Can participatory approaches strengthen the monitoring of cyanobacterial blooms in developing countries? Results from a pilot study conducted in the Lagoon Aghien (Ivory Coast)

Abstract

Monitoring of cyanobacteria in freshwater ecosystems is a complex task, which is time consuming and expensive due to the chaotic population dynamics and highly heterogeneous distribution of cyanobacteria populations in water bodies. The financial cost constitutes a strong limitation for the implementation of long-term monitoring programs in developing countries, particularly in Africa. The work presented here was performed in the framework of an international project addressing the sustainable monitoring and management of surface water resources used for the production of drinking water in three African countries. We tested the potential of a citizen approach for monitoring cyanobacterial blooms, which are a growing threat to the drinking water supply. This pilot study was designed, implemented and evaluated in close interaction with the Pasteur Institute of the Ivory Coast and with the populations of three villages located on the shoreline of a freshwater lagoon located near Abidjan city. Based on the use of a smartphone application, the citizens of the three villages were invited to report water color changes, as these changes could reflect cyanobacteria proliferations. A two-year experimentation period has shown that it is possible to mobilize the local populations to monitor cyanobacterial blooms. The data collected by citizens were consistent with the data obtained by a classical monitoring of cyanobacteria performed over seven months, but it appeared that new approaches were needed to validate the citizen data. This participatory approach also provided great improvements to the understanding and awareness of local populations regarding water quality and cyanobacterial bloom issues. Finally, we discuss some of the difficulties and limitations of our participatory monitoring approach that should be considered by further implementations. Despite these difficulties, our work

Impacts of nutrient loading and fish grazing on the phytoplankton community and cyanotoxin production in a shallow tropical lake: Results from mesocosm experiments

“…This study shows that it is possible to develop mesocosm systems at a moderate cost that are also easy to transport and construct in the field. As already observed during a pilot study on citizen monitoring of Lagoon Aghien (Mitroi et al, 2020), we also showed that it is possible to benefit from active local population support during experiments, in particular, support for the installation of the mesocosms and their monitoring when scientific teams were not present on site. These actions occur when these experiments are prepared by these populations.…”

Fish gut-associated bacterial communities in a tropical lagoon (Aghien lagoon, Ivory Coast)

“…According to Clum et al (2009) , Pirellula strains are able to attach to cyanobacteria, suggesting that some could originate from the phycosphere and be ingested along with the phytoplankton ( Bi et al, 2019 ). Indeed, Aghien lagoon is experiencing frequent cyanobacterial bloom events ( Mitroi et al, 2020 ). The toxin-producing cyanobacterial genus Planktothrix , recently documented from the cyanobacterial phytoplankton community in Aghien lagoon ( Ahoutou et al, 2021 ) was for example found both in water (yet not dominant) as well as occasionally in fish guts.…”

“…In this study, we investigated the effect of host versus environmental factors on the structure of gut-associated bacterial communities in four fish species collected from the Aghien lagoon (Ivory Coast). Aghien lagoon is a eutrophic freshwater lagoon and harbors high biomasses of microbial primary producers including potentially toxic cyanobacteria ( Mitroi et al, 2020 ; Ahoutou et al, 2021 ). In the context of an international project addressing the sustainable monitoring of surface water resources used for the production of drinking water, specimens of commonly consumed fish species were collected over a year.…”

What urban lakes and ponds quality is about? Conciliating water quality and ecological indicators with users’ perceptions and expectations about urban lakes and ponds quality in urban areas

“…Other visual criteria, such as water color and turbidity can nevertheless be shared indicators between expert and profane grids of water quality lectures. Some interesting citizen science experiences have confirmed that citizens can inform cyanobacteria blooms on lakes and shallow waterbodies in relevant ways (Castilla et al, 2015;Mitroi et al, 2020), thereby complementing the institutional monitoring of the trophic status of these aquatic systems (Hadj et al, 2017). In addition to the aesthetic and visual criteria, other factors play a role in the public perception of hardly transformed ecosystems such as the health benefits related to the possibilities offered by these water bodies to enjoy nature or to provide recreational activities (angling, swimming, boating) (Junker & Buchecker, 2008).…”