ICES Annual Science Conference 2019

Theme session J

Harmful algal blooms and jellyfish: Impacts on ecosystems and ecosystem services

Wednesday, 11 September
13:30 - 16:00
Room K

​​​Theme session J will be a unique opportunity for those working in the field of HABs, jellyfish, aquaculture, and ecosystem impacts. ​

Blooms of harmful algae (HABs) and jellyfish can severely affect global ecosystems and ecosystem services. A diverse range of HAB species and impacts are recorded every year within the ICES region. Official monitoring of jellyfish is not routine, but citizen science programmes provide a real opportunity to understand their dynamics.

HABs, jellyfish, and their impacts are relevant to all seven ICES science priorities. Both jellyfish and HABs can cause mortalities in farmed fish, while toxins produced by certain HAB species result in enforced closures of the shellfish harvesting areas. They can also accumulate through the foodweb up to higher trophic levels. High biomass HABs may have other effects; one example are the recurrent cyanobacteria blooms in the Baltic Sea, which contribute to low oxygen areas and has a negative impact on tourism in the region.

Regulatory monitoring of HAB species and their impacts on aquaculture has been conducted for food safety standards, the protection of fish farms, and as part of long-term monitoring programs to understand ecosystem dynamics. In contrast, the lack of regulatory monitoring means that much less is known about jellyfish ecology. The social science and economics of how HABs and jellyfish affect society has yet to be studied in depth. 

Recent advances in HAB/toxin detection and modelling methodologies are feeding into early warning systems, which can lead to improvements in management practices and in the understanding of ecosystem impacts. These 'early warning' systems are actively used in some areas within the ICES region to help shellfish- and fish farmers mitigate losses from HAB events. Such early warning systems for jellyfish are currently less developed.

Climate change is seen as an environmental driver potentially affecting HABs. ICES is currently contributing to a number of global initiatives to advance understanding from a food security, climate change and human health perspective, through the Intergovernmental Oceanographic Commission of UNESCO. Climate change is also thought to influence the dynamics of jellyfish, however a lack of monitoring data means this is less well understood.

Theme session J session will cover:

  • The latest developments in HAB and jellyfish dynamics
  • ICES input into global HAB and jellyfish initiatives
  • Impacts on the aquaculture industry, society and environment
  • New methods to monitor, predict and mitigate those impacts.

Presentations from social scientists and economist are particularly welcome.​

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Eileen Bresnan ​(UK)
Sophie Pitois (UK)
Mike Rust (USA)​


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Theme session J

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