Comments on: The penultimate week…. http://www.ribbletrust.org.uk/2009/09/29/the-penultimate-week/ Wed, 30 Jun 2010 07:52:59 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Dr Clive L. Fetter http://www.ribbletrust.org.uk/2009/09/29/the-penultimate-week/comment-page-1/#comment-64 Dr Clive L. Fetter Sun, 17 Jan 2010 11:34:19 +0000 http://www.ribbletrust.org.uk/?p=600#comment-64 I too have read Nall's excellent book, but you might be interested in some work I undertook for the Sussex Ouse Conservation Society. R. Ouse has a modest run of sea trout but no salmon. Internal examination of returning adult sea trout retained by anglers has shown that the population consists of one quarter cock fish and three quarters hen fish. We believe that this is because about half of the cock sea trout parr do not migrate to sea - instead they become 'brown trout', indistinguishable from the native brown trout in the stream. Also, the EA has told us that they sometimes trap sea trout smolts in places inaccessible to migratory fish so it seems that 'brown trout' sometimes do migrate to sea. So it seems that the proposition that brown trout might migrate to sea is more complex than the opinion given by Nall. There is evidence that this does occur sometime and the reverse, i.e. offspring of sea trout 'reverting' to brown trout probably does occur. You might be interested in my scale reading studies on our website. I too have read Nall’s excellent book, but you might be interested in some work I undertook for the Sussex Ouse Conservation Society. R. Ouse has a modest run of sea trout but no salmon. Internal examination of returning adult sea trout retained by anglers has shown that the population consists of one quarter cock fish and three quarters hen fish. We believe that this is because about half of the cock sea trout parr do not migrate to sea – instead they become ‘brown trout’, indistinguishable from the native brown trout in the stream.
Also, the EA has told us that they sometimes trap sea trout smolts in places inaccessible to migratory fish so it seems that ‘brown trout’ sometimes do migrate to sea.
So it seems that the proposition that brown trout might migrate to sea is more complex than the opinion given by Nall. There is evidence that this does occur sometime and the reverse, i.e. offspring of sea trout ‘reverting’ to brown trout probably does occur.
You might be interested in my scale reading studies on our website.

]]> By: Derek Jebson http://www.ribbletrust.org.uk/2009/09/29/the-penultimate-week/comment-page-1/#comment-46 Derek Jebson Wed, 30 Sep 2009 14:23:45 +0000 http://www.ribbletrust.org.uk/?p=600#comment-46 Thank you jack for all the survey work you are putting into the Ribble catchment on our behalf and trust that in due course of time tthe knowledge gained will be for the benefit of our rivers and streams . I would however be pleased to know the validity of your following statement and factual scientific proof you have for making the following statement "and the clipped juveniles will drop lower and lower down until they find suitable habitat. This might actually be beneficial in making sure the released fish head to sea and return as sea trout." Thus far I have not heard or read any convincing proof that this is so. For a number of years, of which you will be aware, a number of brown trout have been dye marked with the intention of discovering their movement . To date I have not heard of a single 'seatrout' returning with a dye mark. I have no doubt that seatrout and brown trout are of the same species scientifically. Just as we are all Homo Sapiens but my migrating to Austraiia for a few years does not turn me into an Aboriginee .I have heard people say that they have witnessed the brown and the seatrout actually fertilising on the redds. I haven't. but have you any proof that any progeny of this happening has resulted in their survival or moreso these returning from the sea as a seatrout I have no doubt that some Browns do drop down to saline warer in which they find more sufficient food . These slobs whilst growing to a large size do not to my knowledge take on the livery of a seatrout Really all I am asking is whether or not you have any prove of what you are suggesting in that statement. If this statement is not factual and it is repeated often enough then in time it comes to be believed as fact, but not supported by proof. I wonder Jack if you have ever read 'The Life of the Seatrout' by G.H.Nall ? where on page 83 of the same he describes with far better words than I can ever do. The differences of the two fish. If you would care I will send you the extract for your deliberation. Yours sincerely, Derek Jebson Thank you jack for all the survey work you are putting into the Ribble catchment on our behalf and trust that in due course of time tthe knowledge gained will be for the benefit of our rivers and streams .
I would however be pleased to know the validity of your following statement and factual scientific proof you have for making the following statement “and the clipped juveniles will drop lower and lower down until they find suitable habitat. This might actually be beneficial in making sure the released fish head to sea and return as sea trout.”
Thus far I have not heard or read any convincing proof that this is so. For a number of years, of which you will be aware, a number of brown trout have been dye marked with the intention of discovering their movement . To date I have not heard of a single ‘seatrout’ returning with a dye mark. I have no doubt that seatrout and brown trout are of the same species scientifically. Just as we are all Homo Sapiens but my migrating to Austraiia for a few years does not turn me into an Aboriginee .I have heard people say that they have witnessed the brown and the seatrout actually fertilising on the redds. I haven’t. but have you any proof that any progeny of this happening has resulted in their survival or moreso these returning from the sea as a seatrout I have no doubt that some Browns do drop down to saline warer in which they find more sufficient food . These slobs whilst growing to a large size do not to my knowledge take on the livery of a seatrout Really all I am asking is whether or not you have any prove of what you are suggesting in that statement. If this statement is not factual and it is repeated often enough then in time it comes to be believed as fact, but not supported by proof.
I wonder Jack if you have ever read ‘The Life of the Seatrout’ by G.H.Nall ? where on page 83 of the same he describes with far better words than I can ever do. The differences of the two fish.
If you would care I will send you the extract for your deliberation.

Yours sincerely,

Derek Jebson

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