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.