贻贝养殖海域表层水温季节变化及其对紫贻贝生长的影响

Seasonal variation of surface water temperature and its ecological impacts in a mussel aquaculture farm

为获知贻贝浮筏养殖海域表层(3 m)水温的季节变化规律及其对紫贻贝生长的影响,实测多年枸杞岛贻贝养殖场表层水温,并在一个养殖周期内分7航次采集紫贻贝样获取体质量、壳长等数据。结果显示,观测期内最高、最低表层水温分别为29.2℃和4.6℃。夏季表层水温日变幅可超过4℃,而春季与秋季低于2℃。紫贻贝体质量与月龄的多项式回归方程为:W=0.000 6M4+0.006 4M3-0.132 6M2+0.859 9M+0.6568(R2=0.999 1)。紫贻贝壳长与月龄的多项式回归方程为:L=0.000 8M4+0.057 7M3-1.099 7M2+7.536 6M+20.044(R2=0.998 9)。紫贻贝生长速率与水温呈指数关系,其表达式为Rw=0.102 8e0.119 5T(R2=0.741 3),将翌年3月前后紫贻贝的生长速率与水温之间指数关系分段计算时相关性更高,秋冬季为Rw1=0.148 8e0.068 3T(R2=0.936 0),春夏季为Rw2=0.118 8e0.128 9T(R2=0.993 2)。紫贻贝壳长生长速率与水温呈指数关系,其表达式为Rl=0.548 3e0.104 3T(R2=0.952 9)。不同年份之间,枸杞岛贻贝养殖场表层水温存在明显差异。春夏季是紫贻贝生长关键时期,春夏季持续相对低温可影响紫贻贝的产量。对养殖海域的水温进行实时观测,可获取水温变化动态,以及时调整紫贻贝的养殖策略。

To achieve the seasonal variation and its ecological impact on the growth rate of blue mussel,the surface（ 3 m beneath the sea surface） water temperature of the mussel farms around the Gouqi Island was observed for several years.Additionally,the weight and the shell length of blue mussel were also sampled and measured for seven times during a culture cycle.The results showed that the maximum and minimum surface temperature was 29.2 ℃ and 4.6 ℃ during the observation,respectively.The amplitude of daily temperature oscillation could be more than 4℃ in the summer,and less than 2℃ in the spring and autumn.Between the weight and the monthly age,a polynomial regression was found as W = 0.000 6M4＋ 0.006 4m^3-0.132 6m^2＋ 0.859 9M ＋ 0.656 8（ R^2= 0.999 1）.Meanwhile,the polynomial regression between the shell length and the monthly age was found as L = 0.000 8M4＋ 0.057 7m^3-1.099 7m^2＋ 7.536 6M ＋ 20.044（ R^2=0.998 9）.The regression relation between the weight growth rate and water temperature is exponential as Rw = 0.102 8e0.119 5T（ R^2= 0.741 3）.The correlation coefficient is higher when the regression relation between mussel growth rate and water temperature is recalculated by two parts.The exponential relationship is Rw1 = 0.1488e^0.0683T（ R^2= 0.9360） from October to March of the next year,and Rw2 = 0.118 8e^0.128 9T（ R^2= 0.993 2） from April to August.The regression equation between the shell length growth rate and water temperature is exponential as Rl = 0.548 3e^0.1043T（ R^2= 0.952 9）.Surface water temperature in the mussel farms around the Gouqi Island varied significantly at the same time between different years.Spring and summer are the important seasons of mussels＇ growth,continuous relative lower temperature during these two seasons can affect mussel production greatly.The in situ observation of surface water temperature is recommended for the mussel aquaculture,and it could help to adjust culture tactics of blue mussel.