Recently, I was fortunate enough to join some researchers from the Institute for Ocean Sciences at Fisheries and Oceans Canada based out of Sidney, British Columbia, on the west coast of Canada. The ship used for this research was the Canadian Coast Guard Vessel Vector, or, more simply, CCGS Vector.
It was a great opportunity for me, who works on freshwater sampling, to understand how it works on a larger scale and in oceanic environments. I gained many new and interesting insights into different monitoring techniques and got to take some beautiful photos along the way.
This cruise departed from the Institute of Ocean Sciences in Sidney and headed north up the inside coast between the mainland and Vancouver Island. The following two maps show our route over the eight days.
The researchers aboard take regular samples of the ocean water to understand oceanographic conditions better and to improve ocean models being developed for the BC coast. The ship operates 24 hours, day and night, and at any given time we were either travelling to the next station or sampling at one of the stations.
At each station (there were about 100 stations sampled), we would do a Conductivity Temperature Dissolved (CTD) oxygen cast, lowering the CTD at a constant speed down to 5 m from the ocean floor; many of the sites were hundreds of metres deep, ranging from depths of 30 m to almost 600 m. All of the data are displayed in the lab and recorded in real time so the operator can see the data and confirm that the instrument is working properly. A depth sounder is used continuously to tell the operator the depth of the ocean bottom.
The CTD also uses various sensors to measure other parameters such as pH, chlorophyll, turbidity, salinity, light and depth. All of these data are sent up the cable to the displays and recorded.
I found the 1.5 km cable quite impressive, as it provides all the wiring for the instruments and also supports the weight of the CTD and rosette, lowered and raised by a large winch. The rosette (essentially a series of sampling bottles) and CTD are both on the same frame that is lowered by the winch operator, and the A-frame operator swings it out over the edge of the ship so that it can be lowered into the water.
At many of the sites, the rosette is used to sample water at various depths. When the rosette is lowered, all the bottles are open at the top and bottom, and when the desired depth is reached, the operator triggers individual bottles to close, capturing water from that depth. Once the rosette is back on board, each of the bottles (with water from different depths) is sampled by opening the spigot to collect samples for dissolved oxygen, dissolved organic carbon, phytoplankton, chlorophyll, salinity and nutrients. All samples are preserved or frozen as needed, apart from the oxygen samples, which are analyzed within a few hours of collection.
At some of the sites, we also sampled zooplankton. Some of the hauls were to depths of 250 m. Once the net returns to the surface, it is rinsed, the flow meter is read to calculate how much water passed through the net, and the animals are washed into a jar and preserved for identification and counting.
Another major task completed during the cruise was the installation of two new moorings. These are stationary instruments that are sunk to the bottom of the ocean that measure the ocean currents of the entire water column above it. The result is continuous measurements of flow for the entire depth of water where the mooring is installed.
This data is then used to calibrate oceanographic models and is similar to the data used by the Canadian Hydrographic Service.
The following three photos show the deployment of one of the mooring buoys, which includes the large orange float with instrumentation that will be near the ocean floor and a smaller bunch of floats with instruments a few hundred metres higher, but deep enough to be out of the way of ship traffic.
We saw some wildlife, but, unfortunately, I was either too slow with the camera or they were too far away to get a decent photo. We often had sea lions approach the boat and bark at us when we stopped at sampling sites, and we saw a few Dall’s porpoise. (Side note: writing this blog post I got to wondering what we call the sound a sea lion makes; Google reliably informs me that they can bark, belch, squeal and growl—all of which we heard!)
Sampling in Vancouver harbour was interesting, with lots of boat traffic and lots going on. I was amazed at how many cargo ships there were, and how huge they are!
Living on the ship for a week was not difficult at all. The cooks provided three delicious meals a day, and the bunks were very comfortable. I was not sure what to expect regarding seasickness, and I did take medication for it, but the sea was quite calm for that time of year. Everyone I was working with remarked on the unusual calmness of the sea. The only slight challenge I experienced was adjusting to working the midnight to noon shift!
Moreover, working on the ship provided some excellent opportunities to take some beautiful photos…