Azoic hypothesis

The Azoic hypothesis (sometimes referred to as the Abyssus theory) is a superseded scientific theory proposed by Edward Forbes in 1843, stating that the abundance and variety of marine life decreased with increasing depth and, by extrapolation of his own measurements, Forbes calculated that marine life would cease to exist below 300 fathoms (1,800 ft; 550 m).

David Page (1814–1879), a respected geologist, reinforced the theory by stating that "according to experiment, water at the depth of 1000 feet is compressed 1⁄340th of its own bulk; and at this rate of compression we know that at great depths animal and vegetable life as known to us cannot possibly exist – the extreme depressions of seas being thus, like the extreme elevations of the land, barren and lifeless solitudes.

"[2] The theory was not disproven until the late 1860s[3] when biologist Michael Sars,[1] Professor of Zoology at Christiania (now Oslo) University, discovered life at a depth greater than 300 fathoms.

[3] In 1869, Charles Wyville Thomson dredged marine life from a depth of 2,345 fathoms (14,070 ft; 4,289 m), finally dispelling Forbes' azoic theory.

Since being discredited, the theory has been referenced widely in popular culture[citation needed] and alluded to in documentaries that explore and showcase deep-sea marine life.