June 2, 2017

GAA report spells out measures to better manage harmful algal blooms in Chile

The Global Aquaculture Alliance (GAA), a leading standards-setting organisation for farmed seafood, has released a new report that identifies measures to enhance the management of harmful algal blooms (HABs).

The 19-page algal blooms management report, which GAA published on Tuesday, May 30, concluded that while there was much capacity and experience among those studying and monitoring HABs in Chile, fragmentation in monitoring and outreach was apparent.

The report suggested that the Chilean economic development agency CORFO and Chile's minister of the economy establish a committee of scientists and regulators to review existing HAB programmes and recommend how they can be better coordinated and managed.

Early last year, a series of HAB outbreaks hit the coastal waters of southern Chile, affecting finfish (particularly salmon) and shellfish farmers. The outbreaks resulted in losses of farmed and wild finfish, as well as widespread paralytic shellfish poisoning.

A GAA-led team of experts met with Chilean government officials, researchers, and salmon and shellfish aquaculture leaders in August to gain better understanding of the situation.

The GAA report emphasises the timeliness of HAB detection through use of new technologies, and supplementing the work already being done in Chile. Tracking HABs, it said, involves enhanced maintenance of buoys that can identify and count algal cells and transmit results via the internet for near real-time use and satellite-based remote-sensing systems coupled with the application of physical-biological numerical models.

While some types of data are very adequately applied, the report noted that the algal nutrient measurements needed to understand and model the concentrations, sources and fates of the natural and human-sourced nitrogen, phosphorus and silica found near aquaculture facilities in the Chilean Inland Sea were limited.

The algal blooms management recommendations also include further examination of mitigation methods to control HABs near salmon farms including testing of methods that have been successful in other countries.