Scientific diving

Diving into the Classroom

By Sean Sheldrake

Bona fide “cool” job: an EPA diver maps the location of a drum found on a dive survey.

My previous blog posts have featured how EPA diving scientists support cleanups in the nation’s waterways.  In this post, I cover one of my favorite work experiences I do “top side,” namely, talking about my scientific diving experiences in the classroom.

I have found that being a professional diver is a bona fide “cool” job. Not only does this make sharing my work with students fun, but is a great opportunity to energize kids about math and science and illustrate how we can all take action to help protect the environment.

Raise your hand…

I like to start out by taking questions from the students. Often, one of the first is: “what’s the ‘scariest’ thing you’ve encountered underwater.  “Sharks?”  No, but I was pretty scared during my first Alaska dive surrounded by hundreds of sharks—so many they were getting stuck in the crooks of my arms while I attempted to take photos.  “Eels?” No, in fact I actually find wolf eels pretty cute, though one did come out of its den and chase me on one memorable dive!

I almost always get surprised, quizzical looks when I reveal the real answer: “a pipe discharging really mysterious stuff.”   I explain how real harm can be done to the diver and the ecosystem if harmful chemicals, bacteria, viruses, and alike are discharged into our lakes, streams, and oceans.

The other “scariest” thing I’ve seen: stormwater runoff!

Contaminants—used motor oil, metals, pet waste, too much lawn fertilizer, cigarette butts, etc.—that get swept up by  stormwater can be very harmful to water bodies, unless we each work hard to  keep those things where they belong.  Fixing car leaks, recycling and composting, cleaning up after our pets, following the instructions on lawn fertilizers, and other daily actions are all things we can do to make a big difference in what washes off the street and goes down the storm drain, where it can eventually cause major damage downstream.  It all adds up.

“Does math really have any use?”

And speaking of “adding up,” the other major point I like to make in the classroom is dispelling the myth that math and science are some kind of torture. They are critical subjects to some of the coolest jobs out there (such as scientific diving)! After all, multiplication gets exciting when I say that if I don’t know my multiplication tables me and my dive buddy could miscalculate our dive plan and get hurt.  Safe diving science requires math! (EPA has lesson plans for oodles of environment topics that help bring science and math to life.)

Parting thoughts

I always try to leave the students with the knowledge that there are a million things each of us can do to help the environment!  Well, okay, maybe hundreds of ideas growing by the day.  The most important aspect is to take personal action.

If we all take steps to help our planet it will really add up; for my part maybe that storm drain (yikes!) won’t cause the hairs to stand up on the back of my neck anymore.

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.

It’s Not Exactly Rocket Science but…

By Matthew Colip

EPA Scientific Diver trainee Matt Colip returns to the surface following SuperLite 17K Diving Helmet and drysuit training.

Being an EPA Scientific Diver is a lot like being an astronaut; you’re trained with a specific skill-set to “float” through an often unpredictable environment with the purpose of gathering data to advance science and help people.  For me, becoming an EPA Scientific Diver has expanded my scientific capabilities to work in an environment that occupies 70% of the planet and that we all depend on: water.

EPA’s Scientific Diving Program can be traced back over 40 years to a group of divers formed to support the need for diving expertise in contaminated waters for the Federal Water Pollution Control Administration, the predecessor to EPA.

Today, EPA has scientific diving units at strategic locations across the country conducting scientific work for a myriad of federal, state, and local programs.  EPA scientific divers work in both marine and freshwater environments. 

For example, EPA recently conducted a freshwater mussel survey in the Susquehanna River in Pennsylvania.  The divers conducted 12 dives and reported information on the habitat conditions at the river bottom to the surface via wireless communication.  In addition, live and dead mussel shells were collected for species identification.  Ultimately, the information they collected will add to the data Pennsylvania is gathering on the ecological health of the Susquehanna River.

Since joining EPA as a biologist, I’ve wanted to use my recreational SCUBA diver experience to become a member of the Agency’s Scientific Diving Program.  Scientific diver trainees must successfully complete EPA’s Scientific Diver Training Program, which emphasizes safety and includes extensive safety training and drills.

Studying the physics of water pressure and its effects on human physiology, the proper use and handling of oxygen-enriched air, and the unique challenges of diving in polluted waters help us learn important concepts that prevent accidents.

In addition to general safe diving concepts, EPA scientific diver trainees also learn skills to gather data and survey underwater environments. We learn how to use underwater cameras, electronic communications equipment,  conduct a basic benthic survey, sampling techniques for water and sediment, as well as underwater navigation and sampling site survey methods for zero-visibility diving. 

Simply stated, EPA’s Scientific Diver Training Program transforms recreational divers who are scientists, engineers, law enforcement personnel, and/or academics, into EPA-certified scientific divers who use underwater environments as their sampling laboratory.

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

About the Author: Matthew Colip works as a National Pollutant Discharge Elimination System (NPDES) Enforcement Officer in EPA Mid-Atlantic Region’s Water Protection Division, NPDES Enforcement Branch.

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 Green for Science

By Sean Sheldrake

EPA’s Seattle dive van loaded up with a full ton of dive gear—plus a bicycle.

In previous blog posts, we’ve shared how EPA diving scientists support cleanups in the nation’s waterways.  In this post, I’ll talk about how we are working to “dive green” while undertaking EPA’s mission.

Getting On Site

Getting on site to conduct a scientific survey usually involves using some kind of vehicle.  So, we do it as “greenly” as possible:

  • Our gear and our divers like to travel together! The dive van gets virtually the same mileage whether it carries one diver or four – travelling together saves tax dollars.
  • Van pooling this way lowers our environmental footprint – fewer emissions of air pollutants protect the air we breathe and there’s less pollution to wash into our waterways and ocean ecosystem when it rains.
  • Did you know most brake pads contain metals that hurt fish?  Fewer vehicles on the road also lowers the amount of pollution from brake pads getting into the environment and washing into the ocean ecosystem.
  • And we try to be creative – one of our divers bicycled to and from the boat launch to a friend’s house! You can see the bike tucked into the van in the photo above.

No American Idle

EPA vessel at anchor with divers below.

Whether it’s our van or our vessel, we cut the engine whenever possible. After all, what’s good for kids riding on school buses is good for diving scientists carrying out EPA’s mission.  Many of our van drivers are surprised to learn that it’s more efficient to turn the engine off than let it idle for even 30 seconds!

Reducing engine use is important for our vessel, too, since it’s mainly powered by diesel engines, which can generate large amounts of particulates as well as sulfur and nitrous oxides. Anchoring and turning off the engine helps keep the air and our waterways cleaner.

Diving Scientists Need to Eat

EPA diver with a wireless communication unit.

Once out on the vessel divers are a hungry bunch! We pack meals and plenty of snacks, and carefully separate out all compostable material and recyclables to bring back to the lab for proper disposal. On one recent trip on the Elwha, our crew kept some 60 pounds of trash out of the landfill!

“Scotty, I Need More Power!”

Our underwater lights, communications systems, and scientific equipment run on a lot of ‘juice,’ so to cut waste we use rechargeables.   Just one diver using a wireless communications unit to talk to their buddy diving and to their “tenders” topside can go through up to forty AA type batteries per week! Rechargeable batteries that conk out after a few hundred charges get added to the recyclables we take back to the lab rather than sent to a landfill where they might leach heavy metals.

EPA divers make a positive impact on the ocean environment in the work that we do, and the green way we do it.  It’s also a positive example that we hope inspires divers and diving scientists elsewhere!  What else can you think of to reduce our footprint?

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.  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.

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.

Looking for Sea Monsters

By Phil Colarusso

Tunicates covering native eel grass. Photo by Dann Blackwood.

As a diver for EPA, I am often asked, “what’s the scariest thing you’ve ever seen underwater?”  Most people expect the response to be sharks or stingrays.  They are generally disappointed and perplexed when I say sea squirts.

Let me explain.  Sea squirts, also known as “tunicates,” are seemingly benign-looking gelatinous, filter-feeding animals.  They grow in large colonies or as individuals.  They don’t bite, sting or even generally move, once they have attached themselves to a solid object, like a rock or pier.

So why the concern?  Well, here in the northeast, like many other places in the U.S., we’ve been experiencing an invasion of non-native tunicates.  Mooring lines, piers, boat bottoms, rocks, shellfish, and even eelgrass have been overgrown by various invasive sea squirts.  Anything that does not move quickly is at risk of being engulfed by the rapidly reproducing and growing colonial species of sea squirts.

Sea squirts are prolific filter feeders, processing more water per unit body weight than oysters, blue mussels or quahogs.  Very few animals feed directly on them because they are not a native species.

Our dive unit has been studying the impact of these invasive species on the ecology of coastal salt ponds on Martha’s Vineyard.  We initially became interested in this topic while doing eelgrass restoration work, when we noticed large numbers of eelgrass shoots covered with exotic sea squirts.

Tunicates cover a boat hull. Photo by Dann Blackwood.

As part of our study, we quantified the abundance of invasive sea squirts in a number of coastal ponds on Martha’s Vineyard.  We quantified the short term impact of the presence of sea squirts to eelgrass by measuring plant growth, size and morphology and sugar concentrations (end product of photosynthesis).  Finally, we measured light reduction by sea squirts.

We found that sea squirts reduce the amount of ambient light that reaches the plants by between 70-80 percent.  Plants covered with sea squirts grew at a much slower rate and had fewer leaves per plant, so the presence of sea squirts was having a measurable negative effect on eelgrass.

We recently began a new study designed to look at the impact that sea squirt feeding may have on the normal food web dynamics in these coastal salt ponds. We will be using stable isotopes to construct food webs in a test pond with an abundance of sea squirts and compare that to a comparable pond without sea squirts.

The sea squirts are likely competing with native commercial shellfish species (scallops, mussels, quahogs, oysters) for food.  Our concern is that an explosion in the abundance of the exotic sea squirts could result in upsetting normal food web dynamics, potentially reducing populations of commercially important shellfish.

The scariest things in the ocean don’t always look that way!

About the author: Phil Colarusso is a marine biologist in the EPA Region 1 Coastal and Ocean Protection Unit and a member of the  EPA New England Dive Unit. He’s been with EPA since 1989.

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

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.

Drilling for Water – Underwater

By Sean Sheldrake, Rob Pedersen, and Alan Humphrey

In our previous blog posts we’ve talked about how EPA diving scientists support cleanups in the nation’s waterways through collection of samples.  In this post, we’ll talk about miniature wells called “piezometers” that we and other divers place underwater. 

What is a piezometer and what is it doing at the bottom of the river?

Photo 1: close up of a piezometer.

A piezometer (see photo 1) is a miniature well that lets us sample shallow groundwater—essentially a metal tube with a filter on the bottom to allow water to flow in, but keeping most sediment out. They can be installed both on land and underwater. 

But why on earth would someone underwater want to drill for more water?!  We do it to study pollution.

Groundwater that is contaminated by an upland industrial site can discharge into rivers and sounds.  By the time that contaminated groundwater mixes with the water column, the pollution is difficult to detect.  Worse yet, concentrations are far higher in the seafloor or river bottom, potentially harming critical links at the beginning of the food chain.  If levels of groundwater contamination aren’t measured accurately and in the correct place, a big piece of the pollution puzzle could be missed.

How do you collect a well sample at the bottom of an estuary? Here’s what it looks like when we work:

Tending the diver and groundwater sample tubing is a tough job!

Photo 2: preparing piezometer and tubing from the surface.

A surface supplied diver (see photo 2) takes the metal piezometer from the boat to the bottom while spooling out tubes that connects it to the boat or dive platform.

Don’t get tangled! Once underwater (see photo 3), the diver must be very careful to keep all their lines from being tangled; the slightest misstep and the sample line running to the surface could be pulled out, requiring the process to be restarted. 

Photo 3: EPA divers work carefully so they don't get tangled.

(Also see our previous post: Underwater with EPA Divers.)

With the tubing placed, water is pumped through the tube to the surface and checked (see photo 4) on board against samples taken from upland wells to ensure the right kind of sample is being taken. We pump water for the sample for 30 minutes to an hour, depending on the rate at which water will flow through the sediments. Then it’s time to move to the next spot. 

Photo 4: EPA staff collecting a sample.

With the data we collect, cleanup managers can determine whether groundwater and sediments require a cleanup, and once it’s started, whether it’s protecting the water.

For more information on EPA’s groundwater collection techniques, underwater, see: Adaptation of Groundwater Evaluation and Sampling Tools for Underwater Deployment.

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.  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.  Rob Pedersen is an EPA diver with decades of experience in environmental sample collection, and has also served on the EPA safety board. 

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.

Going Digital: Underwater Science Photography at EPA

By Sean Sheldrake, Rob Pedersen, and Alan Humphrey

EPA scientific diver Sean Sheldrake takes pictures with a Nikonos V film camera. Photo by Joe Goulet.

If you’ve followed EPA’s photo series “Documerica,” you may have noticed a drastic improvement in the quality of the images.  That evolution has been equally as dramatic for underwater photography as it has been above ground—and it’s been personal for us and our fellow scientific divers.

Mama Don’t Take my Kodachrome Away.

For years, we used specialty, underwater, film-based cameras.   Although they were state-of-the-art for underwater work, our cameras were rather simplistic compared to their above ground counterparts, especially with the earlier cameras which lacked even built-in light meters. It was a love/hate relationship.

At times, one of us would forget to rewind the film, ruining the pictures from the dive.  Of course there missed shots, too: “That shark came by right after I finished my roll!”  More times that any of us can count we’d reach the end of the roll before finding an item in our survey area that needed to be photographed.

In the end though, dialing in the focal range, previewing the depth of field, and setting the aperture settings was so classic, so pure, that we grew very attached to our equipment.

Then, the digital photography revolution hit, and we couldn’t even get our film of choice developed locally anymore.

It turned out to be just the kick we needed.  Digital has been a whole new world. It’s a lot easier when you can shoot 1,000 pictures on a memory card instead of 36 on a roll of film.  For subjects that don’t move, you can literally shoot and check your photo quality underwater—as long as your air supply (and dive buddy) will allow.

Underwater video housing.

Rob Pedersen shooting video with an older video camera in a large silver housing.

Video was a similar evolution.  Taking early video cameras underwater involved using heavy, bulky housing to keep the ravages of salt and fresh water damage out. Whatever we shot required “dubbing” the original tape to another format for sharing with research partners, often taking days of work. Today, sharing is as easy as downloading to a DVD or a thumb drive. And what’s more, it’s common place these days for still cameras to shoot video, and visa-versa—no more need for two cameras.

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

See our photos on Flickr.

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.  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.  Rob Pedersen is an EPA diver with decades of experience in underwater photography, and has also served on the EPA safety board.

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 the wilds of the Strait of Juan de Fuca; should we stay or should we go?

By Sean Sheldrake, Steve Rubin, and Alan Humphrey 

EPA Survey Crew: from left, Rob Pedersen, Alan Humphrey, Scott Grossman, and Sean Sheldrake.

Survey crew, from the left: Rob Pedersen, Alan Humphrey, Scott Grossman, Sean Sheldrake.

Some of you may have followed our previous blog posts about EPA’s scientific diving program, including part two of the Elwha River story.   

In this third and final part of our story, we return to the Elwha River to talk more about the challenges involved with the survey of invertebrates and algae. 

Between the divers and the boat operator aboard the EPA Monitor (our 30-foot research vessel), we’ve got over a century of boating experience, but making safe boating decisions is by no means easy.  We’ve got a big job to do in collecting data on this first survey after the largest dam removal in North American history.  The total amount of sediment behind the dam is 19 million cubic meters, enough to fill the stadium of the Seattle Sounders Football Club, eight times.   USGS estimates indicate ¼ to ½ of this material could be transported from the former reservoir areas, eventually finding its way to the coast.  The survey will evaluate the impact on the ocean seafloor. 

However, while conducting the survey at the meeting place of the Olympic peninsula and the wild waters of the Strait of Juan de Fuca, we’ve got to stay safe. 

While doing our work, small craft advisories were issued alerting vessels in our class that danger may be approaching.  Would rough seas really hit our boat, or our area, making it treacherous to retrieve divers from the water? 

EPA Boat Captain Doc Thompson. (Photo by Alan Humphrey)

Doc Thompson, a veteran boat operator for EPA, tells our crew, “That’s it boys: it’s blowing too hard out here.”  Doc is an understated fellow—we all know that when he’s concerned, WE’RE concerned.  Out of the clear blue, gale force winds popped up.  We recall the divers and secure our gear to get back to port as soon as possible! 

When over 40 years of boating experience tells Doc it’s time to go, it’s time to get back to port.  But we were back to finishing our survey the next day.  As budgets allow, we’ll be back in 2013 to evaluate the next phase of sediment release from the mighty Elwha River into the Strait of Juan de Fuca. 

For more information on the USGS led study, see: http://www.usgs.gov/elwha

Read more about the latest in EPA scientific diving at facebook.com/EPADivers [http://www.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.  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.  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.

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.

What’s changed? Post dam removal benthic surveys start at the mouth of the Elwha River

By Sean Sheldrake, Steve Rubin, and Alan Humphrey

Tube worms

Schizobranchia insignis tubeworms, Photo by Sean Sheldrake, USEPA.

In this second part of our story (see our earlier blog post), we return to the Elwha to talk more about the techniques involved with the survey.

This USGS-led survey involves counting over 65 species of invertebrates and 23 species of algae—all of which we had to memorize before the survey began.  As if that wasn’t enough homework for the dive crews, you have to “sneak” up on your critters to actually count them!

Species like Mya truncata clams can “see” you coming and will retract if they can feel the pressure wave of the diver approaching.  Likewise, tubeworms are also underwater detectives with their own early warning sensors for approaching divers.  Once Schizobranchia insignis or Eudistylia polymorpha tubeworms retract they look remarkably similar!

In buddy teams, divers go down and count algae (kelp, for example) on one side of the transect, and invertebrates (such as clams) on the other.  Our divers must adjust for this “shy” behavior when they reach the bottom and “change things up.”   Since each diver must count critters and algae on one side of the transect only, the invertebrate scientist tries to count on the downcurrent side of the transect line.  After all, the algae-counting scientist has the benefit of their “prey” not running away from them!

Diver along a transect

EPA diver Scott Grossman conducts a uniform point count along a straight line "transect" placed on the ocean floor. Photo by Alan Humphrey, USEPA.

In addition to counting all the species within one meter of the transect tape for 30 meters for algae and invertebrates respectively, a separate survey is done called a “uniform point count.”  Every ½ meter, the diver puts their finger down along the transect tape and counts only what is beneath it. (Even if the most amazing anemone is an inch away, it doesn’t count!) Statistically, the point count and overall tally of species will give a representative assessment of life in the ocean ecosystem near the Elwha River mouth.

Early survey results included a decrease in algae abundance compared to levels seen before the start of dam removal.  The decrease may have been due to light deprivation rather than loss of suitable substrate as there was little obvious accumulation of sand or mud on the seafloor.  The divers deployed light sensors at many stations to help to document what sort of change in light penetration was occurring at each site.  In addition, it seems that tubeworms are on the increase.

What other changes are there?  The study will show the changes for the nearly 100 species of algae and invertebrates, in addition to fish, for the largest dam removal effort in North America to date.

Find out more about the wild survey conditions next week in part three of our story.

For more information on the study, see: http://www.usgs.gov/elwha.

For more information about the EPA dive program, check out their Facebook page at: http://www.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.  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.

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 in the Silt Plume of the Elwha River

By Chad Schulze, Steve Rubin, and Sean Sheldrake

Mouth of the Elwha River

Overlooking the mouth of the Elwha River.

Some of you may have followed our previous blog posts about EPA’s scientific diving program in It’s Our Environment, but we also wanted to share some recent work led by U.S. Geological Survey (USGS) and supported by EPA divers near the mouth of Washington State’s Elwha River here in It All Starts with Science.

Now that removal of the Elwha River dams is well under way, USGS scientists, assisted by divers with the Lower Elwha Klallam Tribe, EPA, and Washington Sea Grant, will continue studying the impacts of removal-related sediment to the Strait of Juan de Fuca.

As the first EPA crew to visit the site this year, we didn’t know what to expect.

What we did know—the removal of the Elwha River dams will affect marine habitats in the Strait of Juan de Fuca, primarily from the flow and deposition of released sediment that had accumulated behind the dams for nearly 100 years. That sediment can affect marine life in many ways, including: burial, reduced aquatic reproduction, shading and light reduction, damage to animal gills and filter feeding structures, and changing how different species behave individually and together with their different tolerances and responses to the sediment.

EPA Scientific Diver

Diver Steve Rubin, USGS shooting video of a transect to compare to baseline conditions.

Diving in on the first day, we found the conditions to be very different from before the dams were in place—last year visibility might be up to 50 feet!  Not so this year, with some freshwater layers discharging from the Elwha with maybe 6 inches of visibility.

As we descended through this floating “halocline” of different salinity layers (less dense freshwater will sometimes float over the ocean saltwater until it mixes), it was like a “cloud” over the saltwater below.  Visibility improved when we made it through, but it was DARK.  Where last year the sun was sometimes visible on the seafloor, this year, we needed lights to see the bottom.

Things have changed. For starters, where there had been algal forests, we found much less growth compared to last year. We and our partners will continue to survey Elwha nearshore undersea communities during and after dam removal.  Measuring responses to short and long term changes in deposited and suspended sediments offers an unprecedented opportunity to gain insight relevant to managing these important marine resources, and will help to inform how future dam removal projects can be conducted to minimize impact to downstream plants, insects, fish and animals.

For more information on the study, please see this story on the USGS web site: http://walrus.wr.usgs.gov/elwha/

We’ll follow up with another post as we continue to work. Stay tuned!

About the authors:  Sean Sheldrake and Chad Schulze are part of the Seattle EPA Dive unit.  Chad is the lead pesticide enforcement in the Northwest, and Sean is also a project manager working on the Portland Harbor cleanup in Oregon.  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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Is the Cleanup working? SPMDs Help You Find Out.

By Sean Sheldrake and Alan Humphrey

EPA scientific diver.

EPA scientific diver Brent Richmond at work.

Some of you may have followed our previous blog posts about EPA’s scientific diving program in It’s Our Environment, but we also wanted to share some of our experiences with a new kind of environmental monitoring technique here on the It All Starts with Science blog.

In the “old days” of underwater cleanup, scientific divers would use biological sampling methods, dropping a cage or bag containing live specimens of fish or mussels into the deep blue to answer that age old question, “Is there something out there that needs cleaning up?”  But these studies are expensive to implement, and issues can arise before deployment – Oh no!

  • The aeration pumps died and so did the fish! 
  • High temperatures forecast today—our fish can’t take it! 
  • Argh, the aquarium says they won’t have enough juvenile salmonids available to complete our study! And so on…
Close up of SPME

EPA divers use SPMDs, small, solid-state environmental monitoring devices.

Today, we use Solid Phase Microextraction Devices—or SPMDs.  

These new methods give us less expensive and more reliable ways to document whether there are exposure concentrations on or in the seafloor that are at or above acceptable benchmarks. These techniques have emerged as a valuable tool to find out if the cleanup is “getting the job done” of protecting human health and the environment.

How can contaminants be measured?

SPMDs can detect low level contaminants with a special absorptive matrix and are easier to deploy than live specimens.  Using proper correlations to live counterparts, project managers can use such technique to see if a cleanup is needed. If a cleanup is already underway, such as the one at the Pacific Sound Resources (PSR) Site in Puget Sound, SPMD methods can be used to determine if the cleanup is working. 

Partnering with U.S. Army Corps of Engineers and the University of Texas, EPA’s Environmental Response Team and EPA Region 10 divers have placed and retrieved these devices at many Superfund sites, including: PSR, Duwamish, Portland Harbor, Wyckoff, and others.

SPMD are a valuable tool in determining if cleanup is needed, and for monitoring whether containment activities are getting the job done over time.

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.