Trophic structure of shallow-water benthic communities in the sub-Antarctic Strait of Magellan

Andrade, Cláudia; Ríos, Carlos; Gerdes, Dieter; Brey, Thomas

doi:10.1007/s00300-016-1895-0

Cited by 37 publications

(21 citation statements)

References 72 publications

(61 reference statements)

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“…In Antarctica, C and N stable isotope analyses (SIA) have been used to characterise marine taxa [ 18 – 20 ]. Isotopic signatures in a consumer’s tissues reflect those in its food sources [ 21 – 23 ], and have been shown to differ between guilds of primary producers, i.e.…”

Section: Introductionmentioning

confidence: 99%

Time- and depth-wise trophic niche shifts in Antarctic benthos

et al. 2018

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Climate change is expected to affect resource-consumer interactions underlying stability in polar food webs. Polar benthic organisms have adapted to the marked seasonality characterising their habitats by concentrating foraging and reproductive activity in summer months, when inputs from sympagic and pelagic producers increase. While this enables the persistence of biodiverse food webs, the mechanisms underlying changes in resource use and nutrient transfer are poorly understood. Thus, our understanding of how temporal and spatial variations in the supply of resources may affect food web structure and functioning is limited. By means of C and N isotopic analyses of two key Antarctic benthic consumers (Adamussium colbecki, Bivalvia, and Sterechinus neumayeri, Echinoidea) and Bayesian mixing models, we describe changes in trophic niche and nutrient transfer across trophic levels associated with the long- and short-term diet and body size of specimens sampled in midsummer in both shallow and deep waters. Samplings occurred soon after the sea-ice broke up at Tethys Bay, an area characterised by extreme seasonality in sea-ice coverage and productivity in the Ross Sea. In the long term, the trophic niche was broader and variation between specimens was greater, with intermediate-size specimens generally consuming a higher number of resources than small and large specimens. The coupling of energy channels in the food web was consequently more direct than in the short term. Sediment and benthic algae were more frequently consumed in the long term, before the sea-ice broke up, while consumers specialised on sympagic algae and plankton in the short term. Regardless of the time scale, sympagic algae were more frequently consumed in shallow waters, while plankton was more frequently consumed in deep waters. Our results suggest a strong temporal relationship between resource availability and the trophic niche of benthic consumers in Antarctica. Potential climate-driven changes in the timing and quality of nutrient inputs may have profound implications for the structure of polar food webs and the persistence of their constituent species, which have adapted their trophic niches to a highly predictable schedule of resource inputs.

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Section: Introductionmentioning

confidence: 99%

Time- and depth-wise trophic niche shifts in Antarctic benthos

et al. 2018

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“…Therefore, this could suggest that the consumption of invertebrates by N. magellanica is not necessarily accidental. Recently in the Strait of Magellan, stable isotope analyses indicated that species of green and brown algae are preferentially consumed by macroherbivores, because they have higher nutritional value than red algae ( Andrade et al 2016 ). However, the consumption of some macroalgae species by generalist grazers such as Nacella species would more likely be linked to the algal availability in the habitat than to their nutritional profiles ( Chapman and Underwood 1992 ).…”

Section: Discussionmentioning

confidence: 99%

“…However, related information about the trophic ecology of Nacella species is still under study. The diet of Nacella intertidal species ( Andrade and Brey 2014 , Andrade et al 2016 ) was evaluated upon gut content and stable isotopes but only at a very local level (one time and locality) and evaluating macroscopic food content, however the complete characterization of the diet (microalgae, macroalgae and invertebrates) and the temporal and spatial variations have not yet been addressed. Therefore, the dynamics of the trophic ecology of Nacella species remains poorly understood and is essential to comprehend the functioning of the rocky shores ecosystem of the Magellanic channels and fjords.…”

Section: Introductionmentioning

confidence: 99%

Trophic ecology of two co-existing Sub-Antarctic limpets of the genus Nacella: spatio-temporal variation in food availability and diet composition of Nacella magellanica and N. deaurata

Rosenfeld¹,

Marambio²,

Ojeda³

et al. 2018

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Interactions between algae and herbivores can be affected by various factors, such as seasonality and habitat structure. Among herbivores inhabiting marine systems, species of the order Patellogastropoda are considered key organisms in many rocky coasts of the world. Nacella species are one of the most dominant macro-herbivores on the rocky shores of the sub-Antarctic ecoregion of Magellan. However, the importance of its key role must be associated with its trophic ecology. The objective of this work was to evaluate spatial and temporal variabilities in the dietary composition of two intertidal Nacella species, considering grazing on macro- (macroalgae) and microscopic (periphyton) food. The composition of periphyton and the availability of macroalgae in the winter and summer seasons were examined at two localities of the Magellanic province, alongside the gut contents of N. magellanica and N. deaurata. The dietary composition differed between the two Nacella species, as well as between seasons and locations. The differences observed in the diet of the two species of Nacella may be mainly due to their respective distributions in the intertidal zone. Both species presented a generalist strategy of grazing, which is relationed to the seasonality of micro- and macroalgae availability and to the variability of the assemblages between the localities. This research was the first to perform a detailed study of the diet of intertidal Nacella species.

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“…Entire individuals of the small-sized species Jassa herdmani, Pisidia longicornis, Metridium senile, and Diadumene cincta were processed for SIA after gut content clearance. For the other organisms, specific muscle tissues were sampled: cheliped muscle from Necora puber (Reid et al, 2016), foot from Mytilus edulis (Richoux and Ndhlovu, 2015) and peristomial membrane from Ophiothrix fragilis (Andrade et al, 2016). For each species, individuals of similar size were selected to exclude effects of any size-specific shifts in diet (Cresson et al, 2016).…”

Section: Sample Preparationmentioning

confidence: 99%

Resource Niches of Co-occurring Invertebrate Species at an Offshore Wind Turbine Indicate a Substantial Degree of Trophic Plasticity

et al. 2020

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Offshore wind farms (OWFs) in the North Sea are proliferating, causing alterations in local ecosystems by adding artificial hard substrates into naturally soft-bottom areas. These substrates are densely colonized by fouling organisms, which may compete for the available resources. While the distribution of some species is restricted to specific parts of the turbine, others occur across depth zones and may therefore face different competitive environments. Here we investigate the trophic niches of seven invertebrate species: three sessile (Diadumene cincta, Metridium senile, and Mytilus edulis), one hemi-sessile (Jassa herdmani) and three mobile species (Ophiothrix fragilis, Necora puber, and Pisidia longicornis) that occur in multiple depth zones. We hypothesized that these species would be trophic generalists, exhibiting trophic plasticity by selecting different resources in different depth zones, to cope with the different competitive environments in which they occur. We analyzed δ 13 C and δ 15 N of these species and their potential resources across depth zones. Our results show that most of these invertebrates are indeed trophic generalists which display substantial trophic plasticity, selecting different resources in different zones. Degree of trophic plasticity was not related to mobility of the species. There are two possible explanations for these dietary changes with depth: either consumers switch diet to avoid competition with other (dominant) species, or they benefit from the consumption of a non-limiting resource. Only Diadumene cincta was a trophic specialist that consumed suspended particulate organic matter (SPOM) independent of its zone of occurrence. Altogether, trophic plasticity appears an important mechanism for the coexistence of invertebrate species along the depth gradient of an offshore wind turbine.

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Trophic structure of shallow-water benthic communities in the sub-Antarctic Strait of Magellan

Cited by 37 publications

References 72 publications

Time- and depth-wise trophic niche shifts in Antarctic benthos

Time- and depth-wise trophic niche shifts in Antarctic benthos

Trophic ecology of two co-existing Sub-Antarctic limpets of the genus Nacella: spatio-temporal variation in food availability and diet composition of Nacella magellanica and N. deaurata

Resource Niches of Co-occurring Invertebrate Species at an Offshore Wind Turbine Indicate a Substantial Degree of Trophic Plasticity

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