grumpy_o_g
Well-known member
We're a sociable bunch in the RAF...
Thousands of crabs and lobsters washed up on Yorkshire beaches,
- Thread starter Concerto
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We're a sociable bunch in the RAF...
Hydrozoan
Well-known member
'Results of investigation point to a naturally occurring harmful algal bloom being the cause.'
Update on investigation into the deaths of crabs and lobster in the North East - GOV.UK (www.gov.uk)
Update on investigation into the deaths of crabs and lobster in the North East - GOV.UK (www.gov.uk)
Capt Popeye
Well-known member
Just as an aside ; were the Washed Up Shell Fish collected /harvested for Human use ?
Corr an event like that beats Fishing for them !
Corr an event like that beats Fishing for them !
Concerto
Well-known member
The result of the investigation commented:
"While there is no food safety risk from eating crabs that have been caught in waters off the North East coast, it is unsafe to eat dead or dying crabs found on the affected coast. "
It seems they really do not know what has caused the demise of some many crabs and lobsters and an algae bloom is the only suggestions as everything else has been ruled out.
Poignard
Well-known member
Fascinating stuff Fisherman! You should write a book.
Yellow Ballad
Well-known member
There's been reports of dogs falling quite ill up that way after being walked on beaches, I wonder if there's a connection?
Fr J Hackett
Well-known member
I used to have an innate sense of direction then I went to Australia for 2 years, when I came back to the northern hemisphere it had gone.
Hydrozoan
Well-known member
Certainly the toxins from marine ’red tide’ organisms (typically dinoflagellates and diatoms) can be toxic to dogs - as can of course those from blue-green algal blooms (cyanobacteria) in freshwaters. OTOH, the suggestion of a toxic bloom has arisen by the elimination/unlikelihood of other possible causes so we have no idea what organism might have been involved, and dogs might become ill after eating crabs which died from other causes. But it is surely particularly wise to stop dogs scavenging when unusual numbers of dead organisms are evident, anywhere.
Birdseye
Well-known member
did you know or did you just think that you knew? if you were lost, how did you know that you knew?
Birdseye
Well-known member
crabs are often "stored" in large cages by fishermen. could it be that one of these cages has been destroyed by storm, hit by trawler etc and the result washed ashore? or maybe an illegal fisherman in fear of getting caught.
no doubt the usual people will say its all down to global warming and our use of cars.
Hydrozoan
Well-known member
Perhaps you did not see the initial reports? The numbers of dead crabs far exceeded the likely contents of one, or indeed several, cages. If the mass mortality were the result of a toxic algal bloom, excessive levels of micronutrients (N and/or P) are likely causes.
steveinnice
N/A
Unbelievable. I was just going to say when I was in Australia for 40 odd years I just "knew" the way to go . It was very useful as I did a lot of Bushwalking. Moved over this side of the world and I get lost going to the shops! However, I can still tell the time to within 15 minutes without a watch.
fisherman
Well-known member
because we ended up NW of where we left, and that was the way I identified We were going.
kippers26
Member
Expert disputes North East coast shellfish deaths findings. Appears that high levels of the chemical pyridine were found in the samples of crabs and not an algae bloom as reported . Copied from BBC England - tees web page
Expert disputes North East coast shellfish deaths findings
Expert disputes North East coast shellfish deaths findings
Hydrozoan
Well-known member
That report (Expert disputes North East coast shellfish deaths findings - BBC News ) quotes Defra as saying: ‘Our sampling established that no pyridine was present in the water or sediment samples we collected but was detected in crab tissue from both impacted areas and non-impacted areas elsewhere in the country. As such, any levels detected in crab tissue are likely to be linked to biological processes and not necessarily from the environment.’
I cannot find quoted Limits of Detection for the analyses of water or sediment, against which to assess the statement that ‘no pyridine was present’. I’m guessing that the above reference to ‘biological processes’ is to natural production of 1-Methylpyridin-1-ium-2-carboxylate which is found in many marine organisms, including crustaceans - it is named ‘Homarine’ after a genus of lobsters. Homarine functions as an osmolyte / osmoprotectant to help regulate cell volume in the face of changes in osmotic pressure, and may also be a methyl donor in other biochemical pathways. I'm also guessing that the technique used to analyse the tissue samples may well have measured the total of 'Homarine plus pyridine', but I may be wrong about that.
I expect that we may learn more about these and related issues in time. Questions in my mind include: Is pyridine produced by natural degradation of Homarine? Is Homarine produced naturally by crustaceans only from much simpler organic precursors, or is it also formed from pyridine if the latter is present in the environment (either as a pollutant or as a degradation product of Homarine from other organisms)? What was the distribution of high levels of 'pyridine' (and did that include Homarine?) in NE and other crab tissue samples - as I read the article, two NE samples had particularly elevated levels?
An interesting issue, complicated by a naturally-occurring derivative of the same basic molecule as the possible pollutant.
I cannot find quoted Limits of Detection for the analyses of water or sediment, against which to assess the statement that ‘no pyridine was present’. I’m guessing that the above reference to ‘biological processes’ is to natural production of 1-Methylpyridin-1-ium-2-carboxylate which is found in many marine organisms, including crustaceans - it is named ‘Homarine’ after a genus of lobsters. Homarine functions as an osmolyte / osmoprotectant to help regulate cell volume in the face of changes in osmotic pressure, and may also be a methyl donor in other biochemical pathways. I'm also guessing that the technique used to analyse the tissue samples may well have measured the total of 'Homarine plus pyridine', but I may be wrong about that.
I expect that we may learn more about these and related issues in time. Questions in my mind include: Is pyridine produced by natural degradation of Homarine? Is Homarine produced naturally by crustaceans only from much simpler organic precursors, or is it also formed from pyridine if the latter is present in the environment (either as a pollutant or as a degradation product of Homarine from other organisms)? What was the distribution of high levels of 'pyridine' (and did that include Homarine?) in NE and other crab tissue samples - as I read the article, two NE samples had particularly elevated levels?
An interesting issue, complicated by a naturally-occurring derivative of the same basic molecule as the possible pollutant.
Halo
Well-known member
An independent study has linked the deaths of thousands of crabs and lobsters and a mystery dog illness to dredging for the government’s flagship freeport on Teesside – a key to the Conservative’s post-Brexit, “levelling-up” agenda.
The report has led local fishers to reject a government theory that an “algal bloom” is responsible for the huge piles of dead crustaceans that began washing up on beaches along England’s north-east coast in October.
A multi-agency investigation led by the Department for Environment, Food and Rural Affairs (Defra) concluded on Friday that the mass crustacean deaths, which the fishing industry says have threatened their livelihoods and led to fears of a collapsing ecosystem, “potentially resulted from a naturally occurring harmful algal bloom”.
Algal blooms are a rapid overgrowth of algae that can produce dangerous toxins in the water, sometimes marked by a coloured scum on the water. Scientists have warned that they are becoming more frequent and more toxic worldwide, and could be linked to the climate crisis.
Dog walkers on the beach at Saltburn-by-the-Sea in North Yorkshire. Photograph: Christopher Thomond/The Guardian
Tim Deere-Jones, an independent marine pollution consultant and author of the report, said there was “no empirical evidence to support the theory that it’s got anything to do with an algal bloom”. Deere-Jones, who has 30 years of experience around dredging issues as a consultant, instead said the data obtained via freedom of information requests from Defra and other agencies, linked the mass mortalities to a specific chemical, pyridine, which can be released into the environment as a waste product from industrial processes.
“So far, the available evidence points clearly to pyridine as a potential cause of the mortality,” he said. His analyses point to several potential sources of pyridine discharge to the estuary, which could date back decades, but has embedded deep into the seabed. “On the basis of the established fact that pyridine preferentially deposits out into estuarine sediments, rather than remains in the water column, it seems likely that the new deeper dredging being constructed has uncovered and redistributed pyridine-laced sediments to the regional marine environment,” he added.
While Defra said that “any levels [of pyridine] detected in crab tissue are likely to be linked to biological processes and not necessarily from the environment”, Deere-Jones pointed out that samples from control crabs collected in Penzance had just under 6mg per kilogram of the toxic chemical, the Saltburn crabs were found to have more than 400mg per kg. “That’s not a natural level, that’s a human impact level,” he said.
The report has led local fishers to reject a government theory that an “algal bloom” is responsible for the huge piles of dead crustaceans that began washing up on beaches along England’s north-east coast in October.
A multi-agency investigation led by the Department for Environment, Food and Rural Affairs (Defra) concluded on Friday that the mass crustacean deaths, which the fishing industry says have threatened their livelihoods and led to fears of a collapsing ecosystem, “potentially resulted from a naturally occurring harmful algal bloom”.
Algal blooms are a rapid overgrowth of algae that can produce dangerous toxins in the water, sometimes marked by a coloured scum on the water. Scientists have warned that they are becoming more frequent and more toxic worldwide, and could be linked to the climate crisis.
Dog walkers on the beach at Saltburn-by-the-Sea in North Yorkshire. Photograph: Christopher Thomond/The Guardian
Tim Deere-Jones, an independent marine pollution consultant and author of the report, said there was “no empirical evidence to support the theory that it’s got anything to do with an algal bloom”. Deere-Jones, who has 30 years of experience around dredging issues as a consultant, instead said the data obtained via freedom of information requests from Defra and other agencies, linked the mass mortalities to a specific chemical, pyridine, which can be released into the environment as a waste product from industrial processes.
“So far, the available evidence points clearly to pyridine as a potential cause of the mortality,” he said. His analyses point to several potential sources of pyridine discharge to the estuary, which could date back decades, but has embedded deep into the seabed. “On the basis of the established fact that pyridine preferentially deposits out into estuarine sediments, rather than remains in the water column, it seems likely that the new deeper dredging being constructed has uncovered and redistributed pyridine-laced sediments to the regional marine environment,” he added.
While Defra said that “any levels [of pyridine] detected in crab tissue are likely to be linked to biological processes and not necessarily from the environment”, Deere-Jones pointed out that samples from control crabs collected in Penzance had just under 6mg per kilogram of the toxic chemical, the Saltburn crabs were found to have more than 400mg per kg. “That’s not a natural level, that’s a human impact level,” he said.
Hydrozoan
Well-known member
It seems that three local MPs, two having met the Defra scientists, are content with the Defra view that an algal bloom, rather than pyridine released by dredging, was the likely cause.
‘Teesside MPs Simon Clarke [Conservative, Middlesbrough South and East Cleveland] and Jacob Young [Conservative, Redcar] met the Minister for Fisheries, Victoria Prentis, and the top scientists who are leading the investigation into the coastal crustacean incident. ...
DEFRA officials have ruled out the alternative hypotheses noting that there was no evidence of any dredging out of the proposed designated areas and that the level of pyridine was likely to be a naturally occurring substance released as shellfish decay.
The officials also explained that if the incident had resulted from a chemical leak, the volume of chemical required to have fatal effect, taking into account dilution, would have been detected in the waters - no chemical was found.’
Mr Clarke is quoted thus:
“These top scientists were able to assure us however that none of the alternative hypotheses were plausible given the wealth of evidence gathered as part of their investigation. They also agreed to answer any further questions that may arise and to publish a Q and A about the incident with DEFRA. I am assured that this incredibly unusual and alarming event was a result of rare but naturally occurring phenomena."
(Algal bloom the 'leading theory' of North East crab deaths | The Northern Echo , 10 February)
‘Mr Cunningham [Stockton North Labour MP Alex Cunningham] said he’d read the Defra report and was “content for the findings” in the scientific paper. He added: “It doesn’t appear to be the other chemical problem as far as that report is concerned. It’s going to be something they have to keep under review if we get a recurrence of this. The point I was making is that while this may be a natural occurrence, the fishermen up and down the North East coast have lost out considerably. “The government needs to look at how they help them over this period of time.”’
(Call for support for fishermen suffering following crab deaths | The Northern Echo , 13 February)
It will be interesting to read the Q&A when it is published, as it is to be hoped that it will give more details of the Defra scientists’ evidence and reasoning against a pollutant leak from dredging - summarised above in terms of the dredging pattern, natural occurrence of the substance, and the volume required (given the dilution) yet lack of detection in the water column. I’ll try to remember to search for it in due course, but hope that if anybody here sees it first they will post a link to it.
‘Teesside MPs Simon Clarke [Conservative, Middlesbrough South and East Cleveland] and Jacob Young [Conservative, Redcar] met the Minister for Fisheries, Victoria Prentis, and the top scientists who are leading the investigation into the coastal crustacean incident. ...
DEFRA officials have ruled out the alternative hypotheses noting that there was no evidence of any dredging out of the proposed designated areas and that the level of pyridine was likely to be a naturally occurring substance released as shellfish decay.
The officials also explained that if the incident had resulted from a chemical leak, the volume of chemical required to have fatal effect, taking into account dilution, would have been detected in the waters - no chemical was found.’
Mr Clarke is quoted thus:
“These top scientists were able to assure us however that none of the alternative hypotheses were plausible given the wealth of evidence gathered as part of their investigation. They also agreed to answer any further questions that may arise and to publish a Q and A about the incident with DEFRA. I am assured that this incredibly unusual and alarming event was a result of rare but naturally occurring phenomena."
(Algal bloom the 'leading theory' of North East crab deaths | The Northern Echo , 10 February)
‘Mr Cunningham [Stockton North Labour MP Alex Cunningham] said he’d read the Defra report and was “content for the findings” in the scientific paper. He added: “It doesn’t appear to be the other chemical problem as far as that report is concerned. It’s going to be something they have to keep under review if we get a recurrence of this. The point I was making is that while this may be a natural occurrence, the fishermen up and down the North East coast have lost out considerably. “The government needs to look at how they help them over this period of time.”’
(Call for support for fishermen suffering following crab deaths | The Northern Echo , 13 February)
It will be interesting to read the Q&A when it is published, as it is to be hoped that it will give more details of the Defra scientists’ evidence and reasoning against a pollutant leak from dredging - summarised above in terms of the dredging pattern, natural occurrence of the substance, and the volume required (given the dilution) yet lack of detection in the water column. I’ll try to remember to search for it in due course, but hope that if anybody here sees it first they will post a link to it.
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Daydream believer
Well-known member
Because he made a cooing sound, had feathers growing out of his ears & started cr..ping on car windscreens?
Fr J Hackett
Well-known member
I think from a purely chemical point of view that it is highly unlikely that pyridine or its derivatives would exist for any great length of time in an aqueous environment as they / it would be subject to hydrolysis. I used to use the stuff as a solvent many moons ago.
Hydrozoan
Well-known member
Quite possibly - though It appears from my (admittedly very limited!) searching that biologically (bacterially?) mediated decomposition is likely to be more important to its decay in natural waters than is simple chemical hydrolysis (as is of course often the case with organic substances). The Defra scientists will have access to more complete, recent information on mechanisms and rates of degradation in natural waters and, if degradation as well as dilution is germane to their reasoning, the Q&A may presumably say something about it.