Of the 40 balloons Russ reported, 31 were made of Mylar. This is discouraging, as despite their one-time use, Mylar balloons take a long time to degrade. These balloons were more likely than other balloon types to be found individually and still partially inflated. Rubber balloons, another prevalent balloon type, were more likely to be found deflated or shredded, and often tied together in groups. Many of the reported balloons also had a plastic string attached, creating yet another hazard for marine life.