红潮，又称为“赤潮”，是一种水华现象，属于海洋灾害的一种，主要是指海洋水体中一些微小的浮游生物、原生动物或者细菌，它们在一定的环境和条件下突发性增值和聚集，从而导致在一定的时间和范围内水体发生变色的现象。

Red tide is a kind of water bloom phenomenon which is marine disaster. It refers to the sudden increase in value and aggregation of some tiny plankton, protozoa or bacteria in the ocean in a certain environment and conditions, which leads to the discoloration in a certain time period and scope of the water body.

“赤潮”只是一个术语，赤潮也不一定是全是红色，而是许多类似现象的统称。当发生赤潮时，根据引起赤潮的生物的数量和类型，海水通常为红色，黄色，绿色和棕色等。

Red tide, being a general term, does not mean the color of the water is always red, and the color of the water body is usually red, yellow, green and brown depending on the number and types of organisms.

1、赤潮的形成原因The Causesof the Appearance of Red Tide

赤潮的形成主要有浮游生物与人类活动两大原因。

There are two main reasons for the formation of red tide and they are plankton and human activities respectively.

1.1浮游生物Plankton

海洋浮游生物是一类海洋生物，它们缺乏发达的运动器官，没有或仅有很弱的游泳能力，它们悬浮在水层中并经常随洋流运动。其中，通过光合作用将海水中的无机化合物转化为生物代谢所需的有机化合物的称为浮游植物，它们没有这种能力。必须将浮游植物用作诱饵者才称为浮游动物。据初步统计，全世界各种大洋中有180多种可形成赤潮的浮游生物，其中63种在中国的浮游生物中被列出。

Marine plankton are a group of marine organisms that lack developed locomotor organs and have no or weak swimming ability, and they suspend in the water layer and often move with the currents. Among them, those that convert inorganic compounds in seawater into organic compounds needed for biological metabolism through photosynthesis are called phytoplankton which do not have the ability mentioned above, and only those that use phytoplankton as baits are called zooplankton. According to the preliminary statistics, there are more than 180 species of phytoplankton that can lead to red tide in various oceans around the world, and 63 of them are found in China.

1.2人类活动Human Activities

（1）大量工农业或养猪业工厂排放大量猪粪废水和生活污水排入海，特别是未经处理直接排入而导致近海、港湾富营养化程度日趋严重。

(1) A large number of wastes from industry, agricultural production and pig farms and domestic sewage as well are discharged into the sea without treatment, leading to the more serious eutrophication of the offshore areas and harbors.

（2）由于沿海地区发展迅速，海洋水产养殖业扩大，也给海洋环境和水产养殖业自身带来了污染问题；海水养殖的自我污染也是引起赤潮的因素之一。

(2) Due to the rapid development of coastal areas, the expansion of marine aquaculture has polluted the marine environment and the aquaculture industry itself. Besides, the self-pollution of marine aquaculture is also one of the factors causing red tide.

（3）全球海运业的发展导致国外有害赤潮物种的引入。

(3) The development of the global maritime industry has led to the introduction of harmful red tide species from abroad.

（4）全球气候的变化也导致了赤潮经常发生。

(4) Global climate change has also led to the frequent occurrence of red tide.

赤潮发生次数：

The number of occurrences of red tide.