Data from: Spatial structuring and life history connectivity of Antarctic silverfish along the southern continental shelf of the Weddell Sea ...

• Main Authors: Caccavo, Jilda Alicia, Ashford, Julian R., Ryan, Svenja, Papetti, Chiara, Schröder, Michael, Zane, Lorenzo
• Format: Dataset
• Language: English
• Published: Dryad 2020
• Subjects: Pleuragramma antarctica; Antarctic fish; otolith chemistry; biophysical interaction; life-history connectivity; Antarctic; The Antarctic; Weddell Sea; Weddell; Atka; Filchner Trough; Filchner Ice Shelf; Antarc*; Antarctic silverfish; Antarctica; Ice Shelf
• Online Access: https://dx.doi.org/10.5061/dryad.h44j0zpgs; https://datadryad.org/stash/dataset/doi:10.5061/dryad.h44j0zpgs

A multidisciplinary approach was employed to examine a physical-biological population hypothesis for a critical forage species, the Antarctic silverfish (Pleuragramma antarctica). A previous study had shown strong gene flow along the westward Antarctic Slope Current, in addition to spatially recurring length modes that provided evidence for episodic connectivity. In this paper, otolith nucleus chemistry from a subset of fish collected in the southern Weddell Sea as part of a hydrographic survey of the Filchner Trough system was used to test between connectivity scenarios. Nucleus chemistry, which reflects environmental exposure during early life, showed significant spatial structuring despite homogeneity in microsatellite allele frequencies. Mg×Ca-1 and Sr×Ca-1 differentiated length modes, and Mg×Ca-1 showed significant contrasts between Atka Bay, Halley Bay, and Filchner Trough. Physical-biological mechanisms may help reconcile structuring shown by otolith chemistry, length, and abundance data with prior ... : Field sampling Antarctic silverfish were collected in the southern Weddell Sea from January – February 2014 as part of the research cruise PS82 (ANT-XXIX/9) by the RV Polarstern, investigating the Filchner Outflow System. For this, a Seabird 911+ CTD (Conductivity-Temperature-Depth), measuring salinity, temperature, and pressure, attached to a carousel with 24 water bottles, was deployed to investigate the physical environment in the region around the Filchner Trough, including the course of the AACC and MWDW flowing towards the Filchner Ice Shelf (Knust & Schröder, 2014). Conductivity and temperature sensors were calibrated before and after the cruise by Seabird Electronics; in addition, conductivity was corrected after calibration using salinity measurements from water samples measured by two Optimare Precision Salinometers. A total of 142 CTD profiles were obtained for oceanographic transects across and along the continental slope and shelf-break, and across the eastern shelf adjoining the trough. The ...