title: Sewage input reduces the consumption of Rhizophora mangle propagules by crabs in a subtropical mangrove system.
abstract: Mangrove forests are highly productive and play a major role in global carbon cycling. Their carbon accumulation can be influenced through the consumption of nutrient-poor leaves and propagules by herbivore crabs. Anthropogenic nutrient input from sewage contamination is widespread in these often naturally nutrient-limited ecosystems. We hypothesised that sewage-mediated nutrient input to mangrove stands of Paranaguá Bay (southern Brazil), would alter the nutrient sources available for crabs, e.g. through microphytobenthos increase, and that this would reflect in their feeding behaviour. We predicted that propagules of Rhizophora mangle in contaminated stands would experience lower grazing pressure from their two main local consumers (Ucides cordatus and Goniopsis cruentata). We compared herbivory rates on R. mangle propagules in sewage contaminated and uncontaminated mangrove stands. We found that herbivory rates were significantly lower in contaminated than uncontaminated forests, but this pattern could not be clearly attributed to increased nutrient availability.
authors.affiliation: Laboratory of Benthic Ecology, Centre for Marine Studies (CEM), Universidade Federal do Paraná, Av. Beira Mar s/n 83255-976, PO Box 61, Pontal do Paraná, Paraná, Brazil; Ghent University, Biology Department, Marine Biol Lab, Krijgslaan 281-S8, B-9000 Ghent, Belgium. Electronic address: marinebio@frederikeboehm.de.
authors.forename: Frederike Ricarda
authors.initials: FR
authors.lastname: Boehm
authors.affiliation: Laboratory of Benthic Ecology, Centre for Marine Studies (CEM), Universidade Federal do Paraná, Av. Beira Mar s/n 83255-976, PO Box 61, Pontal do Paraná, Paraná, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Sandrini-Neto
authors.affiliation: Ghent University, Biology Department, Marine Biol Lab, Krijgslaan 281-S8, B-9000 Ghent, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Moens
authors.affiliation: Laboratory of Benthic Ecology, Centre for Marine Studies (CEM), Universidade Federal do Paraná, Av. Beira Mar s/n 83255-976, PO Box 61, Pontal do Paraná, Paraná, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: da Cunha Lana
mesh_terms: D000818:Animals; D003386:Brachyura / Q000502:physiology*; D001938:Brazil; D004784:Environmental Monitoring; D043982:Rhizophoraceae / Q000502:physiology*; D012722:Sewage; D053833:Wetlands
chemical_list: D012722:Sewage
keywords: Benthic ecology; Brazil; Herbivory; Mangrove crabs; Mangrove propagules; Nutrients; Rhizophora mangle; Sewage; Ucides cordatus