another for this limited resource.

Drs. Chisholm and Coleman have discovered important micro differences between bacteria of the same species in two oceanic gyres. Now we can better understand how these microbes are working to recycle an important nutrient beneath the whitecaps.

Reference: October 11, 2010 issue of the Proceedings of the National Academy of Sciences

Apr
13
2011

Earth, our place in space
Earth, our place in spaceCourtesy NASA
Life scientists study…well, life. They want to know everything about living things on planet Earth. One of the first things biologists want to know is who’s here. What kinds of plants and animals live in a forest? --or in a field? –or in the ocean?

If you’re an oceanographer who studies marine mammals, perhaps you’d go to sea on a ship with a good pair of binoculars and hunt for whales. As you focused your binoculars you’d be able to see different kinds of whale species. As you looked closer, for example at Humpback Whales, you'd see that each individual whale has a different black-white pattern on its tail. You might even take a biopsy, a small sample of whale flesh, and do a more detailed study of genetic differences among individual Humpbacks.

But what if you’re a microbial oceanographer? You sure can't use binocs to hunt for microbes! How can you study individual differences among tiny creatures that are only one-one-hundredth the width of a human hair? How do you hunt and capture single-celled bacteria, like Prochlorococcus, the most common bacterial species in the world’s ocean?

Invent something!

laser-based micro-fluidic system
laser-based micro-fluidic systemCourtesy C-MORE
Young scientists, Sebastien Rodrigue and Rex Malmstrom, at the Center for Microbial Oceanography: Research and Education (C-MORE) were doing research in Dr. Sallie Chisholm’s C-MORE lab at the Massachusetts Institute of Technology when they adapted a “laser-based micro-fluidic system” used commonly by medical researchers, for the study of marine bacteria. With this method they could put each individual tiny Prochlorococcus cell into its own little pool of seawater.

And then the excitement began.

Prochlorococcus
ProchlorococcusCourtesy Dr. Anne Thompson, MIT
Even in scanning microscope photographs, each Prochlorococcus looks like just another teeny, tiny balloon; we can't see any individual differences. However, Sebastien and Rex used fast and inexpensive genetic methods and discovered an extraordinary variety of individual differences among Prochlorococcus. Of course the variety among these microbes doesn't have to do with tail patterns, like whales. Prochlorococcus vary in their method of getting nutrients, like iron, out of seawater.

So what? Why do we care?

We care A LOT because microbes like Prochlorococcus are operating at the nitty gritty level of cycling not only iron, but also other elements in the ocean. Like carbon. That's right, as in carbon dioxide accumulating in our atmosphere -- and ocean -- causing climate change and associated problems. The more we understand about individual differences among oceanic microbes, the more we'll understand how they influence and respond to changes in Earth's climate.

Mar
17
2011

Aren’t budgets all about money? Don’t they track how many $$$ come in and how many $$$ go out?

That’s right; so what’s a carbon budget? A carbon budget tracks how much carbon, C, goes in and out of a natural area.

Right now, we’re worried about too much C going into our planet’s atmosphere. This excess C is causing global warming, sea level rise, ocean acidification and other environmental problems. These are BIG problems! We can begin to fix these problems if we do a carbon budget and really know how much carbon is where.

Carbon Budget Study Area: How much carbon is in the shallow, coastal seawater?
Carbon Budget Study Area: How much carbon is in the shallow, coastal seawater?Courtesy Sergio Signorini, North American Carbon Program
Along with others, scientists at the Center for Microbial Oceanography: Research & Education (C-MORE), based at the University of Hawai`i, have begun to track C in the ocean off the eastern United States. The study area includes a LOT of water! -- all the seawater from high tide out to 500 meters deep, shown by the black line in the map, in the Gulf of Maine (GoM), the Mid-Atlantic Bight (MAB), and the South Atlantic Bight (SAB.)

Imagine your money budget. Let’s say we track your $$$ in and out of 4 categories. Money comes into your pocket from 2 categories, mowing the neighbor’s lawn and babysitting. Money goes out when you pay for movies and snacks.

In the same way, scientists want to track C as it moves between the coastal water “pocket” and 4 nearby areas: the coastal land, the atmosphere above, seafloor below, and the deeper ocean offshore. Where is C leaving the coastal water? Where is it entering?

But wait! Coastal zones are only small slivers of water, compared to the open ocean around the world. Why bother to track carbon in coastal waters?

Ah ha! Coastal waters are very important in C budgeting. Notice the red color in the map above. Red means there's a lot of chlorophyll. Chlorophyll is the green pigment important in photosynthesis, the process that plants use to take in C and fix it as sugar. The red in the map shows that coastal waters are richer in carbon than the open ocean.

Understanding the C budget of coastal waters is one small but important step in solving global warming and other environmental problems.

Reference: Ocean Carbon & Biogeochemistry Winter 2010 OCB Newsletter; Vol. 3, No. 1.

Jan
28
2011

ocean micro-plastic: These samples were collected from the surface water of the North Pacific Ocean by the SUPER expedition in 2008.
ocean micro-plastic: These samples were collected from the surface water of the North Pacific Ocean by the SUPER expedition in 2008.Courtesy C-MORE
Who hasn’t heard that plastic in the ocean is trouble?

  • Plastic has been found clogging the stomachs of dead albatross and other ocean birds.
  • Plastic ropes and traps have entangled marine life, causing more death.
  • As a long-lasting chemical, plastic floating in the ocean provides long-distance rafts that may move aggressive alien marine life to new areas.
  • Plastic may provide a “sticky” surface where toxins can accumulate, becoming a concentrated source of poison for marine consumers.
  • A "Great Pacific Garbage Patch" has been reported to be an "island the size of Texas" floating in the North Pacific Ocean...but is this really true? Continue reading to find out!

Yep, plastic in the ocean is bad news; so let’s put scientific energy into studying and solving the problem.

manta trawl: The trawl is hoisted above the stern deck of the RV Kilo Moana.
manta trawl: The trawl is hoisted above the stern deck of the RV Kilo Moana.Courtesy C-MORE
In 2008 C-MORE, the Center for Microbial Oceanography: Research & Education headquartered at the University of Hawai`i, with assistance from the Algalita Marine Research Foundation, embarked on an oceanographic expedition aboard the RV Kilo Moana, which means "oceanographer" in Hawaiian. The goal of the expedition, dubbed SUPER (Survey of Underwater Plastic and Ecosystem Response Cruise), was to measure the amount of micro-plastic in the ocean. In addition, oceanographers took samples to study microbes and seawater chemistry associated with the ocean plastic. The Kilo Moana sailed right through the area known as the “Great Pacific Garbage Patch,” between Hawai`i and California.

Early results: there was no garbage patch/island. Once in a while something like a barnacle-covered plastic buoy would float past the ship, but mostly the ocean looked really clean and empty of any kind of marine debris.

manta trawl: The net is being pulled slowly through the ocean's surface water.
manta trawl: The net is being pulled slowly through the ocean's surface water.Courtesy C-MORE
But wait! Scientists looked closer and were amazed. Every single one of the more than a dozen manta trawls, filtering the surface seawater for an hour and a half each, brought up pieces of micro-plastic! Some were as small as 0.2 millimeter, mixed among zooplankton!

Other expeditions have reported similar results (for example, Scripps Institution of Oceanography's 2009 SEAPLEX expedition and Sea Education Association's North Atlantic Expedition 2010): no Texas-size garbage patches, but plenty of plastic marine debris to worry about. The data seem to show that most of the plastic is in the form of small pieces spread throughout upper levels of water at some locations around the world's ocean. In these areas, the ocean is like a dilute soup of plastic.

Dr. White: examining the results of a manta tow
Dr. White: examining the results of a manta towCourtesy C-MORE
C-MORE researcher Dr. Angelicque (Angel) White, assistant professor of oceanography at Oregon State University (OSU) was a scientist on board the SUPER expedition. In recent interviews, (for example: the Corvallis Gazette-Times and Seadiscovery.com) Dr. White cautions us to view the complex plastic marine debris problem accurately. Furthermore, new results will soon be published by C-MORE about microbial diversity and activity on plastic pieces.

In the meantime, as Dr. White says, “…let’s keep working on eliminating plastics from the ocean so one day we can say the worst it ever became was a dilute soup, not islands. “

Plastic in the ocean is trouble. How can you be part of the solution?

Dec
09
2010

Surveying Microbes at Sea
Surveying Microbes at SeaCourtesy C-MORE
There are microbes…and then there are micro-microbes. Oceanographers on C-MORE’s BiG RAPA oceanographic expedition are finding bacteria the size of one-one-millionth of a meter in the oligotrophic (low nutrient), open-ocean of the Southeast Pacific, far from the productive waters off the coast of Chile. But that’s not all; some scientists are looking for the even smaller marine viruses in gallons of filtered seawater. Meet some of these micro-microbes in these video reports:
Prochlorococcus
ProchlorococcusCourtesy Dr. Anne Thompson, MIT

  • Microbe Diversity, Part 1: Prochlorococcus, the most common bacterium in the world’s oceans; nitrogen-fixing bacteria that provide a usable form of nitrogen “fertilizer” for other photosynthesizers
  • Microbe Diversity, Part 2: picophytoeukaryotes with different colored pigments; viruses, which are parasites on other living things

Yes indeed, microbial oceanographers are taking home quite a collection from the South Pacific Ocean. In less than a week the good ship RV Melville will arrive at Rapa Nui (Easter Island), and scientists will step onto land for the first time in almost a month. They and their oceanographic samples will return to C-MORE laboratories around the U.S. The oceanographers are also returning with new hypotheses buzzing around in their heads. Now it’s time for them to take the next step in the Scientific Method: data analysis!