This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses.
Abstract
This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses. For today’s demonstration samples were collected from the deck of the HMS John Strickland operating in Saanich Inlet. An A-frame derrick, with a multi-purpose winch and cable system, is used in combination with Niskin or Go-Flo water sampling bottles. Conductivity, Temperature, and Depth (CTD) sensors are also used to sample the underlying water mass. To minimize outgassing, trace gas samples are collected first. Then, nutrients, water chemistry, and cell counts are determined. Finally, waters are collected for biomass filtration. The set-up and collection time for a single cast is ~1.5 hours at a maximum depth of 215 meters. Therefore, a total of 6 hours is generally needed to complete the collection series described here.
Protocol
Part 1: Water Collection Depths are assigned to each cast. Depths to be sampled and the total volume to be collected for the current cast are determined. It is ensured that the Go-Flo and Niskin bottles are open, and that their valves and spigots are closed. The CTD is loaded onto bottom of the line and lower into water. A bottle for the deepest depth sampled in cast first is loaded onto the line after the CTD; it is ensured that the line is properly fitted into bra…
Discussion
Overall, there is a great deal of preparation and planning required for this type of sampling, so budget 2 days before the trip to get things in order and one day afterwards for cleaning everything up. In general, do not let salt water come into contact with the peristaltic pump or into the aluminum Zarges box used to transport the field equipment. Treat the equipment with respect and it will perform well for a long time to come.
Disclosures
The authors have nothing to disclose.
Acknowledgements
We would like to thank the Canadian Foundation for Innovation, the British Columbia Knowledge Development Fund and the National Sciences and Engineering Research Council (NSERC) of Canada for supporting ongoing studies on low oxygen regions of coastal and open ocean waters. In addition, D.A.W. was supported by fellowships from NSERC, Killam and the TULA foundation funded Centre for Microbial Diversity and Evolution.