Does culture supernatant of Haslea ostrearia containing marennine affect short-term physiological traits in the adult blue mussel Mytilus edulis?

•The diatom Haslea ostrearia produces the blue pigment marennine.•Marennine has biological activities that can be beneficial in aquaculture.•Marennine significantly affects the clearance rate and oxygen consumption of adult mussel Mytilus edulis.•Marennine does not significantly affect the palatability of mussel larvae by the adult mussel.