The duration of nutrient limiting conditions can contribute to shaping subsequent diatom community composition: Insights from laboratory experiments

Climate-driven increases in global surface water temperatures are enhancing upper ocean stratification and likely resulting in more prolonged periods of nutrient limitation. Although nutrient limitation in diatoms and their growth responses to increasing temperatures have been studied extensively, much less is known about their growth response to nutrient injection after prolonged durations of nutrient limitation. This study examines the growth response of three bloom-forming diatom species: Pseudo-nitzschia pungens, P. australis, and Skeletonema costatum after short-term (~2 week) and prolonged (~4 week) periods of nutrient limitation at five temperatures (9, 12, 15, 20, and 25°C). Pseudo-nitzschia species showed shorter lag times and higher specific growth rates than S. costatum after prolonged nutrient stress. These findings demonstrate that certain diatom species can exhibit faster growth recovery after prolonged nutrient limitation and in warmer conditions compared to others, providing new insights on drivers that shape phytoplankton communities.