June 17 - June 24, 2007
Tiburon dives T1103 and T1104, Monterey Canyon
Kristina and Laura R write: Last night we spent a lovely evening in the Monterey Bay, not far from the entrance to the Monterey Harbor.After a good night of sleep in calm waters, we awoke to the movement of the ship as it repositioned for our Monterey Canyon dive. Fortunately, it was calm enough in the Bay in the morning to deploy the ROV. Because the dive was shallow, only about 900 m, it did not take long for the ROV to reach the bottom. The entire science crew, along with the ROV pilots, was thrilled to dive again after three non-dive days due to bad weather, gale force winds, and heavy seas.
As we approached the bottom, we all realized that this dive was going to be different from the dives on the seamounts. We observed a lot more “marine snow” (tiny organic particles raining down from the productive surface ocean) and we even saw a larvacean house on the way down. Another difference between the seamounts and Monterey Bay was that there was a lot of mud, mud, mud on the bottom of the bay. Despite the steep cliffs, the mud seemed to cling easily to the walls of the canyon. On our first stop, we took a couple of push cores in a flat spot near the bottom of the canyon.
Typically, when we collect sediment samples, we pair them with a corresponding water sample. Unfortunately, the ROV pilots could not open the water sampling bottles. The pilots soon realized that the hydraulics were out on the ROV, and we had to pull the dive and bring the Tiburon back up into the Western Flyer. The pilots worked on the Tiburon for a couple of hours and managed to fix the problem. We were back in the water before lunch.
The life on the canyon wall was in some ways much different than the life on the seamounts. We saw lots of flatfish sitting on the bottom, as well as Sebastolobus rock fish and Zoroaster stars. Soon, we came upon an outcrop of the Monterey Formation, and saw what we had been waiting for: the Isidella corals waving in the current. We noted that they seemed to be clustered around the 800 meter contour, and that they managed to attach themselves to the sedimentary rock substrate despite the large amount of mud. The biologists were also excited to see a couple of nudibranchs, which were much smaller than the ones on Davidson. During the early afternoon, the seas picked up and we had to finish the dive early. Despite our disappointment, it was very productive dive. The particular spot we investigated had not been visited in about 15 years, and it was quite interesting to observe how the ecosystem had changed.
Laura W writes: Today we dove in the submarine canyon of Monterey Bay. We were hoping that being in the bay would protect us from some of the nastier winds we have been experiencing over the last few days, but just in case we got an early start. This turned out to be a very wise decision, as within fifteen minutes of reaching the canyon floor, the hydraulic power on the ROV failed, making it impossible for us to collect samples. After recovery and a few hours of troubleshooting, we were ready to send Tiburon back down to the depths. I used my extra time wisely by going back for more breakfast. On our second attempt we fared much better, collecting five Isidella bamboo corals. We also picked up a few other interesting sea creatures for the biologists to puzzle over. When the wind started picking back up to around 30 knots we cut our dive short to recover the Tiburon. Now we will brave the rough seas and transverse back out to Davidson Seamount for a dive or gravity cores…Craig writes: Weather, O’ Weather…you are my fair and fickle lover. On day 4, we sailed on from Davidson to Patton Escarpment, but a 25+ knot wind kept the ROV out of the water. We steamed further south with the intent of diving off the Channel Islands on the sheltered leeward side. However, naval exercises in the area and a further degradation of the sea state (from Moderate Nausea to I Think I Just Puked Up My Spleen) prevented us again from diving. We steamed back north to take shelter in Monterey Bay, taking a full 2 days as we made only 2-4 knots against a tremendous head wind.
Today, we made an impromptu dive within the shelter of the bay to look for corals. Luckily, we also collected two of my sea slugs although they were diminutive compared to those taken from Davidson and Pioneer Seamounts. If you are counting that is 1 dive in 4 days. Scratch off the other seamounts and the escarpment too. At the end of the expedition we will have only visited 2 of originally planned locations. With all the downtime there has been little to do except snack, read, and watch movies. Being in the bay at least allowed cell phone usage to call ashore to complain to our loved ones how bored we were. The current plan is to sail back to Davidson and wait in rough seas until things calm enough to core and/or deploy the ROV.
Kathie writes: What do you do when your dives are canceled owing to inclement seas? My reaction was to write up the results from the previous 2004 cruise (Dive T667 on the Patton Escarpment) for publication, given that there would be no “new” data from this cruise to add to the story. Luckily I brought my laptop, files and notes and have kept myself busy with this task when I was not on “coral and critter” watch in the control room. So far, with much input from my co-author Dave Clague, I have a rough draft with several figures and plates of photomicrographs and ROV sampling shots. Won’t co-author Alicé Davis (on the beach) be surprised at how industrious we have been!