The Xiamen Symposium on Marine Environmental Sciences (XMAS 2027)

The Seward Line in the North Gulf of Alaska has been monitored for nearly 30 years using plankton nets. Recently, we have added an in situ imaging system, the ISIIS-DPI, that is tow-yowed at ~2.5 m/sec along the 260 km transect.  Like most imaging systems, image classification is more accurate for particles of larger size that adequately resolve feature attributes.  With a pixel size of ~50 µm, and an imaging volume of 240 L/sec, major zooplankton groups are well-resolved, with family-level identification possible in many groups. Here we compare predicted abundances of groups as predicted by the DPI to those obtained with traditional plankton nets.  We will also explore overall patterns in the spatial variability estimated by nets and the DPI and relate these to hydrography, nutrients and chlorophyll concentration.