Tag: ocean quahog

Posted on

Jessie Soder: Drag It Along, Dump It Out, Count ‘Em Up, August 14, 2011

NOAA Teacher at Sea
Jessie Soder
Aboard NOAA Ship Delaware II
August 8 – 19, 2011 

Mission: Atlantic Surfclam and Ocean Quahog Survey
Geographical Area of Cruise:  Northern Atlantic
Date: Wednesday, August 14, 2011 

Weather Data
Time:  16:00
Location:  41°47N, 67°47W
Air Temp:  18°C  (64°F)
Water Temp:  16.5°C  (62°F)
Wind Direction:  SE
Wind Speed:  6 knots
Sea Wave height:  0
Sea Swell:  0

Science and Technology Log

A fellow volunteer, Rebecca, and myself measuring clams

When I found out that the Teacher at Sea trip that I would be on was a clam survey, I thought, “Oh, clams.  I see those on the beach all the time.  No problem.”  I learned that the clams are collected using a hydraulic dredge.  I knew  that a dredge was something that you dragged along the bottom of the ocean.  That seemed simple enough.  Drag it along, dump it out, count ‘em up, and you’re done.

Quickly, I learned that this project is not that simple!  A few questions came to mind after we had done a couple of tows:  How many people are needed to conduct one tow for clams and quahogs? (operate the machinery, the ship, sort through a tow, collect the data, etc.)  How many different jobs are there during one tow?

Sorting through contents of a dredge

Those questions are hard to answer, and I don’t have a precise answer.  What I have learned is that it takes a lot of people and everyone that is involved has a job that is important.  I asked the Chief Scientist, Victor Nordahl, how many people he preferred to have on a science team per watch.   He told me that it is ideal to have six people dedicated to working on sorting the contents of the dredge, processing the catch, and collecting data per watch.  Additionally, he likes to have one “floater,” who can be available to help during each watch.  This seems like a lot of people, but, when there is a big catch this number of people makes the work much more manageable.  There are six people, including myself, on my watch.  Four of us are volunteers.

Each time the dredge is lowered, pulled along the ocean floor, and then brought back onto the ship it is called an “event.”  In my last post I included a video of the dredge being hauled up onto the deck of the ship after it had been pulled along the bottom.  An entire tow, or “event,” is no small feat!  During my watch Rick operates the machinery that raises and lowers the dredge.  (Don’t forget the dredge weighs 2500 pounds!)

There are also two people working on deck that assist him.  (You can see them in the video from my last post.  They are wearing hard hats and life vests.)  Additionally, an officer on the bridge needs to be operating and navigating the ship during the entire event.  There are specific times where they must speed up, slow down, and stop the ship during a tow.  They also have to make sure that the ship is in the correct location because there are planned locations for each tow.  Throughout the entire event the science team, deck crew, and the bridge crew communicate by radio.

Rick, in front of the controls he uses to lower and raise the dredge

As I said, this project is not simple!  To make it more complicated, equipment often breaks, or is damaged, which means that the deck crew and the science team have to stop and fix it. On this trip we have stopped to fix equipment several times.  Various parts of the dredge get bent and broken from rocks on the ocean floor.  Before the dredge is lowered, the bottom is scouted with a depth sounder to try to avoid really rough terrain.  On the screen of the depth sounder different substrates are shown in different colors.  For example sand is shown in green and rocks are shown in red.  We try to avoid a lot of rocks.  However, all the rocks cannot be avoided and sometimes we hit them!

Personal Log

Vic getting a hair cut

Before coming on this trip I was told that the work can be strenuous and, sure enough, it is.  Sometimes a tow brings up hundreds of pounds of rocks (with some clams mixed in!) that we need to sort through and, as you know, rocks are heavy!  The work is also a bit, well, gross.  We have to measure all the clams, whole and broken and we also have to collect weights of “clam meat.”  That means that we have to open the shells and scrape the meat out.  I have a pretty high tolerance for gross things, but I am starting to grow weary of clam guts!

In between tows there is a little bit of down time to catch your breath, drink coffee and eat cookies, watch the ocean, and read a book.  During one of these breaks, the Chief Scientist Victor Nordahl, took the moment and had his hair cut!

Posted on

Jessie Soder: Happy as a Clam, August 12, 2011

NOAA Teacher at Sea
Jessie Soder
Aboard NOAA Ship Delaware II
August 8 – 19, 2011 

Mission: Atlantic Surfclam and Ocean Quahog Survey
Geographical Area of Cruise:  Northern Atlantic
Date: Wednesday, August 12, 2011 

Weather Data
Time:  12:00
Location:  41°47.405N, 67°21.702W
Air Temp:  18.4°C  (65°F)
Water Temp:  17°C (63°F)
Wind Direction:  South
Wind Speed:  8 knots
Sea Wave height: 1 foot
Sea Swell:  2 feet

Science and Technology Log

TK holding a monkfish caught in the dredge

When I was a little girl I was always excited to pull the minnow trap up from the end of the dock to see what oddities I had caught accidentally while trying to trap minnows.  I am reliving this excitement on a much larger scale on this research cruise.  The dredge we are using to fish for ocean quahogs and surfclams is 5ft x 20ft, weighs 2500lbs, and is pulled for ¼ nautical mile each time it is towed.  (That means it covers an area of about 9000 square feet.)  As you might imagine it accidentally catches things besides the ocean quahogs and the surfclams that we are fishing for.

The dredge is lowered into the water off the back of the ship.  Once it hits the ocean floor a powerful jet of water is sprayed into the ocean floor in front of it to “liquefy” the sand or mud on the ocean bottom.  This loosens the clams and suspends them in the water, just above the bottom.  (Ocean quahogs and surfclams aren’t far below the bottom; just a few inches.)  Then, while they are suspended in the water the dredge scoops them up.  The dredge is brought back up to the ship and dumped and we sort through the catch.  The ocean quahogs, surfclams, and a few other species are kept to weigh and measure.  Below is a video of the dredge being hauled back on the back deck of the ship.

After three watches I am getting pretty good at identifying ocean quahogs and surfclams.  What is the difference between an Atlantic surfclam and an ocean quahog?  Well, they are very similar!  They are both bi-valve mollusks, which means that they have two shells covering a soft body.  They both burrow into the sand so that only their siphon sticks out.  Both of them filter their food, algae and plankton, through their siphon.  One of the biggest differences between them is in the way that their shells connect, or hinge together.  Another difference is their lifespan.  The ocean quahog lives for more than 150 years and the Atlantic surfclam lives for approximately 30 years.  Their size and shape are different too.  Ocean quahogs are rounder than the Atlantic surfclams, which have a triangular shape.  The  Atlantic surfclam also grows larger than the ocean quahog.

Ocean Quahog (left) Atlantic Surfclam (right)

Just like I was excited as a kid to find crayfish and bullheads in my minnow trap I am excited to see what the dredge brings up each time.  So far our biggest catch was 4400 quahogs!  Conversely, our smallest catch was just three quahogs! Sometimes the dredge is filled with empty shells, or empty shells and sand dollars, or thousands of clams, or sometimes it is really sandy.  Each time it is a surprise and it gives you a brief glimpse of what the bottom looks like.

Personal Log

Empty shells and sand dollars

There are many potential dangers that you can face every day while working on a ship.  In fact, since being aboard we have run three drills; man overboard, fire, and abandon ship.  These drills are run on every trip so that everyone knows exactly what to do.

I think that there is something about being at sea on a ship that heightens your awareness of yourself.  I have experienced that same sort of feeling when I am sea-kayaking in big water, or hiking on a bear trail.  It is the feeling that there is something out there that is bigger than you are.  You sense things in a much clearer and acute way.

This evening the sun was going down on the starboard side of the ship and the moon was coming up on the portside.  We could see for miles and miles.  Earlier today we watched a school of tuna swim past and dolphins in the distance.  It was a beautiful clear and sunny day and we were 140 miles from land.  We are lucky.

Questions to Ponder

The clams and quahogs are collected on this research cruise from the sea floor using a hydraulic dredge.  The dredge is lowered and run along the seafloor for about 5 minutes in order to pick up the clams and quahogs.  Each time this is done it is called a “tow.”  How many people do you think are needed to conduct (operate the machinery and collect the data) one tow for clams and quahogs?  How many different jobs are there during one tow?

Posted on

Anne Artz: August 4, 2011

NOAA Teacher at Sea
Anne Artz
Aboard NOAA Ship Delaware II
July 25 — August 5, 2011

Mission: Clam and Quahog Survey
Geographical Area: North Atlantic
Date: August 4, 2011

Weather Data from the Bridge
Location:  41 10.239 N; 67 36.023 W
Conditions:  Foggy in the morning giving way to partly cloudy skies; warming up, water calm.

Science and Technology Log

Today at approximately 11 am we finished our last dredge of this leg of the clam survey.  We just completed station #371.  There are approximately 500 stations scheduled for the entire clam survey with the final 2-week leg still left to complete.  We return to Woods Hole tomorrow morning and the Delaware II is expected to leave for the final leg on Monday morning, returning to Georges Bank to complete the final station dredges there.

Volunteer clam counters on the Delaware II

The past two days we have encountered some mechanical problems which the very capable crew repaired, and the past 12 hours we have collected large quantities of quahogs and surfclams in our final ten dredges.  We will spend the remainder of today cleaning up the deck, the wet lab, the dry lab, and putting away all the equipment we’ve been using.  The trip home will take approximately 12 hours.  We anticipate arriving in Woods Hole at 7 am in the morning.

Personal Log

It’s been an incredible trip for me — I’ve really come to appreciate what life at sea is like for the men and women who do this day in and day out all year long.  We were fortunate to have excellent weather and relatively calm seas and I can’t imagine what it would have been like to do this type of work in cold, windy rain, rough seas, or even with ice covering the deck and its equipment.  There are two teams or shifts: the day shift (noon to midnight) and the night shift (midnight to noon).  Each shift has a Watch Chief who coordinates the work of the science crew, enters all the data of all the clams and other things we bring up, and communicates with the bridge and Chief Scientist.

Watch Chief Jonathan Duquette
Watch Chief Nicole Charriere

Jonathan Duquette is the day shift Watch Chief and Nicole Charriere is the night shift Watch Chief, both of whom do an excellent job not only coordinating the work in the lab but also keeping the science crew (mostly us volunteers) informed of what we’re doing, where we’re going, and what we can do to help.  They are extremely hard-working and it’s been a privilege to work alongside both of them.

Posted on

Jessie Soder: Introduction, August 1, 2011

NOAA Teacher at Sea
Jessie Soder
Aboard NOAA Ship Delaware II
August 8 — 19, 2011

Mission: Clam and Quahog Survey
Geographical Area: North Atlantic
Date: August 1, 2011

It is hard to leave Alaska in the summer, but on Friday I will  be leaving my home in Gustavus, Alaska, to travel to Woods Hole, Massachusetts.  Last February, I found out that I was chosen to participate in NOAA‘s Teacher at Sea Program and on August 8th, I will be joining Leg 3 of the Atlantic surfclam/ocean quahog survey on NOAA Ship Delaware II.   This survey helps scientists to determine the distribution and abundance of Atlantic surfclams and ocean quahogs.

Students Collecting Data on a Dark November Day
Students Collecting Data on a Dark November Day

Living and teaching in Southeast Alaska has provided me with several opportunities to learn about and spend time on the ocean.  However, this will be my first time on the Atlantic Ocean and I am really excited.  It will also be my first time on a large research ship.  The NOAA Ship Delaware II is 155 feet long.

Not only am I excited, but my students are too.  They love the ocean and learning about the animals that live in it.  I teach all subjects to a multi-age class of 3rd, 4th and 5th graders.  Last year we spent a lot of time at the beach exploring the intertidal zone and collecting data about the animals that live there.  (My students were conducting a year-long study and shared their field reports and photos on their blog.  Check it out:  Gustavus 3rd-5th Grade Blog)    Needless to say, they are just as excited as I am to learn about all the animals that I will be finding during the Atlantic surfclam/ocean quahog survey.  We are all curious to learn about the similarities and the differences between the Atlantic and the Pacific Oceans.

Alaskan Sea Stars
Posted on

Anne Artz: July 30, 2011

NOAA Teacher at Sea
Anne Artz
Aboard NOAA Ship Delaware II
July 25 — August 5, 2011

Mission: Clam and Quahog Survey
Geographical Area: North Atlantic
Date: July 30, 2011

Weather Data from the Bridge
Location:  Off the coast of New York (Long Island)
40 36.212 N; 72 07.159 W
Conditions: Warm, sunny with very few clouds, very little wind, calm water

Science and Technology Log

The process of sampling the ocean bottom for surfclams and quohogs isn’t as easy as it sounds.  Both of these animals live below the surface of the ocean bottom and that ocean bottom can be sand, mud, or contain a large number of rocks.   To get to the clams the dredge is lowered into the water using a large crane and cable.  Once on the ocean floor, a pump directs the edge of the dredge into the sand/mud and at the same time blows back anything collected into the back of the dredge.  The entire time the ship is moving, dragging the dredge along the bottom.  The idea is for the clams and other larger samples to remain in the dredge while mud and sand wash out the sides and the back.  This works most of the time but occasionally we have brought up the dredge filled with grey sticky mud or large amounts of sand and rocks.  We can put the dredge back into the water off the stern (rear) of the ship and wash away some, but the sticky grey mud has caused problems and we keep our fingers crossed each time the dredge comes up.

The dredge that is lowered to the ocean floor to collect samples

Before sending the dredge down, three sensors are loaded onto the top and side.  These are similar to flash drives that collect certain data such as water depth, temperature, and tilt. This data is retrieved and downloaded into the computer after each “event” (the term used for each sample).  I’ve been trained on setting up the event using the computer in the bridge.  It requires communicating with the NOAA Corps officers who are on the bridge navigating the ship.  These people work closely with the winch operator who is lowering the dredge into the water at designated points.

NOAA Lead Fisherman Todd Wilson is responsible for operation of the winch that lowers the dredge.

The winch operator is also in direct communication with the crew on the deck who assist in lowering and raising the dredge and providing for a safe working environment for the volunteers and scientists.  Because of  all the heavy equipment on the deck, we are all required to wear hard hats when on the deck.  Of course, we also wear our life jackets.  The process of lowering and raising the dredge in specific areas is highly technical and one that is worked out well in advance of each sea trip.  Once at sea, it is the job of the Chief Scientist (Jakub Kircun) to monitor our sampling sites.

The Chief Scientist of the Delaware II Jakub Kircun

Occasionally we have to make adjustments, such as yesterday when the blade assembly of the dredge was damaged by rocks.

The broken blade apparatus that had to be removed from the dredge and replaced.

We had to stop our work for almost two hours while the crew removed the damaged part and replaced it with a new one.  This happens with some regularity so the ship carries extra blades and blade assemblies.  There are only two more assemblies left (of the part we replaced yesterday) and approximately three more weeks of sampling.  I asked what would happen if we ran out of blades and/or blade assemblies and was told the last leg (the last two weeks of sampling) may have to be cut short.  If possible, the crew may try to repair the broken part.

Personal Log

I’ve gotten to know my fellow team (those of us on the noon-midnight shift) through our long hours on deck and in the lab.  Two of the volunteers are like me – here for this particular leg.  Brenna O’Neill  is a graduate student at the Florida Institute of Technology and works in marine sciences.  Henry Hope is a NOAA employee who usually works in a lab in Woods Hole, MA but volunteered for this trip to see what kind of science we did at sea.  The other members of our team are all NOAA employees – either working continuously on the ship for all the science expeditions or part time on the ship and part time in a lab.  I was surprised to find out that there are various science expeditions carried out all year long – including in the middle of winter.  One of the crew told me of working on deck having to chip away ice from the equipment before it could be used.  It’s been so warm and humid on this trip I can’t imagine being that cold.  In fact, I brought several sweatshirts and jeans with me thinking it might be cool out at sea but haven’t even looked at them since I arrived.  It’s been all t-shirts and shorts even at midnight.  Last night we had another 2-hour delay because of a lightning storm – this time we DID hear the thunder!

Posted on

Anne Artz: July 27, 2011

NOAA Teacher at Sea
Anne Artz
Aboard NOAA Ship Delaware II
July 25 — August 5, 2011

Mission: Clam and Quahog Survey
Geographical Area: North Atlantic
Date: July 27, 2011

Weather Data from the Bridge
Location:  40 08.301N; 72 07.278 W
Direction:  1140
Wind:  NW @ 10
Conditions:  Breezy, choppy water but warm and sunny, very few clouds

Science and Technology Log

We had an interesting night last night – quite a show from the lightning all around us.  We had to stop working on deck due to lightning concerns and the water was definitely choppy.  Shortly after midnight we resumed our survey dredging

A little history and information about the ocean quahog is in order, since we’ve been spending most of our time the last few days collecting, counting, weighing, and measuring them (along with a few other things we dredge up – more about those later).

The ocean quahog, or Artica islandica, is a marine bivalve member of the phylum Mollusca.  It is native to the North Atlantic (where we are right now) and is commercially harvested as a food source.  The ocean quahog lives in deeper water than the more common clam (the ones you can dig up along the beach) and are collected in much the same way as we are doing on the Delaware II, by dredging the bottom, rinsing off the mud, and throwing away all the other things brought up.

We bring up any where from one to three baskets of ocean quahogs with each dredge.

One of the unique characteristics of the ocean quahog is its longevity.  They are known to live over 100 years.  They are extremely slow-growing and as adults, may take years to add any measurable length to their shells.  Both water temperature and population density appear to play a role in their growth.  From previous NOAA studies, some of the fastest growing populations occur at the Georges Bank region off the coast of Massachusetts.  The National Marine Fisheries Service (NMFS) uses the data collected from this survey to advise policy makers on the best way to protect and ensure the survival of the ocean quahog populations.

So what do we know so far about the ocean quahog’s populations?  Besides the fact that they grow slowly, we know they are suspension feeders of phytoplankton and they themselves are food for a variety of other invertebrates including crab, sea stars, urchins, and some fish such as cod.  The dredging process damages some ocean quahogs making them susceptible to other predators such as sculpin, skates, and flounder.  Every three years the populations in the Northern Atlantic are surveyed and past results indicate the populations are stable despite the dredging methods of collection.  The ocean quahog is not considered endangered at this time and is not considered overfished.

Personal Log

The lightning storm was beautiful to watch – the only  thing missing was the thunder!  Our ship never stops so the engines run continuously, making hearing anything on deck almost impossible.  We’ve brought up some incredibly interesting animals – some I’ve never seen or heard of.  For example, we’ve brought up numerous “sea mouse” samples.

Sea Mouse
A sea mouse, or Aprodita aculeata (member of phylum Annelida)

They are actually carnivorous worms who live on the ocean floor and are covered with long hair-like threads, or setae.  The ones we’ve brought up are 4-6 inches long. Creepy!

We are currently at survey site 229 which for you students translates to trial number 229.  No more complaining to me about having to repeat your experiment 25 times!

Posted on

Anne Artz: July 26, 2011

NOAA Teacher at Sea
Anne Artz
Aboard NOAA Ship Delaware II
July 25 — August 5, 2011

Mission: Clam and Quahog Survey
Geographical Area: North Atlantic
Date: July 26, 2011

Weather Data from the Bridge
Location: 40 32.672 N070 43.585 W
Temperature: 18.5 C
Winds:  Easterly at 3-4 knt
Conditions:  Sunny today, some clouds, ocean calm

Science and Technology Log

Our first full day at sea (and at work)!  We left the dock at Woods Hole, MA yesterday at 2 pm and headed out past Martha’s Vineyard and Nantucket.  While steaming towards our sampling site, we practiced two very important safety drills — a fire drill and the abandon ship drill.  The abandon ship drill was unique in that we had to don our survival suits (supposedly in a minute but I think I took longer than that) that protect us in the water from hypothermia and also help keep us afloat.

Survival Suit
Anne Artz in her survival suit

Around 6 pm we reached our first sample location and the “day team” (that’s me and some fellow volunteers) started our work.  The testing protocol is fairly simple: sample sites have been predetermined by computer.  Survey sites are selected based on depth and location (latitude and longitude).  When we reach those locations, a large sled-like cage called a dredge is lowered into the water and dragged along the ocean floor for a prescribed amount of time (generally 5 minutes).

Sampling dredge on the Delaware II
This cage goes on the ocean floor scooping up samples for our analysis.

The dredge is then brought up and the contents emptied onto the deck.  Our work then takes 10-15 minutes to sort through what is brought up, keeping those items we are surveying or counting, and throwing the rest back into the water.  We attempt to identify organisms we bring up and we count all live bivalves, any gastropods, hermit crabs, starfish and all fish.  Species we identify and measure are the surfclam, the ocean quahog, the southern quahog, and sea scallops.  Once we’ve separated out what we need, we weigh the catch then measure the size of each item collected.  We throw everything back into the water and clean up the deck while heading to our next location.  The procedure is repeated about twice each hour.  For our work on the deck we wear protective clothing, hard hats, and of course, a life vest.

Personal Log

There are seven volunteers aboard this trip, including myself.  They are a varied group from all over but are all very interested in ocean science.  Some of them are college graduates, some are still in college and we are all first-timers on this type of research vessel.  We were assigned a 12-hour shift, either noon to midnight or midnight to noon.  I feel fortunate to be on the noon-midnight shift as that means I don’t have to alter my sleeping pattern much.  It’s tiring work but the good part is there are breaks between each haul so most of us have our books with us on the deck (so handy to have a Kindle!).  The crew here is as varied as the volunteers, from all over the country and they are all very good at what they do.  I initially thought having 4 girls sleeping in a room the size of a walk-in closet would be difficult but it’s not.  At any given time two of us are on deck, on duty, so the room is available for sleeping, changing, showering, etc.  We all respect quiet below deck because at any given time, someone is always trying to sleep!

Interesting Things Seen Yesterday

A shark with a rather large fin above the water was following us from a distance for a while — maybe curiosity?  We brought up several skates (they look like rays) the largest being about 12 inches long.  They are incredibly beautiful up close, looking almost angelic.  It seems a shame they have such a bad reputation!

Posted on

Anne Artz: Introduction, July 14, 2011

NOAA Teacher at Sea
Anne Artz
Aboard NOAA Ship Delaware II
July 25 — August 5, 2011

Mission: Clam and Quahog Survey
Geographical Area: North Atlantic
Date: July 14, 2011

Personal Log

I’ve spent most of my life on the west coast, about a mile from the beach.   I teach Environmental Science and Biology to high school students and we frequently visit the Pacific Ocean to collect data.  This summer, I am doing research on the east coast leaving from Woods Hole, MA aboard the NOAA Ship Delaware II as part of NOAA‘s Teacher at Sea Program.

NOAA Delaware II
NOAA Ship Delaware II

I’m excited about our experiment – collecting data about the Sea Clam and Ocean Quahog.  My students already have a summer reading project about the particular species we are looking for and I hope to be able to share some new information with them when school begins in August.

I love the outdoors and am looking forward to a new adventure at sea in the Atlantic Ocean. I’m guessing it’s going to be different seeing the sun rise over the ocean instead of setting.