Humans are responsible for the extinction of numerous animals from prehistoric times, and hunting communities have developed extremely effective tools and methods to capture their prey. Fishers represent one of the few remaining legacies of this hunting past, and their technological progress and mentality are blamed for the unsustainable management of many aquatic resources that has resulted in the overexploitation of several commercially important fisheries. Applying this mentality and technology, which has proved so effective, may offer positive aspects if used to eradicate invasive species or at least to contain their spread.
Of all the fishing methods fishers employ, traps have a long history of tested effectiveness as harvesting gear for aquatic organisms, and there are extensive examples of commercial fisheries still employing them as their preferred gear. Traps are regularly used to capture crustaceans because they are cheap, small and light, easy to operate, occupy little deck space in the fishing boat, are selective towards the catch, and will maintain a large proportion of the captured organisms alive and permit the return of undersized and unwanted species unharmed back into the water. Traps are a passive fishing gear, where the target organism has to be lured into them by using bait. This relies on the locomotive power of the target animals, which have to approach the gear by themselves; therefore, this technique requires less energy and fuel than active fishing methods used to catch crustaceans, such as trawling. Furthermore, small fishing gear has lower operational costs, can be hauled manually or with smaller line haulers than other gear, and sometimes can be slightly modified so existing gear can be adapted for eradication purposes.
The Japanese collapsible crab traps introduced in this chapter are very effective fishing gear and some designs are already in use for eradication, sampling and research (Behrens Yamada et al. 2006); consequently, improvement in their design can be applied to develop better traps that can be integrated with other eradication strategies (Lafferty and
Kuris 1996); like the creation of a new fishery where there is no tradition of eating these edible crabs; improving habitat, spawning substrate and numbers of natural predators; and perhaps the use of species-specific parasites which can cause infertility or reduce growth rates of the introduced crabs. Collapsible traps occupy less space on deck because they are two-dimensional and can be laid flat until they are assembled, just before being tossed into the sea (Fig. 2). For this reason larger numbers can be carried onboard than those of conventional rigid trap design. Even sport fishers can easily adapt their boats to this type of fishery.
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Lets start by identifying what exactly certain boats are. Sometimes the terminology can get lost on beginners, so well look at some of the most common boats and what theyre called. These boats are exactly what the name implies. They are meant to be used for fishing. Most fishing boats are powered by outboard motors, and many also have a trolling motor mounted on the bow. Bass boats can be made of aluminium or fibreglass.