In Baja California, Mexico, pink abalone (Haliotis corrugala) banks have been found to be heavily infested by endolithic (boring) organisms, which damage the shell, reduce individual growth, and, in many cases, prevent the abalone from reaching the minimum legal size of capture (140 mm). Thus, the accumulation of endolithic borings has a negative impact on the fishery. Infested shells have a different appearance from healthy shells, decreasing their ornamental value. As the size of the muscle scar of pink abalone increases with age, we assume that endolithic infestation affects individual growth and produces adults of a smaller size than normal. The correlation among the degree of muscle scar development, shell length, and percent coverage by endolithic borings was determined. We identified five stages of muscle scar development and found a significant correlation between scar stages and percentage of endolithic boring coverage and shell length. This correlation may be an indication of the profound effects that drilling organisms have on abalone growth rates. Determining the proportion of the population unable to reach the minimum legal size of capture resulting from endolithic borings will be useful in species management. It would also be useful to assess whether global warming favors greater damage to abalone shells by boring organisms and to estimate the possible consequences for the fishery.