General environmental conditions during the spring-summer transitions in 2009, 2010, 2011, and 2012.

Maximum (Max) and mean values were calculated using data from March through August in each year, except as indicated for 2010. Dates are presented as Julian days. Stratification Day (Δσ) was not calculated for 2010 due to discontinuities in the temperature and salinity data.† Shallow temperature and salinity data were available from 30 April to 5 August 2010.General environmental conditions during the spring-summer transitions in 2009, 2010, 2011, and 2012.