Sunday, September 19, 2010

She's baaaack...

Recent reports by NOAA revealed that la Nina has returned to the tropical Pacific and strengthened over the month of August. The sister of el Nino, La Nina is the cool phase of the ocean warming phenomenon, during which surface temperatures of the equatorial east-central Pacific change by at least 0.5 degrees Celsius. Last month, temperatures dropped by 1.3 - 1.8 degrees. It seems like this chilly little girl is back, and she may be sticking around into 2011.

By some oceanic and climatic mystery that remains unsolved, el Nino and la Nina have a powerful influence over the weather conditions in many parts of the world. These events, which tend to alternate in cycles of 3-6 years, can alter seasons, upset fisheries, and increase the occurrence of extreme weather such as floods, droughts, hurricanes, and cyclones. Over the past two years in California, el Nino played a role in everything from nerve-wracking drought to vanishing Chinook salmon. As a result, it was easy to blame el Nino for anything that was at least slightly annoying. Rain on my birthday? Hot temperatures on the day that I decided to wear lined wool pants? Flight delays at SFO? Damn you el Nino.

Will la Nina be as good a scapegoat as her brother? Nature News has some answers.

Friday, June 25, 2010

Pharmaceuticals without a prescription.


As the population ages, healthcare spending swells, and medical technology advances, the use and variety of pharmaceuticals and personal care products (PPCPs) grow to meet the demand of people worldwide. Like all products, the presence of PPCPs in the environment has become as ubiquitous as their use in the human population. Today it is likely that PPCPs are detectable at low levels in all waterbodies adjacent to human settlement. In some instances they have been found to reach concentrations that rival pesticides.

PPCPs enter the environment primarily through the wastewater stream. When a pharmaceutical is administered to a patient, as much as 90% of the dose can be excreted still in its active form. Even the portion that is metabolized can be transformed and excreted as a unique byproduct. Personal care products like shampoos and lotions enter the wastewater stream when we wash our bodies and hands. This ever-changing concoction of chemicals, from analgesics to antibiotics, lipid regulators to synthetic musks, continuously buffets wastewater treatment plants, most of which are only designed to remove conventional pollutants and the basics of human waste. Due to the variety and the novelty of compounds found in PPCPs, many of these chemicals pass through traditional wastewater treatment plants unchanged and enter our streams, rivers, bays, and oceans. A 2009 study by the San Francisco Estuary Institute found 18 common PPCP compounds in treated wastewater effluent and surface water in the South San Francisco Bay. These included acetaminophen (Tylenol), fluoxetine (Prozac), and gemfibrozil (Lopid).

Even though PPCPs are generally detected at low concentrations in our waterways, we cannot be sure of their impact on the environment because their effect on non-human organisms is unknown. People are warned for good reason not to take pharmaceuticals without a prescription or in combination with other drugs, because the synergistic effects can be lethal. But what happens to a Chinook salmon that takes a low dose of Lipitor? And what if that Lipitor is mixed with dozens of other unidentified pharmaceuticals in the water? Because of the seemingly low risk to humans and the sheer number of compounds to be studied, research on the environmental fate of PPCPs is limited and regulation is nonexistent.

A recent study by a team of researchers from Eötvös Loránd University in Budapest and the China University of Geosciences suggests that the risk of residual PPCP exposure to humans may be greater than we think. In some parts of the world, where groundwater supplies must stretched to meet the demand for potable water, riverbank infiltration is seen as a safe and practical method to speed up the recharge of an aquifer. Instead of harvesting drinking water directly from the river, where a wastewater outfall may discharge treated effluent just upstream, water is pumped from wells adjacent to the riverbank, which lowers the water table, changes the pressure gradient, and pulls water from the river into the aquifer. Riverbank infiltration uses the soils of the bank to filter out pathogens, heavy metals, excess nutrients, hydrocarbons, and other pollutants in the same way that stormwater is purified as it naturally percolates through soil; however, with riverbank infiltration this process happens quickly enough to meet the population's needs. Budapest supplies one third of its groundwater through riverbank infiltration of the Danube River, which also receives effluent from two wastewater treatment plants.

Over the course of a full year, Margit Varga and her team sampled water from the Danube River and sediments from within two meters of the bank at three sites adjacent to riverbank infiltration wells. Many PPCP compounds are removed from water when they stick to sediments; however, the research group tested their samples for the presence of four acidic drugs, which have a greater affinity for water and are less likely to grab onto the particles of soil. Three of these drugs - ibuprofen, naproxen, and diclofenac - were regularly detected in the river water. The highest concentrations occurred during the winter when the water level was relatively low and cold temperatures restricted microbial activity that could degrade the compounds. Naproxen and diclofenac were also detected in the sediment samples, suggesting that some amount of these acidic drugs are removed from the water during riverbank infiltration.

The concentration of these drugs in the sediment seemed to be influenced not only by their initial concentration in the water being pulled through the bank, but also by the concentration of total organic carbon in the sediment. Sediment with a high concentration of carbon was more effective at filtering out the drug compounds. Sandy sediment with low carbon content could allow PPCPs to penetrate further into the bank. It is well-known that sediments have different compositions and different abilities to filter out contaminants - this concept has been applied countless times to septic systems and stormwater treatment mechanisms. But Varga's study confirms that the same is true for PPCPs, which are unregulated, poorly understood, and still in the vague category of "contaminants of emerging concern." Given the right combination of low water levels, cold temperatures, increased use of PPCPs, and poor sediment filtration capacity, these compounds could very likely reach drinking water supplies in areas that depend on riverbank infiltration. And as growing demand for potable water brings human populations closer and closer to their treated (or untreated) wastewater, the only way to eliminate the risk of exposure might be the remove PPCPs from the waste stream entirely before they can reach the environment.

Varga, M., Dobor, J., Helenkar, A., Jurecska, L., Yao, Jun., & Zaray, G. (2010). Investigation of acidic pharmaceuticals in river water and sediment by microwave-assisted extraction and gas chromatography-mass spectrometry Microchemical Journal DOI: 10.1016/j.microc.2010.02.010

Photo courtesy of Carly & Art via Flickr

Monday, May 17, 2010

Report from the Emerald Coast.

So far it seems like we have only heard numbers. The numbers describe the gallons of oil spilled from the collapsed Deepwater Horizon rig, the miles of shoreline at risk along the Gulf Coast, the volume of chemical dispersant released into the water, the length of boom laid, and the projected economic losses. I came to the Emerald Coast of Florida with a head full of numbers and no real perspective. After my first day out on the water with Skipper Tonsmeire, and Emerald Coastkeeper Chasidy Fisher Hobbs, I finally understand how catastrophic the Deepwater Horizon oil spill really is.


The barrier islands that enclose the Pensacola Bay extend for miles on either side of the Pensacola Pass as open dunes of white sand. Where other barrier islands and beach cities have been developed into a solid line of condominiums and hotels, long stretches of the Gulf Islands are preserved and protected as the Gulf Islands National Seashore. Of course there are built-out areas too - Pensacola Beach is a popular destination for locals and tourists alike. But once you enter the gates of the park, the human presence feels secondary to the natural processes at work on the island. You can still see evidence of Hurricane Ivan tearing apart the single access road in 2004, and during major weather events the Gulf pours over the island and into the Intracoastal Waterway. Closer to the Pass, Great Blue Herons silently stroll along the waterline while anglers cast their lines, waist deep in the waves.

In Skipper’s boat, we patrolled the inland waterways, inspecting boom placement and studying the pre-impact condition of the shoreline. Some lines of boom had been strategically placed to guard inlets and important ecological areas like Red Fish Point and Big Lagoon State Park. In other areas, like near the Pensacola Pass, the boom has been staged for deployment near the shore. When an oil slick enters the Pass on a flood tide, lines of boom from either side of the channel will be angled toward the middle, creating a funnel to collect and then remove the oil. The boom will then be drawn back to the shore during the ebb tide, honoring the Coast Guard’s request not to interrupt commerce on the Intracoastal Waterway.

Escambia County has done a good job so far of protecting their sensitive inland and shoreline areas with boom, but this method will only be effective at stopping oil on the surface of the water. Reports are now emerging that most of the oil is suspended in the water column, and tarballs have already been seen on Gulf Shores, 90 miles west of Pensacola. Environmental damage to the Gulf Coast from the Deepwater Horizon oil spill may be inevitable if booming is our only protective measure.

Fortunately our patrol gave us the opportunity to swim in the Gulf for what may be the last time in a while. To a person familiar with the bone-chilling water of the San Francisco Bay, the water of the Emerald Coast seems unreasonably warm. Just inside the Pass the water is clear enough to see schools of bait fish at your feet. It could have been a perfect day out on the Gulf, but swimming adjacent to lines of boom conjures up an ominous feeling that is hard to ignore. Anglers continue to fish from the shore, even though commercial fishing has been suspended. Kayakers paddle through inland waters, even though boom excludes them from the more interesting shoreline. People land their boats right on the beach and dive into the water without a second thought about its quality. Even while the Emerald Coast plays this game of sit and wait, it remains a community devoted to its beautiful shoreline and coastal resources.

Tuesday, January 26, 2010

The Toughest Snail on the Planet

Black smokers, a type of hydrothermal vent, create some of the harshest environmental conditions on the planet. These undersea chimneys propel superheated, sulfide-rich water from below the Earth’s crust into the deep ocean. Upon contact with the cold water of the ocean, dissolved iron sulfides precipitate out of solution and deposit onto the surrounding ocean floor. From the extreme heat (roughly 350 deg C), acidity, and suffocating chemical concentration of the water emerging from black smokers to the crushing pressure and complete darkness of the deep ocean, it’s shocking that organisms can even exist in this unforgiving abyss, let alone thrive. Yet as nature has proven time and time again, organisms adapt to exploit the conditions that we terrestrial dwellers consider most inhospitable.

Just like John Rambo, the organisms that can survive an environment as ruthless as a black smoker must be incredibly tough – even tougher than modern soldiers. For this reason MIT’s Haimin Yao has been studying the body defenses of the Scaly-foot Gastropod (Crysomalion squaminferum). The Scaly-foot Gastropod is a resourceful little snail that was discovered nine years ago at the base of black smokers near India, and it just may possess the most effective armor ever discovered.
Yao examined the shell at the nano-meter level to understand how it protects the soft body within from the extreme heat and acidity of black smoker water. It must also withstand the crushing power of predatory crabs. The shell of the Scaly-foot Gastropod is made of three layers, each composed of different materials to serve a different purpose. Together, they form a structure that's completely unlike any known armor, natural or man-made.

The outer layer is the thinnest and toughest, composed of iron sulfide particles extracted from the water surrounding the black smoker. This layer is designed to be sacrificed. When it is crushed by a crab claw (simulated in the lab by a diamond-tipped probe), the outer layer breaks but only into tiny cracks. By allowing these slight cracks, the outer layer dissipates the energy of the attack, and prevents the shell from shattering completely. The tough iron minerals of the shell can also wear down the crab's claw.

The middle layer is thick and soft. It is composed of organic matter rather than minerals. Its spongy consistency also absorbs the force of the crab’s claw, protecting the integrity of the inner layer. The outer and middle layers meet at a wavy junction rather than a flat one. This design keeps the two layers stuck together, preventing them from sliding apart.

Below the first two layers, the Scaly-foot Gastropod resembles the snails we’re familiar with. The inner layer of the shell is composed of calcium carbonate, the most common material for snail shells. If an ordinary snail were exposed to the acidic water of the black smoker, however, its calcium carbonate shell would rapidly dissolve. With the two outer layers, the Scaly-foot Gastropod can protect its inner shell, which provides structural support and prevents the shell from bending under the grip of a crab claw.

The three-layered armor makes this soft, vulnerable creature nearly invincible, even in the most extreme environment. Yao believes that this natural design could help to inspire the next generation of man-made defenses – from body armor to vehicles and sporting equipment. Perhaps we’ll see Scaly-foot Gastropod armor on Sylvester Stallone in the next installment of Rambo – Badass in a Mollusk Suit.

Learn more about the defenses of the Scaly-foot Gastropod in Yao’s article, published in the Proceedings of the National Academy of Sciences.

Photo: Our friend, the Scaly-foot Gastropod, courtesy of Anders Waren.

Sunday, January 24, 2010

Species Profile: Bay Pipefish

Interesting fact from Baykeeper's upcoming Winter Newsletter: San Francisco's Seahorses are not limited to those plastered on the walls in the Powell Street BART Station.

What is a Pipefish?
The Bay Pipefish (Sygnathus leptohynchus) is a member of Syngnathidae – a family of fish that includes Seahorses and Sea Dragons. The Bay Pipefish shares many characteristics with its enigmatic cousins, including plates of bony armor, small tubular mouths, cryptic coloration, and secretive behavior. Like other Pipefish, however, the Bay Pipefish has a long, straight body.

What do they look like?
The Bay Pipefish is a long, thin fish that grows to about a foot in length. Its coloration varies between shades of green and brown. It may be possible that the Bay Pipefish changes its color to match its surroundings, but this is not known for sure. Just like Seahorses and Sea Dragons, the Bay Pipefish has a long tubular mouth formed by fused jaw-bones.


Where are Bay Pipefish found?
The Bay Pipefish inhabits eelgrass beds and shallow estuaries along the Pacific Coast from Baja California to Alaska. Hidden among blades of eelgrass, the long slender fish is almost completely concealed. The eelgrass beds also support an abundance of prey, allowing the Bay Pipefish to thrive. In the Bay Area, the Bay Pipefish can be spotted in eelgrass beds in San Francisco Bay, Suisun Bay, Drakes Estero, and Tomales Bay.

What do they eat?
The Bay Pipefish uses its tubular mouth to suck plankton prey out of the water like a vacuum cleaner, rather than biting it. When it is hunting, the Bay Pipefish remains completely still beneath its prey. Its eyes are capable of binocular vision, allowing it to determine the distance to its prey. When the position is just right, the Bay Pipefish will quickly snap its head up, placing its tiny mouth about an inch from the prey and delivering suction to capture its meal.

How do they reproduce?
Bay Pipefish reproduction begins in the early spring when eelgrass grows and plankton density increases in the water column. Like other male Syngnathids, the male Pipefish has a well-developed brood pouch on the underside of its tail. After the female deposits her eggs within the male's brood pouch, a layer of tissue grows to seal the eggs inside. The male Pipefish carries the embryos for several weeks, providing them with the nutrients, oxygen, and water they need to develop. When ready to hatch, hundreds of Pipefish young split the pouch and emerge into the water, resembling miniature versions of the adults.

What are the threats to Bay Pipefish in the Bay?
The greatest potential threat to the Bay Pipefish in the Bay Area would be the loss of habitat. Luckily for the Bay Pipefish and other eelgrass dependent species, the extent of eelgrass beds in the San Francisco Bay has actually been expanding in recent years. Although there is no commercial fishery for Pipefish species, they are collected for the Chinese medicine trade. At this time Pipefish are abundant, but if the demand for Pipefish by alternative health care markets increases, Pipefish might become as scarce as their Seahorse relatives.

Photo credit: Aquarium of the Bay