Knowledge of heterotrophic aquatic biotic organisms (macroinvertebrates) accumulated in the sedimentary layers of Cocibolca lake from the last 100 years

Abstract

Cocibolca lake is the largest freshwater ecosystem in Central America and has recently gained the attention of the international scientific community due to the planned construction of the interoceanic canal that could potentially cross and impact this system. This study aims to perform a qualitative reconstruction using heterotrophic biological proxies (macroinvertebrates) and their relationship to know extreme natural events, as well as key anthropogenic activities. Through the ²¹⁰Pb analysis, two high-resolution cores of Cocibolca lake were analyzed, for the last century ~100 years, which were collected, one in the eastern zone (PLNI), another near of Ometepe island (PLNII). Relative to the chironomids, a low number of fossils was observed, these conform to the historical limnological records of the lake where this community exhibits low proportions. The high erosion and sedimentation rates, mainly in the southern watershed, provide the system with abundant material rich in nutrients that modify the lake's productivity. Consequently, the benthic assemblages community have been transformed, favoring opportunistic species that are better adapted to extreme weather events that add to increasing enrichment problems, knotted with the anthropic activities that continue to generate changes and advances in the trophic state on a global scale in Cocibolca Lake.