Long-term ecological trajectories of a disturbed Mediterranean coastal lagoon (Biguglia lagoon): Ecosystem-based approach and considering its resilience for conservation?

Abstract

Coastal lagoons are subjected to ever-increasing direct or indirect anthropic pressures and are inexorably deteriorating with serious issues regarding their resilience. In this paper, we assessed the functioning and evolution of the highly disturbed Biguglia coastal lagoon (Mediterranean Sea, Corsica) through an ecosystem-based approach (EBA), using multiple biotic and abiotic proxies (hydro-climatic context and eutrophication), considering its connectivity to sea and watershed and biological compartments (macrophytes, phytoplankton, and invasive species) and taking into account human influence (management actions and fishing activities). The aim of this work is firstly to provide a comprehensive analysis of its long-term (2000–2021) ecological evolution trajectory and then, based on these results, to anticipate management strategies for supporting its conservation and restoration, and the maintenance of ecosystem services it offers. Results revealed that while the lagoon showed these days a good capacity to recover after disturbance and absorb change, it recently exhibited considerable changes in its phytoplankton community composition, developed an increased susceptibility to biological invasion, and experienced a drastic reduction in fish stocks. The major interannual variations of the mean salinity, strongly dependent on management interventions beyond natural climatic variability, summarized this instability. In the future, the lagoon may no longer be able to cope with even small disturbances, which could then be sufficient to reach a breakpoint and tip the system permanently into undesired/degraded states. We demonstrated that local and punctual management actions are not always beneficial for the entire ecosystem or even detrimental in some instances. Such a retrospective ecosystem-based approach is fundamental for producing the holistic insights required to implement efficient integrated ecosystem management. This further helps enhance lagoon resilience and hence preserve its ecosystem services in the context of increasing global changes. Such lessons are useful anywhere for comparable ecosystems.

Harmful algae and pathogens on plastics in three mediterranean coastal lagoons

“…Since then, the whole lagoon surface is a no-go zone with the exception of a small number of professional fishermen allowed to practice this traditional activity. Its sensitivity to invasive allochtonous species has been investigated [ 75 ]. Diana lagoon is relatively deep (mean depth: 6.0 m) covering an area of 570 ha.…”

Small Mediterranean coastal Lagoons Under Threat: Hydro-ecological Disturbances and Local Anthropogenic Pressures (Size Matters)

“…Thirdly, our study focused on a few biotic and abiotic parameters and especially phytoplankton communities for the biotic component. Despite phytoplankton being an excellent indicator of the ecosystem's status, we suggest that an ecosystem-based approach should be taken into account for future studies, especially considering lagoons' connection to adjacent systems (Ligorini et al 2022b). This ecosystembased approach is becoming more and more widely applied, especially in unstable transitional ecosystems, and it would enable a better understanding of ecosystem functioning at multiple levels and help with management decisions (Walker et al 2006;Hobbs et al 2009;Biggs et al 2015;García-Ayllón, 2017;De Wit et al 2020).…”