Electro Fishing

Electro fishing is a common method of counting fish. The results also show the density of fish in each part of the Electrofishing river, and which species are present. On the Findhorn, electro fishing data exist back to 1997, giving useful information on changes in populations over time. There is much less historical data on the Nairn and the Lossie. The 2010 surveys provide a baseline for these rivers.

The 2010 surveys showed good populations of salmon in the Findhorn and the Nairn. While parts of the Lossie had good salmon numbers, other parts were less abundant. Sea trout are also present in all three rivers.

Findhorn

In general the distribution of salmon in the Findhorn catchment was excellent in 2010 with most of the tributaries examined producing juveniles and mean overall densities for each age class were close to the long-term average. This may reflect better runs of adult salmon during the last few seasons coupled with an increase in the catch and release rate allowing more spawning females. However, many other factors are also important.

On the Findhorn, trout fry distribution was somewhat limited, in line with historical data, with the best numbers on the Anaboard and Little Berry Burns within the Dorback and Divie catchment. (The Dorback and Divie are tributaries of the Findhorn.) The Findhorn is not renowned as a trout river, indicating that runs into the river may be low.

Small numbers of eel, stickleback and lamprey were also found.

Nairn

The 2010 survey indicated that salmon and trout were present throughout the River Nairn and its tributaries. Salmon were found in the mainstem from the falls at Alltarder down to Nairn. Salmon were also present in most tributaries with the Brin and Farnack showing very good numbers.

Trout were widespread in the catchment although they were less prevalent in the mainstem than salmon.  Most of the trout were caught in the tributaries, which offer more typical trout habitat. Eels, brook lamprey and 3-spined stickleback were also found.

Lossie

Juvenile trout are present throughout the catchment. Although they are present in the mainstem, they are more abundant in tributaries such as the Linkwood, Black, Corrhatnich and other Burns, which are important areas for sea trout spawning.

Juvenile salmon were more restricted in their distribution, with the mainstem from Dallas downstream to the mouth providing the best densities. The densities of salmon through Elgin are very encouraging. Juvenile salmon were less well distributed in the tributaries. The lower Linkwood Burn and lower Black Burn indicate good densities, but weirs appear to limit their upstream progress. In the upper burns and upper Lossie the salmon distribution and density is patchier, despite the existence of good habitat. It is not clear what may be limiting salmon in this area and further investigation is required.

The Trust plans to conduct electro fishing surveys on one river per year. The Findhorn DSFB plans to conduct surveys of the Findhorn in the other years, to maintain the multi-year data set.

The results of electro fishing surveys and the catch returns (numbers of fish caught or caught and released) helps to advise the DSFBs as they revise their conservation codes for the following year.

Download:

River Findhorn Juvenile Survey Report 2010 (Findhorn 2010 JS Report)
River Nairn Juvenile Survey Report 2012

River Nairn Juvenile Survey Report 2010 (Nairn EF Survey Report 2010)
River Lossie Juvenile Fish Survey 2013

River Lossie Juvenile Survey Report 2010 (Lossie EF Survey Report 2010)