Potential socioeconomic impacts from ocean acidification and climate change effects on Atlantic Canadian fisheries

minimal (S1U–S1X Fig), and amounted to less than 1% of the total predicted landings for the whole of the Atlantic Canadian region. When the modelled projections of this small initial dis- tribution fell to zero, it resulted in relative change of -100%. The outputs based on the third cli- mate model (MPI) predicted higher initial abundances and therefore less extreme declines of snow crab in the area (reductions of 20% and 39%, for RCP 2.6 and RCP 8.5, respectively). Therefore, a mean of the three climate model impacts was adopted for the analysis of this spe- cies. Under this approach snow crab is projected to decline in the Gulf management area by 17–18% in 2050 (RCP 2.6 and RCP 8.5, respectively) and 21–39% by 2090 (RCP 2.6 and RCP 8.5, respectively) from the 30,000 tonnes landed in 2000 (Fig 7). Newfoundland and Labrador management area. The Newfoundland and Labrador management area not only encompasses the largest area of marine waters (Fig 1) but also has some of the highest landings, by weight, with over 50% of the total Atlantic Canadian catch for northern shrimp, snow crab and Stimpson’s surf clam in 2000 (Fig 7). The patterns for north- ern shrimp and Stimpson’s surf clams were similar for both scenarios and time-steps, albeit at different scales, as the shrimp landings were more than four times that of the clam. For both species under the RCP 2.6 scenario there are modest projected increases in landings by 2050 Fig 8. Relative changes in distribution for selected commercially targeted shellfish species. Northern shrimp (a

-top), American oyster (b—middle) and snow crab (c—bottom), for 2050 (left) and 2090 (right) under RCP 8.5, highlighting south to north trend of changing species distributions. Colour scales indicate relative change predicted by DBEM for each half-degree latitude by half-degree longitude cell and do not indicate absolute values. Darkest shades (in both directions) correspond to cells with low absolute values, where small absolute changes result in large relative changes (e.g., a shift of 1T to 2T results in a 100% increase, while a change of 10T to 15T only leads to a 50% increase). Changes that exceeded +100% were set to 100% to maintain coherent colour scales. See S1 Fig for baseline DBEM distributions and figures for other species and climate treatments. https://doi.org/10.1371/journal.pone.0226544.g008 OA and climate change impacts on Atlantic Canadian fisheries PLOS ONE | https://doi.org/10.1371/journal.pone.0226544 January 10, 2020 17 / 29