Wecoma report 27-28 May

Late Saturday (5/26) night and through Sunday (5/27) morning we did a set of stations (CH-1 to CH-7) along the Cascade Head line. Sampling included vertical zooplankton net tows and CTDs on every station, and iron and TAPS profiles at stations CH-1,3 and 6. Early Sunday morning we redeployed SeaSoar, the HTI bio-acoustics sled and the iron sampler and towed on the SmallBox north region (3 E-W lines: one on the CH line and lines 10km to the north and south). Winds during this time were 10-15 knots to the north with overcast and some fog. We had some difficulty getting SeaSoar snagged on old, submerged and abandoned crab pot gear. None of the instruments were damaged, but each episode slows us down. The Wecoma bridge officers are doing a great job dodging the crab pots we can see! The ADCP and hydrographic data still showed the presence of an upwelling jet and front (see sbn2*.gif on COAST realtime results). At 4pm on Sunday, Thompson departed for the inshore end of the southern CP line. Wecoma followed about 4 hours behind, but we headed for the offshore end of a line 22km to the north of the CP line. Just after b'fast on Sunday we did a vertical zooplankton net tow near CP-2, in a region of high chl. The brown diatom water had an estimated chl concentration of 15+ mg/m**3. Bill Peterson identified copepods, euphausiid nauplii and euphausiid eggs (forgive the spelling of this physical oceanographer :).

We then towed SeaSoar/HTI/Fe out the CP line. At 1030 we passed within 1/4 mile of Thompson as they microstructure profiled and pump profiled out the CP line. By coincidence, the R/V Roger Revelle was transitting south and passed within a mile of us. For the moment we had $62K/day of research vessels inshore on Heceta Bank! Rick, the first mate on Wecoma, identified 76 targets on the radar. These are mostly salmon trollers working the Bank. Gonna be a day of dodge the fishing boats. We confirmed the presence of the south inshore mooring, but didn't look carefully for the other moorings. Hopefully Thompson can confirm their continuing presence.

Sunday afternoon and evening we'll head back onshore on a line 15km to the south of the CP line. Winds are out of the west at 15 knots, there are broken clouds and a swell from the W is building. The N-S spacing of our Small Box South lines is dictated by the Bank bathymetry, since we can't tow over the rocky outcrops. Around 9pm we'll be in contact with Andy Dale about whether the Elakha will sail for the dye release tomorrow (Tues) off Cascade Head. If the dye work is a go, we'll transit north and provide two lines of hydro and ADCP data (Smallbox north lines A and B) for the dye work, meeting Elakha around noon. After that we'll start another BigBox at line 1 and work south over two days (Tues PM thru Thurs PM). After that we plan to work around the Thompson on the CP line, alternating SeaSoar/HTI/Fe tows with MOCNESS/CTD/Fe/TAPS sampling. If the dye experiment is delayed, we'll do another repeat of our Small Box sampling in the south before heading north.

Happy holiday! ---jack