Gwennap Head identified steamships were wrecked, stranded or sank in the area. There have been none since 1923. The navigation markers feature as "the Cones of Runnel" in Hammond Innes's 1940 thriller "The Trojan Horse". Gwennap Head is part of the Porthgwarra to Pordenack Point Site of Special Scientific Interest (SSSI) designated for its vegetation of waved maritime heath, and for being of considerable ornithological interest; especially for passage migrants. It is renowned for its relative abundance of passing marine bird species with many common species such as northern gannet ("Morus bassanus"), Manx shearwater ("Puffinus puffinus"), common guillemot, ("Uria aalge"), razorbill ("Alca
Trevor H. Worthy the Waitomo frog ("Leiopelma waitomoensis"). In the 1990s Worthy discovered several fossil bird species new to science, including the long-billed wren ("Dendroscansor decurvirostris") in 1991, Scarlett's shearwater ("Puffinus spelaeus") in 1991, and the Niue night heron ("Nycticorax kalavikai") in 1995. In 1991 he also described the Northland skink, a fossil skink species new to science. In 1998 Worthy excavated subfossil bones in Fiji, where he found remains of the flightless Viti Levu giant pigeon ("Natunaornis gigoura"), the Viti Levu scrubfowl ("Megapodius amissus"), the Viti Levu snipe ("Coenocorypha miratropica"), the giant Fiji ground frog ("Platymantis megabotoniviti"), and the small freshwater crocodile