title: Is the distribution of the lancelet Branchiostoma caribaeum affected by sewage discharges? An analysis at multiple scales of variability.
abstract: Spatial variation in the density and biomass of Branchiostoma caribaeum was analyzed along a sewage contamination gradient identified by fecal steroids in a subtropical estuary, southern Brazil. Sampling, repeated in the austral winter and summer, followed a hierarchical design nested at four spatial scales (sector>1 km; area>100 m; site>10 m; replicate<1 m). Density and biomass were significantly lower at sites characterized by high concentrations of fecal steroids. The best combinations of variables that explained the biological similarities among sites involved contamination indicators. Most of the variation of biological data was found at the smallest scales and could be related with the sediment texture. Our study highlighted the usefulness of a multi-scale perspective to evaluate distribution patterns of benthic invertebrates as a biological indication of environmental pollution. Gradient analyses at larger spatial scales may be invalidated by the patchy distribution of benthic fauna if they do not account for such small scale variability.
authors: Universidade Federal do Paraná, Centro de Estudos do Mar, Av. Beira-mar, s/n, P.O. Box 50.002, CEP 83255-976, Pontal do Sul, Pontal do Paraná, Paraná, Brazil. carlosambarboza@gmail.com
authors: Carlos Alberto de Moura
authors: CA
authors: Barboza
authors: Heliatrice Louise
authors: HL
authors: Hadlich
authors: Leonardo
authors: L
authors: Sandrini-Neto
authors: César de Castro
authors: Cde C
authors: Martins
authors: Paulo da Cunha
authors: Pda C
authors: Lana
mesh_terms: D000818:Animals; D018533:Biomass; D001938:Brazil; D002816:Chordata, Nonvertebrate / Q000145:classification / Q000254:growth & development*; D004784:Environmental Monitoring; D012621:Seasons; D012722:Sewage / Q000032:analysis* / Q000706:statistics & numerical data; D014873:Water Pollutants / Q000032:analysis*; D014876:Water Pollution / Q000706:statistics & numerical data
chemical_list: D012722:Sewage; D014873:Water Pollutants