A unique demersal fish fauna in the Chukchi Borderland, Central Arctic Ocean

The samples of fish were collected in the Chukchi Borderland (east to west: 179.99°E to 154.68°W, anticlockwise; south to north: 73.69°N to 78.38°N), Central Arctic Ocean by the Chinese National Arctic Research Expedition (CHINARE) using bottom trawls during voyages from 2017 to 2020 (detailed in the documents). A suite of elemental concentrations of ratios in the edge and core of the otolith samples were measured in spot mode via laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) at Createch Testing Technology (Tianjin, China) using an ICP–MS instrument (Analytik Jena PlasmaQuant MS, Denmark) coupled with a 193 nm excimer laser ablation system (RESOlution SE 193 nm, RESOlution, Australia). Off-line processing of the analytical data, including background and analyte signals, such as time-drift correction and quantitative calibration, was performed via ICPMSDataCal software. The continuous line scans of otolith were conducted at the Analytical and Testing Center of the Third Institute of Oceanography, Ministry of Natural Resources, China, using an ICP–MS instrument (iCAP RQ, Thermo, USA) coupled with a 193 nm excimer laser ablation system (RESOlution SE 193 nm, RESOlution, Australia). In addition, we took dorsolateral muscle from fish individuals, and the ratios of heavy to light carbon (C) and nitrogen (N) were measured at the Analytical and Testing Center of the Third Institute of Oceanography, Ministry of Natural Resources, China using a Vario ISOTOPE cube elemental analyser (Elementar Analysensysteme GMBH, Hanau, Germany) coupled to an IsoPrime100 isotope ratio mass spectrometer (Isoprime, Cheadle, United Kingdom). Fish body lengths were measured to an accuracy of 1 mm.

Methods
The samples of fish were collected in the Chukchi Borderland (east to west: 179.99°E to 154.68°W, anticlockwise; south to north: 73.69°N to 78.38°N), Central Arctic Ocean by the Chinese National Arctic Research Expedition (CHINARE) using bottom trawls during voyages from 2017 to 2020 (detailed in the documents). 

A suite of elemental concentrations of 43CaCO3 (weight percent, wt%), 88Sr (parts per million, ppm), and 137Ba (parts per million, ppm) in the edge and core of the otolith samples were measured in spot mode via laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) at Createch Testing Technology (Tianjin, China) using an ICP–MS instrument (Analytik Jena PlasmaQuant MS, Denmark) coupled with a 193 nm excimer laser ablation system (RESOlution SE 193 nm, RESOlution, Australia). Off-line processing of the analytical data, including background and analyte signals, such as time-drift correction and quantitative calibration, was performed via ICPMSDataCal software. The continuous line scans of otolith were conducted at the Analytical and Testing Center of the Third Institute of Oceanography, Ministry of Natural Resources, China, using an ICP–MS instrument (iCAP RQ, Thermo, USA) coupled with a 193 nm excimer laser ablation system (RESOlution SE 193 nm, RESOlution, Australia). The analytical data were reduced by Iolite version 4.The dataset contains a .docx file listing the fish species with the otolith microchemical measurements and their station information (No. 1), a .xlsx file listing the elemental ratios determined via spot sampling in the otolith core and edge zones (No. 2), as well as nine .xlsx files of continuous line scans across the otolith structures (Nos. 3.1 to 3.9).

We took dorsolateral muscle from fish individuals, and the ratios of heavy to light carbon (C) and nitrogen (N) were measured at the Analytical and Testing Center of the Third Institute of Oceanography, Ministry of Natural Resources, China using a Vario ISOTOPE cube elemental analyser (Elementar Analysensysteme GMBH, Hanau, Germany) coupled to an IsoPrime100 isotope ratio mass spectrometer (Isoprime, Cheadle, United Kingdom). Fish body lengths were measured to an accuracy of 1 mm (file No, 4).