Models

Ecosystem ecology, food web ecology and macroecology have all influenced the modelling tools that are currently being developed and applied to marine ecosystems around the UK.  The models used in MERP have been selected on the basis of representing the state-of-the-art in ecosystem modelling; their computational efficiency; their application to real ecosystems; the scientists expertise and their availability as open source code.

A summary of the models used in the MERP project can be found below.

European Regional Seas Ecosystem Model (ERSEM)

European Regional Seas Ecosystem Model is a generic lower-trophic level/model designed to represent the biogeochemical cycling of C and nutrients (N, P, Si, O2, Fe) as an emergent property of ecosystem interaction.

Ecopath with Ecosim (EwE)

EwE incorporate diet and biomass data from fisheries and oceanographic datasets and the literature to carry out a mass-balance network analysis (Ecopath), to simulate dynamical change in biomass of functional groups or species through time (Ecosim) and space (Ecospace) at a regional scale. Models available include West of Scotland, Celtic Sea and Irish Sea.

Population-Dynamical Matching Model (PDMM)

The model constructs complex and population-dynamically stable ecological model communities at species resolution by mimicking the natural process. Recent model applications include the Celtic Sea and the North Sea to study the Large Fish Indicator.

Strathclyde end-to-end ecosystem model (StrathE2E)

The model represents the time-dependent dynamics of the ecosystem components in a spatial region. It simulates the fluxes of nutrients (nitrogen) through ecosystems from dissolved inorganic (nitrate and ammonia), through plankton, benthos and fish, to birds and mammals, regeneration through exrection and mineralization of detritus in the water column and sediment and physical exchanges across geographic boundaries. Models available include the North Sea, English Channel, Celtic Sea, Irish Sea and west of Scotland (EU-FP7 project BASIN).

Coupled Community Size-Spectra Model (CCSSM)

The coupled size-spectrum model describes the structure and dynamics of two interacting size structured communities. The pelagic community consists of predators feeding on other predators and on benthic prey that share and compete for detritus.

Species Size-Spectrum Model (SSSM)

The SSSM is a highly simplified description of the dynamics of (spatially unresolved) marine species size-spectra, i.e. of the distribution of community biomass over species of different body sizes.

Multispecies Size Spectrum Model

The model represents the size and abundance of all organisms from zooplankton to large fish predators in a size-structured food web. A proportion of the organisms are represented by species specific-traits and body size while others are represented solely by body size.

Strathclyde length-structured partial ecosystem model (FishSUMS)

The model represents the population dynamics of a set of key trophically linked predator and prey species. For each species the state variables are biomass by length class. FishSUMS has been parameterised for the North Sea with an implementation for the west of Scotland in progress.