[Role of irradiance on the seasonality of Skeletonema costatum Cleve blooms in the coastal area in East China Sea].
With field culture experiments and model calculations, the role of light on why in both spring and summer Skeletonema costatum Cleve blooms can occur in the coastal area in East China Sea were studied. The results show that the growth optimal light intensity (I(opt)) of S. costatum increases gradually to a maximum of 121.6 W x m(-2) with temperature (t) up to 25 degrees C, and a rapid decline in I(opt) accompanies further increases in t beyond 25 degrees C. Such an asymmetric inverse V-shape I(opt)-t curve can be well described by Blanchard's equation. By this equation, I(opt) of each month was calculated based on monthly sea surface temperature, and though changes about 2 months later than light intensity above sea surface (I(0)), I(opt) is closely correlated with seasonal I(0) and transparency of sea water (R2 = 0.907 +/- 0.115, p < 0.001), which indicates that S. costatum adapts to the seasonality of light in sea water in the coastal area by varying I(opt) seasonally. Such an adaptive strategy leads to thick (about 6 m) light-optimal water layers for growth from early spring to late summer. The high adaptability to light and light optimum characteristics in sea water is one of the important reasons for S. costatum blooms in the both seasons in the coastal area in ECS.
Sun
Bai-Ye
BY
Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China. bys298@yahoo.com.cn
Liang
Sheng-Kang
SK
Wang
Chang-You
CY
Wang
Xiao-Bo
XB
Wang
Xiu-Lin
XL
Li
Yan-Bin
YB
D000465:Algorithms; D000818:Animals; D002681:China; D017377:Diatoms / Q000254:growth & development / Q000528:radiation effects*; D005068:Eutrophication; D005843:Geography; D008962:Models, Theoretical; D009792:Oceans and Seas; D010839:Phytoplankton / Q000502:physiology / Q000528:radiation effects; D011156:Population Density; D012621:Seasons; D012623:Seawater; D013472:Sunlight