Six or seven dogfish were drowned after getting caught up in bright orange plastic netting, and washed up on East Beach in Littlehampton, near the East Beach Café.
The skeleton of a seagull caught in rope was strewn on the sand - and in perhaps the most powerful image, the remains of a guillemot was found with a plastic ring stuck on its head.
Matt Palmer from Wick took these images of the sad sight after discovering the animals' remains on a walk with his Siberian husky Bella on Friday at around 4pm.
He said he was 'very saddened' by what he saw, and called for people to stop littering in the sea. He said: "We need to be more aware of how we dispose of plastic. It needs to start at the top in industry and filter down to how we use it.
"That little bit of plastic down on the beach will end up in the water and an animal will eat it."
He picked up the remains and the rubbish, which he said weighted between five and 10 kilos, and 'dragged it' to the nearest bin - where he said he saw 'a vast mountain' of washed-up rubbish that someone else had also collected.
The 36-year-old was most affected by the sight of the guillemot. He said: "That poor guillemot couldn't have got free. It must have been struggling and was getting itself into a worse and worse situation.
"The ring was stuck around its eyes and the base of its skull. It was well on there; it took quite a lot of effort to pull it off."
This comes after children from Shoreham and Worthing campaigned to ban plastic straws because of their negative affect on our environment, and an eco-minded mother organised what it believed to be the UK's biggest beach clean on Shoreham Beach.