Some Characteristics of “Fishbite” Damage on Deep‐sea Mooring Lines1

Abstract

Moored deep-sea installations are frequently set adrift when their synthetic fiber mooring lines arc bitten by some organism, presumably a fish. Some information on the causative organism has been obtained by mooring buoys in 2,000 m of water near Bermuda with lines sheathed or coated with plastic materials that took dental impressions.The evidence provided by this material suggests that the causative organism is active from 150 to over 1,500 m in depth, with the greatest concentration from 600 to 1,000 m. The jaw ranges from 30 to slightly over 100 mm in width and the teeth are located either in the upper or lower jaw but not both. The teeth are sharp with a fine. band of rounded scrrations along the cutting edge.

Shark research : present status and future direction / Bernard J. Zahuranec, editor and workshop convenor.

“…This has been verified by dental impressions and recovery of tooth fragments from various types of plastic cable armor to depths of approximately 1500 feet. Histograms of biting recorded on experimental moorings in Atlantic waters near Bermuda indicated that bites occurred with greatest frequency near the permanent thermocline (Turner and Prindle, 1967). Apparently, "fishbite" on mooring lines and cables is less of a problem in the Pacific, although detailed evidence is lacking.…”

“…Based on examination of recovered deep-sea moorings it has also been hypothesized that sharks may be attracted to cables by visual clues elicited by an assortment of bioluminescent organisms accumulating on the cables' surface (Turner, 1965).…”