a fishing technique
... that salmon conservation measures are threatening the survival of a fishing technique first brought to Britain a thousand years ago by the Vikings?
... that <a href="./Salmon_conservation" id="mwBj8" rel="mw:WikiLink" title="Salmon conservation">salmon conservation</a> measures are threatening the survival of <b id="mwBkA"><a href="./Haaf_net_fishing" id="mwBkE" rel="mw:WikiLink" title="Haaf net fishing">a fishing technique</a></b> first brought to Britain a thousand years ago by the <a href="./Vikings" id="mwBkI" rel="mw:WikiLink" title="Vikings">Vikings</a>?