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It is the fourth time that the research vessel – Dr Fridtjof Nansen – is returning to Northwest Africa to study transboundary bottom-dwelling (demersal) fisheries resources in the deeper part of the continental shelf and the upper slope of Northwest Africa, from Morocco to the southern border of Guinea. The previous four expeditions that covered the same region took place in 2000, 2011 and 2012. In 2020, another expedition was initiated, but an unprecedented outbreak of the COVID-19 pandemic halted some activities and forced the Dr. Fridtjof Nansen to return to its home port in Norway until late 2021. 

The 2022 survey is comprised of two legs and will contribute to an improved knowledge of transboundary resources for stronger fisheries management - one of the broad objectives in the current phase of the EAF-Nansen Programme (2017-2023). Other aspects of this survey aim at enhancing knowledge on composition and diversity of demersal habitats, together with gathering information on environmental conditions and on emerging issues, including the potential presence of marine debris and microplastics. Additionally, samples of benthic habitats and plankton will be taken along planned transects in the region. Special attention will be given to the occurrence of juvenile hake in coastal waters, in the area north of Cap Bojador, the area off Nouakchott in Mauritania and in Senegal. 

Landing and sorting the first catch on board the RV Dr Fridtjof Nansen © Erik Olsen

Scientific objectives of the Nansen surveys are guided by the EAF-Nansen programme Science Plan and correspond to its various Themes. This survey responds to several themes of the three main categories of the Science Plan: Sustainable Fisheries, Oil/Gas/Pollution Impacts and Climate change Impacts. 

“It feels good to be able to go  back to Northwest Africa to carry out a comprehensive survey of the whole region after when the same survey had to be cancelled in 2020 due to the outbreak of the Covid-19  pandemic,” said Dr. Erik Olsen, a scientist from the Norwegian Institute of Marine Research and the cruise-leader of the leg 2.1 of the expedition. “It is important to understand the stock structure of fish resources in the region to improve their management. Also, this survey is the first opportunity in two years to meet in person with partner scientists from the Northwest African countries, to provide training and discuss together science and management challenges they encounter,” concluded Dr Olsen.”

“Monitoring the state of resources as well as establishing reliable and comprehensive assessments in relation to both fisheries and environmental pressures on them is crucial to ensure sustainable management of these fisheries,” commented Dr Ahmed Diagne from the Mauritanian Institute of Oceanographic Research and Fisheries (IMROP). “It’s in this framework that the EAF-Nansen programme research surveys support different national institutions in charge of fisheries management. The programme offers an opportunity to share experiences among scientists from various research centres in West Africa and overseas, with the aim to put in place an efficient framework for assessment and management,” Dr Diagne summed up. 

The northern part of survey area (Senegal – Morocco) lies within one of the major upwelling regions in the world, characterized by high productivity, as well as important pelagic and demersal fish resources.   

Priorities for the Nansen 2022 survey were initially discussed at the 8th Session of the Fishery Committee of the Eastern Central Atlantic (CECAF) Scientific Sub-Committee (October 2018, Abidjan, Côte d’Ivoire), and on the occasion of the 6th session of the CECAF Working Group on the Assessment of Demersal Resources, sub-group North (December 2019, Nouakchott, Mauritania).

CECAF is a Regional Fishery Body and one of the main partners of the EAF-Nansen programme. It also acts as the Regional Steering Committee (RSC) for the Programme. In this role, CECAF provides input to the overall implementation of the EAF-Nansen Programme (i.e. planning and reporting) across the region; It also helps coordinate the programme's activities, together with other ongoing regional activities. The overall objective of the Working Group is to contribute to the improved management of demersal resources in Northwest Africa through conducting stock assessments. Such analyses of the state of the fish stocks help to determine their status according to the following categories: “not fully exploited”, “fully exploited”, or “overexploited”. The end goal of the Working Group is to support sustainable use of fishery resources for the benefit of the coastal countries. 

Twenty-one local scientists and technicians from seven Northwest African countries (Morocco, Senegal, Mauritania, Guinee, Guinea-Bissau, Côte d’Ivoire, The Gambia) are joining the voyage, supported by researchers from the Norwegian Institute of Marine Research (IMR). Moreover, two guest scientists from the University of Vigo in Spain will provide local participants with on-the-job training related to sampling and identification of animals living above the surface of sediments. 

“Nansen surveys represent a very important source of samples and data for biodiversity and habitat characterization studies,” underlined Prof. Marta Gil Gonzáles from the University of Vigo. “During this study, the participants will be given a training in sampling methodology, sorting and identifying benthic species (e.g. crabs, clams, snails, sea stars, and sea urchins) caught in the demersal trawl. In addition, along the coast of Mauritania, we’ll collect sediment samples in order to identify and then analyze animals found inside them,” Prof. Gonzáles further explained.

Collected data will be used for preparation of a survey report and scientific reports/papers, as part of the EAF Nansen Science Plan. The new information will additionally benefit the work of CECAF Working Group (Sub-group North, between Cap Spartel in Morocco and the south of Senegal) on the Assessment of Demersal Resources.