Omega 3s are also found in both plants and animals. The list below shows 5 plant based sources and 5 animal based. It is also possible to supplement your diet with plant based Omega 3, if you wish.
This supplement contain both DHA and EPA, all without the use of fish. Each soft gel provides 320 mg of DHA and at least 130 mg of EPA . https://jp.iherb.com/pr/Ovega-3-Ovega-3-DHA-EPA-500-mg-60-Veggie-Softgels/41142
United States Department of Agriculture National Nutrient Database for Standard Reference
Plant based omega 3s per 100g (mg)
Animal based omega 3s per 100g (mg)
Fish Oil (Salmon)
Fish Roe (Caviar)
Cured & Canned Fish (Smoked Salmon)