sentences:  He was especially concerned about the Bock's lake, labeled CWB ("Crow Wing county - Bock"), as it was one of the few natural bodies of water that had been affected by the deformities.While Helgen was also concerned about the integrity of sites, Hoppe felt that the MPCA, as a public agency was not well equipped to ensure site integrity.The story then takes a detour and discusses the findings of Martin Ouellet, a French-Canadian biologist who was studying the effect of agricultural chemicals on frogs in the St. Lawrence River valley.