Plastic bags and flexible packaging are the deadliest plastic items in the ocean, killing wildlife around the globe.  Discarded fishing line and nets, as well as latex gloves and balloons were also found to be disproportionately lethal.  Ingesting plastic was responsible for killing animals across 80 species..

The review, published in the journal Conservation Letters, analysed 655scientific articles about marine debris and found 79 studies across all inhabited continents detailing deaths of whales and dolphins, seals and sea lions, sea turtles and sea birds.  (CSIRO, Australian government science agency)

My comment: it would be interesting to know how this detritus gets into the sea in the first place.  Cruise ships come to mind as the worst offenders.  An analysis in 2021 , when cruise ships are laid up, might give an indication by showing whether ocean rubbish has grown or diminished during Covid-19.