spawn
... that fish ladders are constructed so that salmon can navigate past hydroelectric dams on their way to spawn?
... that <a href="./Fish_ladder" id="mwDiM" rel="mw:WikiLink" title="Fish ladder">fish ladders</a> are constructed so that salmon can navigate past <a class="mw-redirect" href="./Hydroelectric_dam" id="mwDiQ" rel="mw:WikiLink" title="Hydroelectric dam">hydroelectric dams</a> on their way to <b id="mwDiU"><a href="./Spawn_(biology)" id="mwDiY" rel="mw:WikiLink" title="Spawn (biology)">spawn</a></b>?