scholarly journals Aquatic Macrophytes are Seasonally Important Dietary Resources for Moose

Diversity ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 209
Author(s):  
Tischler ◽  
Severud ◽  
Peterson ◽  
Bump
Keyword(s):  
Stable Isotope ◽  
Aquatic Macrophytes ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Food Sources ◽  
Mixing Models ◽  
Terrestrial Plants ◽  
Growth Variability ◽  
Isle Royale National Park ◽  
Aquatic Food

Moose (Alces alces) are generalist herbivores, but are important aquatic-terrestrial ecotone specialists. Aquatic macrophytes are a high-quality food source for moose during summer, but the importance of aquatic food sources to the moose diet is difficult to study. We used stable isotope analysis of carbon and nitrogen from moose hooves and forage (terrestrial plants, aquatic macrophytes, and arboreal lichen) to assess the diet of moose at Isle Royale National Park, Michigan, USA, using Bayesian mixing models. We also evaluated the isotopic variability along chronologies of serially sampled hooves. Overall, our mixing models indicate that 13%–27% of the summer moose diet was aquatic in origin. Among moose that died during winter, body condition was impaired and hoof 15N was higher where aquatic habitats were sparse. Although isotope chronologies preserved in hooves could significantly enhance our understanding of ungulate foraging ecology, interpretation of such chronologies is presently limited by our lack of knowledge pertaining to hoof growth rate and seasonal growth variability related to age and health. Distinct isotopic values among terrestrial plants, aquatic macrophytes, and arboreal lichens indicate that continued methodological advances in stable isotope ecology will lead to more precise estimates of the contribution of aquatic feeding to moose population dynamics and other ungulates.

scholarly journals Aquatic Macrophytes are Seasonally Important Dietary Resources for Moose

2019 ◽  
Author(s):  
Keren B. Tischler ◽  
William J. Severud ◽  
Rolf O. Peterson ◽  
Joseph K. Bump
Keyword(s):  
Stable Isotope ◽  
Body Condition ◽  
Aquatic Macrophytes ◽  
Aquatic Macrophyte ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Aquatic Habitats ◽  
Terrestrial Plants ◽  
Marrow Fat ◽  
Isle Royale National Park

Moose (Alces alces) are generalist herbivores but are important aquatic-terrestrial ecotone specialists. Aquatic macrophytes are a high-quality food source for moose during the summer, however their relative importance to moose diet is difficult to study. We used stable isotope analysis of carbon and nitrogen from moose hooves and forage (terrestrial plants, aquatic macrophytes, and arboreal lichen) to estimate the diet of moose at Isle Royale National Park, Michigan, USA, and to evaluate the isotopic variability along chronologies of serially sampled hooves. We hypothesized that aquatic macrophyte consumption and winter body condition (as measured by bone marrow fat content) would be greater at the eastern end of the island where aquatic habitats were most abundant. We were unable to evaluate spatial differences in aquatic macrophyte consumption, but overall, our mixing model results suggest that between 13% and 27% of summer moose diet was from aquatic sources. Among moose that died during winter, body condition was impaired and hoof δ15N (measured at the hairline) was higher at the western end of the island, where aquatic habitats are sparse. Although isotope chronologies preserved in hooves could significantly enhance our understanding of ungulate foraging ecology, interpretation of such chronologies is presently limited by our lack of knowledge pertaining to hoof growth rate and seasonal dynamics in relation to age and health. Significant isotope distinction among terrestrial plants, aquatic macrophytes, and arboreal lichens indicate that continued methodological advances in stable isotope ecology will lead to more precise estimates of the contribution of aquatic feeding to moose population dynamics.

Gut content and stable isotope analysis of tadpoles in floodplain wetlands

2018 ◽  
Vol 66 (4) ◽  
pp. 261 ◽  
Author(s):  
J. F. Ocock ◽  
K. J. Brandis ◽  
B. J. Wolfenden ◽  
K. M. Jenkins ◽  
S. Wassens
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Management Strategies ◽  
Isotope Analysis ◽  
Food Sources ◽  
Gut Contents ◽  
Floodplain Wetlands ◽  
Gut Content ◽  
Larval Amphibians ◽  
Aquatic Food

Larval amphibians (tadpoles) are an important link in aquatic food webs, as they can be highly abundant consumers and prey for a wide variety of predators. Most tadpoles are considered omnivores, predominately grazing on algae, detritus and macrophytes, though recent work has identified greater plasticity and breadth in diet than previously considered. We used gut content and stable isotope analysis (SIA) in a baseline study to determine the important dietary items (ingested material) and food sources (assimilated material) for tadpoles of two abundant generalist frog species in regulated floodplain wetlands of the Murrumbidgee River, south-east Australia. We identified a wide variety of dietary items in the gut contents, including whole microcrustaceans, filamentous algae and macrophytes. The composition of several ingested food items was correlated with their availability in each wetland. However, SIA identified biofilm as the food source most consistently assimilated across several wetlands, though microcrustaceans and algae contributed when abundant. Biofilm is likely the most important basal food item for tadpoles in floodplain wetlands because it is ubiquitous and has a high nutritional quality. Identifying important food sources is a crucial step towards developing management strategies for promoting tadpole recruitment in regulated wetlands.

scholarly journals Sample preservation and pre-treatment in stable isotope analysis: Implications for the study of aquatic food webs

2020 ◽  
Author(s):  
Marc Jürgen Silberberger ◽  
Katarzyna Koziorowska-Makuch ◽  
Karol Kuliński ◽  
Monika Kędra
Keyword(s):  
Stable Isotope ◽  
Food Webs ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Mixing Models ◽  
Sample Preservation ◽  
Aquatic Food Webs ◽  
Bayesian Mixing Models ◽  
Aquatic Food ◽  
Pre Treatment

Abstract. Stable isotope analysis has become one of the most widely used techniques in ecology. However, uncertainties about the effects of sample preservation and pre-treatment on the ecological interpretation of stable isotope data and especially on Bayesian stable isotope mixing models remain. Here, Bayesian mixing models were used to study how three different preservation methods (drying, freezing, formalin) and two pre-treatments (acidification, lipid removal) affect the estimation of diet composition for two benthic invertebrate species (Limecola balthica, Crangon crangon). Furthermore, commonly used mathematical lipid normalization and formalin correction were applied to check if they improve the model results. Preservation effects were strong on model outcomes for frozen as well as formalin preserved L. balthica samples, but not for C. crangon. Pre-treatment effects varied with species and preservation method and neither lipid normalization nor mathematical formalin correction consistently resulted in improved model outcomes. Our analysis highlights that particularly small changes in δ15N introduced by different preservation and pre-treatments display a so far unrecognized source of error in stable isotope studies. We conclude that mathematical correction of stable isotopes data should be avoided for Bayesian mixing models and that previously unaddressed effects of sample preservation (especially those arising from preservation by freezing) have potentially biased our understanding of the utilization of organic matter in aquatic food webs.

Food sources for the bivalve Corbicula japonica in the foremost fishing lakes estimated from stable isotope analysis

2006 ◽  
Vol 72 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Akihide KASAI ◽  
Haruhiko TOYOHARA ◽  
Akiko NAKATA ◽  
Tsunehiro MIURA ◽  
Nobuyuki AZUMA
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Food Sources ◽  
Corbicula Japonica

scholarly journals Subcolony Variation in Breeding Success in the Tufted Puffin (Fratercula Cirrhata): Association With Foraging Ecology and Implications

The Auk ◽  
2007 ◽  
Vol 124 (4) ◽  
pp. 1149-1157
Author(s):  
J. Mark Hipfner ◽  
Mathieu R. Charette ◽  
Gwylim S. Blackburn
Keyword(s):  
Stable Isotope ◽  
Breeding Success ◽  
Large Scale ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Egg Yolk ◽  
Foraging Strategies ◽  
Small Scale ◽  
Carbon And Nitrogen ◽  
Tufted Puffin

Abstract Large-scale oceanographic processes are the main drivers of seabird breeding success, but small-scale processes, though not as well understood, can also be important. We compared the success of Tufted Puffins (Fratercula cirrhata) breeding at two subcolonies only 1.5 km apart on Triangle Island, British Columbia, Canada, 2002–2005. In addition, we used stable-isotope analysis to test the hypothesis that parental foraging strategies differed between the two subcolonies, potentially underlying the variation in breeding success. Success was concordant across years at the two sites but, overall, Tufted Puffins bred more successfully at Strata Rock than at Puffin Rock. They raised chicks in all four years at Strata Rock, but in only three years at Puffin Rock; in two of those three years, Strata Rock chicks were, on average, 60 g and 100 g heavier than Puffin Rock chicks just before fledging. Discriminant analysis of carbon and nitrogen stable-isotope ratios in egg yolk and chick blood in 2004 and 2005 indicated that parental foraging differed between the two subcolonies, with both spatial (δ13C) and trophic-level (δ15N) differences involved. Thus, our study demonstrates the existence of foraging asymmetries in a pelagic seabird at a small spatial scale (between subcolonies), complementing patterns found at larger scales (between colonies). Moreover, the foraging asymmetries were associated with inequalities in fitness measures. We conclude that small-scale processes—in this case, systematic differences in the foraging ecology of local groups—can interact with large-scale oceanographic processes to determine seabird breeding success. Variation sous-coloniale du succès de reproduction de Fratercula cirrhata: Association avec l'écologie de la quête alimentaire et implications

Food sources of the pearl oyster in coastal ecosystems of Japan: Evidence from diet and stable isotope analysis

2008 ◽  
Vol 76 (3) ◽  
pp. 704-709 ◽  
Author(s):  
Kayoko Fukumori ◽  
Misa Oi ◽  
Hideyuki Doi ◽  
Noboru Okuda ◽  
Hitomi Yamaguchi ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Pearl Oyster ◽  
Coastal Ecosystems ◽  
Food Sources

Stable isotope analysis reveals partitioning in prey use by Kajikia audax (Istiophoridae), Thunnus albacares, Katsuwonus pelamis, and Auxis spp. (Scombridae) in the Eastern Tropical Pacific of Ecuador

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Rigoberto Rosas-Luis ◽  
Nancy Cabanillas-Terán ◽  
Carmen A. Villegas-Sánchez
Keyword(s):  
Stable Isotope ◽  
Food Web ◽  
Stable Isotope Analysis ◽  
Trophic Ecology ◽  
Isotope Analysis ◽  
Middle Level ◽  
Food Sources ◽  
Thunnus Albacares ◽  
Katsuwonus Pelamis ◽  
Δ13c And Δ15n

Abstract Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.

Stable Isotope Analysis Enhances Our Understanding of Diamondback Terrapin (Malaclemys terrapin) Foraging Ecology

2018 ◽  
Vol 42 (2) ◽  
pp. 596-611 ◽  
Author(s):  
Mathew J. Denton ◽  
Amanda W. J. Demopoulos ◽  
John D. Baldwin ◽  
Brian J. Smith ◽  
Kristen M. Hart
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Foraging Ecology ◽  
Isotope Analysis ◽  
Diamondback Terrapin ◽  
Malaclemys Terrapin

scholarly journals Trophodynamics at the Longqi hydrothermal vent field and comparison with the East Scotia and Central Indian Ridges

2020 ◽  
Vol 167 (10) ◽  
Author(s):  
W. D. K. Reid ◽  
B. D. Wigham ◽  
L. Marsh ◽  
J. N. J. Weston ◽  
Y. Zhu ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
Trophic Ecology ◽  
Tricarboxylic Acid Cycle ◽  
Isotope Analysis ◽  
Southwest Indian Ridge ◽  
Food Sources ◽  
Model Based Clustering ◽  
Indian Ridge

Abstract The Longqi vent field, situated on the Southwest Indian Ridge, is ecologically distinct among known hydrothermal vents fields. It hosts a combination of previously unknown species and those shared at species or genus level with other hydrothermal vents on the Central Indian Ridge (CIR) and East Scotia Ridge (ESR). We investigate the size-based and trophodynamics of consumers at Longqi vent field and compared these with ESR and CIR vent fields using stable isotope analysis. Intra-specific variability in δ13C and δ15N values in relationship to shell length was observed in Gigantopelta aegis but absent in Chrysomallon squamiferum. A model-based clustering approach identified four trophic groupings at Longqi: species with the lowest δ13C values being supported by carbon fixed via the Calvin–Benson–Bassham cycle, the highest δ13C values being supported by the reductive tricarboxylic acid cycle and intermediate values potentially supported by a mix of these primary production sources. These clusters were driven by potential differences in resource partitioning. There were also differences in the spread of stable isotope values at the vent field level when comparing Bayesian stable isotope ellipse areas among Longqi, CIR and ESR vent fields. This was driven by a combination of the range in δ13C value of macrofauna, and the negative δ15N values which were only observed at Longqi and CIR vent fields. Many of the shared species or genera showed inter-vent field differences in stable isotope values which may be related to site-specific differences in food sources, geochemistry or potential intra-field competition. This study provides important information on the trophic ecology of hydrothermal vent macrofauna found within an area of seabed that is licensed for seabed mining exploration.

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