In 1903 he was appointed as Biological Secretary to the International Council for the Exploration of the Sea (ICES), based in Copenhagen.
He made important contributions to fisheries science and produced definitive works which were among the first scientific studies to address the issue of overfishing.
[1] He was an accomplished linguist who translated the works of many Danish and German fisheries scientists and ichthyologists into English.
His magnum opus was a book on the fisheries of Great Britain and Ireland which was published in German.
Kyle appeared to find living in Germany more conducive to his work and he was often assumed to have been a German rather than a Scot.