Scotland's seas host almost half of the European Union's breeding seabirds including about half of the world's northern gannets and a third of the world's Manx shearwaters. Four seabird species have more than 95% of their combined British and Irish population in Scotland, while a further fourteen species have more than half of their breeding population in Scottish colonies. St Kilda, which is a World Heritage Site, is a seabird haven of great significance. It has 60,000 northern gannets, amounting to 24% of the world population, 49,000 breeding pairs of Leach's storm petrel, up to 90% of the European population, 136,000 pairs of puffin and 67,000 northern fulmar pairs, about 30% and 13% of the respective UK totals. The island of Mingulay also has a large seabird population and is an important breeding ground for razorbills, with 9,514 pairs, 6.3% of the European population.