Nature's Logic™ North Atlantic Sardine Oil is derived from harvested wild sardines (sardinus pichardus) which are small planktivorous pelagic fish. This brilliant gold oils is by far the most popular oil used in dietary supplements as a source of the omega-3 fatty acids EPA and DHA. It contains more EPA and DHA than Salmon Oil and has naturally lower levels of environmental contaminants than Salmon Oil. Our human/pharmaceutical grade Sardine oil is purified so the levels of lead, mercury, arsenic and cadmium are less than one part per million. By supplementing Nature's Logic North Atlantic Sardine Oil's natural rich source of long chain Omega-3 Fatty Acids, you are adding one of nature's most bio-available sources of these nutrients to your pet's diet.