Tuesday, December 31, 2013
We know that plastic washes up on our beaches, that turtles eat it and that seabirds die with bellies full of it—but it’s also in the fish we eat.
New research indicates that fish, directly or indirectly, eat bits of plastic, and lots of it. And not just the stuff on the surface but also plastics that drift at depth in the water column.
University of Hawai`i Department of Oceanography researchers Anela Choy and Jeffrey Drazen looked into the stomach contents of hundreds of fish from 10 deep ocean species. One in five had plastic in them. The accompanying image, from the University of Hawai`I at Manoa, shows some of the plastics removed from fishes.
We’re eating these fish, and we don’t fully understand what the impacts of the plastics may have on the fish, or on us,” the authors wrote.
“These observations are the first of their kind in scope and number, and suggest that more attention should be given to marine debris in subsurface waters as well as to poorly understood organismal and food web implications,” they wrote.
Their work, under the title, “Plastic for dinner? Observations of frequent plastic ingestion by pelagic predatory fishes from the central North Pacific,” was published in the journal Marine Ecology Progress Series.
The paper is available here.
You can find a University of Hawaii press release (less technical) about it here.
The researchers had NOAA fishery observers collect the stomachs of the catch from longline fisheries around Hawai`i. They collected samples from mahimahi, two kinds of opah, broadbill swordfish, longnose lancetfish, hauliuli or snake mackerel, walu or Hawaiian butterfish, and skipjack, yellowfin and bigeye tuna.
We tend to be aware of plastics floating on the surface, but this study found plastic in fish that only feed deep in the water column, suggesting that plastic pollution pervades the ocean at multiple levels.
They found that many of the plastics in the fish are not surface floaters, but have a density that allows them to drift at different depths.
The fish may not be eating the plastics directly—but rather already inside smaller creatures. The studied fish are, after all, predators. So, some fish may actually be mistaking plastics for food, but many may simply be feeding on plankton, small fishes, squids or crustaceans that have themselves eaten plastic.
It is all worrisome, the authors say: “Plastic ingestion in large pelagic fishes is more prevalent than previously suggested.”
“Many plastics adsorb PCBs, organochlorine pesticides, polycyclic aromatic hydrocarbons, metals, and petroleum hydrocarbons, some of which may desorb in acidic stomachs resulting in uptake to the animal. Indeed, it has been shown that seabirds that ingested plastic had higher PCB concentrations in their fat tissues, and seabird chicks fed plastics showed increasing PCB concentrations.
“Given the global commercial importance of … large pelagic fishes … future research might
evaluate whether these fishes carry elevated chemical toxin burdens that may ultimately pose a risk to the seafood-consuming public,” the authors wrote.
© Jan TenBruggencate 2013
The latest forecast from the National Oceanic and Atmospheric Administration is that El Nino neutral conditions will continue at least through summer, but that chances of a new El Nino increase then. The last significant El Nino was nearly four years ago.
El Nino is that oscillating climate pattern that has dramatic impacts on rainfall and drought, storm frequency and strength, wind patterns and many other parts of the climate picture. When the pattern is on the warm side, it’s called El Nino, and when conditions are cooler, it’s La Nina.
A strong El Nino involves unusually warm equatorial waters south of Hawai`i and toward the American coast. In the Islands, the main concerns are that it can be associated with more hurricanes, and with drought in winter, when we normally count on rainfall to make up for summer dryness.
They seem to show up every two to five years. In the past two decades, we have seen them in 1991-92, 1994-95, 1997-98, 2002-03, 2004-05, 2006-07 and 2009-10. So, it’s been since the late spring of 2010, so you might say we’re due.
And indeed, the forecast suggests an increasing likelihood of an El Nino developing around the middle of 2014. Says NOAA: “Neutral is favored into the Northern Hemisphere summer 2014, with an increasing chance for the development of El Nino.” But it says some of the computerized climate models suggest it could still remain neutral.
We have had a very quiet decade thus far in Hawaiian waters on the hurricane front. Only two hurricanes made it into the Central Pacific in 2013: Flossie and Henriette, and both were largely played out by the time they made it to Hawai`i. In 2012, there was just one, Hurricane Daniel, and in 2011 and 2010, none.
Could that change in 2014? It could. There are normally four to five named storms in our region each year, and that number rises somewhat in El Nino years. (Named storms include both tropical storms and hurricanes.)
For more on hurricane forecasts, check out this site from the NOAA Hurricane Forecast Improvement Program. That's where the hurricane image at the top of this post is from.
Moving onto a related topic, a paper published a couple of months ago said that El Nino events
during the late 20th century have been significantly more common than in the previous half millennium.
Researchers from the University of New South Wales, the University of Hawaiʻi at Mānoa's International Pacific Research Center and the NOAA Geophysical Fluid Dynamics Laboratory, reconstructed past climate by applying new techniques to clues found in lake sediment, corals and tree rings.
They found that El Nino activity—often referred to as ENSO for El Nino Southern Oscillation-- was more active during 1979-2009 than during any other 30-year period between 1590 and 1880.
“Our results represent a significant step toward understanding where current ENSO activity sits in the context of the past,” said UH Mānoa Professor Axel Timmermann, co-author of the study.
The paper’s lead author, Shayne McGregor, said there are tantalizing clues linking El Nino to climate change, but not yet enough evidence to prove a link.
“Climate models provide no clear indication of how ENSO activity will change in the future in response to greenhouse warming, so all we have to go on is past records.
"We can improve the projections of climate models, however, by selecting those that produce past changes in ENSO activity consistent with the past records. Our new estimates of ENSO activity of the past 600 years appear to roughly track global mean temperature, but we still don't know why,” McGregor said.
Citation: S. McGregor, A. Timmermann, M. H. England, O. Elison Timm, and A. T. Wittenberg: Inferred changes in El Niño–Southern Oscillation variance over the past six centuries. Clim. Past, 9, 2269–2284, 2013. doi:10.5194/cp-9-2269-2013
© Jan TenBruggencate 2013
Monday, October 28, 2013
Cyanobacteria, which have sometimes confusingly and inaccurately been called blue-green algae, are cool critters.
To find a new species to science, in a genus that is only represented by one other species in the world, is cooler still.
And to find it in a hot, 100-year-old volcanic cave on active Kilauea volcano, well, that's so cool it's downright polar.
University of Hawai`i researchers are reporting they found the primitive life form on a film of biological material growing on the rock wall of a Kilauea cave a few hundred feet from Halema`um a`u. To get into it, they had to back feet first through a small entrance into the cave, whose floor radiated heat at 90 degrees Celsius or 190 degrees Fahrenheit.
(Image: The cyanobacteria mat on Kilauea cave wall. Photo courtesy Stuart Donachie, UH.)
They found a glistening purple mat of moist stuff, growing in very low light on the cave wall. When they ran its genetics, they found it fits in a genus of cyanobacteria that wasn’t described until 1974 and has only one other species in it. That one was found in Switzerland on limestone rock, while this one was on basalt. And genetic work showed the two had diverged from each other 280 million years ago.
Why should we care about cyanobacteria? We wouldn’t exist without them. They are largely responsible for much of the oxygen in our atmosphere. Some varieties fix nitrogen, creating nutrients for plants.
They are some of the earliest life forms ever identified on Earth. They’re different from many others in that their cells have no nucleus, making them procaryotes like bacteria. By contrast, humans and other animals, insects, fungi and all plants are eucaryotes: they have their genetic material encased in nuclei within their cells.
“Cyanobacteria are among the most diverse and successful microbes on Earth. As pioneers of oxygenic photosynthesis they permanently changed Earth's atmosphere by emitting gaseous diatomic oxygen, paving the way for the evolution of aerobic metabolism,” says a paper in the journal PLOS One, “Cultivation and Complete Genome Sequencing of Gloeobacter kilaueensis sp. nov., from a Lava Cave in Kīlauea Caldera, Hawai'i.”
The paper’s authors are Jimmy H. W. Saw, Michael Schatz, Mark V. Brown, Dennis D. Kunkel, Jamie S. Foster, Harry Shick, Stephanie Christensen, Shaobin Hou, Xuehua Wan, and Stuart P. Donachie.
As the article title suggests, they’re proposing naming the new species Gloeobacter kilaueensis sp. nov. (sp. nov. simply stands for “new species.”)
A colony of these new cyanobacteria is purple in color, and smooth and shiny. It has a gel or mucous-looking surface, said co-author Stuart Donachie. He said it’s a unique discovery.
"It’s a great find because both species represent an entire taxonomic order distinct from the other 7,500 known cyanobacteria species. They lack the photosynthetic membranes that are found in all those 7,500 species, which means they are also the most primitive known cyanobacteria,” said Donachie an associate professor in the Department of Microbiology at the University of Hawai`i’s College of Natural Sciences.
So how did this cyanobacterium get into a hot, young Kilauea cave?
“That’s a question we get asked all the time. It is a question we could not answer and have not answered,” Donachie said.
The most likely answer, he figures, is that it blew in on the wind. And not from a Switzerland colony.
That suggests there are, somewhere on the planet, other, undiscovered cyanobacteria colonies in the Gloeobacter genus, one of which was the source for Gloeobacter kilaueensis.
© Jan TenBruggencate 2013
Friday, October 18, 2013
The Kaua`i County Council this week passed a groundbreaking piece of legislation, regulating both pesticides and genetically modified crops.
Whether you support or oppose the bill, and whether it is rejected in court or not, it represents a significant legislative event.
Its key features are an aggressive disclosure policy targeted at big farmers, significant buffer zones, and the call for a study of the environmental and health impacts of big ag—specifically big ag that uses both genetically modified crops and any kinds of pesticides.
The bill has taken a circuitous route to the form that is now being considered for signature or veto by Mayor Bernard Carvalho.
Here are key provisions of the document approved by an exhausted Kaua`i County Council, driven by a drumbeat of chants of “Pass The Bill!,” after 3 a.m. on October 15, 2013.
1. Any farm that uses more than 5 pounds or 15 gallons of a restricted use pesticide (the kind that require you be a certified pesticide applicator), must disclose the use of all pesticides of any kind during the following year. Warning signs must be posted at the site of pesticide use 24 hours ahead of time and during and after the application. Farms must also post all such pesticide notifications at a central area for workers.
2. Farms must, before applying pesticides, personally notify neighbors within 1,500 feet of the farm’s property lines. That includes anyone who lives, works, keeps bees or who occupies the property, legally or otherwise. These “Good Neighbor Courtesy Notices” can be sent by phone, text or email. Such messages need to be sent weekly or more often as necessary.
3. Similar messages are also required to be made available weekly to everyone else on the island, through reports to the county that will be posted online. The weekly after-use reports are to include what pesticide is being used including its trade name and EPA registration number, on what day, at what time, on what field, over what acreage, during what wind conditions. Maps of pesticide application locations are to be provided.
4. Farmers must also provide an emergency hotline to provide to medical personnel details of pesticide use when there is a documented medical need.
5. Farms that grow genetically modified crops must file annual reports with the county and state, and those reports are to be posted for the public online. Annual reports are to describe the genetically modified crop being grown, where it is grown and when it was first planted there.
6. The farms that use 5 pounds or 15 gallons of restricted use pesticides must establish 500-foot no-grow zones around care homes, medical facilities, residential houses, and schools. There’s 250-foot buffer around parks, 100 feet along roads (unless signs are posted), and 100 feet along shorelines or streams,
7. A two-part environmental and public health impact study will be outlined by a fact-finding group within 12 months, which will then oversee the conducting of the study by a professional consultant, which has an 18-month deadline. The study is to look into impacts from big agriculture uses of both genetically modified crops and pesticides.
The 2.5-year total for the study may seem generous, but it took the United States from the 1940s, when scientists began expressing concern about DDT, until the 1970s, to ban DDT. Various neonicotinoid insecticides began being marketed in the 1980s and 1990s, but it took until this year, 2013, before significant numbers of studies prompted European restrictions on their use.
In each case, 30 years for a single pesticide or class of pesticides.
An optimistic Kaua`i County Council hopes that on Kaua`i, the problems of pesticides as well as genetically modified organisms can be identified and regulations recommended—in 30 months.
© Jan TenBruggencate 2013
Thursday, October 10, 2013
You can radio tag a bird or a mammal to track their
movements with GPS, but the technology doesn’t work so well under water.
Researchers have overcome this with satellite tags that report locations when whales or seals or turtles come to the surface. And there are tags that automatically release and float to the surface, where they can report their positions.
But tracking a fish that stays down in the water can be a problem, so researchers have adopted sound waves as their tracking systems.
One solution has been acoustic monitoring, since sound travels well in the water. It works this way: you set up an array of precisely located listening devices on the reef. Then you attach small noisemakers to fish, and the sounds collected on the listening devices give you a sense of when fish are present and which microphone they’re closest to.
New research is fine-tuning the information.
“Previous methods were not formulated with the fish, ocean and acoustics in mind. They therefore do not exploit all available information, such as the biology of the fish limiting its range of possible movement.” Martin W. Pedersen, a UH Mānoa postdoctoral fellow.
Pedersen and Kevin C. Weng, manager of the Pelagic Fisheries Research Program at the University of Hawai‘i at Mānoa, published their new fish tracking model in the scientific journal Methods in Ecology and Evolution.
Pedersen and Weng’s new state-space model for estimating individual fish movement is two-part—one part that models the fish behavior, and one that models the detection of that behavior.
The system uses data on fish behavior, along with information on where fish are detected and where they are not detected to help pin down their precise locations.
“Knowing where the fish is not located actually tells you a lot about where it is located, and with our new method, we are able to utilize that information and achieve a better accuracy,” Pedersen said.
Their tracking model was tested in remote Palmyra Atoll, far to the south of Hawai`i, where 51 underwater observation stations were established. They were able to create maps that helped show where the fish were and how they moved.
“It helps us to better understand how they feed, breed and rest,” Weng said. “Ultimately, more accurate movement information will help us to conserve these species.”
© Jan TenBruggencate 2013
Citation: Pedersen, M. W., Weng, K. C. (2013), Estimating individual animal movement from observation networks. Methods in Ecology and Evolution. doi: 10.1111/2041-210X.12086