Ocean Frontier 2025:

Escaped farmed salmon represent one of the most persistent and politically charged environmental challenges in aquaculture governance. Building on Naylor et al.’s 2005 global review, this study provides an updated and comparative assessment of farmed salmon escape policies across 14 major production regions in ten countries. Using government legislation, industry codes, NGO reports, and peer-reviewed literature, policies were analyzed under five key themes: regulatory frameworks, production requirements, reporting and recapture, monitoring, and sanctions. Findings show that all major producing regions now have formal escape regulations, reflecting the growing recognition of this issue within sustainable aquaculture and blue economy strategies. However, the effectiveness of these policies remains uneven. Most frameworks emphasize reporting and monitoring—actions that document rather than prevent escapes, while few impose strong enforcement mechanisms. Only a small number of regions, notably Chile and Norway, apply substantial sanctions or require technological innovations such as triploid fish and escape-proof nets. The analysis concludes that despite regulatory progress, open-net pen infrastructure makes escapes inevitable, limiting the ecological effectiveness of current policies. Strengthening governance will require not only stricter enforcement but also structural transitions toward semi-closed or land-based systems and inclusive co-management of escaped populations.

The global salmon farming industry is experiencing continuous growth. However, the increasing scarcity and rising cost of fishmeal and fish oil have prompted the search for alternative ingredients. Terrestrial plant-based proteins have not fully met salmon’s essential amino acid requirements, while plant-derived oils cannot provide the desired fatty acid profile in fillets. Cyanobacteria are promising alternatives due to their high protein content and bioactive compounds that may enhance fish health. The most commercially available species are Limnospira platensis and L. maxima. Although protein-rich meals produced from cyanobacteria have been investigated since the 1970s in rainbow trout (Oncorhynchus mykiss) and various tropical herbivorous fish species, research on their inclusion in Atlantic salmon (Salmo salar) diets is relatively recent, emerging mainly in the 2010s. Because physiological responses are species-specific, extrapolating findings from other fish species to Atlantic salmon is challenging. In this study, L. platensis meal produced in a phototrophic system in China was used to partially replace 4, 8, and 12% of soy-based ingredients in low fishmeal (13%) diets formulated to meet the nutritional requirements of freshwater phase Atlantic salmon. The cyanobacterial biomass contained 67% protein and 9% lipid (as-fed basis) and was rich in amino acids (glutamine + glutamic acid, asparagine + aspartic acid, leucine), fatty acids (palmitic and linolenic acid), and minerals (potassium, phosphorus, sodium). Anti-nutritional factors such as trypsin inhibitor activity (0.88 TUI/mg) and phytate content (10.8 mg/g) were lower than in typical soy products. The experimental diets were isonitrogenous (43% crude protein), isolipidic (18% crude lipid), and isocaloric (20 MJ/kg gross energy). Main fatty acids were oleic, palmitic, and linoleic acid. Increasing cyanobacterial meal inclusion slightly reduced overall mineral content, except sodium. Fifty Atlantic salmon parr (initial weight: 48 g) were distributed into 16 tanks (0.3 m³ each) using a randomized complete block design with four tanks per dietary treatment. Fish were assessed monthly for production parameters, and final sampling occurred after 129 days. During the first three months, dietary treatments did not significantly affect growth. However, by the fourth month, fish fed the cyanobacterial meal-supplemented diets were significantly larger than those fed the Control diet. In the same period, one tank fed the Control diet experienced nearly 60% mortality, while two others had single mortalities. The concentration of mortality in one tank suggests that external factors may have contributed.

With 70% of the Nova Scotian population living within 20 km of the coast, coastal communities across the province are facing increasing effects of climate change-related hazards, with coastal flooding being one of the primary challenges. Coastal areas are exposed to more frequent and intense storm surges, as well as increasing sea level rise, which are direct consequences of climate change. These coastal hazards exacerbate coastal erosion and threaten coastal communities, the critical infrastructure along coastal areas, as well as coastal habitats and livelihoods. Mahone Bay, NS, is one of the communities affected by climate change-related coastal hazards. Coastal Action, in partnership with the award-winning, Indigenous-owned, and operated company 3D Wave Design, produced an Interactive 3D Flood Map for the coastal community of Mahone Bay. The objective was to communicate climate risks and help visualize storm surge in the Mahone Bay Harbour in a user-friendly manner. The 3D visualization also features the “Living Shoreline” project. This is a nature-based solution located along Edgewater Street opposite Mahone Bay’s Historic Three Churches. Phase 1 consisted of a “Demonstration Site”, constructed in 2022, spanning 60m of shoreline. Phase 2, known as the “Expansion site,” will expand Phase 1 by 100 meters, further mitigating the effects of climate change. By incorporating conceptual designs for the living shoreline in this area, we were able to effectively illustrate its potential impact on flood protection for the community. As the effects of climate change and coastal hazards intensify, we aim to provide decision-makers and residents with as much information as possible through this user-friendly tool, enabling them to prepare for future changes and make informed decisions about their future.

The Atlantic region of Canada sees approximately 1,000 maritime incidents annually, ranging from recreational boating to fishing vessel incidents, to large ship occurrences.  A key factor in the effectiveness of emergency response involves the time for a Canadian Coast Guard Vessel (CCG) to get on scene, and the capabilities of the CCG vessel. The response time depends largely on the distance of the incident to the nearest available CCG Search & Rescue (SAR) vessel, as well as the maximum speed of the vessel, and sea conditions. So a very important consideration is the distribution of the CCG resources, whether anchored at a SAR station or another port, or patrolling at sea. Thus, the problem becomes one of optimizing the spatial distribution of SAR vessels to respond fastest to the most expected incidents possible.  Since incident patterns are seasonal, the optimal placements of the available SAR resources may vary by season. The model is also used to examine the effect of choosing SAR vessels with different capabilities by matching their ability to address distinct types of incidents (ex. a vessel onfire), and a cost-benefit analysis of adding additional capability to the CCG fleet.

Over the global ocean, atmospheric aerosol particles containing carbon make a key contribution to Earth’s climate. These aerosols reflect and absorb incoming solar radiation, as well as modify cloud reflective properties, resulting in both cooling and warming effects. In this study, we explore the contributions to atmospheric aerosols of carbonaceous emissions from the ocean, including 1) dimethyl sulfide, 2) other marine volatile organic compounds (VOCs) such as isoprene and 3) primary marine organic aerosol. Additionally, we examine the role of processes related to these emissions, including 1) chemical ageing timescale of the VOCs, 2) gas-to-particle conversion of carbonaceous compounds that form and grow aerosols in the marine air, and 3) deposition of carbonaceous aerosol particles to the ocean surface. We leverage recently developed capabilities in fine-spatial-resolution global modeling of atmospheric composition and compare simulated atmospheric composition with pole-to-pole measurements over the oceans. This work highlights the importance of atmosphere-ocean carbonaceous exchanges and develops knowledge that advances understanding of Earth’s climate system.

Fog can be a major hazard to marine and air transportation in the Arctic and is known to be difficult to model correctly. We examine two fog cases from Iqaluit, Nunavut with very different fog microphysical properties using observed data from the Environment and Climate Change Canada Iqaluit super site. The fog cases are then modelled using the mesoscale atmospheric model Meso-NH. We examine the model’s ability to reproduce the observed meteorology and bulk microphysical properties. This study develops knowledge about fog formation and properties, which is important to improving the prediction of reductions in visibility that affect airports, ships, and the general public.