Global warming and ultraviolet radiation (UVR) affect marine organisms worldwide. However, we still lack knowledge about the consequences of these environmental changes to range-restricted macroalgae species, such asGelidium canariense, a habitat-forming endemic of the Canary Islands. The aim of this study is to provide useful data for analyzing the conservation status of this endemic species. To do this, (1) we compared distributional data from 1987 with the data collected in 2008 and 2019 along the northern coast of Tenerife; (2) we assessed the variation in macroalgae assemblages dominated byG. canarienseover the last decade on this same cost; and (3) we explored the correlation of these results with the actual trends of sea surface temperature (SST), air temperature at 2 m above the sea surface (T2m), UVR, and downward solar radiation (DSR). The results showed significant changes in the distribution ofG. canariensein the last 30 years at Tenerife. More than 90% of its populations have declined. The endemic macroalgae have been replaced by the globally distributed speciesPterocladiella capillaceaat nearly all the sites studied. The cover ofG. canarienseandGelidium arbusculadecreased significantly with increasing SST and T2m. Additionally,G. canarienseis negatively related to the rise in UVR. These results highlight the vulnerability of both species ofGelidiumto global warming and UVR, but especially ofG. canariense. The drastic decline of this species reveals the need to upgrade its conservation status and implement protection measures to reduce the damage that predicted global change scenario may have to their relict populations.

This study aimed to evaluate the effects of protection from extractive activities on the population structure of two limpets of commercial interest, Patella ulyssiponensis and Patella candei crenata. We evaluated the status of these populations in La Palma Marine Protected Area (MPA), Canary Islands, and in comparable unprotected areas in the lower intertidal zone of the same island. We showed that the density of P. ulyssiponensis depended greatly on the level of protection, whereas the effects of protection on the density of P. candei crenata were less clear and only differences between sites were found. These results are probably linked to the different habitat affinities of the two species studied and demonstrate the need to tailor conservation strategies in MPAs to individual species for appropriate management of local shellfish resources.