Normalized biomass size spectra in high Antarctic macrobenthic communities: linking trophic position and body size

Marine Ecology Progress Series

Eduardo Quiroga¹  Rainer Knust¹  Ute Jacob¹  Am#xe9rico Montiel¹  Dieter Gerdes¹ 

关键词: Macrofauna;    Trophic spectrum;    Trophic level;    Stable isotopes;   

DOI  :  10.3354/meps10807

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Normalized biomass size spectra (NBSS) and the stable nitrogen isotopic composition of food webs were analyzed to determine the inter-specific relationships between trophic level (measured as δ¹⁵N) and body size in macrobenthic communities living on the continental shelf of the southeastern Weddell Sea (SEWS). We found that the relationship between trophic level and body size for the whole macrobenthic community was not significant (r² = 0.08, p > 0.05), probably associated with biomass accumulated in the larger body size fractions, which are represented particularly by suspension feeders such as sponges and tunicates. We used an alternative method of studying trophic structure of the aquatic communities based on the distribution of residuals of the NBSS. Here we demonstrate how residual distribution exhibited dome-like patterns, which may offer an additional quantitative tool for studying the relationship between trophic level and body size. These domes of biomass represent trophic positions derived from relationships between the body size distribution of the predators in one trophic position and their prey in another. We found 4 well defined domes of biomass, which appear when large benthic species are abundant, especially favored in an environment with high organic matter flux. A significant positive relationship (r² = 0.59, p < 0.05) between the trophic level and residuals derived from NBSS suggests that these domes might be considered as functional groups comprising organisms from different trophic levels. We suggest that dome-like patterns in the biomass size spectra can provide a robust framework for conceptualizing and statistically modeling trophic levels of macrobenthic communities.

【 授权许可】

Unknown