Scientific Equipment

Transcription

1 Scientific Equipment On board Sailing School Vessels Corwith Cramer and Robert C. Seamans Operated by Sea Education Association, Woods Hole, MA, USA Winches: Markey DESF-4 Electric Hydrographic Winch with 5000m ¼ wire rope Markey DEBT-3 Auxiliary enhanced BT Winch with 1/8 wire rope Hydraulic J-frame and Dynacon electronic metered wheel Bathymetric Equipment: Benthos 2-7 khz CHIRP-II sub-bottom profiling system consisting of: (8 CC / 9 RCS) TR-109 Transducers, DSP 661/662 signal processor and digital recorder Oceanographic Instrument Systems Model 6000 Pinger Physical/Chemical Oceanographic Equipment: Water sampling Carousel SBE with: SBE Auto Fire Module (2) Seabird SEACAT Profiler Model SBE 19plus Conductivity- Temperature-Depth units, PAR sensor, in-vivo chl and CDOM fluorometers, transmissometer, SBE43 oxygen sensor (12) 2.5-L Water Sampling Bottles Acoustic Doppler Current Profiler (RDI Ocean Surveyor 75kHz) Gyro (Xsea Octans fiber optic gyro on CC, traditional gyro on RCS) RBR towed CTD with optional Seapoint in-situ fluorometer Continuous salinity/temperature/fluorescence logger YSI handheld Salinity-Conductivity-Temperature meter Portable ph meter Ocean Optics Chem2000 digital spectrophotometer Ocean Optics reflectance and oxygen meters Secchi Disk Biological Sampling Equipment: VideoRay Pro-II ROV (150m rating, color and b/w cameras) Sampling Equipment: Sea-Perch ROV (20m rating, color camera) Turner Designs Model 10-AU Fluorometer Fucile SSBP (solid state bathyphotometer for bioluminescence measurements) SeaGear 200, 333, 1000 μm mesh Plankton nets SeaGear 333 μm mesh Neuston nets (1m wide by 0.5m high) SeaGear 63 μm Phytoplankton nets Tucker Trawl multiple opening/closing net Small Otter Trawl net (oceanographic purposes only) Pelagic Electronics Weak Link tension releases Geological Sampling Equipment: Shipek Sediment Grab Rock Dredges Gravity Corer Fisher Sediment Scoop Microscopes: (2) Zeiss stereo dissecting scopes Zeiss Axiostar compound scope with epifluorescence Camera for digital photomicrographs Datalogging: Clean flowing seawater (plastic pump and lines) with SBE45 thermosalinograph and in-vivo chlorophyll fluorometer. System logs these and other parameters along with GPS position every minute during cruise. Computer Network: Desktop and laptop computers, printers, wireless network, automatic data backup Other: centrifuge, stir plate, adjustable micropipets, Milli-Q lab water, aquaria, PAR reference sensor, hydrophone, plankton splitter, Minilog TD sensor, Orion 3Star benchtop ph meter, handheld GPS

2 Physical/Chemical Sampling Equipment Carousel This oceanographic tool is used to collect water samples and data from specific depths throughout the water column. This specific instrument has been deployed to over 3000 meters. A Conductivity Temperature Depth (CTD) unit is attached to take readings throughout the cast. Water samples will be later analyzed for oxygen, nutrients and Chlorophyll-a concentrations. Acoustic Doppler Current Profiler By bouncing high frequency (75kHz) sound waves off drifting plankton and particles underneath the ship and listening for the Doppler shift (think of standing still and listening to a train speeding by) we are able to determine how the currents are moving relative to our ship. These data provide detailed maps of the distribution of water currents and suspended materials through the water column and along the ship s path. ADCP data are often used in studies of ocean circulation and eddy formation. Chirp Subbottom Profiler So named for its distinctive Chirp sound, this subbottom profiler generates pings between 2 and 7 khz. Sound travels from the hull mounted transducers at 1500 meters per second to the ocean floor where it is echoed back to the ship. From time delay in the echo and the strength of echo signal we can determine a number of things about the seafloor and subsurface. For example we can determine the depth of the seafloor, slope angles, the layering history of the seafloor and general information of seafloor composition. Our geologic studies in the deep ocean rely heavily on this instrument. CTD Our CTDs are designed to measure conductivity, temperature, and pressure in marine or fresh-water environments at depths up to 7000 meters (22,900 feet). From these measurements we are able to determine salinity and depth. Profiles of temperature and salinity vs depth are essential to determining the physical structure of the water column. In addition, we are able to collect data from a whole suite of sensors that can be piggybacked onto the CTD. Examples of additional sensors that we carry include, chlorophyll-a fluorometers, colored dissolved organic matter (CDOM) fluorometers, oxygen sensors, transmissometers, and photosynthically active radiation (PAR) sensors.

3 Spectrophotometers For determination of different physical properties of sea water we use a small spectrophotometer. This instrument is arranged so that liquid in a cuvette can be placed between a light beam and a detector. Signal strength at the detector changes as a function of the amount of light absorbed by the liquid. By adding colored compounds that bind to specific substances (phosphate or nitrate for example) we can use a spectrophotometer to determine concentrations of that substance by determining the extent of absorption of light at the appropriate wavelength. The spectrophotometer is very versatile and is used in many chemical oceanography studies. Winch 4000 meters of ¼ wire are spooled on this winch for deployment of many of our oceanographic equipment. The winch can be operated at a maximum velocity of 90 meters per minute, although most stations are deployed much slower. The wire leads through a electro-magnetically metered wheel attached to a J-frame to track the amount of wire that has been lowered. Biological Sampling Equipment Bathyphotometer The Solid State Bioluminescence measuring Bathyphotometer (SSBP) is a free fall profiling instrument designed to provide quick bioluminescence vs. Depth measurements. Ninety percent of deep-sea marine life is estimated to produce bioluminescence in one form or another and the Navy is particularly interested in studying bioluminescence to track submarine movements. Our students who study zooplankton and phytoplankton will often include a bioluminescence component. Chlorophyll-a Fluorometer It is commonly accepted that chlorophyll-a fluorescence, the light reemitted from chlorophyll after photosynthesis, is a good proxy for the amount of phytoplankton present in oceanic waters. We make use of two types of chlorophyll fluorometers, instruments that measure fluorescence light, on board our ships. The in vivo fluorometer can be deployed in the water while attached to a CTD. Data from this fluorometer gives a rough estimate of the amount of phytoplankton present in the water column at different depths. For more exact measurement the extracted chlorophyll fluorometers measures chlorophyll-a fluorosecnece from phytoplankton filtered out of water samples. The presence and amount of phytoplankton in the ocean is essential to almost all biological studies we do.

4 Meter Nets Nets are used in biological studies of the ocean for zooplankton collection at various depth in the water column. Zooplankton are animals whose path through the ocean is determined by the prevailing ocean currents as opposed to the stronger nekton (fish, whales, etc.) Following a Net tow, the biomass is sorted and counted for relative diversity and abundance studies. Neuston Net Studies of air-water interface, a unique environment home to many zooplankton, are accomplished using a Neuston net. This net,1 meter wide and 0.5 meters high, is towed half in and out of the water to better capture organisms that dwell just at the surface. One of the first deployments that students do own their own, this is one of the most common deployments we do. Phytoplankton Net This 63 µm mesh net is deployed for to gather the small plant matter in the ocean. The net is small in that it only needs to be deployed for a very short amount of time to collect a sizable sample. Phytoplankton account for much of the green or brown coloration in coastal waters. They are the basic primary producers and their relative abundance reveals much about a geographical area.

5 Remotely Operated Vehicles In order to study zooplankton, fish, and megafauna in situ (in the place it lives) we often make use of remotely operated vehicles (ROV). Tethered by a cable to the surface, these small ROVs are outfitted with cameras and other sampling devices. Real time video and great maneuverability make these instruments especially useful in shallow nearshore environments. Tucker Trawl Net When discrete zooplankton samples are required we make use of a tucker trawl net. This opening/closing net is composed of three separate nets only one of which is open at any given time. Changing nets is controlled by a messenger. When the messenger slides down the wire and hits the firing mechanism, one net closes while another one opens. This net is often used to study how zooplankton are stratified in the water column. Geological Sampling Equipment Shipek Grab This device is deployed for benthic sampling of the very top layer of the ocean floor. Mostly used in coastal areas, much can be determined about the energy level in a given area by looking at sediment grain size. The composition of the sample can also be analyzed to determine the origin of the various constituents. Gravity Core This is one piece of the larger gravity core unit, including a long section of PVC for sample collection, large 200 lbs of weights for power, and a steering fin to insure the proper angle at contact with the bottom. Gravity cores are used to collect a vertical sample of sediment layers. Analysis of the composition of these layers reveals the climactic history of the area.

6 Rock Dredges Rock dredges consist of a rigid bridal connected to a solid metal opening and chain mesh bag. We tow this behind the ship in shallow waters to sample the ocean floor. The large openings in the mesh mean that we only collect large rock samples. Fisher Sediment Scoop The Scoopfish is useful for quickly obtaining bottom-sediment samples without having to stop the boat. The fin-tailed Scoopfish is designed to descend with its nose downward so that the open cup readily penetrates the bottom sediment. Impact with the sea-bed pushes the partly extended cup back into the body of the Scoopfish, automatically releasing its spring-tensioned, cocked cover-plate. Simultaneously, the arm attached to the lowering line pivots upwards, which shifts the sampler s center of gravity and allows it to be lifted free from the ocean-bed. When the Scoopfish is pulled out of the sediment the hinged cover-plate completely closes the open end of the cup and the sampler then hangs nose-upward from its attached line, avoiding tumbling as it is hauled to the surface. Zeiss stereo dissecting scope Dissecting microscope are configured to allow low magnification of three-dimensional objects- objects larger or thicker than the compound microscope can accommodate. Furthermore, the two separate lenses of the binocular dissecting microscope allow one to see objects in three dimensions, i.e., in stereo. Dissecting microscopes do not magnify to the extent of compound microscopes. These microscopes are the workhorses of our shipboard labs and are used extensively for identification projects including zooplankton, larval fish and sediment studies. Microscopes Compound Microscope with Epifluorescence The typical compound light microscope is capable of increasing our ability to see detail by 1000 times so that objects as small as 0.1 micrometer (um) or 100 nanometers (nm) can be seen. Our compound microscopes are typically used for studies involving phytoplankton. By adding a mercury arc lamp as a light source, which causes certain particles to fluoresce, we are also able to study bacterial and viral populations in the oceans.

7 Sea Education Association PO Box 6 Woods Hole, MA Phone: