Noah did not take every species of animal on board the Ark. Animals designated using the Hebrew words basar, behema, hayya, nephesh, op, remes, and sippor are used to describe the animals which were taken aboard (the common theme is land based oxygen breathing animals with blood).[1]
Animals designated using the Hebrew words sheres and yequm (the common theme is sea creatures, swarming creatures, insects, reptiles, rodents, and amphibians), are not in the list of animals taken aboard.[2]
This limited list of animals saved demonstrates that not all species were preserved in the Ark, which suggests a local flood and also suggests that the animals saved were only those immediately local to Noah.
[1]‘All these words refer to birds and mammals, though some can be used a little more broadly. We see a high correlation between this list and the list of soulish animals God created on the fifth and sixth creation days, animals that held significance in the preparation of Earth for humankind. Clearly, the survival of these creatures would be important to the restoration and survival of human society after the Flood. Nothing in the Genesis text compels us to conclude that Noah’s passengers included anything other than birds and mammals.’, Ross, ‘The Genesis Question: Scientific advances and the accuracy of Genesis’, p. 167 (2001).
[2] ‘While sheres can refer to small mammals, most often it is used for small nonsoulish animals. Likewise, yequm can refer to all animals or just those that merely subsist.’, ibid., p. 167.