TY - CONF A1 - Watzin, M C T1 - SEER: the role of natural versus anthropogenic factors in assessing ecological risk in agricultural watersheds: results of the Year 1 sampling program. N1 - R827784E02 ER - TY - CONF A1 - Watzin, M C T1 - SEER: the role of natural versus anthropogenic factors in assessing ecological risk in agricultural watersheds: results of the colonization experiments. N1 - R827784E02 ER -