​​​​​​​​​​Key message

This indicator evaluates the status of the Baltic Sea area based on salmon smolt production in rivers flowing into the sea, also making use of additional supporting data on numbers of adult spawners. Determination of whether the threshold value that determines good status is achieved is based on a comparison of estimated smolt production with an estimated potential smolt production capacity. 

The evaluation covers the period 2011-2015, and the final result is dependent on the last year.


Abundance_of_salmon_spawners_and_smolt.png
 

Key message figure 1: Status assessment results based evaluation of the indicator 'abundance of salmon spawners and smolt'. The assessment is carried out using Scale 2 HELCOM assessment units (detailed in the HELCOM Monitoring and Assessment Strategy Annex 4. Click to enlarge​.

 

In the Bothnian Bay and The Quark areas, smolt production has increased in recent years due to higher numbers of adult spawners ascending the rivers as a result of stricter management measures. Good status is achieved in three out of 15 rivers associated with these assessment units, and it is probable that it will be achieved in 1-3 more rivers within the next few years. In the Bothnian Sea area, smolt production is low although showing slight signs of increase. In the Gulf of Finland, smolt production is low but has recently shown signs of improvement and three Estonian rivers are evaluated as having achieved the threshold, based on expert judgment. Smolt production in rivers flowing into the Baltic Proper is low and does not show any signs of improvement.

The level of confidence of the evaluation is moderate.

The indicator is applicable in all the countries bordering the Baltic Sea except Denmark Germany, and Poland.


Relevance of the core indicator

Salmon is a long-distance migratory large predatory fish species in the Baltic Sea marine ecosystem. Salmon abundance is mainly affected by commercial fishing at sea and by barriers in rivers to reproduction areas. This indicator has a linkage to the number of adult spawners ascending the rivers and, hence, indirectly to the commercial and recreational fishing pressure at the sea and in the river. The indicator also reflects the state of the ecosystem as smolt production is dependent on river connectivity (effect of dams) and the quality of spawning habitats.


Policy relevance of the core indicator

BSAP segment and objectives

MSFD descriptor and criteria

Primary link

Biodiversity

  • Thriving and balanced communities of plants and animals

  • Viable populations of species

 D1 Biodiversity

D1C2 The population abundance of the species is not adversely affected due to anthropogenic pressures, such that its long-term viability is ensured.

Secondary link


D4 Food-web

D4C4 Productivity of the trophic guild is not adversely affected due to anthropogenic pressures


​Cite this indicator

HELCOM (2017) ​Abundance of salmon spawners and smolt. HELCOM core indicator report. Online. [Date Viewed], [Web link].​

ISSN 2343-2543


Download full indicator report

HOLAS II Component - Core indicator report – web-based version July 2017 (pdf)