Habitat-related differences in recruitment and survival of early recruits of the invasive Sargassum muticum (Phaeophyta, Sargassaceae) in northern Portugal

• Published in: Hydrobiologia Vol. 683; no. 1; pp. 287 - 296
• Main Authors: Monteiro, Carla A., Engelen, Aschwin H., Santos, Rui
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.03.2012; Springer; Springer Nature B.V
• Subjects: Algae; Animal and plant ecology; Animal, plant and microbial ecology; Aquatic plants; Biological and medical sciences; Biomedical and Life Sciences; Demecology; Ecology; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Grazing; Habitats; Intertidal environment; Life Sciences; Nonnative species; Phaeophyta; Plants and fungi; Primary Research Paper; Sargassaceae; Sargassum muticum; Survival; Survival analysis; Zoology; Portugal; Europe; Lunar phase; Grazing; Intertidal; Survival; Recruitment; Sargassum muticum; Algae; Plant juvenile growth stage; Marine environment; Heterokontophyta; Invasive species; Intertidal zone; Population recruitment; Population dynamics; Habitat; Phaeophyceae
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-011-0966-z

Habitat-related differences in recruitment and early survival of the invasive seaweed Sargassum muticum were investigated in relation to the lunar phase (gamete release trigger) and meso-grazing between mid-intertidal and low-intertidal pools in northern Portugal. In situ experiments were performed to determine recruitment and to test the effect of intertidal level (mid-intertidal and low-intertidal pools), grazing (no cage, cage and open cage), and lunar phase (full, new and each quarter moon) on recruit survival during reproductive seasons in two consecutive years. Our results show clearly that recruitment and survival were higher in the mid-intertidal than in low-intertidal environment in both study periods. Caging treatments affected recruit survival in both environments, however, differences in patterns suggesting differences in grazing pressure due to differences in grazer density and/or the assemblages. It therefore seems that grazing on early recruits of this invader might contribute to the resistance to proliferation. Mid-intertidal pools constitute a more favourable environment for recruits of S. muticum than the low-intertidal, which may explain the mainly mid-intertidal distribution of the species in Portugal.