Page 1 of 1

Hatch Mere Gammarus

PostPosted: Tue Apr 05, 2016 12:34 pm
by John_Bratton
Hatch Mere Gammarus:

There are old records of Gammarus lacustris from Hatch Mere on the NBN. Last week I caught G. pulex there. Does anyone know whether it has taken over or do the two species co-exist there ?

John Bratton

Re: Hatch Mere Gammarus

PostPosted: Wed May 25, 2016 10:43 am
by John_Bratton
Here was I naively thinking the LRC might respond to a question like this.

Re: Hatch Mere Gammarus

PostPosted: Thu May 26, 2016 12:45 pm
by fletcher
Hi John,

Sorry for the delay in responding to your post.

Looking at the data we have for Hatch Mere the last record for G.lacustris on site was in the 1980's when it was recorded alongside G.pulex. Since then, even though recorders have been back to Hatch Mere, only G.pulex has been recorded.

Please feel free to contact us directly if you would like more info or if there are other sites you are interested in. We will be more than happy to conduct a data search for you.

Many thanks,

Re: Hatch Mere Gammarus

PostPosted: Thu Jun 02, 2016 5:20 pm
by John_Bratton
Thanks very much.


Re: Hatch Mere Gammarus

PostPosted: Fri Jun 03, 2016 8:54 am
by SteveMcBill

Very few of the 'specialities' of Hatchmere have been recored (if any) in the last 20-30 years. I think the last time the scarcer species were recorded was when Nora McMillan undertook dredging surveys from a boat on the lake many years ago and I am not aware that such survey methodologies have been repeated since. I think all recording since that time has been 'from the bank' and not in the deeper water.

Of course the lack of the more interesting records could be down to reduced water quality and habitat change but until repeat surveys using similar techniques to those used in the past by people such as Nora are repeated (a number of times over the different seasosn and for a couple of years or more) then we may never know whether these 'specialities' are still in existence in the mere.