ABSTRACT
The oceans contain many biological, biogenic, and physical phenomena distributed on fine spatial scales. With the increased use of high-frequency echosounders as survey tools, oceanographers routinely observe scattering features on vertical scales of centimeters to meters and horizontal scales of meters to kilometers (e.g., Wiebe et al., 1996; Holliday et al., 1998). Advances in bio-optical sensors (e.g., multispectral absorption and attenuation meters) and their employment in specialized sampling methodologies have led to the discovery of thin layers — vertically distinct patches of phytoplankton, ranging in thickness from a few centimeters to several meters (Donaghay et al., 1992; Cowles et al., 1998; Dekshenieks et al., 2001). Supplementary acoustic sensing suggested that thin layers may also contain zooplankton (Holliday et al., 1998). The capabilities of a variety of mesozooplankton taxa to form dense, highly localized patches has been documented for a variety of taxa (e.g., Price, 1989; Buskey et al., 1996) and the importance of localized regions of enhanced zooplankton biomass on scales of millimeters to meters was identified as a emergent new issue in zooplankton ecology (Marine Zooplankton Colloquium 2, 2001).
