Filter-feeding molluscs like mussels are often the organisms of choice for marine pollution impact assessment as they store organic waste and heavy metals in the tissues and in the shell that are transiently or permanently present in their environment. The fluorescent age pigment lipofuscin is a waste material of detoxifying processes and predominantly accumulates in the lysosomes. Lipofuscin is also a recognized hallmark of aging as it accumulates with age, presumably caused by ongoing cellular oxidative stress. The ocean quahog Arctica islandica is the longest-lived of all molluscan species. The reported maximum life span for an Iceland population is > 300 yrs. The accumulation of the biochemical age marker lipofuscin and the change in protein oxidation with age was studied in mantle, gill and adductor muscle of A. islandica. Sample material comprised an age range from 5 to 192 years. In mantle and gill tissue the lipofuscin concentration increased with age. In muscle tissue lipofuscin was not visible at any age. The protein carbonyl content was constant with age in mantle and gill. In contrast to lipofuscin, protein carbonyls can be removed from the cell. This may lead to the observed differences in accumulation of both molecules in the tissue. To investigate the lipofuscin accumulation caused by environmental pollutants, age dependent modifications of intracellular processes have to be taken into consideration.