Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Puzzled by Dwindling Fish Population Off Southwest Africa

15.02.2019

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


Casting a net to catch plankton on board the Meteor

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.

Wissenschaftliche Ansprechpartner:

Dr Werner Ekau
Leibniz Centre for Tropical Marine Research
Email: werner.ekau@leibniz-zmt.de

Dr. Susanne Eickhoff | idw - Informationsdienst Wissenschaft
Further information:
http://www.leibniz-zmt.de

More articles from Life Sciences:

nachricht Chip-based optical sensor detects cancer biomarker in urine
06.12.2019 | The Optical Society

nachricht Scientist identify new marker for insecticide resistance in malaria mosquitoes
06.12.2019 | Liverpool School of Tropical Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Developing a digital twin

University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making

In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Solving the mystery of carbon on ocean floor

06.12.2019 | Earth Sciences

Chip-based optical sensor detects cancer biomarker in urine

06.12.2019 | Life Sciences

A platform for stable quantum computing, a playground for exotic physics

06.12.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>