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The paper published in Limnology and Oceanography 67: 784-799 (2022) contains a calculation error. This error concerns the result and discussion sections “Stoichiometric variation in the benthic community”. The benthic community biomass and consequently the community C, N and P content were miscalculated. The corrected benthic community C, N and P content is approximately three times higher than the values presented in the original paper. However, the correction in biomass had no major effect on the community C: N: P ratios. Statistical analysis was performed (two-way PERMANOVA) again for the community stoichiometry, but the results did not change. Importantly, corrections of the community biomass did not affect the main results or the conclusion of the paper. The corrected version of Table 3, Fig. 7 and Supplementary Table 7 are presented below. These corrections change the following: 3 Corrected Table Seasonal variation in the magnitude of the benthic community carbon, nitrogen, and phosphorus pools (g m−2) and elemental ratios. Tot C, N, and P present the values with bivalve shells included, whereas tissue C, N, and P content were calculated without the shells. Molar C:N:P ratios of the community are not accounting for bivalve shells. (Table presented.) 7 Corrected Fig. (Figure presented.) Average community total carbon (C) content g m−2 ± SD over the sampling occasions, and the contribution of the main taxonomic groups to the total biomass. The nitrogen and phosphorus followed the same trend as carbon. 7 Corrected Supplementary Table Results of two-way PERMANOVA show the effect of season and site on community C, N and P content and C:N:P ratios. (Table presented.) Methods: Stoichiometric variation in the benthic community. p. 787: the text should read “The model was based on Euclidean distances, calculated on total C, N, and P content g m-2 and log10(x + 1) transformed C: N: P data (Anderson et al. 2008)”. Results: Stoichiometric variation in the benthic communi, This article corrects the following: Food sources drive temporal variation in elemental stoichiometry of benthic consumers by Saara Mäkelin, Anna Villnäs in Limnology and Oceanography 2022, Volume 67, Issue 4

Benthic consumers profoundly impact nutrient regeneration in coastal marine ecosystems. The concurrent nutrient imbalance and warming of our coastal seas will change the nutritional requirements and metabolic demands of these consumers, which may affect their ability to recycle nitrogen and phosphorous. Here we explore whether nutrient excretion rates of two benthic consumers, the Baltic clam (Macoma balthica) and the invasive spionid polychaete (Marenzelleria spp.) can be quantified with basic biological traits across seasons using allometric and stoichiometric relationships. We found species-specific N and P excretion rates that positively link to allometric traits, i.e., per individual rates increased with body mass and temperature; thus, high mass-specific excretion rates characterized small relative to large macrofaunal individuals. Interestingly, our body size scaling coefficients diverge from predictions by the metabolic theory of ecology (MTE) and the universal model of excretion. Furthermore, stoichiometric traits and stable isotope signatures (delta C-13 and delta N-15) explained a minor additional proportion of variability in excretion rates among species. The excretion rates also varied strongly seasonally, with the highest nutrient recycling rates during summer months, when community NH4-N and PO4-P excretion clearly exceeded net sediment efflux. The seasonal pattern emphasized that changes in temperature and food availability drove metabolic processes and thus excretion rates of the benthic consumers, and indicated that these effects could outweigh the importance of animal biomass. Our results highlight the benefits of using allometric and stoichiometric traits when quantifying species-specific contributions to nutrient recycling in coastal marine environments, and in predicting alteration of function in response to environmental change.

Benthic fauna plays an important role in mediating biogeochemical cycles in coastal areas by storing carbon (C), nitrogen (N), and phosphorus (P) in their body tissues at theoretically homeostatic rates. To maintain homeostasis, the benthic consumers need to be in balance with their resource supply or alter their stoichiometric traits in response to environmental change. However, we lack an understanding regarding the potential variation in the C : N : P content ratios of benthic consumers, especially in marine coastal areas where stoichiometric shifts in macrofauna could have strong effects on sediment carbon and nutrient cycling. By monitoring two sites over a year, we quantified the magnitude and temporal stability of benthic faunal carbon and nutrient pools in coastal soft-sediment habitats. Our results show that benthic fauna is not strictly homeostatic, but instead expresses temporal variation in C : N : P content. These aquatic consumers undergo ontogenetic changes in diet and morphology, which alter their stoichiometric characteristics. In addition, the faunal C : N : P ratios showed strong seasonal variation at both species and community level, and our results suggest that the stoichiometric traits of benthic consumers shift in response to food sources and environmental conditions. The ability to adapt to varying stoichiometric conditions is essential in face of the growing C : N : P imbalance occurring in marine and coastal ecosystems as a consequence of anthropogenic activities. Therefore, it is critically important to identify the stoichiometric plasticity of different species, before environmental change causes a shift in benthic community composition that will alter functions on an ecosystem level.