Harmful Algae Blooms in Chile and Coastal Monitoring with Metabarcoding Analysis

Yarimizu Kyoko

Fujiyoshi So

Fuenzalida Del Rio Gonzalo

I. Mardones Jorge

Paredes-Mella Javier

Rilling Joaquin-Ignacio

Campos Marco

Vilugrón Jonnathan

Nagai Satoshi

Espinoza-González Oscar

Guzmán Leonardo

Jorquera Milko A.

Maruyama Fumito

The dinoflagellate Alexandrium catenella is a well-known paralytic shellfish toxin producer that forms harmful algal blooms (HABs) worldwide. Blooms of this species have repeatedly brought severe marine ecological and economic damages to Chile. A clear mechanism of HABs has been a long term debate. Algal-bacterial interaction is one of the recently discussed potential drivers for HABs. The present study isolated A. catenella strain from Quellón, which has been severely impacted by frequent A. catenella blooms, to study in-situ bacterial diversity in cultured A. catenella. We investigated intact bacteria that have survived for generations in culture A. catenella, postulating that they were essential for A. catenella survival. We monitored the intact bacteria in seawater from Quellón biweekly for two years using metabarcoding analysis. Our laboratory study discovered that the dominant attached bacteria for the culture A. catenella after maintaining years were of the genus of Paraglaciecola 49.86%, Spongiibacter 10.74%, Reichenbachiella 10.01%, and Thalassospira 5.89%. Our field studies showed evidence of the frequent presence of attached Paraglaciecola in seawater in Quellón. The other three bacterial genus were occasionally detected during the two year study period. The study suggests that these bacterial taxa are candidates for playing a pivotal role in A. catenella growth.

eng

© 2021 Kyoko Yarimizu & Fumito Maruyama

[Created] 2021-11-29