Contributions of marine infrastructures to marine planning and protected area networking

Marine infrastructures are becoming ubiquitous as a result of the increasing exploitation of resources in the nearshore environment. These infrastructures are frequently linked with habitat degradation, pollution, and the establishment and spread of alien species. As marine infrastructures are perceived as threats to marine ecosystems, they are typically disregarded in conservation planning schemes. Here, the presence of invertebrates and fish was surveyed in infrastructure areas with prohibited public access, as well as in nearby rocky reef areas that had no infrastructure and were open to the public. It was found that species richness, Shannon diversity, and uniqueness of both fish and invertebrates were significantly higher in the infrastructure habitats than in the rocky reef habitats in most cases. Surprisingly, the findings show that the proportion of alien species was higher in the unprotected rocky reef habitats compared with that in the infrastructure habitats. These counterintuitive findings suggest that marine infrastructures that limit unauthorized access to the surrounding territory may contribute to conservation if they are acknowledged and managed, according to their potential to provide a habitat for marine species. This suggests that these areas should be considered by planners as opportunities to enhance the connectivity of populations and to supplement marine protected areas in heavily impacted marine environments.