dredge – Page 20 – NOAA Teacher at Sea Blog

June 25, 2005March 18, 2021

Mike Lynch, June 25, 2005

NOAA Teacher at Sea
Mike Lynch
Onboard NOAA Ship Delaware II
June 20 – July 1, 2005

Mission: Clam and Quahog Survey
Geographical Area: New England
Date: June 25, 2005

Weather Data

Latitude: 3726.163N
Longitude: 07444.980W
Wave Height: 1 foot
Swell Height: 1
Foot Weather: clear
Visibility: unlimited
Wind Speed: 7 mph

Scientific Log

As we are entering our sixth day aboard the DELAWARE II, we are still collecting data on Atlantic Surf Clams and Ocean Quahogs. It could be that some would question why NOAA, the Federal government, scientists and the commercial industry would be so interested in these species as to fund our research. Today’s log will try to deal with some of the reasons that make this and other surveys of this type important. The citizens of the United States and the World depend on marine resources for jobs, recreation, tourism, medicine and industrial and commercial products. As citizens, we depend on our governments to make informed policy decisions to ensure sustainable resources for future generations while allowing for present well-being and opportunity. These goals may sometimes appear to be at odds, but on further analysis they are interrelated. At no period in history has mankind been so acutely aware of the correlation between environment and human well-being.

The result of this awareness has placed increased public pressure on NOAA to provide optimal stewardship of these resources. NOAA and the Northeast Fishery Science Center have established goals that attempt to reach a balance between conservation for the future and efficient utilization of existing resources. The first goal centers on research and monitoring. This is where the scientific surveys, such as the Clam Survey provide data that helps our society to understand and predict changes in the ecosystems and their subsystems that affect vital marine resources. The second goal is to provide scientific advice that can be used to create sound environmental policies with an ecosystem framework. This advice is provided in order to enhance society’s ability foresee and respond to changes and manage risks. The third goal deals with education and outreach. Communication with individuals, stakeholders, schools, communities and industry is essential if policy and regulations are to be formulated and adhered to. Cooperation can only be achieved through communication and participation. Our current survey, and my participation as a Teacher at Sea are prime examples of NOAA’s commitment to share technical assistance and understanding. Another example of NOAA’s adherence to the goals of conducting and disseminating scientific data have been the Cooperative Clam surveys conducted in 2002, 2004, and soon to be continued in July of 2005. Two of the scientists that participated in the 2004 Cooperative Survey are currently on board our current Clam Survey. Both were happy and enthusiastic to share their experiences and are anxiously awaiting their participation in this years’ 2005 Cooperative Research.

The Atlantic Surfclam supports a multi-million dollar annual fishery along the Mid-Atlantic Coast. Communities, industry, fishermen and the general population are stakeholders in these important resources. Preserving the well being of the surfclam fishery is therefore not solely an objective of environmental agencies. Due to concerns about the status of the surfclam stock, the Cooperative Clam Surveys were developed toaugment the scientific surveys that were being done by NOAA every three years. The surveys that doctors Pickett and Nordahl worked on were cooperative efforts of NOAA, the National Fisheries Institute, The Clam Institute, the North Atlantic Clam Association, The New Jersey Fisheries Information and Development Center, the Rutgers University Haskins Shellfish Research Laboratory and the University of Virginia Institute of Marine Science have worked cooperatively to conduct these surveys. The survey area was the Mid-Atlantic Coast from the Hudson Canyon to Virginia. This survey, however had a noticeable difference: a commercial clammer, the FV Lisa Kim, was used, as well as a commercial clam dredge. The same Stratified Random Sampling Design, utilizing NEFSC clam strata was used as had been done on the DELAWARE II three year Clam Survey. Dredge efficiency was measured via depletion experiments and monitored by using the NMFS Survey Sensor Package (SSP) from the DELAWARE II.

Results from the 2004 survey were catalogued and compared with historical survey data. Tows were made on the same random stations, using the same speed, the same tow duration, and the same count and measurement techniques were employed. The differences were the ship,the dredge and the expertise of professional clammers. Due to the lesser number of scientists on board, measurements of ages, Ocean Quahogs, Southern Quahogs and clappers were not taken. The results in some ways confirmed data that had been accumulated by the DELAWARE II. The research confirmed the patterns of surfclam population movement to deeper waters and a distinct northern migration pattern. Numbers of clams caught suggested that clam populations might be greater than had been previously suggested. Most importantly, the survey produced a sampling of data that allowed the NEFSC to compare their data with scientific data cooperatively produced with participating stakeholders. The data collected by the commercial vessel can now be used to quantify the efficiency of the equipment and procedures used by the DELAWARE II.

True to the goals of NOAA Fisheries, industry, scientists and government are working in coordination to create accurate data from which we can make informed decisions to benefit our present economic needs and the future of our precious marine environments. NOAA has in many ways accomplished its goal of outreach, cooperation and education. By empowering stakeholders and informing society, the future looks bright for the creation of policy and regulations that achieve the balance of present and future needs.

Personal Log

The weather is absolutely outstanding. Calm seas, a slight breeze, moderate to warm temperatures and little humidity. Does it get any better? We are starting to become adjusted to our new sleep patters, and the equipment has required little servicing. We are currently off the coast of Virginia. Have I mentioned the food is great? Everyone’s favorite person is the Chief Steward. The only thing missing… Clams! Oh well, we’re finding where they’re not.

June 23, 2005March 18, 2021

Mike Lynch, June 23, 2005

NOAA Teacher at Sea
Mike Lynch
Onboard NOAA Ship Delaware II
June 20 – July 1, 2005

Mission: Clam and Quahog Survey
Geographical Area: New England
Date: June 23, 2005

Weather Data

Latitude: 3651.23N
Longitude: 07526.591W
Wave Height: 1 foot
Swell Height: 2
Foot Weather: clear
Visibility: unlimited
Wind Speed: 14 mph

Scientific Log

It is now 12 AM Wednesday morning. We were awakened for our shift at 11:20. The unwritten rule aboard ship is that you hustle out and relieve the alternate shift a few minutes early. Things got a little chaotic prior to the end of our second shift on Tuesday. An electrical junction box that operates the high compression pump and water jets on the dredge was damaged on a tow. The electrical wiring was pulled out of the box, allowing water and sand to impregnate the electrical system. The damage was observed prior to the dredge being lowered for another tow, and the work began.

Life at sea requires the crew to wear many hats. There is no WalMart, no Home Depot, no 911, no fire department, and no ambulance. We are a self-sufficient community that must be self-reliant and work as a team in order to problem solve. Tools were brought out, electrical parts were on hand and collective, hands on, can do attitude was applied. The box was repaired and I learned a good deal about how electrical work designed for underwater usage, differs significantly from what is done on dry land. This event prompted me to think about the interesting and challenging aspects of life at sea. Today’s journal log will focus on the job of safety. Starting the first day, we were all assigned fire stations, evacuation stations, general quarters assignments and given safety protocols. Before we left the dock, we had our first fire drill. We were also instructed to go to our evacuation stations and to bring our immersion suits. Everyone was asked to put his or her immersion suit on. It was a fine photographic moment, but also a very serious one. While on a tour of the Osprey IV, prior to our departure, one of our officers pointed out the self-contained oxygen apparatus for fire fighting. In passing, he mentioned, “you know, if we have a fire out here, there’s no one to call”.

Every one of our staterooms has four bunks a bathroom, four drawers and small lockers for your stuff. There are usually never more than two in the room at any time due to watch constraints. But regardless of the constraints on space, each room contains a fire extinguisher, four Emergency Escape Breathing Devices (EEBDs), four life jackets with beacons and two survival (immersion) suits. The “common room” which adjoins the galley is no bigger than 6ft.by 12ft. There is a TV, a stereo, VCR and two couches. Space is limited, but central to it all are an EMT jump box for medical emergencies and an automatic emergency defibrillator for possible heart attacks. In the same room, there is a posting of all crewmembers and their stations and responsibilities in foreseeable crisis events. There are drills for fire, abandon ship, and man overboard. Each of these drills has an associated general stations alarm and whistle designation to identify the nature of the crisis. Hardhats are worn on deck at all times and OSHA regulations for safety are strictly followed throughout the vessel. Immediately inside the stern deck are two emergency showers with eye wash stations. There is a chemical spill kit inside the ready room. There are full-size backboards and short boards dispersed throughout the ship for immobilization involving head trauma or possible spinal compromise.

Before boarding the ship, I observed twos stokes basket that would be used for emergency lift of a diver out of the water, or an overboard crewmember. There is also a contingency on board for an emergency helicopter evacuation. There are nine general fire stations throughout the boat that have hydrants and hoses. There are four life rafts that can be used for evacuation and one rescue vessel that can be used for emergency retrieval of a person overboard. There is a dive locker with underwater breathing apparatus and trained personnel to make the dives. There is a Damage Control Locker that contains three SBA controlled breathing devices and fire suits in case of an onboard fire, as well as HAZMAT materials, and myriad of resources that would be necessary in the event of a collision. On each of the outside decks, there are life rings with locator beacons stationed to be used for a man overboard scenario.

There are a total of eight life rings, six of which have locator beacons. At night, personnel are instructed to continue to release these in order that the ship can find a path back to the crewmember. There are a total of forty-five fire extinguishers onboard. They are a variety of water, CO2 and chemical. There is a chief medical officer and three other officers are current EMTs. All crew, commissioned and civilian have basic first aid training, current CPR, and are routinely presented with safety seminars on ship board policy, firefighting and the use of available equipment such as the emergency defibrillator. At first, these drills and musters, seem to be mere bureaucratic protocol, but when you are at sea for a period, and realize the physical isolation that separates the vessel from services that we have all come to take for granted, you come to realize the nature of being at sea. For me, it was the repair of an electrical box that opened my eyes to the true interdependence that makes a crew a self-sustaining community.

Personal Log

The morning shift from 12 to 6 was great. Temperatures were comfortable and the moonlight made to ocean absolutely beautiful breakfast at six and back to bed. Up at eleven and work to six. Our tows have been moderately successful and we have been keeping busy. I am still operating the shipboard computer for each of the events, and that seems to be a lot easier now with practice. The food is great, but the hours to eat, in proximity to sleep, are all out of whack. This afternoon I suddenly started to get really tired. The whole crew is going through a metamorphosis where the intense curve of learning is beginning to be replaced by an overall fatigue. I am certain that will improve as we acclimate to our schedules. There is another teacher on board, but on the other shift. We are comparing notes as we pass. One of us has always just gotten up and the other has just finished a shift and is heading for the barn. I did a lot of interviewing today, some on a formal basis and a lot of informal questioning of officers, scientists and crew. My clothes are a mess and wash will soon become a reality. The general rule is to wait until you have a full load, as water is a manmade commodity on the DELAWARE II.

June 22, 2005March 18, 2021

Mike Lynch, June 22, 2005

NOAA Teacher at Sea
Mike Lynch
Onboard NOAA Ship Delaware II
June 20 – July 1, 2005

Mission: Clam and Quahog Survey
Geographical Area: New England
Date: June 22, 2005

Science and Technology Log

Latitude: 3726.163N
Longitude: 07444.980W
Wave Height: 1 foot
Swell Height: 1
Foot Weather: clear
Visibility: unlimited
Wind Speed: 7 mph

Scientific Log

Our first real shift for the DELAWARE II Ocean Clam Survey began this morning off the coast of Long Island. The shift stated at midnight, so we were awaked at 11: 15. Our first dredge occurred at 2:15 AM. We are working in a crew of six. Two of us input data into the FSCS computer as the deck crew coordinates with the boatswain in charge of the winch. Safety is a big issue on the NOAA vessel, and scientists are not allowed on deck while the dredge is being lowered off the stern. A high voltage cable is fed out along with the winch cable, and no one is allowed ion the deck until the dredge is in position for tow. Our job upstairs is to coordinate with the Officer of the Day when each step is being done and input his into the computer. Each actual tow takes five minutes, but the entire process of lowering the dredge, dredging and raising the dredge onto the deck takes about 25 minutes. When the dredge is brought up, our job begins.

We often start by places a smaller mesh screen at the front of the dredge in order tot capture the contents and releasing the dredge into a tow to wash away some of the debris and substrate soil. When the dredge is brought in the second time it is hauled up to an enormous table where the contents are released for inspection of our crew. It is then our task to sort through large amounts of shell hash, rock and substrate and find the living organisms. Our trawl today has been averaging at depths of 60 meters (180ft. or 30 fathoms in you want to be really cool and nautical). This is Ocean Quahog territory. True to form, our first three station trawls resulted in large numbers of Ocean quahogs as well as the assorted species. For commercial fisherman, these other species are often referred to as discard. These are unwanted species, or at least not the targeted stock. Today along with the quahogs, we caught several varieties of clams. These smaller clams were varieties such as Asterias, Astarte, Astrope, and Razor. We also collected Sea Scallops and Horse mussels. We Few fish are caught in bottom dredges, but we did catch one small Sea Robin and a small Skate. At first, I thought the unwanted species were called bycatch, but through interviews with on board fishermen and scientists I was informed that the term bycatch more commonly refers to sea mammals, reptiles or marine birds that are accidentally caught or killed in commercial fishing.

For example, in the area of scallop dredging, there has been a great deal of controversy surrounding the bycatch of endangered species of Sea Turtles. After each tow the catch was sorted, measured for length, and weight and catalogued into the computer database. What used to be done by pencil and paper is now done via electronic scans and scales. For quahogs under 40 mm, or above 110 mm in length, we conducted meat weigh measurements as well. This is hard work, and the ship conducts non-stop tows and data collection 24 hours a day. We are learning fast and having fun. The six-hour shift flew by and I was exhausted. A great morning, in bed by 7AM, and ready for the next shift at 11:30 AM. What a weird schedule. We have all been at it for a day and a half, and no one seems to know what day it is. As part of today’s log, I need to share what I have learned about the mysterious Ocean Quahog. The IO\Ocean Quahog, (Antica Islandica) is found from Newfoundland to Cape Hatteras. They are usually found in depths from 8 to 256 meters. They are a relatively cold-water species and are rarely found in waters above 16 degrees Celsius.

Their population densities are greater in off shore waters and they prefer a substrate of fine sand. In Maine they are found in shallower waters, but the populations are small, and the species grows at a slower rate. The average size is about 70mm. But today we had one at 110mm. What are really incredible about Ocean Quahogs are their ages. The scientists we interviewed today estimated that most of the many of bushels of quahogs we captured were in the 45 year old range. Quahogs can be in excess of 170 years old. Their most dramatic growth occurs in their first twenty years of life and the growth process slows significantly. Their ages are incredible, I may have to feel guilty the next time I spoon into clam chowder. Marine biologists have been finding that the Ocean Quahog, like the Atlantic Surf Clam, has shifting population strata. Surveys conducted over the past two decades and commercial fishing statistics show a pattern in which the Surf Clams are establishing themselves in deeper areas where quahogs previously predominated, and that the quahog populations are showing patterns of migration further offshore and further to the North.

One scientist onboard speculated that clam and quahog surveys might be important in the study of global warming. Ocean Quahogs have a commercial market value. The principal commercial fishing for the species occurs off the Delmarva Peninsula, New Jersey, Long Island and even Southern New England. In 1993, the commercial harvest of Quahogs reached its zenith at 25,000 metric tons. In 2000, the harvest had diminished to 14,000 metric tons. The decline in the fishery has been in part due to increased regulations under the Surf Clam- Ocean Quahog Fishery Management Plan (FPM), but also due to a decrease in the number of clamming boats and a depressed commercial market. Despite the reduction in total landings, the Quahog stock may be in jeopardy. The total landings are less than two percent of the total environmental stock, but any greater landings may threaten replacement levels and sustainability of this slow growing species.

Personal Log

Things were going along well until electrical problems with the dredge shut us down. Time to go to work on a different sort of problem.

June 21, 2005March 18, 2021

Mike Lynch, June 21, 2005

NOAA Teacher at Sea
Mike Lynch
Onboard NOAA Ship Delaware II
June 20 – July 1, 2005

Mission: Clam and Quahog Survey
Geographical Area: New England
Date: June 21, 2005

Weather Data

Latitude: 3948.669 N
Longitude: 07302.329 W
Visibility: Clear
Wind: 6-8 mph
Wave height: 1ft.
Swell Height: 3ft.
Swell Direction: 150 degrees

Science and Technology log

Changing one’s hours to six on and six off could be a subject for a scientific study in itself. Our first day on board was a short one. We left Woods Hole at 3PM and began our sail south. We stopped to do a test drop with the trawl and received a crash course in the computerized world of fishery research. The NOAA vessel uses two computer systems to bottom dredge. Computer times are constantly calibrated to ensure that different machines are reading data at the same time. The onboard systems are the Fishery Science Computer System (FSCS), and the Scientific Communication System (SCS). The computers monitor the ship’s exact, location, the time of the dredge, the speed, the water temperature the substrate composition and aspect of the dredge to the bottom. Later this week we will be attaching the video feed as well.

This sure isn’t your grandpa’s fishing. Once the dredge is secured to the ship, and the power is shut down the scientific crew is released to the aft deck to release and sort the contents of the dredge. The clams are sorted by variety and by size. Other invertebrates and fish are sorted weighed measured and released. The contents of the dredge are analyzed and catalogued for its overall percentage of substrate, shell debris and fish and animals. The clams are then measured, weighed and analyzed for age. The weighing and measurements are done electronically and simultaneously cataloged into the database. The ages of the clams and quahogs are determined through visual inspection of growth rings. This takes a practiced eye, especially with the ocean quahogs, which grow very slowly and can reach ages of one hundred fifty years. One of the on board scientists indicated that they will soon receive a scanner that will be able to read the rings on the surf clams and ocean quahogs and determine their precise age and growth rate. It’s all pretty amazing stuff. Needless to say, some monster computer mainframe is crunching numbers and providing some great information in determining the health of the stock, the overall biomass and the condition and patterns in the environment. It’s hard not to be impressed, and somewhat overwhelmed.

We all have a lot to learn about our new duties onboard. We had a quick run down on other experiments we would be conducting at the request of our chief scientist throughout our adventure, and then were on our way to the Delmarva Peninsula (Delaware, Maryland, Virginia). We will start on our first stations at about 3 AM. This will be fishing for real, and learning on the job. We will start in the Delmarva area, and then work our way back up the New Jersey coastline. The New Jersey offshore waters are the area of the greatest concentration of surf clams and also the greatest concentration of commercial fishing. This area is of specific interest to the scientists who are anxious to measure the health of the stock in relation to findings of previous surveys. It is now 1 AM, and we are awaiting our arrival at our first station. I am spending my time reading about surf clams and ocean quahogs. I am so intrigued, I feel compelled to share. Spisula Solidissma, more commonly known as the Atlantic Surf Clam, can be found from the Gulf of St. Lawrence to Cape Hatteras. The largest concentrations are off the Delmarva Peninsula, New Jersey and the Georges Bank. Landings of clams off the coast of Virginia and New Jersey have traditionally accounted for half the landings nationwide.

The Georges Bank however has been closed to commercial fishing since 1990 due to high concentrations of Paralytic Shellfish Poison (PSP). The surf clam can be found in varying depths from the beach to 60 meters, but concentrations below 40 meters tend to be low. Surf clams can reach a maximum size of 222.5cm (8.9in.), but surf clams larger than 20cm (7.9in.) are rare. Surveys are done because clam populations can, and indeed do, move. Movement predominantly occurs in the larval period. Eggs and sperm are shed into the water column, and may bee carried by currents for as many as three weeks before recruitment to the bottom occurs. The ages of surf clams can be determined by counting the rings on their shells. The rings are formed when a thin tissue adheres to the inner surfaces of the shell, called the mantel, and a thickened rim of muscular tissue at the mantel edge deposit new material at the mantel edge. The resulting rings show how old the clam may be. More on the elusive Ocean Quahog will follow tomorrow.

Personal Log

Who the heck sits up reading about clams at one AM? Is this nuts or what? The life of a scientist is indeed a crazy one. I myself do not qualify as a scientist, but they sure are interesting to hang out with. I am learning tons, and anxious for our day to begin. The food is great, everyone is friendly, but the sleeping part is somewhat sketchy. I’m sure it will catch up with us all pretty darn soon.

June 20, 2005March 18, 2021

Mike Lynch, June 20, 2005

NOAA Teacher at Sea
Mike Lynch
Onboard NOAA Ship Delaware II
June 20 – July 1, 2005

Mission: Clam and Quahog Survey
Geographical Area: New England
Date: June 20, 2005

Science and Technology Log

We are preparing for a 2pm departure on the NOAA vessel DELAWARE II. We are departing from Woods Hole, MA. Woods Hole is a small maritime community in scenic Cape Cod. Apart from being a tourist Mecca, and a jump off point to Martha’s Vineyard, Woods Hole is home to some of the World’s foremost institutions in the area of Oceanography and Marine Science. A brief stroll down a picturesque cape-side street takes you by The Marine Biology Libratory, the Woods Hole Oceanographic Institute, the Northeast Fisheries Center, and the National Oceanic aerospace Administration. It short order it becomes quite apparent that Woods Hole is center of learning and scientific research.

Today we will be leaving on the DELAWARE II, which is a stern trawler that was built in 1963. The ship is 155ft. in length and has a displacement of 600 ton. This research vessel is operated by the National Ocean Service’s (NOS) division of the National oceanic Atmospheric Administration (NOAA). NOAA is a government agency with a mandate to study the condition of the world’s environments.

As a steward, NOAA Fisheries has an obligation to conserve, protect and manage living marine resources in away that will ensure their continuation, while affording economic opportunities and enhancing the quality of life of the American public. Our specific mission will be a scientific survey to collect data on fishery stocks and demographics of exploited fish resources. More precisely our target stocks are to be Atlantic surf clams and ocean quahogs. In a brief orientation with our chief scientist, we were told that we would be conducting timed dredges on pre-selected stations to collect data on species recruitment, the health, number and location of incoming classes of fish. We would also be monitoring data on the abundance, location and survival rates of harvestable size clams and quahogs. Our mission will also obtain data that monitors changes in the ecosystem as well as the biomass of the surveyed areas.

In order to gain the needed scientific data, the DELAWARE II will be using a hydraulic dredge to sample the stations of the ocean bottom. The last “clam survey’ was conducted in 2002. This survey is conducted on a three-year basis due to the low exploitation rate of the fishery as well as the slow recruitment rate of the species. For this survey we will be using a five foot wide hydraulic dredge, fitted with water jets, and a submersible electric pump that loosens the substrate and animals in the path of the dredge. The equipment is a modification of that which is used in the commercial industry. The five-foot dredge looks more like mining equipment than fishing gear. It is fitted with a two inch aqua mesh that allows the capture of smaller species than are commercially profitable, in order to get a more accurate sampling of the stock. Clam debris and other associated invertebrates are collected and measured as well. Sensors and photographic equipment will also be attached to the dredge in order to measure bottom conditions and dredge performance. The state of the art sensor package placed on the dredge, gathers a continuous steam of data on dredge performance, bottom temperature, water depth and ship position. Data on catch and dredge performance; location, time and conditions will be catalogued into computer programs that will calculate stock, habitat and location.

Personal log

Day one of our journey has been a flurry of activity. We have received our berth assignments, met new people, gathered our foul weather gear and been introduced to the fantastic fare of the galley. The ship’s crew is busy with a myriad of pre-departure activities, but everyone has gone out of their way to be friendly and accommodating. The weather is beautiful and everyone’s spirits seem to be high. I have had the opportunity to informally interview several of the crew and was given a tour of the ALABATROSS IV as well as our ship, the DELAWARE II. The crew is busy with a cable replacement for the dredge. I and several of the volunteers had the opportunity to have a brief orientation with our chief scientist, and we are awaiting our scheduled 2 PM departure. I will be working two shifts both from 12 to 6. The shifts, along with the scientific work, the interviews and daily logs promise to keep me busy. I am learning a lot, staying out of the way and getting excited. We will be heading south to New Jersey rather than the Georges Bank. Time constraints and equipment repair may have been factors in the change of plan. Woods Hole is a beautiful and picturesque location but also a hotbed of scientific activity.