New Zealand Press Association: Global warming’s evil twin, the increasing acidification of carbon dioxide-saturated oceans is threatening New Zealand’s corals, crustaceans and shellfish. “Ocean acidification is accelerating, ” Dunedin researcher Christina McGraw said. Dr McGraw said this rapid change in ocean chemistry meant that severe damage was imminent. Some of New Zealand’s vulnerable organisms include economically important species such as mussels, oysters, and paua. “These all have …