Big tides and gale force winds from Storm Emma are believed to have caused the huge dump on Fraisthorpe beach near Bridlington.
Many people have filled buckets and boxes with the creatures and carried them away.
Commercial fisherman Jack Sanderson was at Fraisthorpe with a group of fishermen rescuing live lobsters to release back into the sea.
He described the scene as "total chaos".
He said: "There was every form of marine life, velvet crabs, lobsters, whelks, scallops, razorfish, Dover soles, cod, ling, wrasse and sand eels.
“We have had strong easterly winds up to force nine and combined with a 6.2 metre tide and the fact there was a lot of cold, frost and snow, meant the water temperature dropped two degrees in one day, which is massive.
“The combination just stunned everything and the direction of the wind has brought it onto the beach. It is still coming out of the sea; every tide is leaving a fresh batch.”
Mr Sanderson said he had been frustrated by the actions of some members of the public who had been taking under-sized live lobsters off the beach or those carrying eggs, which is against regulations.
“Don’t get me wrong – we earn our living from the sea. But the regulations are there for everybody and it’s only us who comply. We will hopefully release some of the lobsters tomorrow. We will go out five or six miles and let them go.”
Mr Sanderson said he was hopeful the amount of sea life seen on the beach was a reflection of healthy stocks and the natural disaster would not prove “totally catastrophic” for the industry.
The lobsters they picked up have been taken to tanks at Bridlington harbour, where they will be kept until they can be put back into the sea.
Jason Harrison, skipper of the Scarborough shell fishing boat Shannon, added: “There were hundreds of thousands of lobsters, millions of mussels, you can’t count the number.
“The number of velvets was scary. I’d say 80 to 90 per cent of the lobsters were dead. This is the third time I have seen it in 30 years.
“It is nature, it happened before and it will happen again.”
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