Figure 3
From: Exposure history determines pteropod vulnerability to ocean acidification along the US West Coast
Exposure history to low Ωar in the natural environment and its impact on the probability of survival. (a) Survival probability was determined by taking into account pteropod exposure history over the last 5–6 weeks in the CCE, based on the model outputs (b). The survival probability was highest at the offshore stations with no exposure history (stations 37, 50, and 106), followed by a decline at stations of “moderate” exposure (undersaturation days of ~1.5 at stations 26 and 28; exposure conditions represented on Track 3), and the lowest survival probability at the most severe exposures (undersaturation days of ~5 for stations 47 and 38; exposure conditions represented on Tracks 1 and 2, respectively). Station number is shown inside each circle. Tracks not shown for the offshore station. (b) Daily averaged spatial tracks and time history of aragonite saturation state for modeled particles released 1 August 2013 along cross-shelf lines spanning 126.0°W to 123.5°W, and tracked both forward and backward in time to span 1 July–31 August 2013. Particle tracking includes vertical migration of particles between 10 and 100 m. For each track we show the instantaneous values of aragonite saturation state (indicated by shading); these are further illustrated by the Hovmöller diagrams of saturation history for all tracked particles as a function of days since 1 August 2013 (x-axis) and their cross-shelf location on the release date (y-axis). Track 1 (station 47) covers a cross-shelf line near Heceta Head (44.6°N) and Track 2 (station 38) covers a cross-shelf line off Columbia River (46.2°N); both tracks are characterized by severe exposure (0.6 ≤ Ωar ≤ 0.8) for approximately 3–4 weeks). Track 3 (stations 26 and 28) was released just off 47.7°N with exposure to less severe conditions (0.8 ≤ Ωar ≤ 1) for approximately 2 weeks. Circles indicate start locations of a representative subsample of the tracks on 1 July 2013; rectangles indicate their location on 1 August 2013; stars indicate their end locations on 30 August 2013. The figure was created using Ferret version 6 (http://www.ferret.noaa.gov/Ferret/).
