Essential fish habitats and fish migration patterns in the Northern Baltic Sea

Questions this practice may help answer

• What are the essential fish habitats and dispersal areas in the Baltic Sea?
• How can data about the habitats and dispersal areas for fish be used for designating Marine Protected Areas (MPAs)

Implementation Context

Fish habitats and patterns are important data sources for designation of Marine Protected Areas (MPAs). In accordance with HELCOM and OSPAR, four aspects are emphasised when evaluating the ecological coherence of networks of marine protected areas (MPAs) within the BALANCE project, namely:

• Representativity
• Connectivity
• Replication
• Adequacy

These four concepts can be used to analyse descriptions of essential fish habitats (Spawning areas, Nursery areas (for larvae and juveniles), Adult feeding areas, Migratory corridors & Possible specific areas to which a species may be highly restricted) and fish dispersal  (Linkages between populations).

Aspects / Objectives

• Compile the current state of knowledge on essential fish habitats (EFH) and patterns of fish dispersal within BALANCE Pilot Area 3
• Serve as background data for GIS-based analyses of ecological coherence of marine protected areas within BALANCE.

Method

• Explicit spatial analyses may be performed for fish species and life stages for which maps of potential EFH are currently available if the analyses are of appropriate scale and resolution in relation to these maps.
• For the other species an evaluation is made of how well their preferred habitat types correspond to habitat types described within the Habitats Directive.
• Maps of the habitat types presented have previously been produced within BALANCE for Pilot area 3 (the Stock- holm archipelago and Archipelago Sea area). This indirect approach can be used for broad, preliminary descriptions of the distribution of EFHs, but should be replaced by maps based on statistical models as soon as enough information is available for predictive modelling.

Main Outputs / Results

The report shows the main fish habitats and dispersal areas. Furthermore, the report concludes that the current placing of Natura 2000 sites mainly covers shallow water areas around islands, in estuaries or along the coastline, while true pelagic MPAs are a rarity. To ensure viable fish stocks in future, MPAs and no-take areas should be established in both coastal and pelagic areas.

Transferability

The finding of this practice related to the Northern Baltic Sea specifically. However, the practice also shows general issues regarding Nature2000 areas, such as the on sea MPAs and no-take areas, which are lacking at the moment in the Baltic Sea. This could also be the case in other sea basins, so the methodology and findings of this practice can be of an added value for other areas.

Costs / Funding Source

Interreg IIIB Baltic Sea Region

Responsible Entities and Contact Persons

• Samuli Korpinen, Finnish Environment Institute, Mechelininkatu 34a, PO Box 140, FI-00251 Helsinki, Finland

  phone: +358406618977 Email: samuli.korpinenymparisto.fi (samuli[dot]korpinen[at]ymparisto[dot]fi)

• Asa Andersson, WWF Sweden, Världsnaturfonden WWF, Ulriksdals Slott, 170 81 Solna, Sweden, phone: +46-624 74 00
  E-mail: infowwf.se (info[at]wwf[dot]se)