Spider crabs 'were not seen in Welsh waters 20 years ago'
Wales' fishermen are reporting growing "evidence" of climate change, a leading figure from the industry has warned.
Catches of rare fish and extreme sea conditions are all seen as signs of change, said Jerry Percy of the Welsh Federation of Fishermen's Associations.
Mr Percy spoke as he was unveiled as World Wildlife Fund Cymru's second 'climate witness' - people chosen to raise awareness of climate change.
"We need to figure out what is going on in our oceans," he said.
Mr Percy, of Haverfordwest, Pembrokeshire, has a background in commercial fishing and has worked in various roles related to Welsh marine and freshwater life.
As WFFA chief executive he now works in support of more than 600 fishing businesses in Wales.
"Fishermen have told me about changes in species catch and more extreme weather conditions, increased tidal and wind strengths, which they thought maybe be due to climate change," he said.
Mr Percy said he had received reports that once rare or seasonal-only fin fish, as well as southern European shellfish, are increasingly being caught off the Welsh coast.
He said: "From a fishing perspective there is no doubt at all that climate change is affecting species - black bream, spider crab and sea bass are three good examples.
"Twenty years ago you would not have seen a spider crab in these waters at all. They are the most noticeable incomer to Welsh and indeed UK waters in recent times.
"Also once rare or seasonal-only fish such as black bream and sea bass are now being caught by Welsh fishermen for longer periods and, in the case of sea bass, throughout the year.
"Our climate is changing and we should be doing as much as possible to figure out what is going on in our oceans. We need more science and understanding."
Environment minister Jane Davidson said WWF Cymru's climate witness initiative could bring bring home to the people of Wales that climate change was not some academic theory, but a real threat.
She said: "Some people still see the huge challenge we face as a vague and remote threat. I hope Jerry's appointment will help hit home the message that this is not the case.
Anne Meikle, head of WWF Cymru, said: "Jerry's testimonial on behalf of Welsh fishermen shows that climate change is impacting on marine life, the fishing industry and ultimately our Welsh nation.
"If left unchecked climate change will have devastating impacts for people and wildlife across our nation and the world."