Abstract
Mariculture is an important component of the seafood industry in Canada, but climate change presents both risks and opportunities. Using the Global Mariculture Production Model (GOMAP), an integrated framework that projects production potential under combined biophysical and socio-economic constraints, we assessed future changes in mariculture production, farm-gate prices, and employment for 13 key species across Canada’s Atlantic and Pacific coasts. Scenarios included two climate pathways (SSP1-2.6 and SSP5-8.5) and three production approaches. Results show substantial regional contracts with important implications for spatial planning and adaptation policy. The Atlantic region shows modest gains under SSP1-2.6 but steep declines under SSP5-8.5 due to climate stress and habitat loss. In contrast, Pacific Canada, particularly central and northern areas, shows strong growth potential under SSP5-8.5, driven by climate-resilient species like Coho salmon and steelhead trout. However, these gains depend on policy, infrastructure, and spatial planning that reconcile mariculture expansion with conservation, Indigenous uses, and other priorities. Rising farm-gate prices may benefit producers but threaten affordability while employment outcomes diverge, with consistent job losses in Atlantic Canada but potential gains in the Pacific. Our findings highlight the need for region-specific adaptation strategies and investment in sustainable and resilient farming systems.
1. Introduction
Canada has a long coastline and a history of being one of the main seafood producers globally (Noakes 2018; Sidey 2018). While capture fisheries have traditionally been the major seafood sector in Canada, mariculture in Canada has grown substantially in recent years, with production increasing from approximately 92 500 tonnes in 1998 to 159 800 tonnes in 2022. (Figs. 1a and 1b) (DFO 2022a). Approximately half of the mariculture production in Canada is from British Columbia (Pacific Canada), with farms located mainly on B.C.’s south coast (Fig. S1). In Atlantic Canada, mariculture production is primarily from New Brunswick (17% of national production), followed by Prince Edward Island (13%), Newfoundland and Labrador (10%), Nova Scotia (5%), and Quebec (1%). Specifically, salmon farming is the largest mariculture industry in Canada, while Canada is also a major producer of mussels, oysters, and clams (Statistics Canada 2024). Regionally, B.C. produces over 75% of the farmed salmon while farms in Atlantic Canada primarily grow shellfish.
Fig. 1. The regional mariculture production in Canada from 1990 to 2022 by (a) total production (thousand tonnes), (b) farm-gate value (million CAD) and (c) Map of Canada’s Exclusive Economic Zones showing subregions used in this study: North Coast, Central Coast, and South Coast in the Pacific; and Newfoundland and Labrador Shelves, Scotian Shelf, and Gulf of St. Lawrence in the Atlantic.Base map: (Natural Earth 2024). Boundary data: EEZ shapefiles (Flanders Marine Institute 2022). Administrative boundaries: (GADM 2022). Projection: WGS 84/ UTM Zone 10N (EPSG:32610).
Mariculture contributes to food security, livelihood and economy of coastal communities in Canada, although its sustainability remains a pressing concern. Mariculture accounts for about 23% of the country’s total seafood production by weight and 37% by value (DFO 2022a). In 2022, the industry contributed around 1.2 billion dollars to the Canadian economy, a substantial increase from 430 million dollars in 1998 (Oyinlola 2019; DFO 2022a). Approximately 3900 individuals are employed full-time in this sector (DFO 2023), with many of these jobs being located in remote areas where traditional industries such as fishing and forestry may be in decline.
While mariculture has the potential to provide benefits to society, climate change poses a significant threat to the sustainability and economic viability of the sector (Ahmed et al. 2019). Increasing water temperature, ocean acidification, rising sea levels, changing weather patterns, and increasing intensity and frequency of extreme climatic events under climate change are impacting the growth and survival of farmed fish and invertebrates (Rice et al. 2017), reducing mariculture production and increasing production costs globally and in Canada (Oyinlola et al. 2022). Additional sustainability concerns include the ecological footprint of farming operations, the spread of diseases and parasites such as sea lice, and potential conflicts with conservation objectives and Indigenous marine uses (Bennett et al. 2018; Sellars and Franks 2024; Vormedal 2024). Meanwhile, climate change may also create opportunities for mariculture. For example, the changing environment may increase the potential suitable mariculture areas (SMAs), and improve the growth and carrying capacity for some species (Guyondet et al. 2015). Sea surface temperature (SST) has increased significantly in Canada’s exclusive economic zones (EEZs). In the Pacific Ocean, SSTs have risen by more than 2 °C during marine heatwaves such as the 2013–2016 event relative to the late 20th-century average (Bush and Lemmen 2019). In Atlantic Canada, summer SSTs could rise by up to 4 °C by the 2050s under high emission scenarios (Greenan et al. 2018). SSTs are projected to rise by approximately 1.8–3.2 °C in the Pacific and 2.0–4.0 °C in the Atlantic by the 2050s under high-emission scenarios (Daust 2013; Bush and Lemmen 2019; Holdsworth et al. 2021; Bush 2022). These changes have profound implications for marine ecosystems and coastal communities across Canada.
In addition to the inherent stressors, shellfish aquaculture faces further climate-driven challenges, including increased predation pressure, the proliferation of invasive species, and habitat degradation from sedimentation and siltation within coastal estuaries (Holden et al. 2019; Stewart‐Sinclair et al. 2020). Rising water temperatures are also associated with reductions in primary productivity and chlorophyll-a concentrations (Guyondet et al. 2015), with direct implications for the food supply and market size of filter-feeding species, such as oysters and mussels (Neokye et al. 2024a, 2024b). In Atlantic Canada, seasonal ice formation creates substantial operational challenges for mariculture. Ice build-up on salmon cages and vessels not only restricts access to farming areas but also adds structural stress and creates hazardous working conditions, thereby increasing production costs and risks for the aquaculture industry (Cavalli et al. 2025). Furthermore, the genetic interactions between farmed and wild populations pose ongoing ecological concerns that can affect both biodiversity and industry resilience in the face of climate change (McGinnity et al. 2003; Glover et al. 2013; Bolstad et al. 2021; Mordecai et al. 2021).
Despite progress in understanding climate impacts on Canadian aquaculture, there remains a lack of integrated, region-specific, scenario-based assessments for mariculture that combine biophysical and socio-economic drivers. Existing studies have largely focused on global trends or single-sector perspectives, leaving important questions unanswered about how regional disparities may influence Canada’s mariculture sustainability and economic resilience. Here, using an integrated modelling approach, we assess how climate change may shape the regional and sectoral dynamics of Canada’s mariculture sector, focusing on suitable marine area (SMA) for Canadian EEZs subregions (Fig. 1C). The Atlantic coast is subdivided into the Newfoundland and Labrador Shelves, the Gulf of St. Lawrence, and the Scotian Shelf, while the Pacific coast is subdivided into the South, Central, and North Coasts of British Columbia. In addition, we also assess the production potential, farm-gate prices, and employment under contrasting climate and socio-economic scenarios.
