AS more dead marine life is washing up on beaches along the North East coast, experts say they are still unsure of what is causing the devastation.

From crabs and fish, to birds, the last few weeks has seen a devastation of marine life washing up on beaches at Redcar and Seaton Carew.

Dr Jamie Bojko a lecturer in Biology, at Teesside University has been monitoring the situation and has become very concerned.

Dr Bojko said: “The short answer to what is killing our marine life, is that we do not know at this time. The Environment Agency and Centre for Environment, Fisheries, and Aquaculture Science (Cefas) have taken samples for toxicological and pathological analysis, but the results are not yet available.”

Recently fish and porpoise have been washing up on beaches, but experts are unsure if is all related.

Dr Bojko added: “I am extremely hopeful that the diagnostics will be able to answer these questions for us. If the birds and marine life appear to harbour the same toxicological/pathological agent, there may be a clear answer. However, for the moment, it is unclear if the events are linked.

“There have also been reports of fish and a porpoise washing up on this same coastline over the past month - these also remain unlinked currently, but the investigation would benefit from acquiring samples to test and compare."

Experts have put forward some theories as to the cause of the dead crabs.

Crabs live in shallower waters in the summer and then move to deeper waters in the winter.

This leaves them prone to storms and rough weather in the summer which could be a factor in explaining why they are washing up on the beaches.

Environmentalists have also put forward theories of pollution, dredging on the Tees and disease as possible causes.

Dr Bojko added: “If this is a natural disaster, such as extreme weather or an underwater phenomenon, man-made or not, it would not be possible to identify such a cause in the laboratory.

“Instead, we may need to look back at our weather systems, underwater monitoring systems, or (un)scheduled industrial processes, to see if there might be something that coincides with the loss of marine life.

“I am confident that the EA and Cefas will be looking into these systems, to see if there may be a man-made or natural process that could have caused the animals to die.

“Another natural process that could be at play is disease.

"Diseases have been shown to cause large numbers of animals to die - take the crayfish plague that infects our native white clawed crayfish and was introduced by the invasive signal crayfish.

“When this pathogen enters a freshwater system, huge numbers of crayfish can die, and they wash up along the river bank some days later.

"We are aware of lots of diseases that are present in our crab species around the UK, but none of these have been implicated in huge losses like we are seeing on the Tees coastline.

“In this most recent marine event, it is possible that a disease may be to blame for the crabs and other animals washing up; however, if these different events are linked, it is less likely that a single disease would be to blame.

"At this time, it is unclear why the coastline around Teesside is impacted and not elsewhere.

"However, since we are dealing with a localised event it provides a greater capacity to monitor what is happening.

"If the event took place at a much greater scale, it would be harder to find the answers that we need."