1) The study examines the potential prophylactic effect of using the diatom Haslea ostrearia as feed for oysters by determining its allelopathic effects on other diatom species.
2) The methodology involves culturing H. ostrearia with other diatom species and measuring their growth rates and biovolumes over time under a microscope. Marennine concentration is also measured in each culture using HPLC analysis.
3) The results show reductions in growth rates and biovolumes of other diatom species when cultured with H. ostrearia, indicating allelopathic effects of marennine. This suggests H. ostrearia may have potential prophylactic effects for oysters.