Snorkelers impact on fish communities and algae in a temperate marine protected area

Abstract

Multiple-use marine protected areas (MPAs) are used to manage marine resources, allocate space to different users and reduce conflicts while protecting marine biodiversity. In the Mediterranean, MPA managers are increasingly interested in containing the effects of coastal recreation within underwater trails, but snorkelers impacts on the surrounding ecosystem remain largely unknown. In a Mediterranean MPA, an underwater snorkeling trail was established to concentrate snorkelers and increase their awareness of marine habitats and species. The high level of summer frequentation may have negative impacts on the surrounding environment through trampling on the sessile flora or disturbance to the vagile fauna. We used a before-after-control-impact (BACI) design to analyse these potential human impacts. The structure of macroalgae and fish assemblages were used as indicators. Permutational multivariate analyses of variance (PERMANOVA) were carried out to assess potential temporal and spatial changes of the indicators between the trail and a control location within the adjacent no-take/no-use area. Fish communities and macroalgae were subjected to natural temporal trends but no significant impacts of snorkelers were found. Four reasons could explain the absence of snorkelers impact on the surrounding marine environment: (1) the absence of very fragile organisms within the trail (and the control no-take/no-use area) such as gorgonians or bryozoans; (2) the life cycle of the algae with a natural decreasing trend in summer, corresponding to the trail opening period; (3) only a few snorkelers are practicing apnoea; and (4) the information at the entrance and along the trail may influence the snorkelers' behaviour.

Eco-touristic snorkelling routes at Marinha beach (Algarve): Environmental education and human impacts

“…As such, the use of coastal areas for human recreation has always been a concern for scientists, environmentalists and managers, due to obvious conflicts between recreational uses and nature conservation [4][5][6].…”

“…Snorkelling is more accessible as a recreational activity than scuba diving since it requires less equipment and training, ensuring a wider appeal and greater participation [15]. Nonetheless, currently, both snorkelling and scuba diving are amongst the major commercial uses of Marine Protected Areas (MPAs) around the world, and the control of their potential impacts on the marine environment remains a key factor for the management of these recreational activities [4,17]. Snorkelling allows people to visit underwater cultural and natural structures, permitting direct human interaction with the environment, and acting as an excellent tool for environmental education.…”

“…Since then, there have been several examples of snorkelling routes around the world [e.g. 4,18,[21][22][23].…”

Carrying Capacity of East Beach of Bulukumba Regency for Marine Tourism Activities

“…Hal ini didukung oleh Claudet et al (2010) yang meyatakan bahwa kegiatan snorkeling yang terpusat di suatu area dapat meningkatkan ancaman terhadap habitat dan spesies di area tersebut.…”

Effects of recreational scuba diving on Mediterranean fishes: evidence of involuntary feeding?

“…The only two studies formally investigating the effects of recreational scuba diving (Hawkins et al, 1999) and snorkelling (Claudet et al, 2010) on fishes evaluated the longterm (i.e., in terms of weeks/months) disturbance, that potentially affects the entire composition and distribution of fish assemblages. In this study, we focus on short-term responses (i.e., in terms of minutes after human disturbance has occurred) of fishes as a result of a diver's activity (i.e., divers' contact with the benthic substrate) as an immediate disturbance potentially affecting fishes.…”