Resources for Marine Science

The Kaholo is a 42 ft. x 20 ft. twin diesel power catamaran. She was originally built in Honolulu in 1983 as a dive boat off of the Kona Coast. The company operating her was in financial trouble by 1990, and Hawaii Loa College bought her in 1991. Pat, Brian Quinn, and Varis Grundmanis, Ph.D. went to Kona and brought her back to Oahu to be used as Hawaii Loa’s research vessel. When Hawaii Loa College was merged with HPU in 1992, Kaholo became HPU’s research vessel. She has operated in her current capacity continuously for 25 years, logging thousands of days at sea. Kaholo is equipped with a hydraulic A-frame and winch, along with the typical electronics for navigation:
GPS, acoustic depth sounders, VHF radios, AIS receiver, anemometer, digital and analog compasses, and so on. On Kaholo we house several oceanographic and biological research instruments, the following is a list of the most commonly used instruments and their function:

• CTD: The CTD measures conductivity (salinity), temperature, and depth (using pressure). Our CTD is also outfitted with a pH probe and fluorimeter to measure chlorophyll concentration.

• ADCP: The Acoustic Doppler current profiler (ADCP) measure water current direction and speeding using the Doppler effect of sound waves scattered back from particles within the water column.

• “Holey-sock” Current Drogue System: The “holey-sock” current drogue system is a ‘low-tech’ way of doing the same thing as the ADCP. These drogues are dropped at varying depths (surface, 10 meters, 20 meters, 30 meters, etc.) within the offshore ocean and we will follow them around for a period of time documenting in what direction they are moving. This lets us see how stacked parcels of water can be moving in differing directions.

• Plankton Nets: These are used in many marine biology and biological oceanography labs to take a sub-sample of microscopic animals that cannot swim independently of the currents.

• Box Corer, Van Veen Grab, and Mini Multicorer: These are all sediment sampling devices that can be used to look at animals living in the sand or accumulation of sand/silt to the sea floor over time.

• Niskin bottles: Niskin bottles are hung from the wire connected to the Kaholo at specific distances apart from one another in order to collect uncontaminated water samples at several depths at one site. These water samples can be brought back to the lab and tested for water quality parameters such as pH, dissolved oxygen, nitrates, phosphates, salinity, etc.