DOI: 10.6075/j0513wjd
title: Collection event and specimen analysis records for Halobates. In Heavy Metals in the Ocean Insect, Halobates

description: Sample Collection The samples used for analyses were collected from the Atlantic and the Pacific Oceans. They were all collected by net tows during oceanographic cruises operated either by the SIO or other institutions and given to me. Halobates specimens were separated from other plankton organisms and preserved either in 5% formaldehyde or 70% ethanol. Formaldehyde preserved samples were later rinsed several times in fresh water then transferred to 70% ethanol. Sample processing and analyses Insects were removed from preservatives, rinsed in filtered water, blotted dry with Kimwipe tissues and placed in pre-cleaned polyethylene vials with tops covered by Kimwipes. They were then dried in an oven at 60 C for 24-48 hours. They were analyzed for heavy metals using an optical emission spectrometer system specially designed for multi-element analysis of biological tissues (Cheng, Alexander, and Franco, 1976). Confidence in the accuracy of the spectrometric analyses was established by analyzing the Standard reference Material 1577 (Orchard leaves) and 1571 (bovine liver) provided by the U.S. National Bureau of Standards. Agreement was within 10% of the certified values. In order to ascertain that measurements from differently preserved samples were comparable, fresh samples were collected and preserved in formaldehyde, 70% ethanol, freeze-dried or oven-dried for comparison. We were satisfied with heavy metal analyses results. Concluding remarks A total of 844 Halobates samples were analyzed for heavy metals of which 293 were collected from the Atlantic Ocean and the rest were from the Pacific Ocean. Only Cd was analyzed for the Atlantic samples and results have been published (see list of publications; original data are not available). Insect samples from the Pacific were analyzed for 25 elements but only data of the following heavy metals are available: - Cr (chromium), Cu (copper), Pb (lead), Mn (manganese), Ni (nickel), Ti (titanium) and Zn (zinc). Data on cadmium have been published (original data are in Lanna Cheng archive, UCSD) but data on the other 7 heavy metals remain largely unpublished.
description: The "Specimen analysis records - derived data for 7 elements" tables originate from 63 sheets of dot-matrix computer printouts. The sheets were each scanned using an Epson Expression 10000XL flatbed scanner and saved using the TIFF format. The scans were processed in Adobe Photoshop in preparation for the optical character recognition (OCR) process. Headers, miscellaneous markings, and background line colors were removed, and a filter was applied to sharpen font edges. The edited images were saved as JPEGs . These images were next converted into Microsoft Excel XLSX format using OCR software. The converted data in the XLSX files were compared to the JPEG images and corrections were made directly to the XLSX spreadsheet data entries where errors in the OCR conversion were found. In the R programming environment, the 63 corrected XLSX files were read into dataframes, and headers and metal values were added. The dataframes were then concatenated and written to a single XLSX file. The XLSX file was additionally saved in CSV format.