down·stream / ˈdounˈstrēm/ • adv. & adj. situated or moving in the direction in which a stream or river flows: [as adv.] the bridge spanned the river just downstream of the rail line | [as adj.] deforestation could have disastrous consequences for downstream regions. ∎ Biol. situated in or toward the part of a sequence of genetic material where transcription takes place later than at a given point: a termination signal was found downstream from the coding region. ∎  at a stage in the process of gas or oil extraction and production after the raw material is ready for refining.

Downstream

The downstream presentation is useful for calm spring creek and tail water streams. The fly is presented to the fish first without any disturbances from the leader or line. When the casting planes are made away from the fish’s location, the fish are undisturbed by overhead false casting and line spray. Many times fish are wary of overhead motions which may simulate birds of prey. Additionally, the downstream presentation is simple and effective; perhaps its only disadvantage is that the fly needs to be accurately cast.

downstream In the direction of the 3′ end of a DNA sequence as measured from a reference site.