Dataset: Integrated Energy Density data of Marine and Freshwater Organisms

Original sources utilized variable sampling techniques. Our approach for integrating across these sources began by identifying sources containing energy density data for aquatic organisms. First, we conducted a literature search on Web of Science using the search string: “("energy densit*" OR "energy content*" OR "energy equivalen*") AND (marine OR Atlantic).”  The 745 results were rough filtered by a check of the abstract to identify whether they followed the correct topic, with potential sources being inspected more closely for containing data on energy density as a per weight unit (~2/3 sources following the first filter had suitable data). Appropriate conversions were made as necessary with a particular emphasis on conducting a conversion to energy density per gram wet weight as the focal measure of interest within the database. All sources which contained one or more taxon with an energy density measure were included within the database. Additional metadata about the record was gleaned from the source as available including the location and method of capture, storage and analytical technique, and number of replicate samples. Locations of estuarine and marine coastal data were also categorized by large marine ecosystem (LME; Sherman 1991, 2014); open ocean locations were defined by the ocean body; locations of freshwater data were categorized by continent.  Additional sources were sought out through a snowball method by which references for relevant papers on energetics which did not contain measures of energy density but cited sources of data were searched, of note as a source for other original records was the Pelagic Traits Database (Gleiber et al., 2024). Efforts to locate original sources of energy density data were always taken, but in some instances a review paper was included due to complications with accessibility or reference obscurity. The use of data from reviews may result in a “double counting” of individuals when both an original source and review include them in their average. Finally, grey literature was included through a haphazard search and through communications with experts.

Taxonomic classification for each record began with that reported by the original source, primarily a Genus species name but occasionally at broader grades such as Family and Order. Taxonomy for all records was retrieved 26-Apr-2024, from the Integrated Taxonomic Information Service (ITIS), www.itis.gov, CC0, https://doi.org/10.5066/F7KH0KBK. Species names from original records were changed to agree with valid ITIS names as of this date. 

Data were acquired from the original sources as they were published and available online or in print. They were then transferred by copy-paste automation whenever possible and manually in all other instances. The accurate entry of all data was checked by the principal investigator following each source being entered in completion. Missing data represents instances when a variable was not provided by the original source, often due to variable study designs or methodologies, e.g., Bomb Calorimetry studies do not collect data on percent of body mass that was lipid. Errors in values were identified by visualizing (for numeric variables) or tabulating (for character variables) each variable independently. The dataset was thoroughly examined by the principal investigator and original creator of the database, but was checked by the remaining members of the team for any anomalies. Additional independent review of an early draft was provided by S. Gaichas.