Location where sample was collected (FAML: pier at in Corpus Christi Channel, Port Aransas, TX, United States, Fisheries and Mariculture Laboratory of the University of Texas Marine Science Institute (lat. 27.8396111, lon. -97.0827222); MI: Mud Island in Aransas Bay, TX, United States (lat. 27.9362222, lon. -97.0217777); TPWD: Texas Parks and Wildlife Department, Corpus Christi, TX, United States (lat. 27.646877, lon. -97.3150222))
Methods and Sampling:
A sampling of likely egg consumers, egg non-consumers, pelagic plankton, and benthic sediments began in July 2020 and ended in March 2022. Samples were collected from two field sites, one in the vicinity of the Red Drum spawning aggregation (Aransas Pass Inlet) and the other outside the extent of the egg boon (Mud Island in Aransas Bay) by deploying a 500-micron (µm) mesh plankton net. Animals in the plankton net were sorted immediately after collection and transferred to holding tanks to evacuate their guts for 3-4 hours. Each sample was then rinsed twice in distilled water and frozen at -80°C for subsequent fatty acid analysis.
Basal resources were collected by pumping seawater from the Aransas Pass Channel adjacent to the University of Texas Marine Science Institute’s Fisheries and Mariculture Laboratory and filtering the seawater through sieves of three different mesh sizes to obtain three size fractions of plankton samples (10-60 µm, 100-200 µm, and 200-500 µm). Bottom sediment was collected using a grab sampler and passed through a 60‑µm sieve to obtain benthic particulate organic matter. Samples of jellyfish and small fishes were taken with dip nets, cast nets, or seines and processed as described above for analysis.
Fatty acid profiles were measured for samples of fish eggs, marine animals, and basal resources collected from the field as well as eggs and marine animals used in laboratory experiments. The time between collection and analysis ranged from 2 months to a year.
For fatty acid analysis, each sample was lyophilized, homogenized, and weighed. Lipids were cold extracted from a known subsample (by weight) of the homogenized and lyophilized tissue using chloroform/methanol/water (8:4:3 v/v) following the method of Folch et al. (1957. Journal of Biological Chemistry 226:497–507) with 0.01% (w/v) butylated hydroxytoluene as an antioxidant. For small taxa or taxa with low lipid content (e.g., ctenophores), several individuals were pooled into one sample. Fatty acid methyl esters (FAME) were prepared by transesterification with 14% boron trifluoride in methanol (Morrison and Smith 1964. Journal of Lipid Research 5:600–608) following saponification of the total lipid using 0.5M potassium hydroxide in methanol. FAMEs were measured by gas chromatography with flame ionization detector following procedures described by Faulk and Holt (2005. Aquaculture 249:231–243). Measurements were expressed in terms of concentration (mg per g dry weight) and composition (% of total fatty acids). Fatty acids were identified by comparison with commercial standards.
Known Issues:
Quality control procedure
Principal components analysis for each taxon was performed on the mg g-1 dw and percent total fatty acids data, separately. Individual samples for which the score on the first or second principal component axis were greater than 4 standard deviations from the taxon mean were removed from the data set.
A primary check value was assigned as follows:
1 Perfectly fine
2 Data not evaluated because of too few data points for principal components analysis
The quantification limit for individual fatty acids is 0.013 mg g-1 dry weight
Measured values of any fatty acid less than 0.013 mg g-1 dw were changed to 0.000 mg g-1 dw and its corresponding value for percentage of total fatty acids was changed to 0.0%.
FAML: pier at in Corpus Christi Channel, Port Aransas, TX, United States, Fisheries and Mariculture Laboratory of the University of Texas Marine Science Institute (lat. 27.8396111, lon. -97.0727222);
MI: Mud Island in Aransas Bay, TX, United States (lat. 27.9362222, lon. -97.0217777)).
©2020 Biological and Chemical Oceanography Data Management Office.