title: Effect of recreational diving on Patagonian rocky reefs.
abstract: Tourism has grown considerably in the last decades, promoting activities such as recreational SCUBA diving that may affect marine benthic communities. In Puerto Madryn, Patagonia Argentina, sub-aquatic tourism areas (STA) receive about 7,000 divers per year. Diving is concentrated on a few small rocky reefs and 50% of the dives occur in summer. In this work, we evaluated the effect of recreational diving activities on benthic communities and determined whether diving causes a press (long-term) or a pulse (short-term) response. We quantified the percentage cover of benthic organisms and compared benthic assemblage structure and composition between two sites with contrasting usage by divers, 'highly disturbed' and 'moderately disturbed' sites, and two 'control' sites with similar physical characteristics but no diving activity, twice before and after the diving peak in summer. We found differences in benthic assemblage structure (identity and relative abundance of taxa) and composition (identity only) among diving sites and controls. These differences were consistent before and after the peak of diving in summer, suggesting that recreational diving may produce a press impact on overall benthic assemblage structure and composition in these STA. At the moderately disturbed site, however, covers of specific taxa, such as some key habitat-forming or highly abundant species, usually differed from those in controls only immediately after summer, after which they begun to resemble controls, suggesting a pulse impact. Thus, STA in Golfo Nuevo seem to respond differently to disturbances of diving depending on the usage of the sites. This information is necessary to develop sound management strategies in order to preserve local biodiversity.
authors.affiliation: Universidad Nacional de la Patagonia San Juan Bosco, Sede Puerto Madryn, Blvd. Brown 3150, U9120ACD Puerto Madryn, Argentina.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Bravo
authors.affiliation: Universidad Nacional de la Patagonia San Juan Bosco, Sede Puerto Madryn, Blvd. Brown 3150, U9120ACD Puerto Madryn, Argentina; LEEIM- Centro Nacional Patagónico (CENPAT-CONICET), Blvd. Brown 2915, U9120ACD Puerto Madryn, Argentina.
authors.forename: Federico
authors.initials: F
authors.lastname: Márquez
authors.affiliation: Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, 19 Chowder Bay Rd, Mosman, NSW 2088, Australia.
authors.forename: Ezequiel M
authors.initials: EM
authors.lastname: Marzinelli
authors.affiliation: LARBIM-Centro Nacional Patagónico (CENPAT-CONICET), Blvd. Brown 2915, U9120ACD Puerto Madryn, Argentina.
authors.forename: María M
authors.initials: MM
authors.lastname: Mendez
authors.affiliation: Universidad Nacional de la Patagonia San Juan Bosco, Sede Puerto Madryn, Blvd. Brown 3150, U9120ACD Puerto Madryn, Argentina; LARBIM-Centro Nacional Patagónico (CENPAT-CONICET), Blvd. Brown 2915, U9120ACD Puerto Madryn, Argentina. Electronic address: gbigatti@conicet-cenpat.gob.ar.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Bigatti
mesh_terms: D000818:Animals; D001118:Argentina; D044822:Biodiversity; D004242:Diving; D006801:Humans; D007448:Invertebrates / Q000502:physiology; D044423:Kelp / Q000502:physiology; D015999:Multivariate Analysis; D012621:Seasons; D014195:Travel
keywords: Algae; Disturbance; Human impacts; Marine invertebrates; Patagonia; Rocky reefs; SCUBA diving; Tourism