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

In other socioeconomic assessments of potential OA effects on fisheries, an indicator repre- senting alternative employment options has been used as a key component of adaptive capacity [14,17]. This is similarly relevant for fisheries in Atlantic Canada, if the availability of fisheries resources decline people currently employed in the industry will need to shift to other employ- ment sectors. As previously mentioned, due to the seasonal nature of fisheries employment in Atlantic Canada it is difficult to distinguish patterns of employment in fisheries as separate from employment in other sectors. Thus, provincial unemployment rates were used to indicate the potential for alternative employment options to fishing [15,17] following an assumption that low provincial unemployment would mean a higher demand for potentially displaced fishers. Provincial unemployment is particularly relevant in Atlantic Canada where rates were 3% to 10% above national rates during the assessment baseline year [51]. Data were averaged across a 10 year period bracketing the year 2000 baseline for the assessment (i.e. 1996–2005 - [51]). The reciprocal of provincial unemployment values were used so that lower provincial unemployment increased adaptive capacity. Education within a society provides an indication of how well a community will be able to respond to changing conditions and has been used in other socioeconomic assessments of OA [15,17]. Higher education levels are generally seen as presenting more opportunities to adapt,

while lower education rates limit options and capabilities to respond to change. The percent of adult populations with at least some post-secondary education was used to estimate the educa- tion level of the five assessed provinces [52]. As with the unemployment data, provincial edu- cation were averaged from 1996 to 2005. The final element that was considered as part of each province’s adaptive capacity was the extent to which potentially OA-impacted species are currently cultured in the region. Aquacul- ture production is expected to be more resilient to OA and climate change than wild harvest, since many environmental conditions can be at least partially controlled or compensated for– especially when hatcheries are used to rear organisms through the most susceptible life-stages [53]. Thus, a strong aquaculture sector could potentially strengthen a community’s ability to respond to OA and climate change. In Atlantic Canada there is no aquaculture production of crustacean species so the aquacul- ture indicator only includes mollusc production. The indicator was constructed to reflect pat- terns in development within the industry as well as relative contribution to total provincial shellfish production. First, the trend in mollusc aquaculture production was estimated for each province by comparing the average annual production for 2001 to 2010 against average annual production for 1991–2000. Second, the fraction of total shellfish production (including both wild harvest and aquaculture) sourced from mollusc species (using the year 2000 average

annual production) was calculated. These two terms were then multiplied together to obtain the indicator value (Eq 5). Aqp ¼ ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi Aqua2001 2010 Aqua1991 2000 � � � Mol1991 2010 Tot1991 2010 � � s Eq 5 Where Aqp is the aquaculture indicator score for province p. Aqua denotes the average aqua- culture production for the subscripted time-period; Mol indicates mollusc production; and Tot indicates total shellfish production. As with the previous index components, each of the adaptive capacity indicators were trans- formed linearly to score between 0 and 1. To align with the directionality of the other compo- nents in the framework the normalised scores were subtracted from 1 so that weaker adaptive capacity indicators had higher scores (i.e., closer to 1) and therefore contributed to the poten- tial impact. As with the indicators for sensitivity, the individual adaptive capacity indicators OA and climate change impacts on Atlantic Canadian fisheries PLOS ONE | https://doi.org/10.1371/journal.pone.0226544 January 10, 2020 11 / 29