Mangrove blue carbon stocks and dynamics are controlled by hydrogeomorphic settings and land-use change.

Globally, carbon-rich mangrove forests are deforested and degraded due to land-use and land-cover change (LULCC). The impact of mangrove deforestation on carbon emissions has been reported on a global scale; however, uncertainty remains at subnational scales due to geographical variability and field data limitations. We present an assessment of blue carbon storage at five mangrove sites across West Papua Province, Indonesia, a region that supports 10% of the world's mangrove area. The sites are representative of contrasting hydrogeomorphic settings and also capture change over a 25-years LULCC chronosequence. Field-based assessments were conducted across 255 plots covering undisturbed and LULCC-affected mangroves (0-, 5-, 10-, 15- and 25-year-old post-harvest or regenerating forests as well as 15-year-old aquaculture ponds). Undisturbed mangroves stored total ecosystem carbon stocks of 182-2,730 (mean ± SD: 1,087 ± 584) Mg C/ha, with the large variation driven by hydrogeomorphic settings. The highest carbon stocks were found in estuarine interior (EI) mangroves, followed by open coast interior, open coast fringe and EI forests. Forest harvesting did not significantly affect soil carbon stocks, despite an elevated dead wood density relative to undisturbed forests, but it did remove nearly all live biomass. Aquaculture conversion removed 60% of soil carbon stock and 85% of live biomass carbon stock, relative to reference sites. By contrast, mangroves left to regenerate for more than 25 years reached the same level of biomass carbon compared to undisturbed forests, with annual biomass accumulation rates of 3.6 ± 1.1 Mg C ha-1  year-1 . This study shows that hydrogeomorphic setting controls natural dynamics of mangrove blue carbon stocks, while long-term land-use changes affect carbon loss and gain to a substantial degree. Therefore, current land-based climate policies must incorporate landscape and land-use characteristics, and their related carbon management consequences, for more effective emissions reduction targets and restoration outcomes

Status Terumbu Karang dan Ikan Karang di Gili Matra, Nusa Tenggara Barat

This study aims to identify the status of reef fishes and coral reefs in Gili Meno, Air, and Trawangan or Gili Matra waters. This area is part of the North Lombok Regency, West Nusa Tenggara Province. Field observation was conducted on September 2011 at 11 (eleven) diving points. The video-transect method was used for observing the coral reef condition, while reef fishes abundance was observed by using visual-census method. The parameter that used to determine the condition of coral reef in study location are the percentage of live hard coral cover and index of coral mortality. In general, the result shows that percentage of live hard coral cover in each diving point ranged from 4.4% - 37.2% and the Coral Mortality Index (IMK) ranged form 0.40-0.92. The values describe that the condition of coral reef at eleven diving points vary from fair until poor condition. Current status of coral reef condition showed an insignificant increase from bad to moderate during the period 2011 -2018. There were 23 families of reef fishes from 46 genera were found during the study consisting of 16 genera of target fish groups, 5 genera of indicator fish group, and 25 genera of major fish group. The water quality is still within the limits of environmental quality standards.   Keywords: Reef fish, coral reef, Mortality Index, water quality, Gili Matr

Study of Sea Surface Temperature (SST), Does IT Affect Coral Reefs?

HighlightEffect of sea surface temperature on coral reefsCorrelation with NOAA and AQUA MODIS satellite imagery dataSea water quality analysisThe adaptability of coral reefsAbstractThis research aims to identify the influence of Sea Surface Temperature (SST) to coral disease and bleaching using MODIS-Aqua data from 2003-2009 and NOAA Coral Reef Watch data. Field-data collection on coral disease and bleaching was carried out in Bunaken National Park, Wakatobi National Park, and Raja Ampat, in August, October, and November 2009, respectively. The presence of coral disease and bleaching was observed by using time-swim method. A prevalence formula was used to calculate the percentage of coral disease and bleaching colonies. The range of mean SST value from each location: Bunaken from 26.84-31.45oC, Wakatobi from 26.09-31.95oC and Raja Ampat from 27.72-31.36oC. There is an influence of SST anomaly on the presence of dis- ease and coral bleaching. During 2003-2019, the highest SST anomaly that could increase the risk of the coral bleaching phenomenon was found in 2010. Coral disease and bleaching were found at locations with high SST anomaly, low nitrate and available phosphate. However, high SST anomalies were not a main cause of coral disease and bleaching. In many locations in Indonesia, mass-bleaching has occurred and the ability of coral adaptation is the main key in dealing with this phenomenon