Blog on ocean conditions along the Newport Line and the northern CA Current.
The NWFSC has begun its annual Prerecruit and California Current ecosystem survey under highly accommodating weather conditions. We left Newport on Sunday evening (June 12th) with clear skies and light winds and headed slightly north to the Newport Hydrographic Line (NH line) to begin sampling for plankton and ocean measurements as part of the 20 year time-series. Five stations were successfully sampled and then we headed south to the Oregon/California border to begin or regular survey.
Today we finished our first full day of oceanography, plankton, and fish sampling. The fish trawls are conducted at night and we were happy to be able to complete our scheduled 4 trawls with the very limited darkness that we have this time of year. Catches in the trawl were light with some adult hake, several anchovies, flatfishes, and lots of midwater fishes. We only caught 5 juvenile rockfish so far indicating that this year might be similar to last year with low catches, but it’s still too early to tell. Plankton tows nearshore had a lot of phytoplankton and offshore a lot of gelatinous critters, a pattern similar to last year. Some upwelled water was observed near shore and a subsurface chlorophyll maximum is evident.
In collaboration with Dr. Bob Cowen, director of the Hatfield Marine Science Center, and his research group, we’ve added some exciting new sampling gear this year. The In Situ Ichthyoplankton Imaging System (ISIIS) will be deployed during the daytime to determine the cross-shelf, fine-scale distribution of key ichthyoplankton (fish larvae), mesozooplankton (large zooplankton), and microzooplankton (small zooplankton). ISIIS tows will be conducted for 4 to 6 hours on each of the 10 transects used for nighttime trawl sampling. Plankton imagery data is captured with a large camera (50 cm depth of field × 13 cm field of view, 135 L s-1) and a small camera (9 cm depth of field × 4 cm field of view, 9.8 L s-1). The ISIIS is towed at 5 knots in a tow-yo pattern (surface to a maximum of 100 m) and synchronously samples environmental conditions using a suite of sensors, including: CTD, ECO fluorometer, photosynthetically active radiation (PAR) sensor, dissolved oxygen sensor, and mini Doppler velocity log. The data acquisition rate is immense (17 images a second) and will take some time to go through and process in detail, but a quick on board scan of some images showed amazing detail with lots of small plankton and some larval fish viewed so far. We hope to provide some images in future postings so stay tuned.
All science crew doing well and adjusting to life on a moving ship, as the calm seas have helped immensely. Hope to get our complicated schedule down to a routine soon.