Despite a nutrient-rich environment, the fish population in the Benguela upwelling area off Namibia has declined significantly in recent decades. Scientists are now seeking an explanation for these far-reaching changes and are undertaking a research vessel expedition to this upwelling area.
From mid-February to the end of March, the research vessel METEOR is going on a new expedition. On board are scientists from the Leibniz Centre for Tropical Marine Research (ZMT) and nine other research institutions from Germany, Namibia and South Africa.
The research vessel Meteor seen from the dinghy
Photo: Werner Ekau, Leibniz Centre for Tropical Marine Research
The research expedition will explore the large Benguela upwelling area off the southwest African coast. Upwelling areas are highly productive marine ecosystems that provide a significant portion of the world's fishing yields and thus play an important role in feeding the world's population.
From the depths of the oceans, large quantities of nutrients flow to the surface, allowing a great deal of plankton to thrive and thus providing the fish population with abundant food.
In recent decades, however, catches in the region have declined significantly, from around five million tonnes at the end of the 1960s to around 1.7 million tonnes today.
In particular, the popular sardines and anchovies, the most important source of protein for the coastal population, are now scarce in the northern Benguela region off Namibia. The number of predators who feed on these schools of fish, such as horse mackerel, hake, sea birds and seals, has decreased accordingly.
"Overfishing is not the main reason for this,” said Dr Werner Ekau, fisheries biologist at the ZMT and head of the expedition. “Namibia has had very effective fisheries management for 30 years."
The researchers are also surprised that the abundance of fish in the southern part of the upwelling area off South Africa is still considerably higher than in the northern part, although the amount of plankton in the entire Benguela Current is similar and thus provides the fish with a good nutrient basis.
The influence of climate change on the region could provide the researchers with answers. Ocean warming makes plankton thrive even more abundantly in the upwelling region. Large quantities are not eaten, but sink to the depths of the ocean, where they decompose and drive bacterial processes that lead to oxygen depletion in the water.
This in turn causes problems for fish that can no longer complete their life cycle or migrate from the areas. Sardines, for example, have shifted their range south towards the Cape of Good Hope.
On the Meteor expedition, biologists and biogeochemists will jointly investigate the consequences of global environmental changes on the Benguela upwelling area. The ZMT is participating with the work groups Fisheries Biology and Carbon and Nutrient Cycling. The expedition is part of the project TRAFFIC (Trophic Transfer Efficiency in the Benguela Current).
It is being funded for three years by the Federal Ministry of Education and Research and coordinated by the ZMT. TRAFFIC is part of the German Federal Government's programme FONA (Research for Sustainable Development), which aims to protect common ecosystems such as climate, biodiversity, land and oceans.
Dr Werner Ekau
Leibniz Centre for Tropical Marine Research
Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft
Numbers count in the genetics of moles and melanomas
16.08.2019 | University of Queensland
Working out why plants get sick
16.08.2019 | Institut für Pflanzenbiochemie
Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.
Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...
Researchers at TU Graz are working together with European partners on new possibilities of measuring vehicle emissions.
Today, air pollution is one of the biggest challenges facing European cities. As part of the Horizon 2020 research project CARES (City Air Remote Emission...
Over the next three years, researchers from the Vrije Universiteit Brussel, University of Cambridge, École Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI-Paris) and Empa will be working together with the Dutch Polymer manufacturer SupraPolix on the next generation of robots: (soft) robots that ‘feel pain’ and heal themselves. The partners can count on 3 million Euro in support from the European Commission.
Soon robots will not only be found in factories and laboratories, but will be assisting us in our immediate environment. They will help us in the household, to...
Scientists at the University of Leeds have created a new form of gold which is just two atoms thick - the thinnest unsupported gold ever created.
The researchers measured the thickness of the gold to be 0.47 nanometres - that is one million times thinner than a human finger nail. The material is regarded...
An international team of scientists involving the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg has unraveled the light-induced electron-localization dynamics in transition metals at the attosecond timescale. The team investigated for the first time the many-body electron dynamics in transition metals before thermalization sets in. Their work has now appeared in Nature Physics.
The researchers from ETH Zurich (Switzerland), the MPSD (Germany), the Center for Computational Sciences of University of Tsukuba (Japan) and the Center for...
16.08.2019 | Event News
14.08.2019 | Event News
12.08.2019 | Event News
16.08.2019 | Life Sciences
16.08.2019 | Physics and Astronomy
16.08.2019 | Medical Engineering