They boast the most effective desalination gland in nature, located behind the nose. This gathers salt which can then be ejected from the body by ejaculating salty water from their nostrils. This appears like a projectile sneeze and is accompanied by a little sneezing sound.
Marine iguanas often find themselves the unwilling toys of playful sea lions who, despite meaning no malice, sometimes cause them serious injury such as spinal breakage.