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Post by treefella on Oct 31, 2023 16:33:50 GMT
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Post by yeoman on Oct 31, 2023 17:23:03 GMT
That's interesting, Dave.
For what it's worth, the Riverfly results for our area this year were the worst on record.
Couldn't be the water companies, could it?
Or maybe the NFU?
Anyway, I've asked them, so we'll see what comes back.
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Post by treefella on Oct 31, 2023 17:50:05 GMT
If you get to the end of the press release there a link to the whole paper ,for bedtime reading.I just find it hard to believe what they are saying.
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Post by yeoman on Oct 31, 2023 17:54:46 GMT
Funded by NERC so it says.
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Post by halfstoned on Oct 31, 2023 18:00:52 GMT
🤣🤣🤣🤣🤣 go on, tell me another one!!!
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Post by halfstoned on Oct 31, 2023 18:16:06 GMT
"Similarly, abundance was recorded in a semi-quantitative manner before 2000 and so could not be used in assessing the whole 30-year time period. The analysis, therefore, focused on presence-absence recording at the family level, which although not as detailed as species level, was at least consistent over the recording period."
So we're only talking about "presence or absence " and NOT abundance, what a shock!!
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Post by terry on Oct 31, 2023 19:37:47 GMT
My problem is that these days I find it very hard to believe most things I read but I guess you can assume that this report was generated by someone who hasn’t witnessed first hand the decline over the last ten years.
At least this report has been sufficient to roust this beloved board into action once again.
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Post by boisker on Oct 31, 2023 23:28:32 GMT
That the trouble with any science paper, understanding what it is they actually looked at and what they are actually saying is key.
Someone who fishes rivers regularly will undoubtedly be able to point to a decrease in abundance on many rivers, but not that many of those same people fishing would have the knowledge or take the time to accurately monitor new species recruitment…. Or at least I don’t😏
The paper basically says the number of species/family groups has recovered over the last 30 yrs, which is good news../ but makes no detailed claims as to abundance… which has undoubtedly declined, which is appalling.
What we actually need is an increase in both…. An expansion and recolonisation of missing families/species and an increase in abundance.
It’s depressing in that there have been undoubted improvements in water quality, the range of heavy metals / many of the worst chemical don’t enter our rivers like they did for many years, I guess this with the fact that raw sewage is supposed to be treated (as opposed to a a few hundred years of no treatment) has resulted in the improvements at a species level…. Unfortunately the state of our overall system means it’s likely to stay at this species level and possibly decline again, rather than yearly increase in abundance.
Lastly, without actually looking at the spacial spread of the survey / data sites, it’s hard to really understand the overall picture, or the picture close to you…
As an example… speaking to people who have fished the Otter for the last 40 years they would definitely say there has been a decline, certainly in abundance (not sure about species… I’ve never asked), but 40 yrs ago I was still living in Bolton…. All the rivers of Manchester and pretty much any large mill town were pretty much devoid of life…. You wouldn’t have dreamt of fishing in Manchester in 1980…. And yet now, if you follow J Tyzack, you’ll see some great fish, as long as you are happy wading around shopping trolleys… same with Don, Tyne and a whole host of previously polluted hell holes.
The devil is in the detail
Personally I think it’s good news, having worked in conservation for 30yrs you learn to ‘celebrate’ the good news, and use it as a stick to demand more….
But we can all agree our rivers deserve a sh*t load better😏
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Post by johnesmithson on Nov 3, 2023 11:25:14 GMT
If you really want to know what's happening on your local fishery you can look up the data from the RiverFly Partnership (https://www.riverflies.org/about), or even better, get trained to do it yourself and then monitor a specific stretch regularly. There was a training day at Prince Hall last year which I had to pull out of at short notice sadly, but I have asked to be enrolled on any future days.
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Post by halfstoned on Nov 4, 2023 11:25:45 GMT
I have tried looking at the data Johnny but I don't find the format all that easy to wade through in terms of any discernible patterns. Is there anywhere to see the last ten years or so of results for a particular insect at a particular location?
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Post by johnesmithson on Nov 4, 2023 16:01:46 GMT
I agree Chris, not the easiest website to navigate. I have found this is one useful way to get into the nitty-gritty: choose Data from the drop down menu, then Data Explorer (this page riverflies.fba.org.uk/content/DataExplorer). Ignore Catchment but select your river of interest, and you should be able to see the counts for a given point for the last 5 years. There is also a map option (https://riverflies.fba.org.uk/Maps) where you can see each monitoring site in green. Click on that to see the latest sampling date. I'm a complete amateur at all this though: there are others on this Forum who will know much better how to access and analyse the data. |
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Post by yeoman on Nov 4, 2023 16:58:56 GMT
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Post by johnesmithson on Nov 4, 2023 17:46:58 GMT
Thank you for posting this; what a fantastically detailed (if concerning) report.
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