Wash up?

Millions of tons of garbage, most of it plastic debris, ar dumped into the oceans every year.

This may pose a deadly threat to whales, according to a report at an international whaling forum last week.

Thousands of documents from the past 20 years reveal that about 80 species of whales and dolphins have been sickened or killed due to ingestion of plastic waste.

Experts warned that this is emerging as a serious cause of disability and death in large marine animals.

In 2008, for example, two sperm whales were found on the California coast.

One whale had 205 kilograms of fish nets and other debris in its gut.

The other was half-starved because it had wadded plastic blocking its digestive tract.

In 2002, a dead minke whale washed up in France. Researchers later discovered that it had nearly a ton of plastic in its stomach.

However, many scientists have been slow to measure the impact of ocean debris and admit that they do not know how widespread this problem is.

“In many areas of the world, stranded whale carcasses are not recorded or examined, and in areas where strandings are recorded, examination of gut contents for swallowed plastics is rare,” said Chris Parsons, a marine biologist.

He added that the two main threats to whales are still accidental capture in fishnets and climate change.

Q. What does 'wash up' mean in the sentence?

Q. I want to know what the sentence mean based on the context (However~~~ this problem is)