青岛近海赤潮灾害分级与时空分布及赤潮生物的变化

根据赤潮发生面积和赤潮藻类的危害类型,将青岛近海发生的赤潮划分为特大、重度、中度、轻度和轻微共计5个灾害级别。结果表明,1990-2013年青岛近海共计发生赤潮33次,以轻微灾害和轻度灾害为主,其它级别尚未发生;其中,发生面积小于10 km2赤潮占总数的51.5%,60.6%的赤潮由基本无害的赤潮种类引起,发生范围以胶州湾和浮山湾近海为主;赤潮次数和面积基本呈现4~5年的波动周期,高发期集中在每年的6-8月;主要赤潮生物种类是红色中缢虫(Mesodinium rubrum)和夜光虫(Noctiluca scintillans);引发赤潮的生物种类逐渐增多,甲藻比例升高,罕见种类逐渐出现。赤潮种类的变化反映出青岛近海浮游植物的种类组成发生了改变,与期间青岛近岸海洋环境的变化密切相关。

Spatial-temporal Distribution and Hazard Grading of Red Tide and Variation of Red-tide Species in Qingdao Adjacent Sea Area

According to the red tide area and hazard types of red tide algae, red tides were classified into five levels: extra large, heavy, moderate, mild and slight disasters levels occurred in Qingdao Olympic sailing competition venue and adjacent sea area. 33 red tide incidents were recorded from 1990 to 2013 with the slight degree and mild degree were the main levels and other levels has not yet occurred. Among them, the occurrence area of less than 10 km2 accounts for 51.5% of the total numbers of red tides and 60.6% of the red tides caused by harmless red tide species. Jiaozhou Bay and Fushan bay adjacent area were the serious red tide area. The red tide numbers and area fluctuated in the periods of four to five years and from June to August occurs mostly. Main red tide species are Mesodinium rubrum and Noctiluca scintillans. The red tide species numbers and the ratio of Pyrrophytaincreased increased while infrequent species appeared during the resent years. The changes of the red tide species reflected that the Qingdao inshore Marine phytoplankton species composition changed and was estimated to be relate to the Marine changes of Qingdao near-shore areas marine environment during the period closely.