FAO.org

Plankton is a collective term used to describe very small organisms that form the basis of marine life in the ocean. It constitutes a key source of food for many larger marine species, and is the subject of one of the main research themes of the EAF-Nansen Programme in support of the ecosystem approach to fisheries management. Thus, collecting information on plankton is an essential exercise for the scientists on board the R/V Dr Fridtjof Nansen research surveys, in order to improve the understanding of the ecosystem health, functioning and dynamics.

Two recent scientific surveys (legs 3.1 and 3.2) on board the Dr Fridtjof Nansen, were carried out from July to September 2019, during the major upwelling season that takes place every year in the Gulf of Guinea. Even though the West Central Gulf of Guinea is an important upwelling marine ecosystem, it is still poorly studied compared to the adjacent northern Benguela Current and the Canary Current upwelling systems. Intense upwelling events that occur during the summertime along the Côte d’Ivoire-Ghana coastal zone, between Cape Palmas and Cape Three Points, boost productivity of the ecosystem and sustain local communities with small pelagic fish, primarily the commercially important sardinella species.

Two dedicated research teams collected a large number of plankton samples (i.e., phytoplankton, zooplankton, ichthyoplankton) over a dense sampling grid. Part of sample processing was conducted in the well-equipped plankton laboratories onboard the R/V Dr Fridtjof Nansen. Further laboratory analysis of the phytoplankton (plant-like organisms) and zooplankton (tiny animals) samples was carried out on land, by two female plankton biology experts from Ghana and Côte d’Ivoire – two of the Programme’s partner countries – who also participated in leg 3.1. of the survey. Work was executed in close collaboration with the Norwegian Institute of Marine Research (IMR), at the Department of Marine and Fisheries Science, of the University of Ghana from 9 March to 18 May, in the midst of the coronavirus pandemic. On 16 March, the university, like many other establishments in Ghana, was shut down after the confirmation of first few cases of Covid-19 in the country. However, since the two female scientists were already there, and also residing on campus, they were allowed to continue their work.

“Hawa and I wanted to continue working. We couldn’t go back home because the borders were closed. We had a lot of work to do, so we were working all day,”explains Estelle Konan, an expert in phytoplankton at the Oceanographic Research Centre in Abidjan, Côte d’Ivoire.

It took a lot of courage and dedication to carry on with the work in such an unprecedented scenario, and sometimes facing challenges along the way.

“The samples were full of marine debris entangled in them and it was difficult to disentangle the species from the debris. Sometimes it took two days to analyse one sample,” recalls Hawa Bint Yaqub, an expert in zooplankton taxonomy at the Ministry of Fisheries and Aquaculture Development in Ghana. “I wish I had more time to analyse my samples, as it was challenging. When I came back from the lab, I still had to enter the data into an Excel sheet,” adds Hawa.

Even though the outbreak of Covid-19 pandemic has been stressful, both scientists admit that they were well taken care of by the EAF-Nansen Programme’s staff  and the Head and technicians of the Department of Marine and Fisheries Science, who mobilised forces and put all efforts to ensure safe working conditions  of the two scientists during their stay at the University of Ghana.

“I was very stressed to be far away from my family and children and not knowing when I will be able to go back home. But, we were very-well taken care of in Ghana. Dr Kwame Koranteng regularly came to check on us to see if everything was fine,” says Estelle.

“Every time I visited Estelle and Hawa in Legon I found them in good spirit, despite the Covid-19 pandemic. But, I also felt inside me that the separation from their families was taking its toll, even though none of them admitted that. I admire their courage, persistence and hard work,”comments Kwame.

Studying phytoplankton and zooplankton, in particular, has become indispensable in the Gulf of Guinea, because they account for important parameters that contribute to the state of resources in the region. Most eggs and larval stages of marine fish are plankton-related, and almost all marine fish depend directly or indirectly on zooplankton for food. The future of any fish stock would then very much depend on its availability.

“Studying plankton is important for the region, because if we manage to quantify phytoplankton, we can foresee the future condition of the stock,” comments Estelle.  

Yet, for example, current studies on zooplankton dynamics are highly limited in the Gulf of Guinea due to lack of expertise, which, in consequence, hampers any existing research initiatives. Hawa and Estelle are the only female scientists working on plankton in their respective home institutes.

“For plankton, I’m alone and I can’t count on anyone else. Seriously, we need more scientists, women in particular, to work on plankton,” underlines Hawa. Her call to action is echoed in the words of Estelle, who also stresses an important role woman play for the future of plankton research in the region. “I am the only woman involved in plankton studies at the research centre in Côte d’Ivoire, where I work. On the country-level, we are only four women out of nine researchers, and it’s absolutely not enough. We need more female scientists. In my opinion, women do good work, are very rigorous and motivated.”

Plankton sampling and analysis during the Nansen research surveys have become more important under the Programme’s Science Plan.  Coupled with increasing capacity building efforts in the plankton field, this activity is likely to enhance the knowledge of plankton and improve the understanding of its importance for sustainable management of ocean resources, both at the national and the regional level.

“The Nansen Programme is the first to introduce innovation at work, by studying plankton at a regional level. The countries that belong to the Gulf of Guinea have usually been doing their independent country-specific studies on plankton,” explains Estelle.

Promoting gender equality and effective participation of women through all activities is part of the Gender Strategy of the EAF-Nansen Programme. Strengthening partners’ capacities additionally fosters South-South collaboration, by creating networks to address issues of common interest. The Nansen Programme is considered today a unique platform for cooperation, capacity development, knowledge generation and exchange, which continue beyond the work aboard the vessel. 

“Capacity development element of the EAF-Nansen Programme is very well-organised,”comments Estelle. “I didn’t know Hawa before; we met on board the R/V Dr Fridtjof Nansen in 2019 and we keep sharing and exchanging knowledge. The same goes for other colleagues.”

Similar views are expressed by Hawa “I feel very good about the collaboration part of the Nansen Programme; I’m gaining a lot of knowledge. I participated in the surveys in the new phase of the Programme in 2017 and in 2019. I had an opportunity to do analysis and discover species that I’ve never identified before. It was both informing and enlightening,” she continues.

The aim of the 2019 Nansen surveys was to study transboundary demersal and pelagic fish species in the western part of the Gulf of Guinea, where plankton research contributes to the knowledge on recruitment of pelagic fish. It has been observed through earlier studies in the region that sea surface temperatures play a key role in the composition and distribution of the plankton. For example, rising temperatures indicate decline in plankton abundance in the Gulf of Guinea, which can affect the abundance of fish and other living marine resources. Current trend in global climate change (constant warming) could then significantly affect the composition and distribution of the plankton, which as a result will negatively impact the abundance and distribution of fishery resources and productivity of the entire ecosystem. 

In order to enhance the management of resources and environment through the ecosystem approach to fisheries, scientists recommend that plankton sampling, studying and monitoring continue in the region. For this to happen, more scientists from the Gulf of Guinea area should be trained in the field of plankton identification, embracing multidisciplinary techniques such as microscopic identification, scanner technology, flow-imaging technology, and molecular techniques. “We have to train more experts and to encourage them to study plankton. Sampling should continue at least once a year to know what pertains in the Gulf of Guinea waters, particularly with respect to early life stages of fish,” concludes Hawa.

Hawa Bint and Veronica Kaleinasho (University of Namibia) processing zooplankton samples in the plankton laboratory on board the R/V Dr Fridtjof Nansen © Addi Ebenezer Adirnortey