The sunlit sea as distinct from The Bottom of the Sea (1966), but the trouble is that penetration of light is only one of the factors governing distribution of organisms, a fact which is blurred in this loose catalogue of marine plants and animals. And there are other obscurities. ""Almost all the plants that grow in the ocean are algae. Algae have no roots, no leaves, no flowers, and no seeds;"" how do they live and grow? ""The tiny plants and animals that float together in the sunlit sea are called PLANKTON. Plankton is food for many animals"" -- which doesn't reveal that plankton blanket the seas, far surpassing the afore-mentioned (at length) seaweed as a source of food because the other is shore-based (another factor that is omitted). Proceeding to fish, there is no distinction between ""fish living in the upper part of the ocean"" and implied others; regarding animals, some that cling to the bottom (sponges, corals) are included without explanation. Unclear as ecology and otherwise undistinguished.