Complex sentence: In 1841--1842 Edward Forbes undertook dredging in the Aegean Sea that founded marine ecologysical Geography of the Sea, 1855 was the first textbook of oceanography.
Split into simpler sentences: In 1841--1842 Edward Forbes undertook dredging in the Aegean Sea that founded marine ecology. His "Physical Geography of the Sea", 1855 was the first textbook of oceanography.