Spring Observations of Chlorophyll, Zooplankton, & Fish in the eastern Bering Sea Jeffrey Napp 1 Alex DeRobertis 1 Phyllis Stabeno 2 1 NOAA – Alaska Fisheries Science Center 2 NOAA – Pacific Marine Environmental Laboratory

Chlorophyll Data Status: All samples analyzed. Initial QC performed. Underway & near surface groundtruth data submitted. Sections & Final QC next step. Data submission to BEST project database. BEST: 2007 Chlorophyll

What’s All That Golden Brown Stuff? ~ 30 cm

Fig. 3 Five panels show the variability along the 70-m isobath in the spring m Isobath Transect Stabeno, Mordy, and Napp, in prep.

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BEST Fish and Macrozooplankton acoustics Low frequency (38 kHz)High Frequency (120 kHz) Fish school euphausiids Range Distance Frequency difference is the basis for classification Installation of 2 frequency EK60 echosounders on Healy Use same equipment on Miller Freeman Continuous recording of backscatter Classification of signal into “fish” and “euphausiid” classes Similar work planned for IERP

Preliminary Distribution Maps – Healy and Miller Freeman “Euphausiid backscatter”“Fish Backscatter” Figure 2. Acoustic backscatter (S A m 2 nmi -2) attributed to A) fish and B) euphausiids along Healy’s and Miller Freeman's tracklines. The 200, 100, 70 and 50m isobaths are shown as gray dotted lines, and the approximate position of the ice edge at the start of the cruise is given in red. Symbol size and color is proportional to the intensity of acoustic backscatter.

With Thanks Funding – NSF/BEST; NPRB; NOAA/NPCREP Shipboard – B. Blaud, R. Cartwright, J. Clark, E. Cokelet, R. Freyer, D. Kachel, N. Kachel, C. Ladd, A.J. LeFevre, K. Mier, D. Righii, I. Spies Laboratory – R. Freyer, C. Harpold

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