Yaquina Bay and River waters were sampled in May, 1951 "to determine the suitability of these waters for the propagation of fresh market shellfish." (p.1) Found that the intensity and extent of pollution had increased "markedly" since the previous survey of March, 1948. "The waters of the bay are grossly polluted from Toledo to a point about five miles below Toledo." (p.4) Recommended no oyster production between Yaquina and Toledo. Includes hand-drawn map of the bay and river.