From farm sustainability to ecosystem sustainability: Exploring the limitations of farm-applied aquaculture eco-certification schemes.

Aquaculture eco-certification schemes provide standards against which individual farms are assessed, and those farms that comply with eco-certification criteria receive certified status. These schemes aim to improve aquaculture sustainability, but the site-by-site approach of eco-certification can be a barrier to the inclusion of ecosystem perspectives in the evaluation of farm sustainability. However, the ecosystem approach to aquaculture demands a management approach that considers broader scale ecosystem impacts. This study explored how eco-certification schemes and processes account for potential ecosystem impacts of salmon farms. Interviews with eco-certification auditors, salmon producers, and eco-certification staff were conducted. The experience of participants and information from eco-certification scheme criteria and other eco-certification scheme documents were used to identify thematic challenges associated with the consideration of ecosystem impacts including: assessing far-field impacts, managing cumulative effects, and anticipating ecosystem risks. Results indicate that eco-certification schemes work within the limitations of farm-scale application of global eco-certification standards to address potential ecosystem impacts by: (1) including eco-certification scheme criteria that address ecosystem impacts, (2) relying on the experience, expertise, and judgement of eco-certification auditors, and (3) referencing and deferring to local regulations. Results indicate that eco-certification schemes can address ecosystem impacts to some degree, despite their site-by-site approach. The integration of additional tools while supporting the capacity of farms to apply those tools, as well as increasing transparency during compliance assessment could help eco-certification schemes shift from providing assurance of farm sustainability to providing assurance of ecosystem sustainability.

Corticosterone levels of Atlantic puffins vary with breeding stage and sex but are not elevated in poor foraging years.

Corticosterone (CORT) levels in seabirds fluctuate across breeding stages and in different foraging conditions. Here we use a ten-year data set to examine whether CORT levels in Atlantic puffins differ in years with high or low availability of capelin, the preferred forage species. Female puffins had higher CORT levels than males, possibly related to cumulative costs of egg production and higher parental investment. Puffins had higher CORT levels and body mass during pre-breeding than during chick rearing. Yearly mean chick growth rates were higher in years when adults had higher body mass and in years where adults brought chicks a lower percentage of non-fish (invertebrates/larval fish) food. Unlike most results from seabird species with shorter chick-rearing periods, higher CORT levels in puffins were not associated with lower capelin abundance. Puffins may suppress CORT levels to conserve energy in case foraging conditions improve later in the prolonged chick-rearing period. Alternatively, CORT levels may be lowest both when food is very abundant (years not in our sample) or very scarce (e.g., 2009 in this study), and increase when extra foraging effort will increase foraging efficiency (most years in this study). If these data primarily represent years with medium to poor foraging, it is possible that CORT responses to variation in foraging conditions are similar for puffins and other seabirds.