These are disposable lighters, designed to work for at most a few weeks and then be thrown away.
The phrase "thrown away" makes it sound so simple - they have gone, so we forget about them. But if they get into our oceans that won't be true.
Like so much plastic that floats around our seas they don't decay but get broken up into smaller and smaller pieces. They confuse birds such as the albatross to whom they look like squid, hence eat them possibly causing them to choke.
More seriously the small pieces do not at this point disappear, but continue to shrink into microscopic fragments, which then bind with some of the worst pollutants like DDT.
This poisonous powder is becoming ubiquitous in the oceans, ingested by sea life, which concentrates the unwanted chemicals further, until we eat them and hence consume the results of our own pollution.
And we can't stop it - there's too much out already in the oceans, and as it doesn't decay our children's children will be eating it.
All we can do is fish out any bits we see floating by and stop as far as possible anything more entering our waters.
More on this at the BBC - one the the effect of microscopic fragments of plastic and pollutants here, and on experiencing the piles of rubbish on the Pacific island of Midway here.