The interactive effect of herbivory, nutrient enrichment and mucilage on shallow rocky macroalgal communities

PeerJ

article

Sarah Caronni¹  Chiara Calabretti¹  Sandra Citterio¹  Maria Anna Delaria²  Rodolfo Gentili¹  Giovanni Macri³  Chiara Montagnani¹  Augusto Navone⁴  Pieraugusto Panzalis⁴  Giulia Piazza¹  Giulia Ceccherelli² 

[1] Department of Earth and Environmental Sciences, University of Milan—Bicocca;Department of Science for Nature and Environmental Resources, University of Sassari;Mac Pro e Gis;Marine Protected Area of Tavolara Punta Coda Cavallo

关键词: Multiple stressors;    Mediterranean Sea;    Macroalgae;    Interactive effects;    Mucilage;   

DOI  :  10.7717/peerj.6908

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

This paper focuses on the interactive short and long-term effect of three different stressors on a macroalgal assemblage. Three stressors are considered: herbivory, nutrients and mucilage. The experiment was conducted in Tavolara Punta Coda Cavallo Marine Protected Area (Mediterranean Sea) during a bloom of the benthic mucilage-producing microalga Chrysophaeum taylorii (Pelagophyceae); this microalga is recently spreading in the Mediterranean Sea. On a rocky substratum, 36 plots 20 × 20 cm in size were prepared. Factorial combinations of three experimental treatments were applied in triplicate, including three grazing levels crossed with two nutrient enrichment and two mucilage removal treatments. Significant differences were observed among treatments 8 weeks later, at the end of summer. In particular, dark filamentous algae were more abundant in all enriched plots, especially where mucilage and macroalgae had been removed; a higher percent cover of crustose coralline algae was instead observed where nutrients had been increased and no grazing pressure acted. Furthermore, the abundance of Dictyota spp. and Laurencia spp. was significantly higher in enriched mucilage-free plots where the grazing pressure was null or low. However, the effects of the treatments on the overall assemblage of the macroalgal community were not long persistent (36 weeks later). These results illustrate the capacity of a shallow-water macroalgal community to quickly recover from the simultaneous impacts of herbivory, nutrient enrichment, and mucilage.

【 授权许可】

CC BY