Temperate tube worms demise and the plastic oyster?

The two tube worms featured are from Early December till late January in the millions in Qs south east at two sites.

Once the ocean hits 25c they start their massive die off that happens every year unless a rain event wipes them out first,that has happened two years in a row now.

These tube worms are only found in Australia’s east coast, so that makes the massive die off each year twice as sad.

The oyster that is pictured is transparent and I would imagine few have seen one of these.

I have never been able to get and ID on its name, but I assume it is a type of oyster due to three types we find in the south east of Queensland on many trips and where they exist.