Hi all, I think it is the other way around. Anthocyanin production is meant to be stimulated by blue and UV light, and the anthocyanins block these wavelengths (red wavelengths of light are reflected).
Amongst other benefits, the red pigments act as a "sunscreen" to protect the photosynthetic systems (principally photosystem II) from photoinhibition.
I don't know about any research in aquatic plants, <"
but in "Lollo Rosso" lettuce"> anthocyanin production is almost entirely dependent on exposure to UV light (wavelengths shorter than 370 nm).
From Tsormpatsidis, E., et al. "UV irradiance as a major influence on growth, development and secondary products of commercial importance in Lollo Rosso lettuce ‘Revolution’grown under polyethylene films."
Environmental and Experimental Botany 63 (2008): 232-239.cheers Darrel