The Introduction of the Otter Trawl

The Northern Mariner / Le marin du nord, XVIII, No. 4 (Autumn 2018), 327-46The Northern Mariner / Le marin du nord I here present that extended development, as an account of a watershed in global fisheries history, with major implications for marine environments, but also as a case-study in technological innovation. PrecursorsOtter trawls comprise one family within a broader class of nets drawn across the seabed, many varieties of which emerged down the centuries in small-scale, coastal fisheries.Most have been lost to knowledge but Duhamel du Monceau and Sañez Requart have left us detailed accounts of pre-nineteenth century French and Spanish fishing gears. 2 Besides beach seines, they illustrated assorted nets drawn by boats, some being seines and others of bag-like shape.Each type of gear had the challenge of spreading the net's mouth both vertically and laterally.The former could be achieved with floats on the headrope and weights on the footrope, 3 though rigid spreaders were often added.Lateral spread was easy when beach seining, the ends of the net being hauled from separated points, but was problematic at sea. du Monceau illustrated variants with poles lashed across the mouth of a net and other gears in which the warps were taken either to spars projecting widely from the fishing vessel or else to each of a pair of boats.The fishermen of other nations appear to have employed similar nets but the Dutch and English also used beam trawls.4 In those, a wooden beam was held above the seabed by an iron trawl head at each end, the beam and heads together providing both vertical and lateral spread (Figure 1).The net's headrope was lashed to the beam while the long footrope dragged behind.Thus, fish herded towards the centre, or bosom, of that footrope were surrounded, with the seabed below and netting above, reducing opportunities for escape.Beam trawls proved both practical to handle and efficient for the capture of valuable flatfish.Trawling was long limited to minor, coastal fisheries, meeting local demand.Rapid expansion began around 1750, linked to growing markets, improved roads (hence affordable rapid transport of fresh fish) and the adoption of smacksdecked, gaff-rigged vessels of about twenty tons-in place of earlier inshore boats.By the 1830s, smacks from Brixham, Devon were trawling throughout the English Channel, the Irish Sea and along the North Sea coast of England.Population growth, urbanization and industrialization were then creating a mass market for low-cost seafood, linked to landing ports through swift, efficient 2 H.-L. Duhamel du Monceau, Traité Général des Pesches (Premiere Partie) (Paris: Saillant, Nyon & Desaint, 1769), pag.var.; A. Sañez Requart, Diccionario histórico de los artes de la pesca nacional (Madrid: Ibarra, 1791-95), pag.var.3 Fisheries terminology is inconsistent.For clarity, I here use headrope and footrope throughout for the ropes to which the leading edges of seine-or trawl-net webbing are attached (ignoring any bolsh lines).4 The development of English trawling has been outlined in many works but most usefully by R. Robinson, Trawling (Exeter: University of Exeter Press, 1996), which I follow in this section except where otherwise noted.a seagoing workforce of nearly 20,000 men and boys.6 The centre of the industry had moved north to the Humber ports: Grimsby and Hull.Elsewhere, small-scale fishing with local gears continued but only French, Belgian and Dutch fishermen adopted the English techniques.Boulogne, the one major Continental trawling port, had a fleet of merely some sixty large smacks.7 Trawling technology changed little before 1880.Larger smacks were built and, from the mid-1860s, they were given two-masted rigs.Steel wire replaced hemp trawl warps from the 1870s.Steam capstans were tried, though without much success until 1884.The trawls themselves were unaltered, except for being larger, with beams up to fifteen metres long.8 Meanwhile, there had been multiple, mostly unsuccessful, attempts at steam trawling.Efficient steam trawlers worked out of Arcachon, on the French coast near Bordeaux, from 1868 9 but their employment in the North Sea awaited advances in marine engineering, allowing increased boiler pressures and improved fuel economy.Those were first applied in Zodiac of Grimsby, built in 1881.She was thirty metres overall, with a compound engine and a large steam trawl winch, 10 allowing the wire warp to be conveniently stowed on the winch barrel.Her success led to construction of many similar trawlers, Grimsby having fifty steamers by 1890 and 425 before the end of the century, 11 when Britain had nearly 1,250 in all.French fishermen were slow to adopt steam but had 103 trawlers in 1903, while a new German fleet emerged and grew to over 500 vessels by 1907.12 Until 1895, however, they carried beam trawls unchanged from those of the smacks, save for a further size increase to seventeen metres.13 By then, otter trawls had existed for at least three decades, though who invented them and when remain obscure.Willam Carmichael McIntosh (or sometimes M'Intosh), Scotland's preeminent marine scientist, later claimed their use in the Firth of Forth in 1858.14 They were certainly known a decade later.15 19 March 1921, 61.6 A.W. Ansell, "On trawling," International Fisheries Exhibition, (London: Clowes, 1883), 6. 7 H.-E. Sauvage, "La Pêche a Boulogne-Sur-Mer," Revue Maritime et Coloniale, 122, (1894), 213.8 Anon., "The history of trawling," 65; E.J. March, Sailing Trawlers (London:

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