Models used for resource management are rooted in ecological theories on the functioning of populations and ecosystems, which have undergone paradigmatic changes over the past decades. The concept of equilibrium states of populations and ecosystems has been confronted with that of ever changing states of biotic entities, and the role of environmental vs. biological forcing („bottom-up, top-down“) in determining population sizes and harvest potentials of aquatic resources is hotly debated. Depending on the type of resource (long-lived, short-lived; tropical, temperate; fish, invertebrate etc.), data availability, level and kind of training of fisheries modeller, a diverse set of models are presently being applied for the management of aquatic resources. The ZMT working group resource management concentrates on the following main themes:

Single species stock assessment

Traditional tools and models for single species stock assessment are being applied to coastal resources of the tropics to derive estimates of current exploitation rates and to provide the basis for a sustainable fishery. In doing so, vital population parameters such as growth and mortality rates are being determined and factors are identified that determine the stock-recruitment relationships and interannual fluctuations in stock sizes.

Ecosystem based resource modelling

In recent years the ecosystem-based modelling approach (EBMA) has gained much ground worldwide, as it allows to model the resource in its ecosystem context and to explore the effect of resource use and/or protection via marine protected areas (MPAs) on the socio-ecosystem. At the same time, an increasing number of scientists have tried to also incorporate climate variability into the fisheries models allowing for improved harvest predictions.

The Resource Management group at the ZMT follows the EBMA approach and also looks into the role of climate variability in regulating resource productivities. Through computer simulations of resource use and climate impact scenarios, resource management recommendations are being elaborated, which also take into account the socio-economic context of the fishery.

News

The fisheries assessment program package TropFishR, which was elaborated in the Resource management working group by Tobias Mildenberger, is published to CRAN and is now publicly available. It is also linked to the FishR webpage of Prof Derek Ogle


Marcela Grijalba is a scholarship holder from the University Jorge Tadeo Lozano (Colombia) visiting the resource management group of Matthias Wolff for June and July 16. She will elaborate size spectrum data of fish catches of the Caribbean Sea, which is part of her dissertation, which is co-supervised by M. Wolff.

 

Capacity development

ISATEC (International Studies in Aquatic Tropical Ecology), International Master of science program at University Bremen directed by Prof. Dr. M. Wolff (since 1999); ISATEC is part of the DAAD program “Development-Related Postgraduate Courses” and citizen of developing countries may apply for scholarships.


Research Projects

WG-Projects

Colombia
Understanding and valuing mangrove ecosystem function and services in the Panama Bight eco-region (Dr. Gustavo Castellanos-Galindo), Postdoctoral Project funded by the Alexander von Humboldt Foundation

Sustainability drivers for the artisanal fisheries of the Colombian Pacific Coast (M.Sc. Pilar Herron, PhD-Project funded by CEMarin (DAAD, Colciencias)

Hydroacustic evaluation of the fisheries resources, bathymetry and sea bottom characteristics in shallow waters of “Cayo Serrana, Biosphere Reserve Seaflower“ (Dr. Jorge Paramo, Uni Magdalena, and others) (Project/Expedition funded by the Colombian Comission of the Ocean)

Costa Rica
Project MONICOYA (Modeling two decades of change of the Nicoya gulf (Costa Rica) ecosystem: implications for future management); ZMT Project conducted with partners from Universidad de Costa Rica (UCR, CIMAR); Prof. Dr. Alvaro Morales, Prof, Dr. Jorge Cortes

Eastern tropical Pacific and Humboldt Current system
Comparative assessment of trophic structure and resource productivity of Eastern Pacific Tropical Ecosystems (ETPE) of the Seascape region (Galapagos, Malpelo, Gorgona, Coiba, Coco) (Prof.Wolff, Dr. Diego Ruiz, M.Sc. Manon Fourierre); funded by ZMT and UCR (Costa Rica)

Galapagos project COGA (Functional role of carbonate secreting organisms in upwelling and non-upwelling zones of the Galapagos marine ecosystem (Wolff, Westphal, Reymond, Ruiz, Halfar, Riedl); funded by ZMT, UoT (University of Toronto), NOVA (Nova Southeastern University), NAZCA (Ecuadorian NGO) and CDF

Ethiopia
Fishery and population dynamics of the fish stocks in the Rift Valley Lake Koka, Ethiopia (Tesfaye, Wolff); funded by DAAD and Ethiopean Ministry of Fisheries

Gambia
Impact of climate change on the Tanbi wetland reserve and its ecosystem services (Dr.(cand.) Adam Ceesay) Project sponsored by WASCAL (West African Science Service Centre on Climate Change and adapted land use) the Centre for Development Research, Bonn University and ZMT

Indonesia (within ZMT SPICE III-Programme)
Changes in trophic flow structure of the Segara Anakan over the past two decades and socio-economic impacts (Dr. Erwin Ardli, Prof. Wolff); funded by DAAD

Ghana
Comparative analysis of trophic structure and fisheries productivities of 3 reservoir systems in Ghana (Seth Mensa Abobi) (PhD-Project funded by DAAD)

Kenya
Assessing the state and impact of the artisanal reef fisheries and their socio-economic implications in Diani Chale, Kenya (PhD-Project funded by DAAD)

Peru
Project SASCA (Sustainability analysis of scallop management in Sechura Bay, Peru)
Project aims at a holistic analysis and modelling of the carrying capacity of the bay for scallop bottom cultures (Prof. Wolff; Dr. (cand) Lotta Kluger); funded by BMBF/IB

Philippines
Biological and socio-economic impacts of destructive/illegal fishing operations in the Danajon municipal fishery, North western Bohol, Philippines (M.Sc. Regina Bacalso) (funded by the Ecosystem Improved for Sustainable Fisheries Project, ECOFISH and DAAD

Zanzibar
SUTAS (Sustainable Use of Tropical Aquatic Systems) (SAW-Project 2013-2016) (Graduate School Project with regional focus on Zanzibar) (Prof. Dr. M. Wolff, leader, Prof. Dr. Hildegard Westphal, Prof. Dr. Achim Schlüter, co-applicants)

Fisheries assessment of the Matemwe (coral reef) and Chwaka (mangrove) ecosystems (Dr. (cand) Jennifer Rehren) PhD project funded by SUTAS (Leibniz Association)