Cruise Types

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The type of research project you do will determine the research sites you will visit and what equipment you will use.

The following are generic descriptions--research stations, equipment, and procedures--for possible research cruises. Each cruise, however, will be tailored to the students' specific research needs.

• Plankton studies
• Land use vs. water quality
• Benthic organisms
• Fish biodiversity
• Crab studies
• Other projects

Plankton Studies

Students towing the plankton net .

Typical Research Stations: R10, R20, R30, R40, R50, R60.

Equipment: Plankton net, hydrolab, sampling bottles, tape and markers to mark the bottles, plastic bins and nutrient testing kits (if needed).

A plankton cruise focuses on the free-floating organisms, both phytoplankton and zooplankton, in the Chesapeake Bay and its tributaries. During a typical cruise you will visit five predetermined stations. At each station we mark the coordinates using the boat's GPS unit and take water quality readings using the hydrolab. At three of the five stations we will also take a plankton sample. A plankton sample is taken by pulling the plankton net behind the boat at a low speed for about 5-10 minutes, after which the net is pulled on board and rinsed on the inside to make sure all the organisms that were trapped in the net are washed down into the container. The container is then emptied into a pre-labeled sampling bottle.

After the cruise we analyze the plankton samples in the lab. Using the dissecting and compound microscopes, you can identify and count plankton species. What species will be counted depends on your research objectives.

How does land use around SERC impact the Rhode River and the Bay?

Land Use vs. Water Quality

Typical Research Stations: R10, R20, R30, R60; Depending on the research question, several sites can be of interest. Using maps and aerial photographs we will determine what research sites to include to collect the samples and data you need. Most likely you would study comparable sites on both the Rhode River and the Severn River to find a correlation between land use and the water quality parameters you are measuring.

Equipment: Hydrolab, nutrient test kits, camera.

At each station we mark the coordinates using the boat's GPS unit and take water quality readings using the hydrolab. If you are interested in nutrient concentrations you can use the horizontal bottle sampler to collect a water sample for nutrient analysis with the test kits. We will also take photos of the land surrounding the research station to show land use of the shoreline.

Benthic Organisms

Typical Research Stations: R0, R10, R40, R50, R60; Benthic organisms can be studied along the shoreline or out underwater. We will visit areas with sandy sediment and muddy sediment to allow a comparison between organisms in different sediments.

Equipment: Hydrolab, the horizontal bottle sampler, the bottom sediment grab, sampling bottles, and sediment testing sieves of various screen grids.

At each station we mark the coordinates using the boat's GPS unit and take water quality readings at the surface and the bottom using the hydrolab. After that we use the grab sampler to collect a bottom sample and pull it up into a bucket on the boat. By pouring the sediment through sieves with different mesh sizes, using water to wash the sediment down, we will look for organisms in the sample, such as clams, amphipods, insect larvae and worms. All organisms are identified and counted. Unidentifiable organisms are brought back to the lab for further study.

Fish Biodiversity

Typical Research Stations: R0, R50, R60.

Equipment: Trawl net, hydrolab, rulers, buckets, fish identification guides, and gloves.

On this research cruise you will typically visit two predetermined stations where we will put the trawl net into the water. At each station we mark the coordinates using the boat's GPS unit and take water quality readings at the surface and the bottom using the hydrolab. Next a trawl net is set out behind the boat and pulled for a specified amount of time, usually five minutes. After that time the net is brought to the surface and pulled back into the boat. When we open the net, you can identify, count, and measure the fish and other organisms that were caught. While sorting the organisms you can keep them in buckets with water to keep them alive. You can decide to pull the trawl net two or three times at a station as long as you are consistent in the number of trials at each location.

Crab Studies

Typical Research Stations: R0, R50, R60.

Equipment: Trawl net, hydrolab, rulers, buckets, fish identification guides, and gloves.

A research cruise to investigate crabs is very similar to the fish biodiversity research cruise described above. This time, however, you would only count and measure the blue crabs. Please note: The best time for samping blue crabs is late spring to mid autumn, which makes this kind of study not convenient for most school deadlines, unless you are willing to sample in the summertime.
You can choose to do a project with crabs in captivity.

Other Studies

It is not required that you use a research cruise for the field sampling part of your project. Projects can include seining for fish along the shoreline; lowering settling plates into the water off of a pier or dock; monitoring water quality for seasonal changes at one location; or studying organisms like crabs into a captive environment. Other ideas are also welcome and we will work with you to make these projects possible.

See also Student Research Guide Step 2: Field Sampling.