Smolt trap week ending 6th May 2013

Spring arrived all of a sudden on Speyside at the weekend, unfortunately it was accompanied by heavy rain and both the Truim and Tromie traps were out of action for two days in the big water. They were operating again on Sunday and ready for the daily inspection on Monday. Normally we go to the Truim first but slow moving traffic on the A9 prompted a quick change of plan so the Tromie was visited first.

There were a few more in the Tromie trap.

185 fish int he Tromie trap

185 fish in the Tromie trap

Most of the catch were trout but there were 64 first capture salmon smolts, the highest daily catch of the year. The water temperature went above 8 degrees at the weekend but the relatively low catch for the conditions suggests that we had missed a lot of smolts in the high water. The first capture smolts were ventral marked and released at the upper release point.

Tromie birch buds just about to open

Tromie birch buds just about to open. With the sudden arrival of spring the tree buds were opening and the first flush of green was apparent on many trees on the route up to the traps. The Tromie release point is at an altitiude of almost 1000′, spring is just a little later up there.

Most of the fish trapped were trout ranging from small one year old parr to adults of 300mm. Establishing whether any of the trout are smolting is always a matter of debate. We reckon most of the trout from these upper tributaries are destined to be river or loch resident trout but the occasional one exhibits some signs of smolting, e.g. silvering. The one photographed below was a distinct black band on the edge of its tail, this is a feature I have always associated with smolts.

Black edge to trout tail - a sign of smolting?

Black edge to trout tail – a sign of smolting?

The Truim trap took a battering again at the weekend with the smolt box lid swept open and got bashed. There were very few smolts in the trap yesterday. This year we have trapped less then 200 in the Truim, this compares to over 5000 trapped last year. It is looking increasingly likely that we have missed most of the run in the frequent high water events.

There were a lot of  mayflies hatching yesterday and the birds (female chaffinches) were having a field day catching them in mid air as they emerged from the river. One mayfly managed to avoid the avain threat and landed on the record sheet.

I think this is a March Brown, it has the characteristic light patch in the middle of the wing and there are faint dark blotches on the femur.

I think this is a March Brown, it has the characteristic light patch in the middle of the wing and there are faint dark blotches on the femur. Slightly surprising to see them in an upper tributary rather than the mainstem.

It looks like 2013 will be one of those years when we don’t learn much about the characteristics of the smolt run.

In the afternoon we had a committment in the lower river at Spey Bay with an electrofishing demo as part of the “Really Wild Fest”. I had anticipated that a rise in the river was likely and had forewarned the organisers that we may struggle on the day. This turned out to be the case and it was impossible to electrofish with the river up 2′. In the flooded side channel, where we had intended to do the demo, there were many smolts/parr rising. We tried to catch a few with the electrofisher but to no avail, the current in the Spey even in these side channels is deceptively strong. Still it was good to see plenty evidence of smolts there and also on the Easter Elchies beat.

Lower Spey birch, not really much difference in the timing despite nearly 900' difference in altitude

Lower Spey birch, not really much between here and the Tromie timing wise despite nearly 900′ difference in altitude

 

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