Area of Operations:
Eastern Bering Sea
Date depart / port: July 21, 2000 / Victoria, BC
NOAA - Alaska Fisheries Science Center (AFSC)
Cruise Objectives:This cruise was part of a joint participation project with Japanese scientist to monitor the physical and biological conditions of the eastern Bering Sea shelf in late summer. We wanted to continue a time series of stations that have been occupied repeatedly over the past 6 years to compare walleye pollock (Theragra chalcogramma) abundance and the corresponding oceanographic conditions. We also hoped to encounter a reoccurring coccolithophore bloom and collect water samples from this area.
Summary of Operations:
Summary of Cruise:Narrative:
The cruise was a complete success. All of the historical core stations were occupied and sampled. Methots were conducted at 21 station (Fig. 1), and four extra samples were taken to investigate the relationship of size and abundance of larvae above and below the thermocline. 20 cm and 60 cm bongo tows and CalVET tows were conducted at eight stations. We again encountered a coccolithophore bloom at the northeastern most stations and were able to collect comparison water samples both in and out of the patch.
Pollock larvae and juveniles were found at all but one station (station 2) we sampled this year (Figs. 2 and 3). There were also several stations (stations 10 and 12 come to mind first) where there was a high abundance of very small pollock larvae that were not retained quantitatively by the Methot net. This became apparent when we washed down the net and small larvae were extruded through the relatively large mesh of the Methot net and codend. Lorenzo Ciannelli made additional collections of pollock larvae both in and out of the coccolithophore blooms for gut analysis.
Jellyfish abundance and weight were also measured at each station. Sebastes spp. larvae were collected at one station (21) and retained for genetic identification studies.
Days Lost to Weather:None
Days Lost to Equipment Failure:None
Acknowledgments:The scientific party would like to acknowledge the hard work and support of the officers and crew of the Oshoro maru for all of their hard work and good cheer. Everyone from Captain Yamaguchi to the last cadet was as helpful as possible and patient with our inability to speak Japanese. It was a great pleasure to sail on her, and we look forward to doing so again in the near future. Also we would like to thank Dr. Sei-ichi Saitoh and the rest of the scientific party for all their help, hard work and friendship while conducting our sampling. Without them we would not have been able to complete our tasks and our time here would have been much less joyful.
Attachments:Table 1. Cruise Summary
Figure 1. Station Map
Figure 2. Pollock Abundance Map
Figure 3. Contour Map of Pollock Abundance