Formation and Transfer of Fatty Acids in Aquatic Microbial Food Webs: Role of Heterotrophic Protists

2009 ◽  
pp. 25-42 ◽  
Author(s):  
Christian Desvilettes ◽  
Alexandre Bec
Keyword(s):  
Fatty Acids ◽  
Food Webs ◽  
Microbial Food Webs

scholarly journals Preliminary Estimations of Insect Mediated Transfers of Mercury and Physiologically Important Fatty Acids from Water to Land

Biomolecules ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 129 ◽  
Author(s):  
Sydney Moyo
Keyword(s):  
Fatty Acids ◽  
Food Webs ◽  
Organic Contaminants ◽  
Aquatic Insects ◽  
Total Mercury ◽  
Empirical Studies ◽  
Aquatic Insect ◽  
Terrestrial Ecosystems ◽  
Energy Subsidy

Aquatic insects provide an energy subsidy to riparian food webs. However, most empirical studies have considered the role of subsidies only in terms of magnitude (using biomass measurements) and quality (using physiologically important fatty acids), negating an aspect of subsidies that may affect their impact on recipient food webs: the potential of insects to transport contaminants (e.g., mercury) to terrestrial ecosystems. To this end, I used empirical data to estimate the magnitude of nutrients (using physiologically important fatty acids as a proxy) and contaminants (total mercury (Hg) and methylmercury (MeHg)) exported by insects from rivers and lacustrine systems in each continent. The results reveal that North American rivers may export more physiologically important fatty acids per unit area (93.0 ± 32.6 Kg Km−2 year−1) than other continents. Owing to the amount of variation in Hg and MeHg, there were no significant differences in MeHg and Hg among continents in lakes (Hg: 1.5 × 10−4 to 1.0 × 10−3 Kg Km−2 year−1; MeHg: 7.7 × 10−5 to 1.0 × 10−4 Kg Km−2 year−1) and rivers (Hg: 3.2 × 10−4 to 1.1 × 10−3 Kg Km−2 year−1; MeHg: 3.3 × 10−4 to 8.9 × 10−4 Kg Km−2 year−1), with rivers exporting significantly larger quantities of mercury across all continents than lakes. Globally, insect export of physiologically important fatty acids by insect was estimated to be ~43.9 × 106 Kg year−1 while MeHg was ~649.6 Kg year−1. The calculated estimates add to the growing body of literature, which suggests that emerging aquatic insects are important in supplying essential nutrients to terrestrial consumers; however, with the increase of pollutants in freshwater systems, emergent aquatic insect may also be sentinels of organic contaminants to terrestrial consumers.

The transformation of long chain polyunsaturated fatty acids in benthic food webs: The role of sea urchins

2011 ◽  
Vol 409 (1-2) ◽  
pp. 229-234 ◽  
Author(s):  
Adam D. Hughes ◽  
Elizabeth J. Cook ◽  
Heather Orr ◽  
Maeve S. Kelly ◽  
Kenneth D. Black
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Food Webs ◽  
Sea Urchins ◽  
Benthic Food ◽  
Benthic Food Webs ◽  
Long Chain

Modelling the role of highly unsaturated fatty acids in planktonic food web processes: a mechanistic approach

2012 ◽  
Vol 20 (3) ◽  
pp. 155-172 ◽  
Author(s):  
Gurbir Perhar ◽  
George B. Arhonditsis ◽  
Michael T. Brett
Keyword(s):  
Fatty Acids ◽  
Food Webs ◽  
Unsaturated Fatty Acids ◽  
Trophic Levels ◽  
Efficient Energy Transfer ◽  
Highly Unsaturated Fatty Acids ◽  
Planktonic Food ◽  
Aquatic Food ◽  
Biochemical Research

Highly unsaturated fatty acids (HUFAs) are a subgroup of fatty acids characterized by chains of 20 or more carbon atoms with multiple double bonds, which potentially limit the growth of zooplankton. Zooplankton require high HUFA concentrations during periods of rapid growth, but co-limitation with nutrients is also likely to occur. Recent modelling results suggest food webs with high quality (nutritional and biochemical) primary producers can attain inverted biomass distributions with efficient energy transfer between trophic levels. In this study, our objective is to highlight the recent advances in studying the role of HUFAs in aquatic food webs. We take a first-principles approach to investigate the chemical nature of HUFAs, and the role they play in zooplankton ecology. To this end, we introduce a novel zooplankton growth sub model that tracks the interplay between nitrogen, phosphorus, and HUFAs in plankton population models. Our aim is to produce a sub model that incorporates the knowledge gained from decades of biochemical research into management-oriented predictive tools.

Alcohol intake impairs glucose counterregulation during acute insulin-induced hypoglycemia in IDDM patients. Evidence for a critical role of free fatty acids

Diabetes ◽  
1993 ◽  
Vol 42 (11) ◽  
pp. 1626-1634 ◽  
Author(s):  
A. Avogaro ◽  
P. Beltramello ◽  
L. Gnudi ◽  
A. Maran ◽  
A. Valerio ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Alcohol Intake ◽  
Critical Role

scholarly journals Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pianpian Wu ◽  
Martin J. Kainz ◽  
Fernando Valdés ◽  
Siwen Zheng ◽  
Katharina Winter ◽  
...  
Keyword(s):  
Climate Change ◽  
Fatty Acids ◽  
Organic Matter ◽  
Food Webs ◽  
Essential Fatty Acids ◽  
Trophic Levels ◽  
Climate Change Scenarios ◽  
Essential Nutrients ◽  
Aquatic Food Webs ◽  
Aquatic Food

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.

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