Risk Assessment Refinement

BARRIERS TO MIGRATION

Aerial ImageryCapture and Processing

Derive Channel TypologiesDevelop Remote Sensing Methods

Fieldwork Contracts 2006 and 2007Morphology and Biology Field Data

Programmes of Measures

Populate a morphology database

Developing the Morphological Assessment Process

RISK

ASSESSMENT

CLASSIFICATION & MONITORING

PoMS STUDY

Decision Support Tool

Assessment of Barriers in the Nore Catchment

The study will use an approach for the assessment of the impact of in-river barriers to fish migration, on

a case study basis in the River Nore (Southern Regional Fisheries Board area), which can be used subsequently to assess river barrier impacts nationally.

Methodology

• The Southern Regional Fisheries Board has compiled an extensive data set on the distribution of artificial and man-made barrier throughout the Nore system.

• The risk of each barrier to upstream migration has been assessed

• A system is required so that this information can be used to assess the risk of delaying or preventing salmon and other fish migration which can adversely impact on the status of the water body.

R. Nore catchment: Barrier to fish passage

Key information datasets to aid risk assessment

• CFB Wetted Area Database

• Location of salmon spawning areas (GIS layer)

• Distribution and abundance of juvenile salmon (GIS layer)

• Relating the distribution of juvenile salmon and/or the location of salmon redds to the barrier information will allow assessment of the degree to which specific barriers are impeding the upstream passage of salmon.

The GIS layer on location of potential and known salmon spawning areas on the Nore Catchment is being updated

` This will be related to the barrier information

Information on the distribution and extent of juvenile salmon on the Nore Catchment is being updated

Targeted electro-fishing upstream of high risk barriers has been undertaken

Eel and Lamprey anadromy

Sea-, river- and

Brook lamprey

R. Nore: Location of Sea Lamprey redds

Nore Sea lamprey redd counts 2000 (n=48) & 2004 (n=52)

0

5

10

15

20

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53

Distance upstream from Inistioge in kilometres

Nos

. of

red

ds

No. of redds (2000)

No. of redds (2004)

Bennetsbridge

Thomastown Weir

BallyraggetInistiogeBridge

Risk Assessment

The CFB wetted area database, when integrated with the salmon spawning and juvenile salmon distribution, will allow the extent of freshwater habitat upstream of barriers to be determined.

Overall Risk Assessment

• Compass Infomatics will integrate information on barriers and the distribution of salmon and/or lamprey with the wetted area data for the Nore Catchment

• This would allow assessment of the benefit of removing a particular barrier and allow calculation of the additional wetted area to be gained.

• This will provide input for the development of a barrier risk assessment scheme by the WFD group.

Barrier Risk Assessment

• While a barrier or series of barriers may not act to stop salmon or lamprey ascending, barriers may delay upstream movement.

• This may have implications for salmon angling upstream or delay multi-sea winter salmon from reaching headwaters, cause stress etc.

• This may be dependent on time of year, for example lamprey spawn in summer and may be prevented from moving upstream to spawn in low summer flows.

• The complexities of barriers or series of barriers relating to fish movement and risk is being addressed.

R. Nore: barrier to fish passage