The fatty acid content and composition of the Antarctic krill Euphausia superba Dana, 1850 were investigated using samples collected by a commercial fishing vessel. This dataset allowed comparison between seasons, years (2013–2016), and different fishing locations. Quantities of omega 3 fatty acids 20:5n-3 and 22:6n-3 (mg/g dry mass; DM) were highest in autumn and decreased through winter to reach a spring low. Quantities of the flagellate marker 18:4n-3 and diatom marker 16:1n-7c were variable and did not display the same seasonal fluctuations. In summer, krill had high percentages (% total fatty acids) of 20:5n-3 and 22:6n-3, total PUFA, and low 18:1n-9c/18:1n-7c ratios, indicating a more herbivorous diet. Krill became more omnivorous from autumn to spring, indicated by increasing ratios of 18:1n-9c/18:1n-7c and percentages of Σ 20:1 + 22:1 isomers. Bacterial fatty acids (Σ C15 + C17 + C19 isomers) were minor components year-round (0.9–1.8 %). Seasonal levels of herbivory and omnivory differed between years, and levels of specific fatty acid ratios differed between fishing locations. The fatty acid 18:4n-3 was a major driver of variability in krill fatty acid composition, with no obvious seasonal driver. This is the first study to report krill fatty acid data during all four seasons over consecutive years. This large-scale study highlights the value of using fisheries samples to examine seasonal and annual fluctuations in krill diet and condition.

These data consist of the fatty acid composition (percent of mass) of adipose tissue samples from polar bears in Alaska's southern Beaufort Sea. Fat biopsy samples were collected from polar bears that were either captured or biopsy darted along the north coast of Alaska or on offshore ice during March, April, or May from 2004 to 2016. The data also include an identification code unique to an individual bear, sex, age class, and the date of sample collection.

These data consist of the fatty acid composition (percent of mass) of adipose tissue samples from polar bears in Alaska's southern Beaufort Sea. Fat biopsy samples were collected from polar bears that were either captured or biopsy darted along the north coast of Alaska or on offshore ice during March, April, or May from 2004 to 2016. The data also include an identification code unique to an individual bear, sex, age class, and the date of sample collection.

This dataset contains fatty acid data expressed as mass percent of total fatty acids from Chukchi Sea polar bears.

In coastal ecosystems, seaweeds provide habitat and a food source for a variety of species including herbivores of commercial importance. In these systems seaweeds are the ultimate source of energy with any changes in the seaweeds invariably affecting species of higher trophic levels. Seaweeds are rich sources of nutritionally important compounds such as polyunsaturated fatty acids (PUFA) and are particularly rich in long-chain (≥ C20) PUFA (LC-PUFA). In southern Australia, the ‘Great Southern Reef’ has one of the most diverse assemblages of seaweeds in the world, which support highly productive fisheries and have been recognised as a promising resource of omega-3 LC-PUFA. Despite this, there is little information on the biochemical composition of most species and how it varies between sites and seasons. To address this knowledge gap, we undertook a survey to assess seasonal variability in the biochemical composition (fatty acids and nitrogen content) of abundant understory seaweeds across three sites in eastern Tasmania. The availability of nutritional compounds differed between sites and was primarily driven by differences in the biomass and the biochemical composition of the nutritious red seaweeds at each site. This variability may explain regional differences in the productivity of commercial fisheries. At the species level, seasonal changes in fatty acid composition were highly variable between species and sites, indicating that multiple environmental drivers influence fatty acid composition of seaweeds in this system. This finding suggests that commercial harvest of seaweeds from eastern Tasmania will need to consider species and site-specific variability in fatty acid composition.

Fish chemistry data (d13C, d15N, C:N, lipid content) published in Rapid Commun. Mass Spectrom. 2015, 29, 2069–2077 DOI: 10.1002/rcm.7367. This dataset is associated with the following publication: Hoffman , J., M. Sierszen , and A. Cotter. Fish tissue lipid-C:N relationships for correcting ä13C values and estimating lipid content in aquatic food web studies. Rapid Communications in Mass Spectrometry. Wiley InterScience, Silver Spring, MD, USA, 29(21): 2069–2077, (2015).

Data set covers metrics and metadata related to wild collected copepods Calanus spp. (C. hyperboreus, C. glacialis, C. finmarchicus) and Metridia longa: - body size in prosome length [PL] - dry weight [DW] - lipid content (oil sac area [OSA] and oil sac volume [OSV]) Spatial coverage: North Atlantic sampling sites - Scotian Shelf (SS) - Gulf of Saint Lawrence (GSL) - Gulf of Maine-Georges Bank-Nantucket Shoals (GoM) - Newfoundland shelf (NFL) Cite this data as: Helenius LK, Head EJH, Jekielek P, Orphanides CD, Pepin P, Plourde S, Ringuette M, Walsh HJ, Runge JA, Johnson CL. Calanus spp. size and lipid content metrics in North Atlantic, 1977-2019. Published September 2022. Ocean Ecosystem Science Division, Fisheries and Oceans Canada, Dartmouth, N.S. https://open.canada.ca/data/en/dataset/72e6d3a1-06e7-4f41-acec-e0f1474b555b

Inferences about ecological structure and function are often made using elemental or macromolecular tracers of food web structure. For example, inferences about food chain length are often made using stable isotope ratios of top predators and consumer food sources are often inferred from both stable isotopes and fatty acid (FA) content in consumer tissues. The use of FAs as tracers implies some degree of macromolecular conservation across trophic interactions, but many FAs are critically important for particular physiological functions and animals may selectively retain or extract these critical FAs from food resources. Here, we compared spatial variation in two taxa that feed on the same (or similar) food resources to assess which FAs appear to be responding to a common gradient in food resources. Filter feeding caddisflies (Family Hydropyschidae) and dreissenid mussels (Genus Dreissena) both consume seston, and had similar spatial variation in stable isotopes (C and N) across 13 sites in the Great Lakes region of North America. Only one of forty-one FAs measured showed strong spatial co-variance in these taxa (α-linolenic acid; ALA), indicating other FAs are responding to other environmental gradients in at least one of these taxa. Based on other experimental studies, ALA does appear to be driven by food availability in caddisflies, so it seems likely that ALA spatial co-variance reflects spatial variation in this food resource in this study. We conclude that inferences made using FAs as tracers of food web structure may be very sensitive to the individual taxa studied.

In 1992, the Marine Mammal Protection Act established the Marine Mammal Health and Stranding Response Program (Title IV) which operates in support of the Recovered Protected Species goal of NMFS’s Strategic Plan. The Northwest Fisheries Science Center (NWFSC) is the NMFS lead for the biomonitoring components and quality assurance of chemical analyses for the MMHSRP. Information generated by this activity addresses deficiencies in data quality and quantity on the levels of toxic chemical contaminants in marine mammals and their prey, refines methods and approaches for understanding linkages between exposure and specific biological effects and measures, and improves the dissemination of the information to constituents and resource managers. Furthermore, these data will provide a measure of the quality of marine mammal habitats. Various analytical methods developed at the NWFSC will be used for the following marine mammal projects: integrated assessment studies of contaminants and other chemical tracers to assess feeding ecology or population health; monitoring of contaminants from stranded animals in support of studies and from species for which few data exist; continued investigations of potential relationships between contaminant exposure and population effects; participation in Interlaboratory Comparison Exercises conducted by National Institute of Standards and Technology and other similar entities comparing analytical results for chemical tracers; and development of quality control materials and quality assurance criteria for new analytical methods as they are developed as part of our Quality Assurance Program. The results of the chemical tracer analyses will be summarized in a report that will be sent to the Office of Protected Resources by the 4th quarter of FY18. Concentrations of POPs, polycyclic aromatic hydrocarbons and their metabolites, total lipid and lipid profiles, fatty acids, and stable isotopes in samples derived from marine mammal biopsies and necropsies.

Antarctic krill (Euphausia superba) are a keystone species in the Southern Ocean, but little is known about how they will respond to climate change. Ocean acidification, caused by sequestration of carbon dioxide into ocean surface waters (pCO2), is known to alter the lipid biochemistry of some organisms. This can have cascading effects up the food chain. In a year-long laboratory experiment adult krill were exposed to ambient seawater pCO2 levels (400 μatm), elevated pCO2 levels that mimicked near-future ocean acidification (1000, 1500 and 2000 μatm) and an extreme pCO2 level (4000 μatm). The laboratory light regime mimicked the seasonal Southern Ocean photoperiod and krill received a constant food supply. Total lipid mass (mg g -1 DM) of adult krill was unaffected by near-future levels of seawater pCO2. Fatty acid composition (%) and fatty acid ratios associated with immune responses and cell membrane fluidity were also unaffected by near-future pCO2, apart from an increase in 18:3n-3/18:2n-6 ratios in krill in 1500 μatm pCO2 in winter and spring. Extreme pCO2 had no effect on krill lipid biochemistry during summer. During winter and spring, krill in extreme pCO2 had elevated levels of omega-6 fatty acids (up to 1.2% increase in 18:2n-6, up to 0.8% increase in 20:4n-6 and lower 18:3n-3/18:2n-6 and 20:5n-3/20:4n-6 ratios), and showed evidence of increased membrane fluidity (up to three-fold increase in phospholipid/sterol ratios). These results indicate that the lipid biochemistry of adult krill is robust to near-future ocean acidification.