Author: Vinicius  Faria Patire,  PhD Student (Universidade Federal da Bahia)

Designation: 

Description:
Mangroves provide valuable ecosystem functions and services including carbon storage, which makes this ecosystem a key player in mitigating climate change effects. However, large declines in mangrove areas have occurred due to human activities. We assessed the impacts of shrimp farming and the recolonization of a decommissioned shrimp farm pond on the soil carbon stocks and accumulation rates in the mangroves of Todos os Santos Bay, Brazil. We collected 27 soil profiles in i) shrimp farming ponds; ii) dry ponds (being prepared for a new culture cycle); iii) mangroves receiving shrimp farming effluents; iv) mangroves not influenced by the shrimp farm but impacted by domestic sewage; and v) a decommissioned shrimp pond that is being recolonized by mangroves.  We analyzed sediment grain size, 210Pb concentration profiles, organic C (OC) and N, and their isotopes in the soils. The conversion of mangroves into shrimp ponds increased the soil dry bulk density and decreased the content of fine sediments, and the physical disturbance of the soils promoted mixing, erosion, and alteration of physico-chemical properties. Conversion of mangroves to shrimp farming and its degradation by effluents caused loss of up to 90% of soil OC stocks due to an increase in OC remineralization and changed the organic matter composition of the soils.  The recolonization area showed organic matter content 2 times higher than the bare soil in dry ponds. Natural recolonization indicated recovery of the soil characteristics (OC content, grain size, and DBD) through the restoration of mangrove forest.

Category: Scientific Program Abstract > Special Sessions > SS14 Blue Carbon science for a sustainable future