| Abstract from DBPedia | An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. Algal bloom commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest. Algal blooms are the result of a nutrient, like nitrogen or phosphorus from various sources (for example fertilizer runoff or other forms of nutrient pollution), entering the aquatic system and causing excessive growth of algae. An algal bloom affects the whole ecosystem. Consequences range from the benign feeding of higher trophic levels to more harmful effects like blocking sunlight from reaching other organisms, causing a depletion of oxygen levels in the water, and, depending on the organism, secreting toxins into the water. Blooms that can injure animals or the ecology, especially those blooms where toxins are secreted by the algae, are usually called "harmful algal blooms" (HAB), and can lead to fish die-offs, cities cutting off water to residents, or states having to close fisheries. The process of the oversupply of nutrients leading to algae growth and oxygen depletion is called eutrophication.水の華（みずのはな）あるいは藻類ブルーム（そうるいブルーム、英: algal bloom）は、微小な藻類が高密度に発生し水面付近が変色する現象。 日本では淡水域における浮遊性藍藻や緑藻、ユーグレナ藻の大発生を指すことが多い。欧米では海水域において珪藻や渦鞭毛藻などが大発生して水面が褐色になる現象も water-bloom と呼ばれるが、日本語ではこうした褐色や赤系統の変色は赤潮と呼んで区別する傾向が強い。温帯では冬季に水塊中の躍層が消滅して水面近くの有光層に栄養塩が供給され、春季に気温の上昇とともに水の華が生じる現象が見られ、これをspring bloomと呼ぶ。 (Source: http://dbpedia.org/resource/Algal_bloom) |
