Wrack Removal as Short-Term Disturbance for Talitrus Saltator Density in the Supratidal Zone of Sandy Beaches: an Experimental Approach

• Published in: Estuaries and coasts 2016-07, Vol.39 (4), p.1113-1121
• Main Authors: Ruiz-Delgado, Mª Carmen, Vieira, Jenyffer Vierheller, Reyes-Martínez, Mª José, Borzone, Carlos Alberto, Sánchez-Moyano, Juan Emilio, García-García, Francisco José
• Format: Article
• Language: English
• Subjects: Adaptability; adults; Algae; Animal populations; Aquatic life; Beaches; biodiversity; Biomass; Brackish; Coastal ecology; Coastal Sciences; Coasts; Dominant species; Earth and Environmental Science; Ecological function; Ecology; ecosystems; Environment; Environmental Management; Estuaries; field experimentation; Field experiments; Freshwater & Marine Ecology; juveniles; Macroalgae; Marine; Marine ecosystems; Population density; Sea grasses; seagrasses; Spain; Water and Health; Young animals
• ISSN: 1559-2723; 1559-2731
• DOI: 10.1007/s12237-015-0060-2

A distinctive feature of sandy beaches is the stranded wrack, which represents a key element in the maintenance of their biodiversity and ecosystem function. However, these materials are commonly removed from beaches worldwide. In October—November 2012, a field experiment following an M-BACI design was conducted to assess the effect of wrack removal on sandhopper populations on two sandy beaches on the Atlantic southwest coast of Spain. The beaches, Levante (36°33'N, 6°13'W) and Cortadura (36°28'N, 6°15'W) differed in their morphodynamics (dissipative and intermediate, respectively) and in the dominant wrack sources (seagrasses vs. macroalgae). Wrack removal diminished the density of the sandhopper, Talitrus saltator, a dominant species in the supratidal zone especially under wrack, but the difference between impacted and control plots was shortlived (several days). Juvenile sandhoppers appeared more sensitive to this disturbance than adults, although this was found only at Levante. This study highlights the adaptability of this sandhopper to a single wrack removal event and shows that the magnitude of the effect is likely dependent on the particular characteristics of individual beaches. The consequences of frequent wrack removal from these beaches on sandhopper populations remain to be determined.