Assessing the Role of Seagrasses as a Socio-Ecological System: A Case Study from Cape Verde (Gamboa Bay)

Abstract

The marine ecosystems are extremely productive and highly valuable, with importance for the overall health of both marine and terrestrial environments. However, climate change and intensive exploitation of natural resources have significant impacts on ocean ecosystems, including seagrasses. Seagrasses provide essential habitat and food sources for many aquatic species. Although they cover a small portion of the ocean’s surface, they have a great ability to sequester and store blue carbon. Globally, important areas of seagrass ecosystems have been lost, with no certainty for future recovery. In West Africa, the knowledge of seagrasses is still rudimentary, and their presence has been confirmed in only seven countries. Climate change, combined with direct anthropogenic pressures, may decrease the resilience of seagrasses to adapt to changing conditions leading to their degradation and subsequent loss of ecosystem services. The first record of seagrass in Cape Verde was reported in 2016 at Gamboa bay, Praia, Santiago Island; the only documented site of a seagrass meadow and known as habitat and food source for marine species. However, the site is exposed to human activity such as coastal development, with no study exploring the impacts on seagrass health and status. This study aims to assess and compare the present to previous state of the seagrass meadows in Gamboa and then evaluate fishers’ perception of seagrass. Field assessments were used to collect and compare ecological parameters, and a questionnaire was used to assess stakeholders' perceptions. The study results show that parameters such as total cover, biomass, rhizome, and canopy height of Halodule wrightii species of seagrass identified have increased, while the shoot density has decreased between 2016 and 2021. The actual shoot density is 5-fold less than that reported in 2016, and the total biomass is 1-fold more than that reported in 2016. The ten (10) patches of 20 m2 recorded then have extended to 6243 m2. Fishers understand the importance of the sea and are conscious about its cleanliness but not fully aware of seagrasses, their ecosystem services and not sure about how to protect them. If further conservation and management of seagrasses are intended, socio-economic adjustment is required to provide guidance and information that can positively impact conservation and management activities.