Perna perna
...that the Brown mussel Perna perna aggregates in such large amounts that it is able to sink navigational buoys?
...that the <a class="mw-redirect" href="./Brown_mussel" id="mwCVY" rel="mw:WikiLink" title="Brown mussel">Brown mussel</a> <i id="mwCVc"><b id="mwCVg"><a href="./Perna_perna" id="mwCVk" rel="mw:WikiLink" title="Perna perna">Perna perna</a></b></i> <a href="./Biofouling" id="mwCVo" rel="mw:WikiLink" title="Biofouling">aggregates</a> in such large amounts that it is able to sink <a href="./Sea_mark" id="mwCVs" rel="mw:WikiLink" title="Sea mark">navigational buoys</a>?