A barrier for reducing erosion along shorelines includes a barrier body formed as a unitary, molded plastic structure. In one embodiment, the barrier body has at least one elongate passage extending through it, between oppositely disposed first and second sides, and an interior reservoir. A port formed into the barrier body communicates with the interior reservoir to facilitate filling the reservoir with material to thereby add weight to the barrier. The barrier further includes at least one anchor formed into a side of the barrier body and associated with the passage to control shrinkage of the barrier body as it is being molded. In another embodiment, a method of making the barrier body includes placing plastic material in a mold, manipulating the mold to distribute the plastic material within the mold and thereby form the barrier body as a unitary piece, and reducing the shrinkage of the molded barrier body with the anchor.