Aquatic Foods in Sustainable Healthy Diets

Why Aquatic Foods Matter

Across the globe, more than 3 billion people rely on fish and other aquatic organisms as a primary source of protein. Aquatic foodsincluding fish, crustaceans, molluscs, seaweed, and emerging products such as algaebased proteinsprovide essential nutrients while often requiring fewer natural resources than terrestrial livestock.

Nutritional Benefits

Key nutrients supplied by aquatic foods are:

• Highquality protein: Complete amino acid profile, easily digestible.
• Omega3 fatty acids (EPA & DHA): Crucial for brain development, cardiovascular health, and antiinflammatory effects.
• Vitamins: Vitamin D, B12, A and niacin, especially abundant in oily fish.
• Minerals: Iodine, selenium, zinc, iron and calcium (particularly in small fish eaten whole).
• Bioactive compounds: Peptides, antioxidants and prebiotic fibres found in seaweed.

Including a 23 serving per week variety of fish and shellfish can help meet the World Health Organizations recommendations for omega3 intake while reducing reliance on red meat.

Sustainability Aspects

When sourced responsibly, aquatic foods deliver nutrition with a lower environmental footprint than many landbased protein sources.

Resource Efficiency

• Feed conversion ratio (FCR) for many fish species ranges from 1.1:1 to 1.8:1, compared with 2.5:16:1 for poultry and beef.
• Integrated multitrophic aquaculture (IMTA) recycles nutrients: finfish waste feeds shellfish and seaweed, reducing waste discharge.

Greenhousegas Emissions

Per kilogram of edible protein, most wildcaught fish emit 0.10.3kgCOe, while cattle emit 2030kgCOe. Cultured fish can achieve similar low emissions when powered by renewable energy.

Biodiversity & Ocean Health

Adopting certified fisheries (e.g., MSC) and supporting smallscale community fisheries helps preserve marine ecosystems, maintain fish stocks, and secure livelihoods.

Current Challenges

Despite their benefits, several hurdles limit the full integration of aquatic foods into sustainable diets:

• Overfishing: 34% of global fish stocks are overexploited, threatening food security.
• Food safety: Mercury, microplastics, and antibiotic residues can accumulate in certain species.
• Supply chain losses: Up to 35% of caught fish is lost postharvest due to inadequate handling.
• Consumer perception: Limited awareness of the environmental advantages of species such as sardines, anchovies, or seaweed.

Practical Guidelines for a Sustainable Aquatic Diet

1. Choose certified, lowimpact species. Look for MSC, ASC, or local ecolabel symbols.
2. Prioritize small, oily fish. Sardines, mackerel, and herring are nutrientdense and reproduce quickly.
3. Include shellfish and seaweed. They require no feed, filter water, and add dietary fibre and iodine.
4. Limit highcontaminant species. Pregnant women and young children should avoid shark, swordfish, and king mackerel.
5. Buy from local, seasonal sources. Reduces transport emissions and supports regional fishers.
6. Practice proper storage and preparation. Keep fish chilled below 4C, cook to an internal temperature of 63C, and use wastereducing methods such as deboning for broth.
7. Explore plantbased aquatic alternatives. Algae oils and fermented seaweed snacks can complement animalbased seafood.

Sample Weekly Menu

• Monday Grilled sardines with lemon & herbs, quinoa salad.
• Tuesday Shrimp stirfry with mixed vegetables, brown rice.
• Wednesday Seaweed soup with tofu and ginger.
• Thursday Baked salmon (MSCcertified) with roasted sweet potatoes.
• Friday Fish tacos using battered cod, cabbage slaw, avocado.
• Saturday Mussels in white wine broth, wholegrain garlic bread.
• Sunday Vegrich paella with squid ink, peas, and red peppers.

Adopting even a few of these steps can help individuals meet nutritional needs while contributing to a healthier planet.