Scientific diving

Diving into the Sandstorm

A blog post by Sean Sheldrake, an EPA scientific diver and frequent contributor to It All Starts with Science, was recently featured on the Smithsonian Institution’s Ocean Portal blog. We are reposting it again here for you to enjoy. 

By Sean Sheldrake

Ship with a large pipe off the side with a stream of sand coming out.

U.S. Army Corps of Engineers removing a sandbar off Virginia Beach, VA.
U.S. Army Corps of Engineers image

Diving can be a wild ride that evokes more than a little trepidation, especially in the Pacific Ocean’s famously big, cold waves. Waves that are otherwise fun for my weekend surfing can turn a scientific dive into a serious challenge. But then, diving to support the mission of the Environmental Protection Agency (EPA) can be full of surprises. At a seafloor survey site at the mouth of the Chetco River off the Oregon coast, waves transmit so much energy that divers can feel the swells nearly 80 feet down on the seafloor. As divers swim along the bottom, these swells often push them several feet forward, then “suck” them backward several feet.

Such natural water movements not only make diving difficult, but can also drastically alter the underwater terrain. Humans further these changes by digging up sand and sediment from the bottom of a river or ocean and depositing it elsewhere, a process known as dredging. Ports might dredge an area to clean up the seafloor, or make an area deep enough for large ships to navigate. Without it, sandbars would grow to such enormous heights that river entry would be worrisome to even the most experienced captains. Such large sandbars can wreck ships; one was nicknamed the “Graveyard of the Pacific” (PDF) in the early days of Columbia River navigation. And, on one beach I often surf, the wreck of the Peter Iredale remains as an eerie reminder to respect “the bar.”

EPA divers from Atlanta place this instrument in Charleston Harbor in order to monitor currents and better predict sand movement.

EPA divers placed this instrument to monitor currents and better predict sand movement. EPA image

But if you’re going to dig up a bunch of sand, you have to put it somewhere. EPA divers around the country evaluate dredge material disposal sites regularly, where ports deposit literally tons of sand into the ocean. How much? In 2013, more than eight million cubic yards of sediment will be removed from Oregon’s Columbia River alone. This, and many other dredging operations upriver, help move 42 million tons of cargo from Oregon, Washington, and Idaho farms to market each year with as few bumps as possible.

Placing dredged material from a river or harbor into the ocean is not necessarily a problem, as long as it’s a load that is small enough to not overwhelm the creatures that live there, like crabs or sea stars.  For example, if the load just adds several inches of sand to the area, crabs and sea stars can ‘hop’ up above that material. But if several feet were placed all at once, it’s likely that these critters would be buried. Sometimes, new sand can be beneficial to certain ecosystems, such as sandy beaches that have eroded. However, when sand is placed on rocky reefs or other sensitive environments, it can change the habitat. A rocky reef that gets buried in sand can no longer support its vital organisms, such as anemones and urchins.

That’s where the divers come in. EPA’s scientific divers visit and observe dredge deposit sites to make sure there is no damage to marine life on the seafloor—critters like worms, clams, crabs, and other tiny organisms that live in the bottom sediments—as ordered by the Marine Protection, Research, and Sanctuaries Act. To do this, we visit locations before and after dredged sand has been dumped to see if habitat has changed slightly, been dramatically transformed, or remained relatively unchanged since our last visit. For some areas, we might also use remote sensing techniques like sonar to quickly direct divers toward areas that need to be monitored more closely, like those sensitive rocky reefs. If we find the impacts to an area are too severe, the dredge disposal may be moved or future deposits will be stopped altogether in that location.

Because ports continually accumulate sediment—from human dredging, natural erosion and runoff—the cycle of dredging, dumping and observation happens on a regular basis, even twice a year for some sites. All to make sure that ecosystems stay healthy, ports can continue working, and that beachgoers and surfers like me can continue to enjoy them.

Read more about the latest EPA scientific diving.

About the AuthorSean Sheldrake is part of the Seattle EPA Dive unit, and a project manager working on the Portland Harbor cleanup in Oregon.  He serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.   

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Salmon Recycling: Waste Not, Want Not

EPA scientific diver and frequent “It All Starts with Science” contributor Sean Sheldrake recently shared some of his work on the Smithsonian’s Ocean Portal blog. The following was originally posted there.

By: Sean Sheldrake

Underwater pipe discharges fish waste.

Pipe discharges fish waste from processing factories. Photo byBruce Duncan, EPA

As a research diver for the US Environmental Protection Agency (EPA), one of my jobs is to make sure that people and companies working in the fish industry don’t dump too much waste in the ocean. On my first dive at an underwater waste site, my old salt of a dive partner hinted, “you might see a shark… or three” with a wink. “Okay,” I thought, “I can deal with a couple of sharks.”

Descending to the dump site, I soon saw circling dogfish and salmon sharks extending all the way from 80 feet to the surface—maybe 50 sharks, perhaps more. All those dogfish were drawn to a pile of Alaskan salmon fins, intestines, and other fish, legally unloaded into the ocean. I hand-signaled my partner, pointed up at the schooling swarm, and then shook my head to let him know that I wasn’t very happy with his low-ball estimate.

Every year, tons of fresh salmon are flown and shipped from Alaska to the lower 48 states. Before they’re flown south, the fish are sliced and diced into ready-to-cook filets, creating “inedible” fish waste. Under the Clean Water Act, people and industries handling fish and fish products are allowed to dump some of their waste back into the sea. But the EPA regulates these discharges with help from the states to ensure that waste does not degrade waterways. We all value our lakes, streams, and oceans, and the Clean Water Act helps to protect them.

Fish waste is often discharged down a permitted outfall, which is a pipe carrying waste into the ocean. This creates a ‘zone of deposit’ or ZOD on the seafloor. Life on planet ZOD is pretty limited—bacteria that live without oxygen predominate, and hydrogen sulfide gas (the stuff that smells like rotten eggs) is belched out occasionally. Outside of the oxygen-free zone, the ZOD attracts scavengers. On that surprising first dive, so many small dogfish filled the water that they were getting caught between my legs, in the crooks of my arms, and bumping me from every other direction to see if I had a handout—or if I were a handout!

The ZOD is supposed to be confined to a small area on the seafloor, but it often extends much further than allowed: some waste piles, though permitted only to an acre or less, extend to dozens of acres and may even grow so tall that navigation by boats can be obstructed. This is where inspections come in. I and other EPA divers check the type of waste being discharged and map out the size of the ZOD, to make sure it doesn’t cover more seafloor than allowed.
 

When the EPA finds that a company is violating its permit, one option is to ask its managers to recycle their waste. Seafood waste can be made into a variety of products from salmon cakes to gourmet pet food to high value fertilizer. Many fish processing plants have jumped into recycling technology, making good use of nearly all their “waste”. That’s a lot of happy kitties (although the dogfish might not appreciate the loss in food)!

Recycling fish products instead of creating a permitted outfall is better for ecosystems. To encourage this behavior, ask at your grocery store if the seafood company you’re buying from recycles their waste. Buy recycled products whenever possible—voting with your dollars makes a definitive statement that you want to see more recycling!

Read more about the latest in EPA scientific diving at the EPA Divers Facebook page.

About the AuthorSean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon.  He serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.  

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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On Vacation with EPA Science

By Elizabeth Blackburn

Rafting (lge)My family is always giving me a hard time about the difficulty I seem to have completely disconnecting from work. Not only does my ever-present, e-mail-spewing smartphone mean I can keep in touch with my colleagues from virtually any location and at any time, but my job can be really interesting!

As the director of science communications for EPA’s Office of Research and Development, I get a firsthand look at just about every science story that flows from the Agency’s world class scientists and engineers, as well as from a partnership community uniting EPA researchers and other innovators from across the government, academia, business, and beyond. I get a “sneak peak” at an incredible breadth of stories covering everything from tiny nanoparticles, to children’s environmental health, ecosystems assessment, and global climate change adaptation.

With all that going on, you can understand why I find it hard to unplug. Even so, I made a commitment to do my best on a recent family trip. I traveled clear across the country with my husband to visit our son, who lives in the “other” Washington (Washington State).

There, thousands of miles from the office, surrounded by some of the best rafting opportunities anywhere in the world, I came across something that brought my mind right back to work: dam removal. That’s something that our scientific divers have been blogging about right here on It All Starts with Science.

Dam removal has a special place in my heart as there was a dam removed on the river my son—a rafting guide—works on. In fact, we rafted a portion of the White Salmon that had been previously underwater. The canyon was magnificent and it was awesome to see steelhead trout swimming upstream and jumping up waterfalls that they had previously been unable to reach because of the dam.

So, not only did I get to enjoy a somewhat harrowing raft trip with my family, but I got to share what I do and why I like it with a captive audience. For those of you who didn’t have the opportunity to join us on the raft, check out this morning’s blog from our scientific divers about their latest observations and findings. It answers some of the same questions I had about dam removal and what they are learning.

While I’d love to share more about my family vacation and the glorious Pacific Northwest, I’ve got to get back to work. (Oh goodie!)

About the Author: Elizabeth Blackburn is the Director of Communications for EPA’s Office of Research and Development, and an avid fan of wild and scenic rivers anywhere.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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The Algae “Strike Back”: Post Dam Removal Benthic Surveys at the Elwha River Mouth

By Sean Sheldrake, Steve Rubin, and Rob Pedersen

EPA science diver photographs kelp samples on board boat.

EPA diver Rob Pedersen photographs samples.

Some of you may have followed our previous blog posts about EPA’s scientific diving program, including 2011 and 2012 reports from the Elwha River mouth in the Strait of Juan de Fuca.

The field site is downstream from the largest dam removal and restoration project to date, a large scale effort to restore wild salmon habitat and other aspects of the natural ecosystem. (For a great overview of the project, check out the webinar series posted by Olympic National Park.)

In this 2013 installment, we share some interesting findings about our benthic survey on how the dam removal is affecting things at the mouth of the river.

This survey involves counting 72 species of invertebrates and 13 species of algae—all of which are experiencing changes, some dramatic, as a result of the largest dam removal and restoration project to date: an experiment of grand scale for Elwha River mouth seafloor residents!  The survey is led by the U.S. Geologic Survey, and the team includes Washington Sea Grant, the Lower Elwha Klallam Tribe, and EPA divers.

Stationary light sensor placed near the Elwha River mouth.

Stationary light sensor placed near the Elwha River mouth.

Although divers reported seeing fewer algae, the scientists are still crunching the numbers. Early indications suggest a decrease in algae abundance, including the famed, forest-forming “bull kelp” since the removal of the dam. These changes may be due to decreased light levels, a loss of suitable substrate (a growing surface like a rock of some size, or even as small as gravel), or a combination of the two.  The team of divers used light sensors at many stations to help to document whether changes in light penetration were occurring at the dive sites to supplement quantitative data about the changes in the seafloor substrate.

In addition, it seems that tubeworms are on the increase in some areas.

This year, early reports indicate a late growing season for algae, perhaps due to the “silt cloud” hanging over areas near the river mouth. A few surprises may be in the works, too, such as the appearance of the rare kelp species pictured below, a sample the team of scientific divers could not immediately identify underwater—a discovery suggesting that as algae are faced with reduced light levels, a species or two not found during previous surveys might be trying to join the party.

Diver holds kelp sample underwater.

Mystery kelp.

Early suspicions from USGS and other experts narrowed down the mystery alga to either Laminaria ephemera or Laminaria yezoensis, and follow up examination confirmed it to be Laminaria ephemera. The unfolding story was covered in the local Peninsula Daily News.

To answer a few questions you might be wondering about all this:

  • Why does algae matter?
    Answer: Well it’s quite a nursery for young marine life and a grocery store for young and old that live in the sea.  It’s not unusual to see gray whales and their young grazing in the ‘kelp forest.’ Changes for shellfish are also of great importance to local fisheries.  The river is connected to the ocean in so many ways—and the silt keeps coming!
  • What other changes are there?
    Answer: The ongoing study will show changes for nearly 100 species of algae and invertebrates, in addition to fish, for the largest dam removal effort in North America to date.

For more information on the USGS-led study, see: http://www.usgs.gov/elwha, http://pubs.usgs.gov/sir/2011/5120/seaLife/.  For a full set of 2013 photographs, see: Elwha 2013.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the AuthorsSean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon.  Sean Sheldrake serves on the EPA diving safety board, responsible for setting EPA diving policy requirements, where Rob Pedersen has served for many years.  In addition, they both work to share contaminated water diving expertise with first responders and others.  Steve Rubin is an aquatic biologist specializing in algal species with the USGS and a lead scientist on the survey.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Around the Water Cooler: Be It Ever So Humble, There’s No Place Like Home

Reposted from It’s Our Environment.

By Phil Colarusso

Wednesday had been a long day in the field, and it was great to be home. It was early evening and I was processing the last seagrass sample. Seagrasses provide habitat for many organisms, so it is not unusual to find small invertebrates crawling around in our eelgrass samples.

I poured the last sample bag onto the sorting tray and separated the small rocks, shells and other material from the shoots of eelgrass. It was at this point I saw it: a small hermit crab lay motionless. It had ditched the snail shell it had been living in, which I subsequently found among a small pile of rocks. The crab was dead and I was immediately overwhelmed with guilt. Hermit crabs only leave the safety of their adopted shells, their homes, under periods of extreme stress. As I contemplated the poor crab’s fate, I wondered what extreme event it would take to make me leave the security of my home. I have lived in homes that survived hurricanes, the snow and coastal flooding of the Blizzard of 1978, and countless other events.

A sense of discomfort gnawed at me as my tired mind wandered. Our oceans are home to millions of species. Global climate changeocean acidification and eutrophication are some of the processes making our waters inhospitable to many plants and animals that live there. Warmer water temperatures change the normal distribution of animals and plants. Shellfish, which use calcium carbonate to build shells, will find that harder and harder to do as ocean pH levels continue to become more acidic. Sensitive habitats, such as coral reefs and seagrass beds, rapidly decline as waters near shore get over-enriched with nitrogen. What happens to all the fish that depend on those habitats? What do you do when you can’t go home?

Photo by Giancarlo Lalsingh (Tobago_Pictures on Flickr)

Photo by Giancarlo Lalsingh (Tobago_Pictures on Flickr)

As I was putting away my scuba gear, something fell out of my fin. In the dark it looked like a small rock. I picked it up off the garage floor with the intent of throwing it into the backyard. I realized it was not a rock, but another hermit crab, still tucked snugly in its snail shell. There was but one thing to do. I hopped in the car and drove the 15 minutes back to the nearest salt water. I returned this crab back to a safe location and he scrambled away. As he wandered away, I marveled at the resiliency of life. It reaffirmed to me the importance of the work I do. Nothing is more important than that place we call home.

Read more info on EPA’s work to protect ocean and coastal areas in New England.

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About the author: Phil Colarusso is a marine biologist in the Coastal and Ocean Protection Section of EPA New England, and is an avid diver. He’s living the dream in Wenham, Massachusetts with wife JoAnn, two kids, dog and white picket fence.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Diving into Nutrients: How much is too much?

By Sean Sheldrake

An EPA diver kept isolated from contaminants.

An EPA diver kept isolated from contaminants.

There’s a nutrient “problem”?

Did you know nutrient pollution, primarily in the form of too much nitrogen and phosphorus, is one of the nation’s most widespread, costly and challenging environmental problems?  Some 16,000 waterways are impaired, and 78 percent of assessed coastal waters suffer from nutrient pollution, affecting water used for drinking, fishing, swimming and other recreational purposes.  These impacts also threaten tourism, home and property values and public health.

Nitrogen and phosphorous are food for some plants, like algae, and too much can spark a large algal bloom that can end up consuming all the dissolved oxygen in a waterway, causing fish to be starved for that critical gasp of O2.  Fish die-offs are common with extreme nutrient problems.

Where does it come from?

Excessive nitrogen and phosphorus are often the result of human activities. Primary sources include agriculture (manure, excess fertilizer and soil erosion), inadequately treated wastewater, stormwater runoff, air pollution from burning fossil fuels and—us! Huh? Whenever we do things around the house that add nitrogen and phosphorus to the local watershed we are part of the problem. That can include not cleaning up after your dog, using too much fertilizer on the lawn or garden, or washing your car on the driveway (most soaps contain nutrients).

How can I help?

Washington Department of Ecology Image.

Washington Department of Ecology Image.

The good news is that since we are all part of the problem, we can all be part of the solution.

Bag the dog waste, apply fertilizer according to the label (or better yet, switch to using some backyard compost!) and park your car on the lawn instead of the driveway when you wash it, or go to a carwash. We can really make a dent in the problem.

How about a little science to help out?

But it’s not all up to individuals alone. EPA scientists are working on solutions, too.

EPA divers help deploy and retrieve scientific instruments, such as Acoustic Doppler Current Profilers (ADCPs), to help study nutrient pollution.  For example, in one project in Puget Sound we deployed ADCPs to collect information on water flow, a critical first step that EPA computer modelers use to calculate the level of nutrients a water body can tolerate.  Ensuring the proper placement for data collection is paramount for data quality.

EPA diver deploys an ADCP.

EPA diver deploys an ADCP.

Getting into the water can be a challenge though!  Divers may have to upgrade to protective equipment and do a decontamination wash after the dive to ensure the safety of each diver getting in the water to collect data.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

 

About the AuthorSean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon.  He serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.  

Join us for a Twitter Chat to Learn More!
Got questions? Want to learn more? Join us for a Twitter chat this Thursday (July 18, 2013) at 2 pm ET on nutrient pollution and harmful algal blooms. Use #waterchat to ask a question or participate. Not on Twitter but have a question? Please add it to the comments section below. 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Diving Safety: We’re All In

By Sean Sheldrake and Alan Humphrey

Our previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways.  In this post, we talk about how our divers stay safe through the development of safe practices and standards, well before they hit the water, so that the best science is delivered safely.

Sometimes things go wrong

We’ve all heard about a diver fatality at one time or another in the news, and such tragedies are particularly hard hitting when it is a colleague.  The dive community is a close knit one, and these tragedies hit close to home.  A diver’s death brings us together to grieve and—perhaps more importantly—to learn.  Are human factors the source of what occurred or should our safety rules be changed so we don’t have a similar event? We work to prevent repeating mistakes, and avoiding future tragedies. “Near misses” are evaluated for safety protocol improvements as well.

Peer groups make the difference

EPA Diving Control Board

The diving control board meets to discuss safety.

Under the Occupational Safety and Health Standards for scientific diving, scientific divers must operate under a “diving control board” that meets regularly to update their standards for recent safety issues.  Annually, the control board meets to discuss safety incidents that occur with military, commercial, or scientific divers and determines how to change the diving rules to keep us safe.

Beyond our own control board, we look to other “standard setters” in the dive industry.  The American Academy of Underwater Sciences, Association for Dive Contractors International, and others develop standards that exceed basic OSHA requirements.  Indeed, this type of diving safety peer review is part of the reason why the data suggest scientific diving is among the safest forms of diving (Dardeu et. al., Diving and Hyberbaric Medicine, 2012).  Developing “best practices,” such as sharing critical information across the profession is key for working safely in such an unforgiving environment!

Always learning

Divers learn early that their training never ends.  In addition to learning from diving accidents and standards of industry, the board disseminates critical new information to divers on the ground.

Deputy unit diving officer Chad Schulze demonstrates a new first aid oxygen delivery system.

Deputy unit diving officer Chad Schulze demonstrates a new first aid oxygen delivery system.

Though the demands of the underwater environment are relatively static, technology changes much of what we know about the effects of pressure on a diver’s body.  Sifting through new research, changing dive rules, and informing working divers about new practices is the control board’s number one job in keeping EPA divers safe.

EPA’s diving culture is all about safety.  Every diver can refuse to dive for any reason, and every divemaster can call off a dive.  Not only have each of us aborted more than one dive, we often gauge newer divers most on their concern for safety. Have they considered not diving due to a cold, an equipment issue, or just a feeling that the stars are not completely aligned? That’s what we want. Whether it’s conditions, equipment, or anything else, we all work together to pursue our underwater science safely.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the authors:  Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon.  He and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements.  In addition, they both work to share contaminated water diving expertise with first responders and others. 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Ebb and Flow: Feeling Like a Yo-yo

By Sean Sheldrake

My previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways.  In this post, I talk about how our divers study the connection between groundwater and our waterways to support EPA cleanups.  (Hint: it’s not a one way street!)  Understanding which way groundwater is flowing is critical to implementing a successful cleanup—and protecting our nation’s waterways and oceans.

Groundwater: coming or going? 

We all know storm drains connect to our waterways, but how about groundwater? In a given stretch of a stream, lake,  river,  or the seafloor, groundwater may be feeding the waterway—or the opposite—that stream, lake,  river, or ocean could be losing water into groundwater in that location.  The direction of the flow can change by the hour, day, season, and conditions (such as drought)—a reality of the interconnectedness of water in the environment.

Gaining or losing? Mapping out the flow to get the cleanup right

Determining whether a river loses or gains water from the ground is a big deal when devising the best course of action to take during cleanup activities, as we need to follow the contaminated water to wherever it goes.  With this information, we can decide on important details, such as where to install caps in a riverbed to stop the flow of contaminated discharge, or how many and how fast pumping wells should be employed to move contaminated groundwater to a treatment plant.

Seepage meter installed by an EPA scientific diver near a Superfund Site in Lake Washington. Photo: Rob Pedersen, USEPA.

Seepage meter installed by an EPA scientific diver near a Superfund Site in Lake Washington. Photo: Rob Pedersen, USEPA.

Making such a determination is an ongoing process. For example, in an estuarine river (the part of a river that is near the sea), this may take a lot of monitoring locations over time to know we’re choosing the right kind of cleanup. A lot of factors also need to be considered, including the location, direction, and volume of local ship traffic.  EPA divers often must check various locations in the sediment near an active cleanup to determine where groundwater is discharging into the river—and vice versa.

Low-tech goes underwater

At some sites near marine environments, we use conductivity mapping to determine where groundwater discharge is occurring.  Because salt water conducts electricity better than fresh water, we tow an array of electrical cables that measure electrical fields to produce a map of where fresh ground water is discharging into salt water.  In other sites, we can use a more low-tech approach.

The photo above shows one such technique. Here, we use a five-gallon bucket, cut in half, stuck into the lake bottom. We then outfitted it with a sampling bag filled half way with water.  We use this simple device to determine the direction of the water flow by noting what happens to the sampling bag. If it begins to empty we know the direction of water is OUT of the lake (and bag) and into the ground, and if it fills up, we know the water is flowing in the other direction: from the ground into the river.   We can also seal the bag and bring it to our lab for analysis, getting and even better understanding of the rate of contaminant discharge into a lake or stream.  Over time, divers come back to visit the site to map the wonderful complexity of water’s connections.  The map allows us to understand the movement of historical pollution and to determine how to best conduct a clean up.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the author:  Sean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon.  Sean Sheldrake serves on the EPA diving safety board, responsible for setting EPA diving policy requirements. 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Diving for Science at EPA: ‘SCUBA’ or ‘Surface Supply’?

By Sean Sheldrake and Alan Humphrey

Our previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways.  In this post, we talk about different ways in which we might dive to carry out EPA’s mission.

What is SCUBA?

Self-contained Underwater Breathing Apparatus, or “SCUBA,” is the mode of choice for many diving scientists, and many diving scientists at EPA.  It involves carrying your entire breathing supply with you, and requires a fair amount of strategic planning, especially for difficult diving conditions such as low visibility, and cold or polluted water.

What is surface supplied diving?

An EPA surface supplied diver entering the water. You can see the hose providing air to the face mask, and the emergency breathing gas (yellow bottle) on the diver’s back. Photo by Rob Rau, USEPA.

Is that a trick question?  Well no, it is what it sounds like—air is provided to the diver from above through a long hose.  This can be quite limiting if you want to swim far from the boat, so it doesn’t work everywhere.  Also, the dive vessel must be anchored to keep it from moving.  If the vessel was moving, the diver working on the seafloor could become the boat’s anchor after drifting into a rock.  Now that’s a bad day at the “office”!

Even though this kind of “dope on a rope” diving may feel restricting to the diver, it can be crucial in low visibility, contaminated water.  Often times—especially where visibility is only a few inches—it can be difficult or impossible to keep track of your dive buddy.

I’ve been diving in the Willamette River in conditions where I’ve been close enough to hear my dive buddy’s breath, but we couldn’t see each other. In conditions like that, we might not be able to find each other in case of trouble. And even more basic than that, divers can’t check vital gauges such as pressure and air supply under such conditions. In those cases, surface supply is the way to go. Topside support can be your ‘buddy’!

Don’t hold your breath!

Photo of an oil covered diver undergoing decontamination on surface supply. Photo by Alan Humphrey, USEPA.

With a surface supplied diving system there is plenty of air to keep the diver working. That means no cutting dives short before the scientific mission on the bottom is completed, or needing to account for an air supply that includes keeping the diver completely sealed in for an extended decontamination process, like when they might be covered with oil (see picture). Surface supply offers more efficiency and safety for the diver for certain projects—in most cases the diver can continue to work until the sampling or other task is completed (or when nature calls).

Want to learn more? Download the EPA publication “Use of Surface-Supplied Gas for Scientific Diving” presented at the 30th symposium of the American Academy of Underwater Sciences: http://1.usa.gov/ZPxS6b.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

About the authors:  Sean Sheldrake and Alan Humphrey both serve on the EPA diving safety board, responsible for setting EPA diving policy requirements.  In addition, they both work to share contaminated water diving expertise with first responders and others.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

One Man’s Trash Another Man’s Treasure

Greetings from New England!Each Monday we write about the New England environment and way of life seen through our local perspective. Previous posts

By Phil Colarusso

A shelf in my home holds old bottles, pieces of broken china and a porcelain imported mustard jug, treasures I found while diving. If I had found any of these objects on the street, I would not have bothered to pick them up. The fact that they were underwater added mystery and value to each of them.

In the sea, sunken vessels, railway cars, surplus army tanks, airplanes and a whole host of other things very quickly turn into artificial reefs. The sea and the life in it quickly claim as their own just about anything that humans have placed in it. I do not advocate dumping trash in the sea, but the ocean does seem to possess a remarkable redemptive quality.

The Atlantic Ocean has more than its share of discarded tires, which eventually become home to a variety of creatures. Lobsters, crabs, sea stars, sea urchins and a variety of small fish will happily live in the steel belted radial. The tire no doubt provides refuge from predators, waves and currents.

The most unique use of a tire I‘ve seen was by a male lumpfish (Cyclopterus lumpus). The cartoonish lumpfish is about the size of a football. With seemingly undersized tails and pectoral fins, they resemble miniature Goodyear blimps. Large suction disks on the belly allows them to adhere to surfaces. They are awkward, slow swimmers, and come in a variety of colors. Lumpfish, predominantly found among large rocks that support macroalgal and kelp growth, spend days moving as little as possible among the kelp looking for worms, crustaceans, mollusks and small jellyfish. On occasion they actively forage, but generally prefer to ambush prey. They will remain motionless, securely attached to a surface until some unsuspecting creature comes within range.

While collecting samples in an eelgrass bed, I saw a tire in the meadow. On the edge of the tire sat an adult lumpfish, a surprise since adult lumpfish aren’t normally associated with eelgrass. The greater surprise was the large clutch of eggs found inside the tire. Female lumpfish lay up to 150,000 eggs, then leave them with the male until they hatch. The male guards the nest and blows water over the eggs to aerate them. We backed away and allowed the male to maintain his vigil undisturbed.

Back in my office, I Iearned scientists have not identified the preferred spawning habitat of lumpfish in the Gulf of Maine. I envisioned my next scientific paper: “Goodyear blimp fish found to spawn in Goodyear tires”. I decided the lumpfish’s secret was safe with me.

About the Author: Phil Colarusso is a marine biologist in the Coastal and Ocean Protection Section of EPA New England, and is an avid diver. He’s living the dream in Wenham with wife JoAnn, two kids, dog and white picket fence.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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