Fig 1.
Map of study sites along the Oregon coast.
Subtidal bathymetry is shown with gray lines, and scaled in m depth.
Fig 2.
Wasting frequency at nine (eight in 2015) sites spread across three capes in 2014 and 2015.
A. and D., CF = Cape Foulweather; B. and E., CP = Cape Perpetua; and C. and F., CB = Cape Blanco. Note that the y-axis scale varies among capes for 2015 data. See Fig 1 for site names, here coded as initials.
Fig 3.
Frequency of small/juvenile P. ochraceus with wasting compared to frequency of adult P. ochraceus with wasting, averaged across sites within capes (± 1 SE).
Asterisks indicate months in 2014 in which juveniles had lower % wasting, and matched pairs statistics indicate overall differences across months within capes. Data were sine-1 square root-transformed for analysis. If September data are dropped for CB, t = 3.33, p = 0.004, n = 11.
Table 1.
Comparison of percentages of total number of P. ochraceus that were “normal” or “wasting” (shown in paired columns) in all combinations of color and subhabitat by month, summer 2014a.
Fig 4.
Frequencies of sea star wasting symptoms for P. ochraceus through time, summer 2014, at 9 sites.
Top row = Cape Foulweather sites, middle row = Cape Perpetua sites, and bottom row = Cape Blanco sites. See Fig 1 caption for site names.
Fig 5.
Decline in adult and juvenile P. ochraceus density, spring and summer 2014, at six sites.
Differences in overall average densities (ln-transformed data in a 2-way ANOVA testing site and month without interaction term) are shown by lower case letters in legend, where sites sharing the same letter were not different at p > 0.05.
Table 2.
Log-linear regressions of change in P. ochraceus density from April through August 2014a.
Fig 6.
Magnitude of change from summer 2014 to summer 2015 in density (number/m2) of P. ochraceus at seven sites.
Sites are color coded by cape, with blue = Cape Foulweather, red = Cape Perpetua, and green = Cape Blanco. A. Change in adult density, B. Change in juvenile density, C. Change in recruit density, D. Change in total sea star density. Weight ranges for each life history stage are approximate, and based on Menge 1974, which found that animals up to ~70g were non-reproductive and animals from ~100 g and larger had ripe gonads (before spawning). See Fig 2 caption for site names.
Fig 7.
Average (+ 1SE) proportion of recruits of P. ochraceus over time at seven sites.
Sample sizes were ~200 individuals per site per sample date. See Methods for details.
Fig 8.
Size frequencies of P. ochraceus from 2012 to 2015 at three representative sites, one per cape.
Samples were taken in spring (black bar) and summer (white bar) in each year except for Boiler Bay, where high wave action prevented collection of the summer 2015 sample. Sample size was ~200. Mean wet weight (± 1 SE) is shown for each sample date.
Fig 9.
Annual average (± 1SE) number of P. ochraceus settlers at four sites.
Vertical dashed line indicates the onset of SSWD.
Table 3.
Test of effects of cape, zone, year and month on P. ochraceus settlementa.
Fig 10.
Comparison of predation rate on mussels, Mytilus californianus, in summer 2014 compared to rates averaged across 1990–2013 at six sites.
Numbers above each pair of bars show the magnitude of decrease in predation rate.
Table 4.
Nested 2-way analysis of variance testing the effects of cape, site nested within cape, and era (prewasting vs wasting) on predation rates on transplanted musselsa.
Fig 11.
Air and water temperatures by month at three sites.
Fogarty Creek and Cape Blanco North climatologies (black lines) were averaged from 1999 to 2014, and at Strawberry Hill from 1993 to 2014. The red line shows 2014 data. Climatologies are monthly means ± 1 SD and 2014 data are monthly means ± 1 SE.
Table 5.
Two-way analyses of variance testing effects of cape and month on intertidal air and water temperatures at Capes Foulweather, Perpetua, and Blanco for April-June 2014.
Fig 12.
Log-linear regression between water temperature averaged over the previous two weeks of the sample date and the frequency (arcsin-transformed) of SSWD on the sample date.