Effect of recreational diving on patagonian rocky reefs.

BRAVO G.; MARQUEZ F.; MARZINELLI E.M.; MENDEZ M.M; BIGATTI G.

MARINE ENVIRONMENTAL RESEARCH

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2015 vol. 104 p. 31 - 36

0141-1136

Tourism has grown considerably in the last decades, promoting activities such as recreational SCUBAdiving that may affect marine benthic communities. In Puerto Madryn, Patagonia Argentina, sub-aquatictourism areas (STA) receive about 7,000 divers per year. Diving is concentrated on a few small rocky reefsand 50% of the dives occur in summer. In this work, we evaluated the effect of recreational diving activitieson 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 benthicassemblage structure and composition between two sites with contrasting usage by divers, ?highlydisturbed? and ?moderately disturbed? sites, and two ?control? sites with similar physical characteristicsbut no diving activity, twice before and after the diving peak in summer.We found differences in benthicassemblage structure (identity and relative abundance of taxa) and composition (identity only) amongdiving sites and controls. These differences were consistent before and after the peak of diving insummer, suggesting that recreational diving may produce a press impact on overall benthic assemblagestructure and composition in these STA. At the moderately disturbed site, however, covers of specifictaxa, such as some key habitat-forming or highly abundant species, usually differed from those incontrols only immediately after summer, after which they begun to resemble controls, suggesting a pulseimpact. Thus, STA in Golfo Nuevo seem to respond differently to disturbances of diving depending on theusage of the sites. This information is necessary to develop sound management strategies in order topreserve local biodiversity.