Cultivated microalgae spills: hard to predict/easier to mitigate risks

• Spills from massive microalgae production could cause environmental disruption.
• Risks for non-native algae cannot be modeled due to the ‘paradox of the plankton’.
• Deleting genes unneeded in culture but required in natural ecosystems mitigates risks.
• Such mitigation is needed for both non-native wild type and some transgenic algae.

Cultivating algae on a large scale will inevitably lead to spills into natural ecosystems. Most risk analyses have dealt only with transgenic algae, without considering the risks of cultivating the corresponding non-transgenic wild type species. This is despite the long-studied ‘paradox of the plankton’, which describes the unsuitability of laboratory experimentation or modeling to predict the outcome of introducing non-native algae into a new ecosystem. Risk analyses of transgenic strains of native algae can be based on whether they are more fit or less fit than their wild type, but these are not possible with non-native species. Risks from spills can be minimized by mutagenically or transgenically deleting genes that are unnecessary in culture but obligatory in nature.