The spread of infection from reservoir host populations is a key mechanism for disease emergence and extinction risk and is a management concern for salmon aquaculture and fisheries. Using a quantitative environmental DNA methodology, we assessed pathogen environmental DNA in relation to salmon farms in coastal British Columbia, Canada, by testing for 39 species of salmon pathogens (viral, bacterial, and eukaryotic) in 134 marine environmental samples at 58 salmon farm sites (both active and inactive) over 3 years. Environmental DNA from 22 pathogen species was detected 496 times and species varied in their occurrence among years and sites, likely reflecting variation in environmental factors, other native host species, and strength of association with domesticated Atlantic salmon. Overall, we found that the probability of detecting pathogen environmental DNA (eDNA) was 2.72 (95% CI: 1.48, 5.02) times higher at active versus inactive salmon farm sites and 1.76 (95% CI: 1.28, 2.42) times higher per standard deviation increase in domesticated Atlantic salmon eDNA concentration at a site. If the distribution of pathogen eDNA accurately reflects the distribution of viable pathogens, our findings suggest that salmon farms serve as a potential reservoir for a number of infectious agents; thereby elevating the risk of exposure for wild salmon and other fish species that share the marine environment.

Although billions of dollars have been spent restoring degraded watersheds worldwide, watershed-scale studies evaluating their effectiveness are rare. To mitigate damage from past logging activities, the floodplain of the upper Chilliwack River watershed (ϳ600 km 2 ) was extensively restored from 1996 to 2000 through off-channel habitat restoration. The contribution of restored habitat to watershed-scale production of wild coho (Oncorhynchus kisutch) smolts was estimated through an extensive mark-recapture program in 2002. 27%-34% of the production of the estimated 247 200 out-migrating coho smolts could be attributed to the 157 000 m 2 of newly created habitat. Area-based habitat models from the literature performed reasonably well in predicting smolt production from restored habitat, providing an acceptable first-order approach for evaluating production benefits of restoration. The costs of smolt production integrated over 30 years ranged from US$0.69-US$10.05 per smolt, falling within the range of hatchery production costs reported elsewhere (typical cost of ϳUS$1.00 per smolt) at the most cost-effective restoration sites. This study demonstrates that large-scale habitat restoration can effectively enhance fish production at a watershed scale, at a cost that may be comparable to hatchery smolt production.Résumé : Bien que des milliards de dollars aient été dépensés à restaurer des bassins versants dégradés dans le monde entier, les études à l'échelle du bassin versant qui s'intéressent à l'efficacité de ces actions sont rares. Afin d'atténuer les dommages causés par les activités de coupe de bois passées, la plaine inondable du bassin versant du cours supérieur de la rivière Chilliwack (ϳ600 km 2 ) a fait l'objet d'une vaste restauration de 1996 à 2000 reposant sur la restauration d'habitats à l'extérieur du chenal. La contribution des habitats restaurés à la production de saumoneaux sauvages de saumons cohos (Oncorhynchus kisutch) à l'échelle du bassin versant a été estimée dans le cadre d'un vaste programme de marquage-recapture en 2002. De 27 % à 34 % de la production d'un total estimé de 247 200 saumoneaux cohos ayant migré vers la mer peut être attribuée aux 157 000 m 2 de nouveaux habitats créés. Les modèles d'habitat reposant sur la superficie recensés dans la littérature prédisent raisonnablement bien la production de saumoneaux d'habitats restaurés, fournissant une approche de premier ordre acceptable pour évaluer les avantages de la restauration en ce qui concerne la production. Les coûts de la production de saumoneaux intégrés sur 30 ans allaient de 0,69 $US à 10,05 $US par saumoneau, soit dans la fourchette des coûts de production en écloserie rapportés dans d'autres ouvrages (coût typique de 1,00 $US par saumoneau) pour les sites restaurés les plus efficaces en terme de coûts. L'étude démontre que la restauration d'habitats à grande échelle peut accroître efficacement la production de poissons à l'échelle du bassin versant à un coût qui pourrait se comparer à la production de saumoneaux en écloser...

Ports play a central role in our society, but they entail potential environmental risks and stressors that may cause detrimental impacts to both neighboring natural ecosystems and human health. Port managers face multiple challenges to mitigate risks and avoid ecosystem impacts and should recognize that ports are embedded in the wider regional coastal ecosystem. Cumulative impacts of anthropogenic stressors have the potential to further burden the existing suite of natural stressors, particularly where ports are located in embayments and estuaries. Environmental monitoring in ports should thus develop a comprehensive, holistic, multilayered approach integrated in the wider ecosystem that will help managers better achieve sustainable development, a major goal of the United Nations’ 2030 agenda and Decade of Ocean Science for Sustainable Development (2021–2030). This practice bridge showcases the experience of the second Canadian Healthy Ocean Network (CHONe2) in Baie des Sept Îles (BSI, Quebec; the fourth largest industrial port in Canada) laying the foundations of holistic environmental monitoring in ports. We describe the partnership model (i.e., engaging scientists, local authorities, an independent organization, and local industries), synthesize the multidisciplinary studies that turned environmental monitoring into a systemic investigation of the biological and physical components of BSI, integrate the developed scientific knowledge into a social–ecological–environmental system, present an innovative near real-time monitoring approach, and discuss implications for management and policy. The CHONe2 experience in BSI aligns with the decade’s road map for sustainable development and provides elements that could be adapted to other commercial ports. By suggesting a set of best practices (e.g., multidisciplinarity, transparency, inclusivity, participatory modeling), we hope to spark new interest in environmental monitoring as a path to conciliate development and sustainability of ports and other high-use marine areas.