Can you get essential Omega-3 fatty acids from something other than fish oil?

Yes, you can get all the essential fatty acids from non-fish sources, even vegan sources. However, it isn't necessarily the easiest or most commonly-recommended way to get it. The two Omega-3 fatty acids in question are DHA and EPA. Alpha-linolenic acid (ALA) is another important Omega-3 but it's easy to get from vegetable oils. DHA and EPA are not so easy to get. Your body can make DHA and EPA from alpha-linolenic acid, but not efficiently. This is why many experts recommend fish oil. But the Vegan Society says: "Many factors affect the rate of conversion and one factor seems to be a high food intake of linoleic acid which is typical of vegan diets and may suppress the body's ability to convert alpha-linolenic acid to DHA. Vegans can achieve a better balance of PUFAs in their body tissues by using less sunflower, safflower and corn oils and more oils containing alpha-linoleic acid such as rapeseed (canola) oil, or soya bean and walnut oils. This would encourage their tissues to make more DHA."