Spatial and temporal changes in zooplankton abundance, biovolume, and size spectra in the neighboring waters of Japan: analyses using an optical plankton counter

Zoological Studies

Table 3 Comparison on regressions between OPC derived mass and directly measured mass, ranges of abudance, and biovolume of mesozooplankton

Location (period)	Regression ( *n, r* ² *, p* )	Abundance (ind. m ^-3 )	Biovolume (mm ³ m ^-3 )	References
35° to 44° N, 155° E	Y = 1.05X + 0.05	351.7 to 579.5	177.1 to 678.9^a	Yokoi et al. (2008)
(May to June 1993 to 2004)	(234, 0.63, p < 0.0001)
22° to 53° 30′ N 165° E/165° W	Y = 116X	226.3 to 430.9	190.7 to 523.3^a	Matsuno and Yamaguchi (2010)
(June to August 2003 to 2006)	(96, 0.79, p < 0.0001)
35° to 51° N, 180°	Y = 1.176X	128.0 to 562.0	96.0 to 880.0^a	Fukuda et al (2012)
(June 1981 to 2000)	(351, 0.521, p < 0.0001)
20° to 45° N, 126° to 155° E	Y = 0.950X	16.8 to 1,075.9	2.2 to 1,006.7	This study
(May to Aug. 2011)	(78, 0.691, p < 0.0001)

Evaluated by OPC analyses in the North Pacific. For regressions, Y, biovolume in mm⁻³ and X, mg m⁻³.
^aBiovolume data were calculated from dry mass unit in the references.