China
Africa
Explore chapters and articles related to this topic
Artificial neural networks
Published in A. W. Jayawardena, Environmental and Hydrological Systems Modelling, 2013
Abundance of certain types of phytoplanktons such as Noctiluca scintillans, Skeletonema costatum, and Gonyaulax polygramma cause the waters to turn red to brown in colour, leading to what is commonly referred to as the appearance of ‘red tides’. When such an occurrence takes place, the water quality is adversely affected. The red tides block sunlight necessary for photosynthesis and use up the oxygen in the water. Certain types of red tide organisms produce chemicals that can be harmful to fish, shellfish, and humans. For example, Alexandrium catenella is toxic to humans, Gymnodinium is harmful to fish, and Dinophysis is harmful to shellfish and therefore also to humans thorough the food chain. It is also known that severe rapid oxygen depletion resulting from their presence causes fish kill. The water discoloration itself can significantly impair recreational uses of coastal waters. If the timing and magnitude of algal blooms could be predicted in the primary stage, then many of these deleterious effects can be prevented or minimized.
Optical remote sensing of marine, coastal, and inland waters
Published in P. Dakin John, G. W. Brown Robert, Handbook of Optoelectronics, 2017
Ocean color monitoring allows real-time observation of red tides and other phytoplankton blooms. When a bloom has negative impacts on other organisms or humans, it is known as a harmful algal bloom. A harmful bloom may be toxic, causing large-scale mortality of fish or shellfish poisoning in humans. Other plankton species, while not containing toxic chemicals, may be present in such number that they smother other organisms, for example, by clogging their gills. Intense blooms can also cause widespread deoxygenation of bottom waters when they decompose; so they can be a major cause of death for bottom-living organisms. Typically, only one or a small number of phytoplankton species are involved.
Glossary of Terms
Published in Louis Theodore, R. Ryan Dupont, Water Resource Management Issues, 2019
Louis Theodore, R. Ryan Dupont
red tide: a proliferation and accumulation of certain microscopic algae, predominantly dinoflagellates, in coastal waters; some species produce toxins that are labeled harmful algae blooms, or HABs, that pose a serious and recurring threat to human health, wildlife, marine ecosystems, fisheries, and coastal aesthetics.
An environmental management system in seaports: evidence from Malaysia
Published in Maritime Policy & Management, 2022
Jagan Jeevan, Nurul Haqimin Mohd Salleh, Nur Hidayati Abdul Karim, Kevin Cullinane
Secondly, sewage treatment is found to be an important influencing factor for port Klang. Even after the rapid development of national sewerage systems that has been implemented in recent years, they are still inadequate. This is because many older houses in both urban and rural areas still use an individual tank, with kitchen waste discharged directly into rivers (Belin et al. 2019). The proper handling of sewage treatment could help to ensure the environmental sustainability of the area, but especially for Port Klang. The most important primary feature of raw sewage from a disposal point of view is the oxygen demand—i.e. the amount of oxygen that will be consumed by bacteria as they feed on and degrade the sewage waste. When the amount of oxygen required is unstable, then serious problems may arise. For example, excessive nutrient discharge into coastal waters will result in eutrophication. Red tides are caused by phytoplankton blooms, which deplete oxygen in coastal waters, causing the mass death of aquatic organisms (Krishnakumar and Asokan 2017). Thus, the treatment of sewage has emerged as a very important factor in the development of Port Klang as a green port of the future.
Isolation and characterization of an algicidal bacterium against the bloom-forming algae raphidophyte Heterosigma akashiwo
Published in Environmental Technology, 2023
Zhenzhen Zhang, Junyue Wang, Guangwei Hu, Jinwang Huang, Lei Chen, Yue Yin, Yuefeng Cai, Xin Shen, Nanjing Ji
Microscopic algae in marine and freshwater ecosystems not only serve as the base of the food web and constitute a critical nutrient source for aquatic organisms (e.g. filter-feeding shellfish and finfish larvae) but also play an important role in the sequestration of atmospheric carbon dioxide (CO2) into deeper water [1]. However, some algae species cause significant damages to marine ecosystems, local economies, and human health when they rapidly proliferate and reach critical biomass. These events are known as harmful algal blooms (HABs) but are also commonly referred to as red tides because some blooms (e.g. dinoflagellates) create a characteristic red or brown discoloration in aquatic environments [2–5].
Nitrogen and phosphorus treatment of marine wastewater by a laboratory-scale sequencing batch reactor with eco-friendly marine high-efficiency sediment
Published in Environmental Technology, 2018
Seonghyeon Cho, Jinsoo Kim, Sungchul Kim, Sang-Seob Lee
Nitrogen and phosphorus accumulation caused by industrial activities is a major concern in the eutrophication of coastal habitats. Coastal marine eutrophication has recently become a global concern [1,2]. Harmful algal blooms (HABs) cause red tide in the ocean, and can damage marine ecosystems, human health, and fishery activities by their secreted toxins [1,3].