The dramatic increase in sport diving and related travel has, perhaps inevitably, returned people to the sea.
Dangers exist in the sea, as with any environment for which humanity is poorly adapted.
By no means the least of these dangers is our contact with hazardous marine organisms. Many sea creatures have improved their survival through the evolutionary development of offense and defense systems, often elaborate mechanisms for delivering poison or venom to a prey or predator. The majority of these organisms are located in temperate oceans, especially in the Indo-Pacific regions. Envenomation may result from a vast array of vertebrate and invertebrate creatures. This chapter will, however, focus on the 300 invertebrate species of the phylum Mollusca, the cone shells.