scholarly journals Effect of diet on breeders and inheritance in syngnathids: application of isotopic experimentally derived data to field studies

2020 ◽  
Vol 650 ◽  
pp. 107-123 ◽  
Author(s):  
M Planas ◽  
A Chamorro ◽  
A Paltrinieri ◽  
S Campos ◽  
A Jiménez ◽  
...  
Keyword(s):  
Fish Species ◽  
Field Studies ◽  
Enrichment Factors ◽  
Hippocampus Guttulatus ◽  
Relative Contribution ◽  
Source Contributions ◽  
Trophic Enrichment ◽  
Isotope Mixing Models ◽  
Derived Data ◽  
Isotopic Effects

Syngnathids are vulnerable ovoviviparous fishes in which males undergo repeated brooding within a reproductive season. The isotopic effects of diet on both breeders (pooled sexes) and parent-egg transmission have been demonstrated in a few fish species but never in syngnathids. Quantifying isotopic changes due to diet is necessary to assess parent-newborn conversions and to estimate accurate trophic enrichment factors (TEF). We assessed the isotopic (δ13C and δ15N) effects of 3 experimental diets on TEFs in seahorse Hippocampus guttulatus breeders and isotopic inheritance. Our results suggest that H. guttulatus follows an income-capital continuum pattern for parent-egg transmission. The isotopic variability in diets for breeders and the resulting experimentally derived TEFs were compared with fixed TEFs from reviews to estimate their impact on the relative contribution of potential prey sources in syngnathids from the Cíes archipelago (Atlantic Islands National Park, NW Spain). We estimated source contributions using stable isotope mixing models (SIMMs) by combining prey sources into ecologically informative groups and incorporating informative priors. We demonstrate that (1) most frequently used TEFs from reviews might not be suitable for all fish species, particularly syngnathids, and (2) dietary source variability has a great effect on source contribution estimates. This study is also the first to provide specific TEFs for syngnathids.

Provenance of detrital sediments in Santa Barbara Basin, California, USA: Changes in source contributions between the Last Glacial Maximum and Holocene

2019 ◽  
Vol 132 (1-2) ◽  
pp. 65-84 ◽  
Author(s):  
Tiffany J. Napier ◽  
Ingrid L. Hendy ◽  
M. Florencia Fahnestock ◽  
Julia G. Bryce
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Sediment Flux ◽  
Santa Barbara ◽  
Santa Barbara Basin ◽  
Last Glacial ◽  
Sediment Routing ◽  
Source Contributions ◽  
Terrestrial Sediments ◽  
Isotope Mixing Models

AbstractDetrital terrestrial sediments preserved in near-shore marine basins bear distinctive geochemical identifiers that can be used to identify the on-shore sediment sources and sediment routing through time. Santa Barbara Basin (SBB), offshore of southern California, USA, contains a well-known, continuous, high-resolution Holocene flood record that can provide insights into the frequency and changes in on-shore sources across time for such events. Here SBB-adjacent stream bed sediments are characterized using mineralogical, elemental, and radiogenic strontium and neodymium isotopic compositions. Modern and Holocene SBB flood deposits and Last Glacial Maximum (LGM) sediments were similarly analyzed. The Southern Slopes of the Santa Ynez Mountains and Topatopa Mountains account for ∼85% of SBB Holocene flood deposit sediments, as calculated from Sr-Nd isotope mixing models. During the LGM sea level low stand, the Southern Slopes contribution increased (to ≥90%), while relative sediment contribution from Santa Clara River diminished. This loss was likely compensated, however, by increased sediment flux from the Southern Slopes and the Channel Islands.

scholarly journals Trophic Enrichment Factors for Blood Serum in the European Badger (Meles meles)

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e53071 ◽  
Author(s):  
David J. Kelly ◽  
Andrew Robertson ◽  
Denise Murphy ◽  
Tara Fitzsimons ◽  
Eamon Costello ◽  
...  
Keyword(s):  
Blood Serum ◽  
Meles Meles ◽  
Enrichment Factors ◽  
European Badger ◽  
Trophic Enrichment

Use of soil organic biomarkers for tracing the origin of eroded sediment: case study in Petzenkirchen (Austria)

2020 ◽  
Author(s):  
Lionel Mabit ◽  
Modou Mbaye ◽  
Arsenio Toloza ◽  
Max Gibbs ◽  
Andrew Swales ◽  
...  
Keyword(s):  
Climatic Conditions ◽  
Organic Carbon Content ◽  
Relative Contribution ◽  
Stream Bank ◽  
Dominant Soil ◽  
Maize Cultivation ◽  
Austrian Study ◽  
Organic Biomarkers ◽  
Isotope Mixing Models

<p>Compound-specific stable isotopes (CSSI) technique based on the measurement of δ<sup>13</sup>C signatures of organic biomarker compounds such as fatty acids (FAs) has been used since the end of the 2000s to reinforce the knowledge about sediment production and budget in various ecosystems.<br>The watershed of Petzenkirchen, located 100 km west from Vienna (Austria), was selected to establish the origin of the sediment produced at its outlet using δ<sup>13</sup>C-FAs analysis. The climatic conditions of the area are temperate with continental influences with a mean temperature of 9.5˚ C and yearly precipitation of 823 mm. The dominant soil types are Cambisols and Planosols. Based on existing land-use records, most of the agricultural fields are dominated by a rotation of winter wheat followed by maize cultivation.<br>Considering the specific geomorphology, the flow of the runoff, the significant interaction of roads, the distance and connection of the potential sources to the outlet, the contributing area of the site has been set to around 50 ha and 7 sources most likely to contribute to the sediment at the outlet were investigated. Using the mixing polygons approach, the δ<sup>13</sup>C of saturated long chain FAs (i.e. C24:0 and C26:0) allowed the best discrimination for establishing the contribution of sources to the sediment collected at the exit of the watershed (i.e. the mixture). The relative contribution to the soil mixture of the different source soils identified has been determined using the Stable Isotope Mixing Models in R (SIMMR) and the specific organic carbon content of each source. The simulated results derived with SIMMR highlights that more than half of the sediment reaching the outlet of the watershed originates from stream bank. <br>This Austrian study confirms that the information gained with δ<sup>13</sup>C-FAs analysis could provide unique support for allowing effective agroecosystems management.</p>

Dietary Variation in a Freshwater Fish Species: Relative Contributions of Biotic Interactions, Abiotic Factors, and Spatial Structure

1994 ◽  
Vol 51 (12) ◽  
pp. 2856-2865 ◽  
Author(s):  
Pierre Magnan ◽  
Marco A. Rodríguez ◽  
Pierre Legendre ◽  
Sylvain Lacasse
Keyword(s):  
Spatial Structure ◽  
Freshwater Fish ◽  
Fish Species ◽  
Environmental Variables ◽  
Brook Trout ◽  
Diet Composition ◽  
Abiotic Factors ◽  
Biotic Interactions ◽  
Relative Contribution ◽  
Dietary Variation

We used multivariate analyses to examine which variables among the environmental and spatial components can best account for dietary variation in a freshwater fish, brook trout, Salvelinus fontinalis. The diet composition of brook trout was quantified in 37 lakes of the Laurentian Shield, Québec, Canada. Among the 25 measured environmental variables, fish species composition, sampling date, macrophyte abundance, and trout body length were the best predictors of diet composition. The total variation in diet composition was partitioned into four components: pure environmental 21.6%, pure spatial 23.2%, shared 19.9%, and unexplained 35.3%. A significant spatial trend in diet composition existed even after accounting for the main effects measured by the environmental variables. The two sets of spatial variables, when combined with the environmental descriptors, extracted different components of the dietary variation. The study allowed us to (1) highlight the role of spatial structure in diet variation of brook trout, (2) determine the relative contribution of both environmental and spatial components, and (3) generate testable hypotheses concerning mechanisms underlying the observed structure. Dependent variables other than diet composition, such as the density of different species at different sampling sites, can be used within the same statistical framework in studies of community ecology.

scholarly journals Evaluating the utility of camera traps in field studies of predation

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6487 ◽  
Author(s):  
Christopher K. Akcali ◽  
Hibraim Adán Pérez-Mendoza ◽  
David Salazar-Valenzuela ◽  
David W. Kikuchi ◽  
Juan M. Guayasamin ◽  
...  
Keyword(s):  
Observational Data ◽  
Video Recording ◽  
Field Studies ◽  
Camera Traps ◽  
Relative Fitness ◽  
Natural Habitats ◽  
Predator Species ◽  
Additional Information ◽  
Relative Contribution ◽  
Mammalian Predators

Artificial prey techniques—wherein synthetic replicas of real organisms are placed in natural habitats—are widely used to study predation in the field. We investigated the extent to which videography could provide additional information to such studies. As a part of studies on aposematism and mimicry of coral snakes (Micrurus) and their mimics, observational data from 109 artificial snake prey were collected from video-recording camera traps in three locations in the Americas (terra firme forest, Tiputini Biodiversity Station, Ecuador; premontane wet forest, Nahá Reserve, Mexico; longleaf pine forest, Southeastern Coastal Plain, North Carolina, USA). During 1,536 camera days, a total of 268 observations of 20 putative snake predator species were recorded in the vicinity of artificial prey. Predators were observed to detect artificial prey 52 times, but only 21 attacks were recorded. Mammals were the most commonly recorded group of predators near replicas (243) and were responsible for most detections (48) and attacks (20). There was no difference between avian or mammalian predators in their probability of detecting replicas nor in their probability of attacking replicas after detecting them. Bite and beak marks left on clay replicas registered a higher ratio of avian:mammalian attacks than videos registered. Approximately 61.5% of artificial prey monitored with cameras remained undetected by predators throughout the duration of the experiments. Observational data collected from videos could provide more robust inferences on the relative fitness of different prey phenotypes, predator behavior, and the relative contribution of different predator species to selection on prey. However, we estimate that the level of predator activity necessary for the benefit of additional information that videos provide to be worth their financial costs is achieved in fewer than 20% of published artificial prey studies. Although we suggest future predation studies employing artificial prey to consider using videography as a tool to inspire new, more focused inquiry, the investment in camera traps is unlikely to be worth the expense for most artificial prey studies until the cost:benefit ratio decreases.

Isotope mixing models require individual isotopic tracer content for correct quantification of sediment source contributions

2018 ◽  
Vol 32 (7) ◽  
pp. 981-989 ◽  
Author(s):  
Hari Ram Upadhayay ◽  
Samuel Bodé ◽  
Marco Griepentrog ◽  
Roshan Man Bajracharya ◽  
William Blake ◽  
...  
Keyword(s):  
Mixing Models ◽  
Sediment Source ◽  
Isotopic Tracer ◽  
Source Contributions ◽  
Isotope Mixing Models

The role of social media in compensating for the lack of field studies: five new fish species for the Mediterranean Egypt

2021 ◽  
Author(s):  
Sara A.A. Al Mabruk ◽  
Abdulghani Abdulghani ◽  
Ola Mohamed Nour ◽  
Mohammed Adel ◽  
Fabio Crocetta ◽  
...  
Keyword(s):  
Social Media ◽  
Fish Species ◽  
Field Studies ◽  
The Mediterranean ◽  
New Fish Species

scholarly journals Best practices for use of stable isotope mixing models in food-web studies

2014 ◽  
Vol 92 (10) ◽  
pp. 823-835 ◽  
Author(s):  
Donald L. Phillips ◽  
Richard Inger ◽  
Stuart Bearhop ◽  
Andrew L. Jackson ◽  
Jonathan W. Moore ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Concentration Dependence ◽  
Probability Distributions ◽  
Mixing Models ◽  
Web Studies ◽  
Source Contributions ◽  
Spatio Temporal ◽  
Discrimination Factors ◽  
Isotope Mixing Models ◽  
User Friendly

Stable isotope mixing models are increasingly used to quantify consumer diets, but may be misused and misinterpreted. We address major challenges to their effective application. Mixing models have increased rapidly in sophistication. Current models estimate probability distributions of source contributions, have user-friendly interfaces, and incorporate complexities such as variability in isotope signatures, discrimination factors, hierarchical variance structure, covariates, and concentration dependence. For proper implementation of mixing models, we offer the following suggestions. First, mixing models can only be as good as the study and data. Studies should have clear questions, be informed by knowledge of the system, and have strong sampling designs to effectively characterize isotope variability of consumers and resources on proper spatio-temporal scales. Second, studies should use models appropriate for the question and recognize their assumptions and limitations. Decisions about source grouping or incorporation of concentration dependence can influence results. Third, studies should be careful about interpretation of model outputs. Mixing models generally estimate proportions of assimilated resources with substantial uncertainty distributions. Last, common sense, such as graphing data before analyzing, is essential to maximize usefulness of these tools. We hope these suggestions for effective implementation of stable isotope mixing models will aid continued development and application of this field.

Nitrogen isotope fractionation as a tool for determining denitrification in constructed wetlands

2007 ◽  
Vol 56 (3) ◽  
pp. 167-173 ◽  
Author(s):  
A.K. Søvik ◽  
P.T. Mørkved
Keyword(s):  
Constructed Wetlands ◽  
Municipal Wastewater ◽  
Ph Value ◽  
Nitrogen Isotope ◽  
Enrichment Factors ◽  
Natural Abundance ◽  
Relative Contribution ◽  
Nitrogen Isotope Fractionation ◽  
15N Enrichment ◽  
Groundwater Systems

Constructed wetlands (CWs) treat municipal wastewater through the retention of nutrients and particles. The retention of nitrogen (N) was studied in the laboratory using columns and meso-scale trenches filled with shellsand and light-weight aggregates (LWA). The objective was to examine whether measuring the natural abundance of δ15N in NO−3 could be used to estimate the relative contribution of denitrification to the total NO−3 removal in these treatment systems. In both the columns and the trenches it was seen that denitrification was more efficient in shellsand and LWA collected from on-site treatment systems compared to new LWA. This was due to the high pH value (about 10) of new LWA. The enrichment factors (ε) from the column study were in general lower than values found in laboratory tests of isotope discrimination in denitrification, but similar to ε values found for denitrification in groundwater systems. No enrichment factors could be found for the trench study due to simultaneous denitrification and nitrification and inhomogeneous N transformation patterns. When NH+4 was partially nitrified in the upper parts of the trench, this diluted the 15N enrichment of NO−3 due to denitrification. Thus, in systems with high NH+4 concentrations and partial aerobic conditions, the method of natural abundance is not suitable for estimating the relative contribution of denitrification to the total NO−3 removal.

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