Perspectives on marine zooplankton lipids 1 (original) (raw)
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Perspectives on marine zooplankton lipids
Canadian Journal of Fisheries and Aquatic Sciences, 2007
We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker lipids, and (iv) potential impact of climate change. The first addresses the role of lipids in membranes, storage lipids, and buoyancy with the following key question: How are the properties of membranes and deposits affected by the various types of lipids? The second deals with the importance of various types of lipids during reproduction, development, and resting phases and addresses the role of the different storage lipids during growth and dormancy. The third relates to trophic marker lipids, which are an important tool to follow lipid and energy transfer through the food web. The central question is how can fatty acids be used to identify and quantify food web relationships? With the fourth, hypotheses are presented on effects of global warming, which may result in the reduction or change in abundance of large, lipid-rich copepods in polar oceans, thereby strongly affecting higher trophic levels. The key question is how will lipid dynamics respond to changes in ocean climate at high latitudes?
ISRN Oceanography, 2013
Lipids provide the densest form of energy in marine ecosystems. They are also a solvent and absorption carrier for organic contaminants and thus can be drivers of pollutant bioaccumulation. Among the lipids, certain essential fatty acids and sterols are considered to be important determinants of ecosystem health and stability. Fatty acids and sterols are also susceptible to oxidative damage leading to cytotoxicity and a decrease in membrane fluidity. The physical characteristics of biological membranes can be defended from the influence of changing temperature, pressure, or lipid peroxidation by altering the fatty acid and sterol composition of the lipid bilayer. Marine lipids are also a valuable tool to measure inputs, cycling, and loss of materials. Their heterogeneous nature makes them versatile biomarkers that are widely used in marine trophic studies, often with the help of multivariate statistics, to delineate carbon cycling and transfer of materials. Principal components anal...
Individual body size as a predictor of lipid storage in Baltic Sea zooplankton
Journal of Plankton Research
The size structure of a zooplankton community is frequently used as a trait reflecting functional properties, including biochemical composition. Therefore, a shift in zooplankton body size can reflect shifts in the nutritional quality of zooplankton. In dominant Baltic copepods and cladocerans, neutral to polar lipid ratio (NL/PL ratio), a proxy for the mass-normalized lipid storage, was determined and related to individual body weight. A significant relationship between the NL/PL ratio and body weight was found; the latter was the strongest and the most significant predictor of the lipid storage capacity across different species and developmental stages. These findings provide support for using mean body weight in zooplankton community as a proxy for lipid storage capacity of zooplankton prey and justify applicability of zooplankton mean size as an indicator of nutritional conditions for Baltic zooplanktivores.
Polyunsaturated fatty acids in zooplankton: variation due to taxonomy and trophic position
Freshwater Biology, 2006
1. Food quality has major effects on the transfer of energy and matter in food webs, and essential long-chained polyunsaturated fatty acids (PUFAs) can affect the quality of phytoplankton as food. In a study of oligotrophic lakes in north-western Sweden, we investigated the fatty acid composition of four planktonic cladocerans and two calanoid copepods, representing herbivorous and carnivorous species. We also collected seston samples. 2. The proportions of long-chain PUFAs in the organisms increased with their increasing trophic position. Thus, both their quality as food for other organisms, as well as their requirement for fatty acids (FAs), differed among taxa and depended on their trophic position. 3. We found taxon-specific differences in the FA composition of zooplankton that were not related to sestonic FA composition. This implies that the variation in zooplankton FA composition is constrained by phylogenetic origin, life history characteristics, or both. 4. The cladoceran taxa contained 12-23% eicosapentaenoic acid (EPA) but only 0.9-2.1% docosahexaenoic acid (DHA) of the total FA content. In contrast, the calanoid copepods contained 7-11% EPA and 14-21% DHA. Thus, our results show that differences in the PUFA content among zooplankton species could have repercussions for both food web structure and function.
Can physicochemical factors predict lipid content in phytoplankton?
Freshwater Biology, 1997
We hypothesized that a large collection of reasonably standardized data for natural algal assemblages would reveal the influence of environmental factors on the fraction of recently produced photosynthate allocated to lipid. 2. Our analysis of photosynthate allocation in fresh-and saltwater systems showed that allocation of carbon to lipid was not well correlated with any one environmental factor. 3. Allocation to lipid increases with temperature up to 12°C (lipid allocation ϭ 11.7 ϩ 1.70*temperature (°C), n ϭ 48, r 2 ϭ 0.50, P Ͻ 0.001) but not above. 4. The relationship between temperature and lipid allocation appears to be caused by a unique convergence of nutrient limitation (nitrate or silicate) in the presence of facultative lipid-producing algae (diatoms or other chrysophytes) which occurs at or below 12°C during stratification of the water column.
Lipids of Prokaryotic Origin at the Base of Marine Food Webs
Marine Drugs, 2012
In particular niches of the marine environment, such as abyssal trenches, icy waters and hot vents, the base of the food web is composed of bacteria and archaea that have developed strategies to survive and thrive under the most extreme conditions. Some of these organisms are considered -extremophiles‖ and modulate the fatty acid composition of their phospholipids to maintain the adequate fluidity of the cellular membrane under cold/hot temperatures, elevated pressure, high/low salinity and pH. Bacterial cells are even able to produce polyunsaturated fatty acids, contrarily to what was considered until the 1990s, helping the regulation of the membrane fluidity triggered by temperature and pressure and providing protection from oxidative stress. In marine ecosystems, bacteria may either act as a sink of carbon, contribute to nutrient recycling to photo-autotrophs or bacterial organic matter may be transferred to other trophic links in aquatic food webs. The present work aims to provide a comprehensive review on lipid production in bacteria and archaea and to discuss how their lipids, of both heterotrophic and chemoautotrophic origin, contribute to marine food webs.
Essential fatty acids in the planktonic food web and their ecological role for higher trophic levels
Limnology and Oceanography, 2004
We measured concentrations of essential fatty acids (EFAs) in four size categories of planktonic organismsseston (10-64 m), microzooplankton (100-200 m), mesozooplankton (200-500 m), and macrozooplankton (Ͼ500 m)-and in rainbow trout (Oncorhynchus mykiss) in coastal lakes. Size-dependent patterns in concentrations of specific fatty acids (FAs) are important for ecosystem function, because planktivorous fish and some invertebrates are size-selective predators. We demonstrate that the retention of individual FAs differs among the four size categories of planktonic organisms in our study systems. Changes in individual EFA concentrations within the planktonic food web were similar in all coastal lakes sampled, which indicates the generality of our findings. Although concentrations of arachidonic acid, eicosapentaenoic acid (EPA), and linoleic acid increased steadily with plankton size, the concentration of ␣-linolenic acid decreased slightly in larger size fractions of zooplankton. Concentrations of another EFA, docosahexaenoic acid (DHA), declined sharply from mesozooplankton to the cladoceran-dominated macrozooplankton size class. Our results indicate that the retention of EFAs, as a function of plankton size, is related, in part, to the taxonomic composition of planktonic food webs. We suggest that, in general, zooplankton exhibit an EPA-retentive metabolism with increasing body size, whereas different taxonomic groups within the planktonic food web retain DHA differently. Finally, we conclude that EPA is highly retained in zooplankton, whereas in rainbow trout DHA is highly retained.
Microalgal lipids: A review of lipids potential and quantification for 95 phytoplankton species
Biomass and Bioenergy, 2021
Phytoplankton have great potential for biodiesel production and offer promises and opportunities in the long term. Phytoplankton species reach higher growth rates, and thus productivity, than conventional forestry or agricultural crops and other aquatic plants. The oil yield in phytoplankton is an order of magnitude larger than terrestrial oleaginous crops. To meet the potential of phytoplankton-based biodiesel there is a need to radically increase lipid yields, which are generally produced under adverse conditions. Nutrients stress and alterations of cultivation conditions are commonly used as lipid enhancement strategies. It is difficult to get a clear picture of the most efficicent factors affecting lipid accumulation and productivity from the abundant literature on this topic, dispatched into a large variety of species and stresses. This article seeks to summarize the widely reported information on TAGs accumulation in phytoplankton and to decipher the regulation mechanisms triggered along the diversity of enhancement strategies. Most of the factors affecting lipid content and composition were analyzed, such as nutrient starvation, temperature, irradiance, salinity, oxidative stress, metals, CO 2 flux, pH and metabolic engineering. In this review, we compiled 213 experiments with lipid analysis, dealing with 95 marine and freshwater phytoplankton (microalgae and cyanobacteria) species. Quantitative indicators (lipid content and productivity), stress level and exposure time, are presented. This review highlights the complexity of comparison between phyla due to differences in culture conditions, analytical methods and/or growth phase. It provides valuable tools for triggering phytoplanktonic lipid biosynthesis and opens the door for enhanced quality and quantity of phytoplankton-based biodiesel.