Durable underwater adhesives are a major objective in biomedical technologies. Mussels have adapted to highly polar and turbulent environments in aquatic near shore habitats through a stabilizing, self-engineered holdfast called the byssus. Understanding the naturally occurring adhesive system of the California mussel, Mytilus californianus, may lead to the development of more biocompatible, biodegradable sealants and coatings, particularly for wound suturing within the medical and dental industries. Strong adhesion has been observed in the plaques of the byssus by means of L-3,4-dihydroxyphenylalanine (DOPA), a post-translationally modified amino acid. However, when DOPA is oxidized it loses its adhesive properties. Recently it has been shown that adhesion can be restored via a redox active protein called mussel foot protein-6 (mfp-6). This project aimed to quantify the longevity of mfp-6’s DOPA saving antioxidant activity in mussels attached to two varying substrates. Proteins extracted from plaques deposited over a two week time span were assayed to test for relative antioxidant activity and compared to total DOPA content. Constant antioxidant activity over time could suggest that mfp-6 is a regenerative system dedicated to compromised DOPA bond restoration. Differing antioxidant activities between substrates might signify ‘smart adhesion’ in which the mussel recognizes the substrate and accordingly modifies plaque protein composition.