Leaching from stone crab traps dipped in fungitrol: diesel fuel preservative.

Abstract

The stone crab fishery is one of the most important commercial fishing industries in Florida. Since stone crabs are generally caught and harvested by trapping, trap construction and longevity are crucial to the success of the industry. For years, stone crab fishermen have been fishing with wooden traps. Over time, traps become infested with wood-boring animals such as shipworms and isopods, leading to the destruction of the trap. Various wood treatments have been applied to keep wood-borers from infesting the traps in an attempt to increase their longevity and reduce fishing costs. For the past several years, stone crab fishermen have been using a copper-based substance called Fungitrol[sup R] with diesel fuel as a carrier to inhibit wood-borers. Fungitrol (Huls America) is a Cu-naphthenate fungicide containing 8% Cu and is normally used to protect fibrous substrates. Initially, most fishermen dip the wood for their traps in a Fungitrol:diesel fuel mixture (1:10) for anywhere from a few minutes up to 10 days. The traps are then constructed from the treated wood and are allowed to sit outside for up to 5 months before using them for crabbing. In subsequent seasons, the traps are dipped for only 1-3 minutes, then are allowedmore » to sit outside until the opening of the season. The concern with using diesel fuel as a carrier in the dipping process is that this refined petroleum product has been found to be more toxic to marine animal s than many crude oils. Hydrocarbons found in other petroleum products (including fuel oils and crude oils) have been shown to have both lethal and sublethal effects on crustaceans. Various studies have been conducted on wood preservatives and the changes that occur in treated wood with prolonged exposure to water. This study investigates many of the same characteristics of a leachate from marine woods as do the others; however, this particular leachate, diesel fuel, has not been studied until now. 10 refs., 2 figs., 1 tab.« less