Based on pigment data, theCHEMTAX(Mackey et al., 1996) program
was used to retrieve the group composition of the phytoplankton.
CHEMTAX software runs inMATLAB, togetherwith amatrix of field pigment
data and the initial input of a matrix of pigment: Chl a ratios for
each phytoplankton group. The input pigment ratios matrix used in
the CHEMTAX calculation was based on knowledge of the common
phytoplankton groups present in the YS and adjacent areas (Furuya
et al., 2003; Liu et al., 2012).