Standard Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

The Effects of Harmful Algal Blooms and Marine Heatwaves on the Early Life Stages of Green-lipped Mussels (#57)

Hannah Greenhough 1 2 , Kirsty F Smith 1 , Julien Vignier 1 , Christopher M Brown 2 , Nathan J Kenny 2 , Anne Rolton 1
  1. Cawthron Institute, Nelson, New Zealand
  2. University of Otago, Dunedin, New Zealand

The green-lipped mussel (GLM), Perna canaliculus, is the most valuable aquaculture species in Aotearoa New Zealand (NZ), with an export value of over $423M NZD1. The industry is reliant on the availability of wild juvenile GLM (spat), 30% of which originates from Te Tau Ihu (top of the South Island of NZ)2. In the last 20 years a decline in spat quantity has been observed. Climate change stressors, including marine heatwaves, extreme weather events and other stressors, such as the increasing frequency and duration of harmful algal blooms (HABs) are likely contributing3.

This work investigates the impact of the paralytic shellfish toxin producing HAB species, Alexandrium pacificum, and marine heatwave stress, both alone and in combination, on the early life stages of GLM from gametes to spat. Using both in vivo and in vitro experimentation, and incorporating multidisciplinary approaches including histology, transcriptomic and analytical chemistry analyses, we observed toxicity of A. pacificum towards gametes and embryos4, impaired growth of D-larval stages, and mortality and reduced byssal plaque production in spat. This research demonstrates how multiple stressors, more prevalent in a changing world, can impact the lifecycle of important coastal species.

 

  1. Aquaculture New Zealand, Aquaculture for New Zealand, New Zealand Aquaculture: A Sector Overview with Key Facts and Statistics for 2023. 2023. p. 1-32.
  2. Atalah, J. and B.M. Forrest, Forecasting mussel settlement using historical data and boosted regression trees. Aquaculture Environment Interactions, 2019. 11: p. 625-638.
  3. Rolton, A., et al., Effects of Harmful Algal Blooms on Fish and Shellfish Species: A Case Study of New Zealand in a Changing Environment. Toxins, 2022. 14(5): p. 341.
  4. Greenhough, H., et al., Exposure to Alexandrium spp. impairs the development of Green-lipped mussel (Perna canaliculus) embryos and larvae. Harmful Algae, 2023. 127: p. 102465.