No. There are three different types of omega-3 fatty acid: EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) and ALA (alpha-linolenic acid). You’ll find EPA and DHA in cold-water fatty fish, such as salmon, whereas ALA is found in plant-based foods, including walnuts.
Read more about good fats on the plant-based foods page.