Global Perspective on Applied Research on Nutrient Management - Nutrient Loading and Harmful Algal Blooms: Research Advances and Tools for Management in Asian Waters

Abstract

Enrichment of seawater by nutrients favor increased growth, primary production and biomass of photosynthetic organisms (micro and macroalgae), which produce oxygen and constitute the base of marine food webs. Thus, the appropriate nutrient supply plays a fundamental role in providing seafood and other goods for the human benefit. However, excess nutrients, or unbalanced nitrogen to phosphorus (including inorganic and organic forms) and/or silicate ratios, can facilitate the selective proliferation of certain taxa. The excessive biomass accumulation of such organisms, which can also produce biotoxins, causes negative impacts in the environment (usually through hypoxia) and human health and wellbeing. These events are known as harmful algal blooms (HABs).

In the last decades, scientific research has made progresses in the understanding on how nutrient supply interacting with other physico-chemical and biological and ecological processes favor HABs occurrence. The gained knowledge has helped to design policy strategies that have been proven useful in certain areas to minimize the impacts of HABs.

This presentation will summarize the main HAB events that affect Asian marine ecosystems, with negative impacts on human health and economy. It will discuss the main factors that modulate their occurrence, with special emphasis on the role of nutrient supply. In this context, possible strategies for nutrient management will also be presented, along with the available scientific and technical tools to monitor and forecast the occurrence of HAB events. Altogether, management and scientific efforts can contribute to the sustained use of the natural resources of the seas for the benefit of the human communities that inhabit the Asian coastal areas