Other language confidence: 0.9470909628649196
Fecundity of marine fish species is highly variable, but trade-offs between fecundity and egg quality have rarely been observed at the individual level. We investigated spatial differences in reproductive investment of individual European sprat Sprattus sprattus (Linnaeus 1758) females by determining batch fecundity, condition indices (somatic condition index and gonadosomatic index) as well as oocyte dry weight, protein content, lipid content, spawning batch energy content, and fatty acid composition. Sampling was conducted in five different spawning areas within the Baltic Sea between March and May 2012. Sampling was conducted in the Baltic Sea during three cruises of the German RV “Alkor” in March (https://www2.bsh.de/aktdat/dod/fahrtergebnis/2012/20120331.htm), April (http://dx.doi.org/10.3289/CR_AL390), and May (http://dx.doi.org/10.3289/CR_AL392) 2012. Five different areas were sampled: KB, AB, Bornholm Basin (BB), Gdansk Deep (GD), and Gotland Basin (GB). Fish were caught with a pelagic trawl. Trawling time was in general 30 minutes per haul. The total lengths (TL, ±0.1 cm) of at least 200 sprat per haul were measured for length frequency analysis. Only female sprat with ovaries containing fully hydrated oocytes were sampled, running ripe females were rejected to avoid possible loss of oocytes, as this would lead to an underestimation of batch fecundity. Sprat were sampled immediately after the haul was on deck and stored on crushed ice. The sampled fish were weighed (wet mass WM, ±0.1 g) and measured (TL, ±0.1 cm), and their ovaries were dissected carefully. Oocytes were extracted from a single ovary lobe, rinsed with deionized water, and counted under a stereo microscope (Leica MZ 8). A counted number of oocytes (around 50 oocytes per fish) were transferred to pre-weighed tin-caps (8 x 8 x 15 mm). These samples were used to determine the oocyte dry weight, lipid content, and fatty acid composition. In addition, a counted number of oocytes (around 10 oocytes per fish) were sampled in Eppendorf caps for determination of protein content. Oocyte samples were stored at -80 °C for subsequent fatty acid and protein analysis in the laboratory. Finally, both ovary lobes were stored in 4% buffered formaldehyde solution for further fecundity analysis. Ovary free body mass (OFBM, ±0.1 g) of sampled frozen fish and fixed ovary mass (OM, ±0.1 g) were measured (Sartorius, 0.01 g) in the laboratory on land, to avoid imprecise measurements due to the ship's motion at sea. Absolute batch fecundity (ABF) was determined gravimetrically using the hydrated oocyte method suggested by Hunter et al. (1985) for indeterminate batch spawners. For ascertainment of the relative batch fecundity per unit body weight (RBF), ABF was divided by OFBM. Further, a condition index (CI) was determined: CI = (OFBM/〖TL〗^3 )× 100. A gonadosomatic index (GSI) was calculated with the following formula: GSI = (OM/OFBM)× 100. Oocyte dry weight was determined to the nearest 0.1 µg (Sartorius SC 2 micro-scale), using the samples stored in pre-weighed tin caps, after freeze-drying (Christ Alpha 1-4) for at least 24 hours. After subtracting the weight of the empty tin cap, the average oocyte dry mass (ODM) was then calculated by dividing the total weight by the number of oocytes contained in the tin cap. The fatty acid signature of oocytes was determined by gas chromatography (GC). Lipid extraction of the dried oocytes was performed using a 1:1:1 solvent mix of dichloromethane:methanol:chloroform. A five component fatty acid methyl ester Mix (13:0 - 21:0, Restek, Bad Homburg, Germany; c = 8.5 ng component µl-1) was added as an internal standard and a 23:0 fatty acid standard (Restek, Bad Homburg, Germany, c = 25.1 ng µl-1) was added as an esterification efficiency control. Esterification was performed over night at 50 °C in 200 µl 1% H2SO4 and 100 µl toluene. The solvent phase was transferred to 100 µl n-hexane and a 1 µl aliquot measured in a Thermo Fisher Trace GC Ultra with a Thermo Fisher TRACETM TR-FAME column (10 m*0.1 mm*0.2 µm). For more details on sample preparation and GC settings, see Hauss et al. (2012). The total lipid content per oocyte was determined by adding up the weights of all detected fatty acids. To ensure comparability with past studies, results for FA are given as a percentage of the combined weights of all detected FA. An average of 10 oocytes were transferred to 5*9 mm tin cups (Hekatech) and dried at 50 °C for >24 h. Total organic carbon (C) and nitrogen (N) content was measured using a Thermo Fisher Scientific Elemental Analyzer Flash 2000. From the total amount of N in the sample, the oocyte protein content was calculated according to Kjeldahl (Bradstreet, 1954), using a factor of 6.25. The oocyte gross energy content was calculated on the basis of measured protein and lipid content, which were multiplied with corresponding energy values from literature. The measured amount of proteins per given oocyte (P, mg) was multiplied by a factor of 23.66 J mg-1 and was added to the total amount of lipids per oocyte (L, mg) multiplied by 39.57 J mg-1 (Henken et al. 1986). Consequently, the oocyte energy content of each individual female sprat was multiplied by its relative batch fecundity in order to obtain a standardized estimate of the total amount of energy invested into a single spawning batch (SBEC, J g-1 OFBM): SBEC = [(P × 23.66 (J )/mg)+(L × 39.57 (J )/mg)]× RBF
This dataset contains compound-specific hydrogen (δ2H) and carbon (δ13C) isotope compositions and concentrations of long-chain n-alkanes and fatty acids (n-alkanoic acids) from the ROT21 sediment record of Rotsee, Central Switzerland (47°04′10″N, 8°18′48″E, 419 m a.s.l.). Sediment cores were retrieved in October 2021 using a UWITEC gravity corer, and the dataset spans the past ~13,000 years based on 19 radiocarbon dates (terrestrial and aquatic macrofossils) integrated with 210Pb and 137Cs profiles (see De Jonge et al., 2025). Laboratory analyses were conducted between February 2023 and November 2024 at the University of Basel. Sediment samples (~2–5 g) were sub-sampled, freeze-dried, spiked with internal standards (n-C19-alkanoic acid, n-C36-alkane, 2-octadecanone, and n-C21-alkanol), and extracted with dichloromethane/methanol (9:1, v/v) using an Accelerated Solvent Extractor (Dionex ASE 350, Thermo Fisher Scientific). Following saponification, neutral fractions were separated via silica gel chromatography, and fatty acids were converted to fatty acid methyl esters (FAMEs). Both n-alkanes and FAMEs were further purified to isolate saturated compounds using AgNO3-impregnated silica gel columns, then analyzed and quantified by gas chromatography with flame ionization detection (GC-FID). Peak areas were normalized to recovery standards to account for potential losses during sample handling, and compounds were identified by comparison with external standards. Compound-specific δ2H and δ13C values were determined by gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and normalized to the VSMOW-SLAP (δ2H) and VPDB (δ13C) scales. Analytical precision was ±3-5 ‰ for δ2H and ±0.2–0.3 ‰ for δ13C. The dataset was generated to reconstruct past hydroclimate and vegetation dynamics in Central Europe using plant wax δ2H records. Full methodological details are provided in the study: Central Europe hydroclimate since the Younger Dryas inferred from vegetation-corrected sedimentary plant wax δ2H values (Santos et al., 2026).
Surface sediment were extracted 4 times by ultrasonication with dichloromethane: methanol (9:1, v/v) for 15 min for FAs and alkanes. For quantification of FAs and alkanes, known amounts of 19-methylarachidic acid and squalane were added as internal standards prior to extraction. Supernatants from each extraction were obtained by centrifugation and combined. The total lipid extracts were concentrated and evaporated under a nitrogen stream. The total lipid extracts were saponified for 2 h at 80 °C with 1 mL of KOH (0.1 M) in methanol: H2O (9:1, v/v). After saponification, the neutral fractions were liquid-liquid extracted with n-hexane and alkanes were eluted from the neutral fractions by silica gel column chromatography with n-hexane. The remaining KOH solution was acidified to pH 1, from which FA were liquid-liquid extracted into dichloromethane. The extracted and dried FAs were converted to methyl ester derivatives (FAMEs) in methanol: HCl (95:5, v/v) at 60 °C for 12 h. After methylation, the FAME fraction was further purified by silica gel column chromatography using dichloromethane: hexane (2:1, v/v) to remove residual polar compounds. FAMEs and alkanes were analyzed on a 7890A gas chromatograph (GC) equipped with a DB-5MS fused silica capillary column (60 m, 250 µm, 0.25 µm) and a flame ionization detector (FID). Peak areas were determined by integrating the respective peaks and concentrations were calculated against the internal standards. FAME contents were subsequently corrected for the derivative methyl carbon to determine FA contents. FAs and alkanes were normalized to OC content.
In March 2022, 56 surface sediments were collected from the Helgoland Mud Area and surrounding sandy areas in the North Sea. These surface sediments were analyzed for grain size, organic carbon (OC) content, total nitrogen content (TN), stable carbon isotope of OC, and abundances of source-specific alkanes and fatty acids, in aim to determine and quantify composition and sources of OC, to understand the degradation and sequestration of marine and terrestrial OC in sediments, and to estimate the burial fluxes and burial efficiencies of marine and terrestrial OC in the Helgoland Mud Area. Detailed dataset interpretation can be found in Wei et al. (2024, in preparation).
Fatty acid (FA) composition has increasingly been used to estimate the dietary preference of marine organisms. Specific fatty acids and fatty acid ratios serve as trophic markers (FATM) and have the potential to provide insights on the long-term dietary preference of organisms. FATM have been applied for this purpose on various zooplankton, fish and up to whales. We aim to build up a database of new and published data on fatty acid content of mesopelagic fish and their predators from the central and Northeast Atlantic, and the Mediterranean Sea, to use in FATM food web studies, investigating the importance of mesopelagic organisms as predators and prey in the marine ecosystem. Here we compiled FA content (i.e., the proportion of each FA measured in sampled tissues or in the whole body of organisms in relation to total FAs analysed) of 36 fish species or genera, 15 seabirds, five marine mammals, two cephalopods, one turtle, one jelly fish, and one shark. For each record, we included all FAs with values above 0.1% of total FAs and report the percentage values as provided in the original data source. Each data record is associated with information on the sampling location, geographic coordinates, month and year of sample collection, method of sample collection, taxonomic ranks (phylum, class, order, family), number and size (or size range) of sampled organisms, as well as the reference and DOI of the original data source, for further details on the samples analysed and/or the analytical techniques used.
| Organisation | Count |
|---|---|
| Bund | 2 |
| Europa | 1 |
| Wissenschaft | 22 |
| Type | Count |
|---|---|
| Daten und Messstellen | 21 |
| Förderprogramm | 2 |
| License | Count |
|---|---|
| Offen | 23 |
| Language | Count |
|---|---|
| Englisch | 23 |
| Resource type | Count |
|---|---|
| Archiv | 6 |
| Datei | 15 |
| Keine | 2 |
| Topic | Count |
|---|---|
| Boden | 11 |
| Lebewesen und Lebensräume | 14 |
| Luft | 3 |
| Mensch und Umwelt | 21 |
| Wasser | 14 |
| Weitere | 23 |