The Hidden Destroyer of Seattle’s Waterfront

Our wharf structures are becoming a leading property interest of the city. To the eight old wharves and their warehouses, mills and numerous other buildings have lately been added the coal-bunkers, pier and two-mile bridge of the S. W. W. R. R. Co., and the extensive wharves now under construction along Front Street. There is here, as in all other salt waters, a drawback to marine improvements in that unconquerable foe of the wharf-builder called the Teredo navalis. These diminutive destroyers operate in all salts of the ocean the world around, and almost all species of timber alike fall a prey to their industry. Even sheathings of copper and iron are considered doubtful preventives in the case of piling. The worst thing about them is their insidiousness. They will attack and eat off the piles of a wharf at or below the surface without making any sign. The outer surface will be apparently as sound as when first driven, while under the bark the wood is completely devoured. The insect is so small when it first enters the pile that its puncture is invisible; but it 'grows by what it feeds upon' and leaves as wide a channel in the heart of the stick as a musket ball. Here, on the Sound, we have not lacked instances of calamities from this cause. In the spring of 1873, the wharf of Sloane and Burnett, then still considered new—not more than three or four years old—went down with a warehouse filled with a $3,000 shipment of merchandise and a quantity of costly furniture. Later, a wharf fell in at Port Gamble, also involving serious loss. It is considered that the presence of fresh water, as near a river mouth, is an antidote to the depredations of the teredo; but these facts demonstrate the necessity of taking careful precautions against future calamities by thoroughly embanking all wharves by means of earth, rock or slabs before it is too late.