The spiny dogfish is the most common living shark, yet two populations in the northwest and northeast Atlantic are at great risk due to overfishing. This shark is caught for food, liver oil, and is used to make sand paper, vitamins, leather, fertiliser, and pet food. Between 1900 and 1910, when the dogfish was at its peak abundance, it was estimated that up to 27 million spiny dogfish were caught off the Massachusetts coast every year.