PMC

Change in species composition on a per unit basis in Southeast Alaska (A–E) and Southcentral Alaska (F–H). Each panel represents the number of units dominated by a given species in the Cameron surveys (A and F, dragon kelp; B, giant kelp; C and G, bull kelp; D and H, mixed bull–dragon kelp; E, mixed bull–giant kelp), and the bars in each panel show the number of units dominated by each species or mix of species in the ShoreZone surveys (E: dragon kelp; M: giant kelp; N: bull kelp). The numbers of units that had no change in species composition are highlighted in colour and with kelp species icons.

(A) pH traces from automated loggers in kelp beds (green) and urchin barrens (grey) at St. Helens Island (SHI); for shallow kelp beds (LHS plot, from 29^th to 31^st Oct 2013; see legend), and for deeper (16 m depth) kelp beds and barrens ground (RHS plot, from 5^th June to 7^th Aug 2014); temperature traces in kelp beds and barrens (navy blue and red, respectively) and open ocean pH (blue) are also shown, see legend. (B) Composite plot of mean diurnal pH for shallow kelp beds (Oct 2013), deep kelp beds (June-Aug 2014), regional open ocean surface pH (June-Aug 2014 at Maria Island (MI)), and urchin barrens (June-Aug 2014); see S3 Fig for seaonality in regional open ocean surface pH and temperature in .

Correlation matrices for the 2020–2021 farm season. Within each season’s correlation matrix, the upper triangle represents the pairwise correlations of collected traits for skinny kelp related progenies (sugar kelp x skinny kelp). In contrast, the lower triangle represents the pairwise correlations of collected traits for only sugar kelp related progenies (sugar kelp x sugar kelp). Numbers represent correlation coefficients between every two variables. Significant correlations (P < 0.05) have circles with the circle size indicating the absolute values of correlation coefficients

Correlation matrices for the 2019–2020 farm season. Within each season’s correlation matrix, the upper triangle represents the pairwise correlations of collected traits for skinny kelp related progenies (sugar kelp x skinny kelp). In contrast, the lower triangle represents the pairwise correlations of collected traits for only sugar kelp related progenies (sugar kelp x sugar kelp). Numbers represent correlation coefficients between every two variables. Significant correlations (P < 0.05) have circles with the circle size indicating the absolute values of correlation coefficients