This study aimed to provide relevant knowledge about the dynamics of the hydrological parameters in the river-estuary continuum of the Wouri-Nkam river estuary for a sustainable management program. The hydrological parameters were recorded in eleven stations spanned out on the basis of population density and human activities. Water quality parameters (Temperature, salinity, dissolved oxygen, pH, Total dissolved solutes, Redox potential and conductivity) were collected in subsurface water using a multiple parameter. Surface currents and morphometric (depth and width) parameters were recorded using a drifter, sonar depth and GPS. The field measurements took placed between 18/05/2019 to 08/09/2020 and were divided into six (06) cruises. The data were later subjected to an analysis of variance (ANOVA) and Principle Component Analysis using XLSTAT 2017 (2.7 version) software. Results obtained revealed that, the water quality parameters were spatially more stable not signficant at (df = 9, p < 0.05) with a relatively low temperature (25.5˚C -27˚C) during the wet period. The limit of the frontal zone extended to S5 (Bonalokan, 8.25 km from S1) during the snapshot of the dry period, spring phase and flood tide conditions. Inversely, during wet period, this extension reduced to S1 (Bridge) and relatively increases slightly to S3 (Bonangang) during the neap phase and ebb tides of this season. This result revealed a change in the axial gradient of about eight (08)

The recently constructed Besseke’s flood drain is always filled with water due to individual or combined effect of the tide, urbanization drainage, underground plumes and precipitations runoffs. This study focused on the analysis of small scales dynamics inferred from short term tidal measurements to mitigate the daily flooding in the Besseke’s flood drain. The methodology used is based on field measurements observation. The sampling of water level was conducted during two (02) different tidal regimes in May 2019. The volume of brackish water moving in and out of the Besseke’s flood drain was calculated using the formula of O’Brien. The results showed that Spring conditions had greater amplitudes than Neap tide conditions. During Spring tides, the tidal prism that passed in the midsection of the Besseke’s flood drain (S4) was 3.5 × 101 m3. This means that only a negligible amount of the incoming brackish water reaches the Besseke’s flood drain, amplifies and causes the daily flooding. The unexpected stronger amplitudes and dynamics observed in S4 could be due to its sub estuary nature. Furthermore, the percentage composition of water in this section, showed that the fraction of brackish water changes from 85.7% during Spring tide to 77.8% in the Neap tide conditions. The overall spatial evolution revealed that, the trend in tidal prism (during Spring conditions) was (S0) > (S2) > (S1) > (S3) > (S4) with corresponding values of 2.1 × 104, 1.3 ×104, 1.0 × 104, 2.5 × 102 and 3.5 × 101 m3 respectively. Finally, Tidal prism and Cross-sectional area showed a perfect correlation (r2 = 0.96). The best fitted Cross-sectional area-Tidal prism relationship was obtained in S3 (Market) during Spring tide condition.

Evaluating fishing methods and associated gears over the time is one key to understanding the sustainability of fisheries resources. Well-managed fishery is expected to use gear that catch most of the available species at sizes that do not undermine sustainability. This study investigates effects of two fishing gears used in two landing sites of Kribi and sustainable exploitation of fishery resources. The semi-direct survey included questionnaire interview from fishermen and direct observation of fishing gears at the time of operation was chosen to collect information. A total of 299 bottom-set gillnets with mesh sizes ranging from 15 mm to 100 mm and 17 beach seines were listed at both landing sites. Beach seine catches combined as well as pelagic, demersal or benthic species. Among the species caught, Ilisha africana was the dominant species followed by Pseudotolithus senegalensis, Pseudotolithus typus. Cath profile of bottom-set gillnet showed that Pseudotolithus typus, Pseudolithus senegalensis, and Cynoglossus sp. were the three dominant species. No growing stage is spared by the beach seine catches and the minimum size obtained was 4 cm for Selenne dorsalis and Pseudotolithus senegalensis. The reduction in size and relative high number of landed species result from pressure on fishery resources, non-compliance with regulations in terms of gear and fishing techniques.