Nutrient cocktail in coastal zones of the Baltic Sea – improving understanding of the transformation and retention of nutrients and organic matter in the coastal zone 

Coordinator: Jacob Carstenssen, BNI Denmark/ Aarhus University, Denmark

Total budget: EUR 4.0 million

Duration: 4 years, 1.1.2014-31.12.2017

Official web page

COCOA in short:

COCOA is an interdisciplinary project with 14 institutes from 8 countries and organized in eight Work Packages). The project integrates different disciplines with the overall objective of identifying the major pathways of nutrients and organic material across the diversity of coastal ecosystems and assess management implications.

The goal is to:

* synthesize the results into state-of-the-art ecosystem models, allowing the researchers to provide combined expertise to construct a nutrient management framework for managing the coastal zone of the Baltic Sea.

* improve current decision support tools used for the implementations of the HELCOM BSAP, EU WFD and MSFD.

COCOA will investigate four different types of coastal ecosystems:

1) river- dominated estuaries, 2) lagoons, 3) archipelagos, and 4) embayments with restricted water exchange to:

- Understand the changing nutrient (C/N/P/Si) cocktail across the land-sea continuum.

- Quantify processes that transform and accumulate nutrients.

- Estimate nutrient retention across coastal ecosystems.

- Investigate potential feed-back processes sustaining alternative stable states.

- Analyse how these process rates may have changed over time.

- Evaluate consequences of altered nutrient pathways on ecosystem services.

- Identify possible management responses for present and future projections.

COCOA will analyse the pathways of nutrients in the coastal zones of the Baltic Sea by:

  1. quantifying the role of bacteria, phytoplankton, benthic microalgae, seagrasses, macroalgae and fauna in transforming and accumulating nutrients using novel measurement techniques employed in four different types of coastal ecosystems (learning sites: lagoons, river-dominated estuaries, embayments, and archipelagos),

  2. developing dynamic state-of-the-art coastal models for these learning sites with a strong focus on quantifying benthic-pelagic coupling and integrating the improved process understanding to the ecosystem level,

  3. developing empirical models to estimate the nutrient retention across coastal ecosystems,

  4. improving the model formulations for coastal nutrient retention in the decision support system NEST, used for the revision of the Baltic Sea Action Plan.

Through model experiments, COCOA will investigate feedback processes, associated with hypoxia and loss of key biological functions, and examine the potential existence of alternative stable states leading to hysteresis responses and identify critical thresholds associated with such responses.

COCOA will use models and statistical analyses to examine changes in nutrient retention over the past and in the future given scenarios for climate change and management responses. Consequences of altered nutrient pathways on coastal ecosystem services will be assessed and used for identifying optimal management strategies.

Read more about COCOA in the latest BONUS In Brief

List of Work Packages

List of Principal Investigators and BNI researchers

Link to offical project webpage

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Web editor: Marmar Nekoro

Updated: 2014-03-12
Baltic Nest Institute Sweden
Baltic Sea Centre, Stockholm University
SE-106 91 Stockholm, Sweden, +46-8-16 37 18
Baltic Nest Institute Denmark
Aarhus University, Fredriksborgsvej 399
DK-4000 Roskilde, Denmark, +45 4630 1200
Baltic Nest Institute Finland
Finnish Environment Institute, P.O. Box 140
FI-00251 Helsinki, Finland, + 358 20 610 123