The modelling of Furcellaria lumbricalis habitats along the Latvian coast

Questions this practice may help answer

• What is the current state of habitats shaped by Furcellaria lumbricalis in the Baltic Sea?
• What model can be used to research macroalgae in a specific coast?
• How can the modelling of macroalgae be used in the designation of Nature 2000 areas?

Implementation Context

This practice describes the modelling of habitats shaped by Furcellaria lumbricalis at the Latvian Baltic Proper coast. Presence or absence of Furcellaria lumbricalis, the only macroalgae species adapted to the high wave exposure along the almost linear shoreline, shapes the characteristics of hard bottom habitats on the underwater slope. 

Aspects / Objectives

• Model the occurrence of Furcellaria stands on rocky substrates associated with hard bottom fauna, which is – along the Latvian Baltic Proper coast - dominated by the blue mussel, Mytulis edulis.
• Use modelling as a tool to designate the protected Nature 2000 areas described by Annex 1 of the EU Habitat directive

Method

Detailed observations with precise spatial coordinates of macrophyte communities, the associated hard bottom fauna, together with information on sediment type, were avail-able from a coastal strip in the southern part of the Latvian Baltic Proper coast, extending approximately 35 km along the coast. This area was used to calibrate general additive models of Furcellaria distribution. Further, these models were applied to predict the probability of presence/absence of Furcellaria stands for the entire Latvian Baltic Proper coast.

Main Outputs / Results

The report provides an overview of the habitats shaped by Furcellaria lumbricalis. In the model calibration area, the most successful model correctly reflected 75 % and 94 % of Furcellaria stand presences and absences, respectively. Model extrapolation to the entire Latvian Baltic Proper coastline was limited by the quality of bottom type and depth information available from published maps.

Transferability

The practice refers to habitats shaped by Furcellaria lumbricalis at the Latvian Baltic coast specifically and is therefore non transferable. However, the methods used and the lesssons learned can be applied for by other researchers modelling different kinds of macroalgae.

Costs / Funding Source

INTERREG IIIB Baltic Sea Region

Responsible Entity

Barbel Muller-Karulis & Juris Aigars

Latvian Institute of Aquatic Ecology,Voleru str. 4, LV-1007, Riga, Latvia phone:
+371 67601995. Fax: +371 67601995

E-mail: hydrolatnet.lv (hydro[at]latnet[dot]lv)