Mangrove rehabilitation dynamics and soil organic carbon changes as a result of full hydraulic restoration and re-grading of a previously intensively managed shrimp pond

Abstract

Hydraulic restoration by opening the shrimp pond banks facilitated the establishment of planted mangroves and colonisation by non-planted mangrove species and was shown to be an effective method of mangrove rehabilitation. Planted Rhizophora apiculata and Rhizophora mucronata had grown significantly in 6 years, to 300 and 350 cm, respectively. However, the growth rate of Bruguiera cylindrica was merely 150 cm in the same period despite vigorous growth in the initial stage. About 15 non-planted mangrove species had colonised within 6 years after reopening the banks, with the dominant species being Avicennia marina (46.9%) followed by B. cylindrica (27.0%) and Ceriops tagal (14.9%). After the enhancement, soil organic carbon increased considerably from 110 to 160 tonC ha -1 in 2 years at the lower elevation, indicating that hydraulic restoration could stimulate carbon recovery through enhancement of mangrove growth. However, soil organic carbon decreased by almost half in the higher ground, suggesting that carbon decomposition was accelerated due to drying of soils.

The state of the world’s mangroves in the 21st century under climate change

“…Huge efforts are being put into mangrove rehabilitation and creation at landscape scales. While such large-scale efforts are generally unsuccessful due to poor species selection, inappropriate choice of rehabilitation locations, and local governance issues (Lewis, 2005;Primavera & Esteban, 2008;Elliott et al, 2016;Kodikara et al, 2017), some efforts are becoming more successful as elements of species biology and hydrological requirements are incorporated into the design and implementation of rehabilitation projects (e.g., Matsui et al, 2010;Oh et al, 2017). On a larger scale, climate change may promote some positive gains, especially at the northern and southern latitudinal limits of mangroves, as mangroves encroach on and replace saltmarsh species in some localities, which was a major theme of the 4th Mangrove and Macrobenthos Meeting (MMM4) held in St. Augustine, Florida in 2016.…”

Ten Year Evaluation of Carbon Stock in Mangrove Plantation Reforested from an Abandoned Shrimp Pond

“…Rehabilitation of mangroves through restoring a natural hydrology was emphasized by Lewis [18,19]. Moreover, successful restorations of mangroves were achieved through restored hydrology alone [20], by hydrologic reconnection to the river [21] and by reopening obstructing banks [22].…”

Size at sexual maturity and body size composition of mud crabs Scylla spp. caught in Don Sak, Bandon Bay, Gulf of Thailand

“…Coupled with habitat degradation, mainly due to the loss of mangrove forests through their conversion to shrimp culture ponds, this fishing pressure has led to a decline in mud crab populations [11,12,15]. Moreover, a serious outbreak of shrimp virus disease and poor water quality caused by discharges from polluted ponds have caused a drastic decline in the productivity of shrimp culture ponds, and this has prompted farmers to abandon their ponds and produce wastelands [20][21][22]. Therefore, the restoration of wastelands to mangrove forests and fishing regulations such as prohibiting the capture of immature crabs should assist in the recovery and/or sustainable utilization of mud crab resources.…”