Monitoring programme: Biodiversity - Fish
Programme topic: ​Fish, shellfish and fisheries

Sub-programme: migratory fish

 

​table of contentS

Regional coordination

Purpose of monitoring

Monitoring concepts

Assessment requirements

Data providers and access

References


REgional Coordination

The monitoring of this sub-programme is: partly coordinated. The sub-programme is partly coordinated within ICES WGBAST. Missing: sea trout parr densities and most of eel monitoring.

 

Purpose of monitoring (q4K)

Follow up of progress towards:

Baltic Sea Action Plan​ (BSAP)​ ​ ​ ​Segments ​Biodiversity
​Ecological objectives ​​Viable populations of species
Marine strategy framework directive (MSFD) ​ ​ ​Descriptors D1 Biodiveristy
D3 Commercial fish and shellfish
D4 Food webs
​Criteria (Q5a)
​1.1 Species distribution
​1.2 Population size
1.6 Habitat condition
3.1 Level of pressure of the fishing activity
3.2 Reproductive capacity of the stock
3.3 Population age and size distribution
4.1 Productivity (production per unit biomass) of key species or trophic groups
4.3 Abundance/distribution of key trophic species
​Features (Q5c)

Habitat types:
Identification and mapping of special habitat types, especially those recognised or identified under Community legislation (the Habitats Directive and the Birds Directive) or international conventions as being of special scientific or biodiversity interest.

Biological features:
Information on the structure of fish populations, including the abundance, distribution and age/size structure of the populations

​Activities (Q7a, 7b)

Extraction of living resources: ​Fisheries

Other relevant legislation (Q8a)
​Common Fisheries Policy (CFP) and Data Collection Framework (DCF)
Habitats Directive
Water Framework Directive


 


 

Assessment of: (Q4k)
State/Impacts ​​X temporal trends,
spatial distribution,

status classification
Pressures
Human activities
causing the pressures
X

Effectiveness of measures



Scale of data aggregation for assessments: (Q10a)
HELCOM assessment unit Level 1: Baltic Sea
​HELCOM assessment unit Level 2: Subbasin
HELCOM assessment unit Level 3: Subbasins with coastal and offshore division​
HELCOM assessment unit Level 4: Subbasins with coastal WFD division

​Other: Salmon assessment units/river specific

X

Monitoring concepts

Coordination Elements
Q9a (Q5c)
Parameter
Q9a (Q5c)
Method
Q9c, Q9d
QA/QC
Q9e, 9f
Frequency
Q9h, 9i
Spatial resolution
Q9g, 9i
Link to HELCOM core indicators Link to
MSFD GES characteristics

Q5b 
Spatial scope
Q4i
Monitoring started
Q4h
CPs monitoring
ICES
Fish abundance Life history stage (e.g. egg, juvenile, adult) Sea trout parr density surveys- rivers Other Yearly Targeting river basins Abundance of sea trout spawners and parr ​1.1.1 Distributional range, 1.2.1 Population abundance and/or biomass, 1.3.1 Population demographic characteristics, 1.3.2 Population genetic structure MS land/FW Varies by river – earliest 1976 SE, FI, RU, EE, LT, PL, DK, DE
ICES Fish abundance Life history stage (e.g. egg, juvenile, adult) Sea trout parr density surveys - areas Other Yearly Targeting areas Abundance of sea trout spawners and parr ​1.3.1 Population demographic characteristics, 3.3.1 Proportion of fish larger than the mean size of first sexual maturation), 3.3.4 Size at first sexual maturation Territorial waters Varies by area – earliest 1980 FI, RU, EE, LV, LT, PL
ICES Sampling from sea trout catch Composition of catch Biological sampling Other Yearly Main fisheries - ​1.3.1 Population demographic characteristics, 3.3.1 Proportion of fish larger than the mean size of first sexual maturation, 3.3.4 Size at first sexual maturation Territorial waters Early 2000s All HELCOM Contracting Parties
ICES Population dynamics  salmon Population size (abundance) Stock assessment Other Yearly Stock wide assessment Gulf of Finland -
​3.2.1 Spawning Stock Biomass (SSB), 3.2.2 Biomass indices, 1.3.1 Population demographic characteristics, 1.2.1 Population abundance and/or biomass, 3.1.1 Fishing mortality, 3.3.1 Proportion of fish larger than the mean size of first sexual maturation, 4.3.1 Abundance trends of functionally important selected groups/species EEZ 1993 All HELCOM Contracting Parties
ICES Population dynamics  salmon Population size (abundance) Stock assessment Other Yearly Stock wide assessment Main Baltic Basin and GoB and on river basis -
​3.2.1 Spawning Stock Biomass (SSB), 3.2.2 Biomass indices, 1.3.1 Population demographic characteristics, 1.2.1 Population abundance and/or biomass, 3.1.1 Fishing mortality, 3.3.1 Proportion of fish larger than the mean size of first sexual maturation, 4.3.1 Abundance trends of functionally important selected groups/species EEZ 1993 All HELCOM Contracting Parties
ICES Catch statistics of salmon Composition and number of retained/landed catch Time series of catches of salmon Other 3-monthly Offshore, coastal, river, commercial and angling -
​3.1.1 Fishing mortality MS land/FW 1972 All HELCOM Contracting Parties
ICES Salmon parr densities Life history stage (e.g. egg, juvenile, adult) Electrofishing Other Yearly River areas, rolling programme Abundance of salmon spawners and smolt ​1.1.1 Distributional range, 1.2.1 Population abundance and/or biomass), 1.3.2 Population genetic structure MS land/FW 1980 All HELCOM Contracting Parties
ICES Salmon spawning runs Reproduction rate Monitoring at fish ladders with traps or DIDSON Other Yearly At the few index rivers Abundance of salmon spawners and smolt ​3.2.1 Spawning Stock Biomass (SSB) MS land/FW Traps since 1990s, DIDSON since 2008 All HELCOM Contracting Parties
ICES Salmon smolt production Life history stage (e.g. egg, juvenile, adult) Traps and mark recapture Other Yearly At the few salmon index rivers and other rivers Abundance of salmon spawners and smolt ​1.2.1 Population abundance and/or biomass, 1.3.2 Population genetic structure MS land/FW 1990 All HELCOM Contracting Parties
ICES Sampling from salmon catch Composition of catch Biological sampling Other Yearly All main fisheries - 1.3.1 Population demographic characteristics, ​1.3.2 Population genetic structure, 3.3.1 Proportion of fish larger than the mean size of first sexual maturation, 3.3.4 Size at first sexual maturation MS land/FW 2003 All HELCOM Contracting Parties
ICES under WGEEL Group
Yellow eel recruitment Life history stage (e.g. egg, juvenile, adult) traps Other Yearly At 5 Baltic rivers -
​1.3.1 Population demographic characteristics, 3.2.1 Spawning Stock Biomass (SSB), 3.3.1 Proportion of fish larger than the mean size of first sexual maturation, 3.3.4 Size at first sexual maturation MS land/FW 1950  SE and DK
​ICES under WGEEL Group​Yellow eel abundance
​Population size (abundance)
​traps​other​Yearly​2 locations
​​1.2.1 Population abundance and/or biomass​MS land/FW
​2004​SE
ICES Silver eel escapement Life history stage (e.g. egg, juvenile, adult) Catch per unit effort of silver eel Other Yearly 3 locations in Sweden -
​ 1.3.1 Population demographic characteristics, 3.2.1 Spawning Stock Biomass (SSB),  3.3.1 Proportion of fish larger than the mean size of first sexual maturation, 3.3.4 Size at first sexual maturation Territorial waters 1950  SE
ICES Eel commercial catch Composition and number of retained/landed catch Monitoring of catches Other Yearly Across the Baltic -
​3.1.1 Fishing mortality Territorial waters 1945 All HELCOM Contracting Parties


 


Brief description of monitoring

Detailed information on monitoring frequency and spatial resolution has not yet been collected from all countries but will be added.


​Element / parameter
Salmon, sea trout, eel/catches
​Method All catches are monitored.
Spatial resolution The catch monitoring occurs across the Baltic. ​Catch monitoring collates national catch records (but method varies by country across sea trout, salmon and eel).


 


 

​Element / parameter
​Salmon population/stock assessment
​Method Smolt and parr surveys (traps, DIDSON and electrofishing) at index rivers, and other locations. Stock assessments exist for the main salmon population in the Baltic and the overall trends for Gulf of Finland salmon determined using various methods f interpolating monitoring trends. Stock assessments integrate time series trends and biological information.
QA/QC Either by ICES protocol, benchmark or workshop. Some though use national approaches.
Frequency

The frequency varies, with some series stopping and then starting again. Varieties of rivers can be monitored each year. The salmon index rivers should be monitored annually.

Sea trout and salmon don't occur parallel in all rivers, selection of index rivers need to be considered separately for salmon and sea trout.

Spatial Scope

Monitoring for salmon is carried out by assessment unit.

Spatial resolution Stock assessments are region specific. The surveys of recruitment, escapement, smolts or parrs are river specific (see ICES SGBALANST REPORT 2007 page 10 for a summary of sea trout monitoring in the Baltic ; ICES WGBAST REPORT 2013 page 18 for a table of biological sampling of salmon in the Baltic in 2012 and page 270 for assessment units).


 

​Element / parameter
Sea trout population/Stock assessment
​Method Smolt and parr surveys (traps, DIDSON and electrofishing) at index rivers, and other locations. Stock assessments exist for overall trends for sea trout, determined using various methods of interpolating monitoring trends. Stock assessments integrate time series trends and biological information.
QA/QC Either by ICES protocol, benchmark or workshop. Some though use national approaches.
Frequency

The frequency varies, with some series stopping and then starting again. Varieties of rivers can be monitored each year. The salmon index rivers should be monitored annually.

Sea trout and salmon don't occur parallel in all rivers, selection of index rivers need to be considered separately for salmon and sea trout.

Spatial Scope

​Region specific / River specific. Assessment is river specific, results can be summed up by coastal area or sub basin.

Spatial resolution Stock assessments are region specific. The surveys of recruitment, escapement, smolts or parrs are river specific (see ICES SGBALANST REPORT 2007 page 10 for a summary of sea trout monitoring in the Baltic ; ICES WGBAST REPORT 2013 page 18 for a table of biological sampling of salmon in the Baltic in 2012 and page 270 for assessment units).


 

​Element / parameter
Eel population/Stock assessment
​Method The abundance trends of various life stages (recruits, yellow eel and silver eel) are monitored. Yellow eel monitoring by traps in specific locations. Silver eel by catch per unit of fishing effort estimates. The Baltic is a component of the Europe wide stock assessment. Overall trends for eel are determined using various methods of interpolating monitoring trends. Stock assessments integrate time series trends and biological information.
QA/QC Either by ICES protocol, benchmark or workshop. Some though use national approaches.
Frequency

The frequency varies, with some series stopping and then starting again. Varieties of rivers can be monitored each year. The salmon index rivers should be monitored annually.

Spatial Scope

Most monitoring for eel is carried out in Sweden.

Spatial resolution Stock assessments are region specific.



 

assessmenT REQUIREMENTS

Monitoring requirements and gaps

Monitoring is to be carried out to fulfill assessment requirements of HELCOM ecological objectives that are specified through HELCOM core indicators. The requirements on monitoring can include number of stations, the sampling frequency and replication.

Monitoring
requirements

The current management regime requires an evaluation of the status of individual salmon stocks. This implies that stock-specific information needs to be collected from all salmon rivers; currently there are about 40 spawning rivers of salmon in the Baltic Sea (and 16 rivers in Kattegat). The regime has a high priority to establish at least one index river in each Assessment Unit (AU) of Baltic salmon.

Data from an index river consists of monitoring of salmon spawning runs and their composition, smolt runs, river catches and parr densities. Monitoring in all non-index salmon rivers should be arranged so that each juvenile cohort is sampled at least once before smoltification. Electrofishing surveys in non-index salmon rivers are of high priority but it is not necessary to have annual surveys in every river. Periodic smolt trapping in non-index rivers and monitoring of the M74 mortality in a subset of rivers supplement assessment by improving the accuracy of stock estimates.

Updating any information relevant to the migration and/or reproduction possibilities of salmon in rivers (e.g., changes in migration obstacles, restoration of river habitat, measures affecting water quality and/or flow regimes) is also needed.

Assessment requirements concerning monitoring at sea covers: fishing effort and catches (incl. discarding and estimates of unreporting), catch sampling from which the stock composition and the origin (wild/hatchery-reared) is analysed. These data are needed on fleet basis (offshore/coastal fishing by gear type). Also catch data on recreational fisheries at sea and in rivers is necessary and used in the salmon assessment.

Monitoring requirements concerning sea trout are very similar to those of salmon. However, the current trout assessment does not require as broad range of datasets as is required for salmon assessment. The datasets of highest priority are: parr densities and inventories of river habitat. Establishment of index rivers similar to salmon index rivers is highly recommended. This would enable supplementing of parr density information with counts of trout smolts and ascending spawners in a part of rivers. Catches, tag recaptures from fisheries, and information about fishing pressure and fishing pattern (gear and mesh sizes used) are also required for in-depth assessment of sea trout stocks.

There is no such thing as Baltic eel. Eel is pan-European, so the monitoring programmes must be European wide.

​Gaps Currently, few salmon index rivers in the Baltic Sea provide a full set of information (monitoring of salmon spawning runs, smolt runs and river catches, and parr densities) required from index rivers. Full scale monitoring takes place only in Finland and Sweden and covers Assessment Units 1, 2 and 4. More index rivers with full set of information are especially needed from Assessment Units 5 and 6. Complete and more accurate estimates about recreational salmon catches are needed both from the sea and the rivers. The spatio-temporal coverage of catch sampling from sea may need to be increased for assessment efforts serving stock specific management and restoration of weak stocks. For sea trout, establishment of index rivers similar to salmon index rivers is highly recommended.


 


Adequacy for assessment of GES (Q5d)

Monitoring should provide adequate data and information  to enable the periodic assessment of environmental status, and distance from and progress towards GES as required by MSFD under Article 9 and 11.

​Adequate data?​
​Yes
Established methods for assessment?
​Yes. Expert evaluations are available and a substitutive model to estimate reference densities in a certain areas is available, but a generally working model for all areas is still missing. In addition a criteria for selection of monitoring sites need to be developed.
​Adequate understanding of GES?
​​Yes i.e. 50% of the max. reference density.
Adequate capacity to perform assessments?
Yes. ICES WGBAST have a capacity to perform the expert evaluation on the status of stock and to run potential models.


 


Assessment of natural variability (Q5e)

Quantitative and by expert opinion. Natural variation is quantified by analytical assessment tools (life cycle models for salmon and other statistical analyses methods for sea trout) and the results are complemented by expert opinions, trend analyses etc.



 

Data providers and access

​Data access point
National databases
Data type (Q10c)
Processed Data sets
Data Products
Modelled data
Data availability (Q10c)​

Provide location of data in national data centre: Modelled data available in the Finnish Game and Fisheries Research Institute.

Provide location of data in international data centre (e.g. RSC, ICES, EEA, EMODnet): Catch sampling data of salmon available in the ICES Regional database.

​Data access (Q10c)
Restricted by specific licence
Data will not be available

​INSPIRE standard (Q10c)
Species distribution
When will data become available? (Q10c)
Unclear
Data update frequency (Q10c)
​Yearly
Describe how the data and information from the programme will be made accessible to the EC/EEA ​Unclear
​​Contact points in the Contracting parties

​Contact point to national monitoring programmes will be added

​Has the data been used in HELCOM assessments?
​Yes


 

REFERENCES


Stock assessment of Gulf of Finland Salmon

Stock assessment of salmon in Baltic main basin and Gulf of Bothnia

Monitoring of smolts and migrating adults: Annex of the WGBAST report

Study group on data requirements and assessment needs for Baltic Sea trout (SGBALANST)

SALAR project

Report of the Joint EIFAAC/ICES Working Group on Eels (WGEEL)

Electrofishing method manual: Bohlin T, S Hamrin, T G Heggberget, G Rasmussen & S Jakob Saltveit (1989) Electrofishing — Theory and practice with special emphasis on salmonids. Hydrobiologia 173: 9-43.