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Science Onboard: Onboard Equipment

The OSV Bold supports a variety of monitoring and educational tasks. The ship carries high-tech instruments to collect data from the water column, sediments, and even marine life. The Bold also carries onboard equipment that can take underwater video, side-scan sonar, and sampling instruments such as corers, dredges, and trawls. Onboard laboratories allow scientists to process, analyze, and store samples while they are out at sea.

A-Frame

The sturdy A-frame on the back deck of the Bold, helps the scientists deploy the equipment for sampling and monitoring.

A-frame on the back deck of the Bold
A-frame on the back deck of the Bold

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Bottom Grab

Deployment of Bottom Grab
Deployment of Bottom Grab

A bottom grab, does exactly what it sounds like! This piece of equipment catches muddy sediment, and it can collect down to about two feet into the bottom. The grab is lowered to the bottom by a cable and water is able to flow through it as it is lowered down. When it hits the bottom, it releases a catch that allows the two doors to close, capturing the mud. Scientists use this grabbing technique to measure the concentrations of pollutants in the mud or to look at the small marine invertebrates, such as worms (polychaetes), crustaceans (such as amphipods), or mollusks (such as small clams) that may live in the surface of the sediments. This type of sample is incredibly important. Scientists can tell if the study area is a healthy environment or polluted depending on the types of species of organisms they find in the mud grabs.

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Computer Lab

Next to the onboard dry lab, there is a computer room. In here, scientists can use remote control equipment to steer the side scan tow fish, tell the CTD how deep to go and watch underwater video of the area they are studying!

Computer Lab on the Bold
Computer Lab on the Bold

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CTD

Deployment of CTD
Deployment of CTD

A CTD is the primary tool for understanding the physical properties of sea water that are essential for supporting marine life. C stands for "Conductivity," T stands for "Temperature," and D stands for "Depth". A CTD gives scientists an accurate and comprehensive charting of the distribution and change in water temperature, salinity, and density for the water column they are studying. All of these are important for understanding how healthy an area of water is for supporting marine life.

How does a CTD work?

The CTD is made up of a set of small high tech probes, attached to the large metal rosette water sampler. The rosette is lowered on a cable down to the depths that the scientists want to evaluate, sometimes all the way to the seafloor. While the CTD is still underwater it reports electronic messages through a cable back to the onboard computer lab. While the CTD is gathering data underwater, computers on the ship are constantly reading that data and creating charts and line graphs. This helps the scientists understand right away the changes in the water column as the CTD goes deeper and deeper.

A typical CTD drop, or hydro-cast as the scientists like to call it, can take 5 to 15 minutes depending on how deep the scientists want to go. For the work that EPA does, generally within depths of 300 feet, gathering a complete set of CTD data can take less than 20 minutes.

True or False?
Salinity and conductivity both refer to the amount of dissolved salt in a body of water.

Answer:
TRUE! Electrical conductivity estimates the amount and concentration of total dissolved salts (TDS), or the total amount of dissolved ions in water. Scientists onboard the BOLD and other Ocean Survey Vessels use the conductivity readings to find out more about the salinity of that particular water sample. The computers onboard can mathematically calculate the conductivity readings to determine salinity.

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Inspecting organisms under microscopes at the dry lab
Inspecting organisms under microscopes at the dry lab

Dry Lab

Up in the dry lab, on board the ship, scientists can look at organisms under microscopes. These organisms can be collected in the mud, or water and by looking at the species, the scientists can tell if the environment is healthy or polluted, or even being taken over by invasive species that don't naturally belong there.

Believe it or not! Some oceanic organisms like pollution, and there presence in a mud sample can tell a scientist a lot about that underwater environment.

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Otter Trawl

Deployment of the 4.9m otter trawl to sample hard-bottom associated fish and invertebrates, from off-reef biotropes.
Deployment of the 4.9m otter trawl to sample hard-bottom associated fish and invertebrates, from off-reef biotropes.

The otter trawl is a specialized net for catching fish on the bottom of the ocean in sandy, silty seabeds. Contrary to the name, it is not used for collecting otters! When scientists are trying to determine the health of ocean bottom environment, it is sometimes helpful to collect real fish for the study.

If the ocean bottom is too muddy, or has too many rocks or boulders, the otter trawl doesn't work very well. When it is slowly dragged on the bottom, (at about 2 knots, or 2 mph) the scientists do not want it to get snagged on a boulder that could tear it!

In 2007, this type of trawl helped scientists on the OSV Bold check on some close-to-shore habitats for winter flounder in Rhode Island Sound. The population of winter flounder has decreased dramatically off the coast of Rhode Island in the past 25 years. To try to better understand why this has happened, the scientists wanted to identify the most important nursery zones for flounder. The Bold helped scientists collect data from off shore adult flounder to compare with younger, juvenile flounder still living in the near-shore nursery habitats. By a trace chemical, "fingerprint technique", the scientists could tell which nursery zone the adult flounder had come from. Once EPA and the state of Rhode Island have a better idea where most of the flounder are coming from, everyone can work to better protect those important habitats.

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Bottom Dredge and Rocking Chair Dredge
Bottom Dredge and Rocking Chair Dredge

Rocking Chair Dredge

A rocking chair dredge is like the trawl, as it is slowly pulled behind the boat. This type of dredge is used to collect or sample for shellfish such as clams, or scallops in the bottom sediments, it works well in sandy bottom environments. The dredge rocks up and down in the sediment collecting the shellfish, which are contained in its mesh bag.

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Rosette Water Sampler

Rosette Water Sampler
Rosette Water Sampler
This cylindrical piece of equipment holds multiple specialized water bottles that can take separate water samples at different depths every time it goes in the water. Scientists onboard the Bold can use specialized computer equipment to remotely control the water bottles to open and close as it moves up and down in the water column. Water sampling is often done at specific depths so scientists can learn the physical properties of the water column at that particular place and time.

While EPA scientists usually collect waters samples within 300 feet deep, this equipment has the ability to go down thousands of meters.

Question:
How many feet are in 1 meter?

Answer:
There are just over 3 feet in each meter. 1 meter = 3.28 feet.

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Juvenile French Angelfish
EPA New England Dive Team

Scuba Diving

Read about the latest dive mission in Puerto Rico!
Every day, I commute to my EPA office in downtown New York. However, twice a year, I'm assigned to work on EPA's Ocean Survey Vessel BOLD. I am currently on assignment in Puerto Rico to monitor coral reefs. Read More »

Coral Condition Survey Continues
We spent the first eight days of BOLD operations deploying dive teams to 60 locations spread across the entire southern coast of Puerto Rico to collect data on the corals. Read More »

Juvenile French Angelfish
Juvenile French Angelfish
French Grunts
French Grunts
Rosette Water Sampler
Puerto Rico Survey 2010

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Prepping the Side Scan Sonar
Prepping the Side Scan Sonar

WATCH IT! Click here to watch how the sonar works!

Side-scan sonar

Side-scan sonar is a type of sonar system that is used to be able to understand what lies at the bottom of the sea floor. On the Bold, the side-scan sonar "tow fish" can create an image of the sea floor so that the scientists can understand the hills, valleys, reefs and debris that are in the study area. This tool is used for mapping the seabed for a wide variety of purposes, including creation of nautical charts and detection and identification of underwater objects and bathymetric features.

Fun Facts
Bathymetry is the study of underwater depth. Check out this map! Purple areas are the deepest, yellow shows areas of land above the surface of the water.

Bathymetric map of an Atlantic Trench
Bathymetric map of an Atlantic Trench

Side scan sonar can be used to conduct surveys for maritime archaeology; along with seafloor samples, the sonar can help scientists understand the different materials and textures of the seabed. The pictures that the sonar tow fish sends back to the ship oftentimes find debris items left from human activities. Check out our gallery of side scan images!

What else can side scan sonar help with?

  • Find seafloor obstructions that might be dangerous for shipping.
  • Fisheries research
  • Environmental studies
  • Harbor dredging operations
  • Military mine detection

On the Bold, the side-scan sonar is called the "tow fish" because it is pulled behind the ship underwater. Slowly, and carefully, the ship’s crew guides the ship in a set path to gather an image of the ocean floor beneath.

To make the image, the sonar "tow fish" sends out a fan shaped series of pulses (sound frequencies) down toward the seafloor. The intensity of the acoustic reflections from the seafloor of this fan-shaped beam is recorded in a series of cross-track slices. When stitched together by a computer, these slices can form an image of the sea bottom within the swath (coverage width) of the beam.

Diagram of a side-scan sonar
Diagram of a side-scan sonar

One of the inventors of side-scan sonar was German scientist, Dr. Julius Hagemann, who worked for the US navy Mine Defense Laboratory in Florida after WW II. His work is documented in US Patent 4,197,591, which remained classified by the US Navy until it was issued in 1980.

In 1963 Dr. Harold Edgerton, Edward Curley, and John Yules used side-scan sonar to find the sunken Vineyard Lightship in Buzzards Bay, Massachusetts.

A team led by Martin Klein developed the first successful towed, commercial, (non-military) side-scan sonar system from 1963 to 1966.

In 1967, Klein's sonar helped find King Henry VIII's flagship Mary Rose. That same year the side scan sonar also aided in the archaeologist George Bass, find a 2000 year old ship off the coast of Turkey.

In 1968 Klein founded Klein Associates, Inc, the company that designed the side scan sonar that is used on the Bold.

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Side-Scan Sonar Image Gallery

  • Side-scan sonar image of the Frank A. Palmer and Louise B.Crary.
    Side-scan sonar image of the Frank A. Palmer and Louise B.Crary.
    Courtesy of NOAA/SBNMS and NURC-UConn.
  • Remains of the submarine USS O-9 (SS-70) off the Isle of Shoals, NH in more than 400 feet of water.
    Side-scan sonar image of the remains of the submarine USS O-9 (SS-70) off the Isle of Shoals, New Hampshire in more than 400 feet of water.
    Courtesy of NOAA.
  • A side-scan sonar image of the passenger freighter Robert E. Lee, collected by the HUGIN 3000 AUV in 2001.
    A side-scan sonar image of the passenger freighter Robert E. Lee,collected by the HUGIN 3000 AUV in 2001.
    Courtesy of NOAA, MMS, C & C, and the 2004 Gulf of Mexico Shipwreck Survey Expedition science party.
  • Side-scan sonar locates missing plane
    Side-scan sonar locates missing plane
    Courtesy of NOAA.
  • A side-scan sonar image (410 kHz) of the German U-boat U-166 collected by the HUGIN 3000 in 2001.
    A side-scan sonar image (410 kHz) of the German U-boat U-166 collected by the HUGIN 3000 in 2001.
    Courtesy of National D-Day Museum, New Orleans, LA.
  • A side-scan sonar image (410 kHz) of the German U-boat U-166 collected by the HUGIN 3000 in 2001.
    This side scan sonar image shows the wreck of the Herbert D. Maxwell, a schooner that sank in the Chesapeake Bay on May 16, 1910.
    Courtesy of NOAA.

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Wet Lab

Sieving sediment in the wet lab
Sieving sediment in the wet lab

Why do YOU think this area is called the WET LAB? This room is right on the deck where scientists on the Bold deploy the sampling equipment. This way, a mud grab can be put directly into the wet lab to be studied. Sometimes the scientists hose down the sediment to see what organisms are in it and it can get a little messy!

The wet lab is equipped with a sieve station (sieving tables and trays), wash station with hot and cold, freshwater and salt water, an ice machine for sample preservation, refrigerator, and an electronic navigation chart that displays the ship’s location and navigation information.

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