Stable isotope and fatty acid biomarkers of seagrass, epiphytic, and algal organic matter to consumers in a pristine seagrass ecosystem

2012 ◽  
Vol 63 (11) ◽  
pp. 1085 ◽  
Author(s):  
Laura L. Belicka ◽  
Derek Burkholder ◽  
James W. Fourqurean ◽  
Michael R. Heithaus ◽  
Stephen A. Macko ◽  
...  

The relative importance of the identity and abundance of primary producers in structuring trophic ecology, particularly in seagrass-dominated ecosystems, remains unclear. We assessed the contributions of seagrass, epiphytes, macroalgae, and other primary producers to the diets of resident animals in the nearly pristine seagrass-dominated environment of Shark Bay, Australia, by combining fatty acid composition with carbon, nitrogen, and sulfur stable isotopes of primary producers and consumers. Overall, mixed inputs of these primary producers fuel secondary production, with tropical detrital seagrass inputs supporting most fish species, likely through benthic intermediates. Epiphytic organic matter inputs were most closely associated with snails, whereas seagrass detritus, macroalgae, gelatinous zooplankton, and/or phytoplankton may all contribute to higher trophic levels including sea turtles and sharks. The fatty acid and isotope data suggest that diets of large-bodied consumers were highly variable – future food web studies need to incorporate large sample sizes to account for this variability.

2020 ◽  
Vol 77 (7) ◽  
pp. 1209-1220
Author(s):  
L. Chavarie ◽  
J. Hoffmann ◽  
A.M. Muir ◽  
C.C. Krueger ◽  
C.R. Bronte ◽  
...  

Fatty acids are well-established biomarkers used to characterize trophic ecology, food-web linkages, and the ecological niche of many different taxa. Most often, fatty acids that are examined include only those previously identified as “dietary” or “extended dietary” biomarkers. Fatty acids considered as nondietary biomarkers, however, represent numerous fatty acids that can be extracted. Some studies may include nondietary fatty acids (i.e., combined with dietary fatty acids), but do not specifically assess them, whereas in other studies, these data are discarded. In this study, we explored whether nondietary biomarker fatty acids can provide worthwhile information by assessing their ability to discriminate intraspecific diversity within and between lakes. Nondietary fatty acids used as biomarkers delineated variation among regions, among locations within a lake, and among ecotypes within a species. Physiological differences that arise from differences in energy processing can be adaptive and linked to habitat use by a species’ ecotype and likely explains why nondietary fatty acid biomarkers can be a relevant tool to delineate intraspecific diversity. Little is known about the nondietary-mediated differences in fatty acid composition, but our results showed that nondietary fatty acid biomarkers can be useful tool in identifying variation.


2013 ◽  
Vol 64 (12) ◽  
pp. 1169 ◽  
Author(s):  
Hyun Je Park ◽  
Eun Jung Choy ◽  
Kun-Seop Lee ◽  
Chang-Keun Kang

Stable isotope and fatty acid analyses were used to examine trophic transfers within a seagrass bed and its adjacent shallow subtidal and intertidal habitats in a macrotidal embayment system in Korea. Suspended particulate organic matter (POM), sedimentary organic matter, benthic microalgae (BMA), green and decomposing leaves of Zostera marina, its epiphytes and a variety of consumers in different habitats were collected between May and June 2007. Z. marina, epiphytes and BMA were more 13C-enriched than offshore POM. The δ13C values of consumers from all habitats overlapped with those of BMA, Z. marina leaves and epiphytes, indicating the trophic importance of locally produced organic matter. Tissues of the dominant consumers in all habitats contained high quantities of fatty acid biomarkers for diatoms, but very low quantities of fatty acid biomarkers for seagrass. Principal component analysis based on fatty acids of consumers showed a very complex distribution, suggesting that they have diverse nutritive origins irrespective of feeding guilds and habitats. The isotopic mixing model showed that epiphytes and BMA served as major nutritional sources for consumer production in the seagrass and the adjacent intertidal habitats. Moreover, our results suggest that epiphytes and BMA outwell into the adjacent shallow subtidal habitats and provide considerable trophic subsidy for consumer production.


2012 ◽  
Vol 69 (7) ◽  
pp. 1277-1288 ◽  
Author(s):  
Hildur Petursdottir ◽  
Stig Falk-Petersen ◽  
Astthor Gislason

Abstract Petursdottir, H., Falk-Petersen, S., and Gislason, A. 2012. Trophic interactions of meso- and macrozooplankton and fish in the Iceland Sea as evaluated by fatty acid and stable isotope analysis. – ICES Journal of Marine Science, 69: . A trophic study was carried out in August of 2007 and 2008 on the pelagic ecosystem in the Subarctic Iceland Sea. Carbon and nitrogen stable isotopes and fatty acid biomarkers were used to study trophic linkages and the trophic ecology of the most important pelagic species in this ecosystem, with emphasis on capelin (Mallotus villosus). According to 15N enrichment results, there are 3–4 trophic levels in this ecosystem excluding organisms of the microbial loop and birds and mammals. The primarily herbivorous copepod Calanus hyperboreus occupies the lowest trophic level of the animal species studied, and adult capelin and blue whiting (Micromesistius poutassou) occupy the highest level. Calanus spp. proved to be an important dietary component of most of the species studied, the euphausiid species Thysanoessa inermis and T. longicaudata being exceptions. The chaetognath Eukrohnia hamata is a pure carnivore, feeding heavily on Calanus spp., whereas most of the other zooplankton species studied practice an omnivorous–carnivorous feeding mode. The amphipod species Themisto libellula is important in the diet of adult capelin. Adult capelin and blue whiting share the same feeding habits and could therefore be competing for food.


2008 ◽  
Vol 28 (18) ◽  
pp. 2535-2549 ◽  
Author(s):  
R.J.K. Dunn ◽  
D.T. Welsh ◽  
P.R. Teasdale ◽  
S.Y. Lee ◽  
C.J. Lemckert ◽  
...  

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1893-P
Author(s):  
AMBER B. COURVILLE ◽  
SHANNA BERNSTEIN ◽  
MIRELLA GALVAN-DE LA CRUZ ◽  
ANTHONY ONUZURUIKE ◽  
NIRUPA R. MATTHAN ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  

AbstractClimate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of food webs (i.e. seston; the most edible plankton size for zooplankton) in subalpine lake ecosystems. The interaction of higher temperature and tDOM increased the burden of MeHg in seston (< 40 μm) and larger sized plankton (microplankton; 40–200 μm), while the MeHg content per unit biomass remained stable. However, PUFA decreased in seston, but increased in microplankton, consisting mainly of filamentous algae, which are less readily bioavailable to zooplankton. We revealed elevated dietary exposure to MeHg, yet decreased supply of dietary PUFA to aquatic consumers with increasing temperature and tDOM supply. This experimental study provides evidence that the overall food quality at the base of aquatic food webs deteriorates during ongoing climate change scenarios by increasing the supply of toxic MeHg and lowering the dietary access to essential nutrients of consumers at higher trophic levels.


Polar Biology ◽  
2021 ◽  
Author(s):  
Paula A. Ruiz-Ruiz ◽  
Sergio Contreras ◽  
Ángel Urzúa ◽  
Eduardo Quiroga ◽  
Lorena Rebolledo

2002 ◽  
Vol 59 (10) ◽  
pp. 1606-1615 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish

Pathways of methyl mercury (MeHg) accumulation in zooplankton include ingestion of organic matter (OM). We analyzed fatty acid (FA) biomarkers in zooplankton to (i) investigate the effect of allochthonous and autochthonous OM ingestion on MeHg concentrations ([MeHg]) in zooplankton and (ii) examine how algal and bacterial food sources affect MeHg bioaccumulation. We partitioned bulk zooplankton samples (i.e., >500, 202, 100, and 53 μm) from Lake Lusignan (Québec) and measured [MeHg] and [FA] in each fraction. [MeHg] increased with increasing body size and was significantly higher in pelagic than in littoral macrozooplankton (>500 μm). The amount of the ingested terrestrial FA biomarker 24:0 indicated that less than 1% of the total FA in zooplankton was derived from allochthonous sources. More than 60% of the ingested FA originated from algal biomarkers and <10% from bacterial biomarkers. Relative amounts of algal-derived essential FA and bacterial FA were not associated with [MeHg] in any size fraction. In pelagic zones, the amount of MeHg in zooplankton related positively to the number of large organisms such as Calanoid copepods and Daphnia. We propose that the accumulation of MeHg in lacustrine zooplankton depends on the zooplankton habitat rather than on the quality of ingested food.


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