DOI: 10.5061/dryad.2pm6f
title: Data from: Oxygen depletion in coastal seas and the effective spawning stock biomass of an exploited fish species

description: Environmental conditions may have previously underappreciated effects on
 the reproductive processes of commercially exploited fish populations, for
 example eastern Baltic cod, that are living at the physiological limits of
 their distribution. In the Baltic Sea, salinity affects neutral egg
 buoyancy, which is positively correlated with egg survival, as only water
 layers away from the oxygen consumption-dominated sea bottom contain
 sufficient oxygen. Egg buoyancy is positively correlated to female spawner
 age/size. From observations in the Baltic Sea, a field-based relationship
 between egg diameter and buoyancy (floating depth) could be established.
 Hence, based on the age structure of the spawning stock, we quantify the
 number of effective spawners, which are able to reproduce under ambient
 hydrographic conditions. For the time period 1993–2010, our results
 revealed large variations in the horizontal extent of spawning habitat
 (1000–20 000 km2) and oxygen-dependent egg survival (10–80%). The novel
 concept of an effective spawning stock biomass takes into account
 offspring that survive depending on the spawning stock age/size structure,
 if reproductive success is related to egg buoyancy and the extent of
 hypoxic areas. Effective spawning stock biomass reflected the role of
 environmental conditions for Baltic cod recruitment better than the
 spawning stock biomass alone, highlighting the importance of including
 environmental information in ecosystem-based management approaches.
description: Hinrichsen et al_Royal
 Society Open Science_Bongogrid_Fig1This file contains the
 geographic coordinates of the specific locations where plankton samples
 (including cod eggs) for analyses in this manuscript were collected (see
 read me file for details).Hinrichsen et al_Royal
 Society Open Science_Baltic cod spawning stock size and age
 composition_Fig2This worksheet
 summarizes the Baltic cod stock characteristics (number per age class,
 mean weight, spawning stock biomass, mean age) for the time-series
 1966-2011(see read me file for details).Hinrichsen et al_Royal
 Society Open Science_Egg survival_Fig3This worksheet contains
 the mean hydrographic conditions and resulting egg survival for the period
 1951-2010 for Bornholm Basin (see read me file for
 details).Hinrichsen et al_Royal
 Society Open Science_cod egg diameter and water density
 correlation_Fig4This worksheet lists the
 mean measured diameter of cod eggs derived from multinet hauls across
 Bornholm Basin and the correlated water density in which they were caught
 (see read me file for details).Hinrichsen et al_Royal
 Society Open Science_O2 and survival on water density levels
 BB_Fig5This file contains six
 worksheets, each with a datasets on O2 content and the corresponding
 oxygen related survival of cod eggs on the positional grid of the Bornholm
 Basin (1 dataset for each combination of 3 different water density levels
 x 2 timepoints) (see read me file for details).Hinrichsen et al_Royal
 Society Open Science_spawning area extensions and corresponding egg
 survival_Fig6 and 7This worksheet contains
 data for spawning area extensions, and mean oxygen content and oxygen
 related cod egg survival for each area, for different water density levels
 and months for the time period 1993-2010 (see read me file for
 details).Hinrichsen et al_Royal
 Society Open Science_Stock-recruitment_Fig8This worksheet contains
 the data underlying the stock-recruitment plots in this manuscript for the
 years 1966-2012 (see read me file for details).