The video below from Al Jazeera shows that fish also contains high concentrations of microplastics. How do these microplastics enter our oceans? Whenever we wash clothes, the synthetic fabrics in our t-shirts or other clothing leech microplastics into the water used to clean clothes. When the water is drained, it is released into the ocean where it accumulates into fish who swim in industrial toxins. If we eat fish, we eat microplastics as well as other industrial toxins.
How then do we get the benefits of fish (protein and omega 3) without any of the contaminants? Simply switch to plant-based protein, e.g. one bag of beans costs $1.70 and contains 100 grams of protein. Vegan protein powder such as pea protein is also very price competitive compared to dairy-based whey protein.
As for omega 3, I personally take a DHA and EPA supplement from Deva Nutrition that contains omega 3 fatty acid derived from algae grown on land under controlled conditions. As such, there is no industrial contamination. Deva Nutrition is a reputable business that is accredited and approved by the Vegan Society. If you cannot find this product at your local chemist, look at reputable online retailers such as Amazon or iHerb (iHerb has worldwide shipping).
If you'd like to be further educated about industrial pollutants in fish, watch the videos below:
Food sources of PCB chemical pollutants (NutritionFacts.org)
Flame Retardant Chemical Contamination (NutritionFacts.org)