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

(10% and 6% for shrimp and clams, respectively). However, under this scenario projected pro- duction to the end of the century remains relatively unchanged, with shrimp staying at 10% above 2000 levels, and clams increasing slightly to 9% over 2000 landings. In contrast, under the RCP 8.5 scenario both species continue to increase in production through to 2090 (Fig 7). As observed in the other management areas, snow crab is also projected to decline in the Newfoundland and Labrador management area. The losses are similar between the RCP cli- mate scenarios, while the landings for 2090 declined slightly from the 2050 values, from 13– 12% in 2050 (RCP 2.6 and RCP 8.5, respectively) to 16% in 2090 (for both climate scenarios). The area is expected to see minor changes for lobster, scallop and mussel landings under the quartet of projections, with mussel production presenting an exception under RCP 8.5 at the end of the century with an expected increase of 21% by 2090 under RCP 8.5. Nevertheless, all three species represent minor fractions of the region’s landings and have much higher pro- duction values in the other two management areas. Impact assessment results Exposure. Scaling the DBEM-modelled changes in landings by species value in 2000 resulted in an array of indicator scores representing the changes in the seven assessed species (Table 2). In most quartets of exposure scores, the 2090 time-step had higher exposure than the 2050 time-step—NL was an exception to this trend under the RCP 8.5 scenario (Table 2).

The RCP 8.5 climate scenario drove increased landings for some fisheries, thus the scores cor- responding to this climate scenario were higher for both the Gulf and the Newfoundland and Labrador management areas. Conversely, they were lower in the Maritime management area (and for the region as a whole) (Table 2). The Maritime management area was projected to experience losses across its quartet of exposures with the 2090 time-step and RCP 8.5 climate scenario resulting in losses of nearly 50% of the value-scaled landings (Table 2). The scores for this management area were relevant to the NB-mar and NS-mar provincial sub-sections. Conversely, the Gulf area scored slightly positive in all scenarios, however 2090 for both climate scenarios had slightly reduced scores compared to 2050 (Table 2). The Gulf management area scores were applied to PEI and Que as well as the Gulf sub-sections of NB and NS. Notably, the Newfoundland and Labrador man- agement area scored (slightly) negative under the RCP 2.6 scenario for both time-steps, but had positive scores under the RCP 8.5 scenario, largely due to the stronger gains in shrimp for the area under the latter treatment (Table 2). The Newfoundland and Labrador management area was only applied to the province of NL. The score as calculated for the whole Atlantic region was slightly negative under the quartet of treatments, although the region as a whole was not included in the final index calculation (Table 2). Social vulnerability. The scores for each of the indicators that contributed to vulnerability

are presented in Tables 3 and 4. The scores are presented as both the raw scores before normal- isation of the data, as well as the normalised indicator scores which were used to calculate the final impact index scores. The cumulative vulnerability scores (i.e., combinations of sensitivity and adaptive capacity) are presented in the final risk index in Table 5. Quebec scored very low in nearly all of the indicators contributing to vulnerability (Tables 3 and 4). The aquaculture indicator was the only exception due to the relatively small shellfish aquaculture sector in the province (Table 4). The low scores are likely a result of the social structure of Que being unique among the assessed provinces in many respects. Industry in the province is less dependent on natural resources and its population is an order of magnitude larger than any other province in the assessment–the population of Que is more than three times larger than the four other provinces combined. Conversely, Que has the smallest OA and climate change impacts on Atlantic Canadian fisheries PLOS ONE | https://doi.org/10.1371/journal.pone.0226544 January 10, 2020 18 / 29