Until recently little was known about the effects of mangrove removal on the environment, or the best practices for mangrove removal to minimise or avoid adverse impacts and achieve desired removal outcomes. And research indicates they store four times as much carbon as other tropical forests. Summary. Lower density was measured in the mangrove region than in the non-mangrove region. The species and species quantity at all sites in October 2015 (A); the species and species quantity at all sites in February 2016 (B); the species and species quantity at all sites in August 2016 (C). Some studies have analyzed the effects of mangrove removal, but few have evaluated the effects of large-scale removal efforts. WMC: recently cleared habitat
Sampling for macrobenthos was conducted monthly from October 2015 to September 2016. The dominant mangrove species on the tidal flats are Kandelia candel, Avicennia marina, and Rhizophora mucronata. Silty (mud-dominated) sediments occur to depths greater than 5 cm in the cleared site WMA, suggesting that the mud is either continuing to accumulate and/or is not being redistributed after mangrove removal. The authors declare there are no competing interests. mud present at both sites. and will receive updates in the daily or weekly email digests if turned on. This creates a relatively calm water environmen… Siangshan Wetland, located in Hsinchu, Taiwan, is an important muddy wetland with abundant species and biodiversity. WMA: cleared and mown habitat
Satyanarayana et al. Indeed, the effects of mechanical removal of mangrove trees could be more intense during removal periods, resulting in oxidation of sediments and release of soluble Fe to overlying waters. The first study focused on the effects of incineration of mangrove detritus (Riddell, 2005), the second looked at impacts of mangrove removal on vegetation (Wildland Consultants, 2005), and the third assessed the effects of vegetation removal on benthic fauna. In northern New Zealand, the Northland Regional Council granted an environmental permit (CON20031099401) to remove a 0.26-ha fringe of mangrove trees from Mangawhai Harbour to improve water access; this project was remarkable in that it enabled researchers to observe what ecological consequences removing mangroves has on estuarine ecosystems (Alfaro, 2010). The most extensive studies on mangrove impacts to fish have been done on Moloka‘i (Demopoulos et al. Environment Waikato collected a series of benthic samples in November 2005, and again in November 2006. They also investigated the consequences of mangrove removal on benthic organisms and adjacent habitats from October 2015 to September 2016, and the density, species count, Shannon–Wiener index (H′), and Pielou’s evenness index (J′) of the mangrove and non-mangrove regions were compared. NDVI represents reaction to photosynthetic activity; the relevant equation is NDVI = (NIR − RED)/(NIR + RED) (Schowengerdt, 1997; Kovacs et al., 2004; Matsushita et al., 2007), where NIR represents the reflectance of near-infrared radiation and RED represents the reflection of visible red radiation, as measured by a satellite radiometer. The non-mangrove region exhibited more variations than the mangrove region. The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) are appropriate for vegetation studies (Ren et al., 2008; Son et al., 2013), and demonstrate a good range and sensitivity for monitoring and assessing spatial and temporal variations in vegetation amount and condition (Son et al., 2013). The area studied in this work extends from the Sanxing stream to the Haishan Fishing Port, all of which lie to the west of Hsinchu, Taiwan. This region could shed light on such synergistic effects when studied at the latitudinal boundary of mangrove extent in south Australia and north New Zealand. Ju-Der Wei performed the experiments, approved the final draft. The spatial variations of species composition are shown in Fig. This work was supported by the Ministry of Science and Technology grant number MOST 102-2221-E-236-004 and MOST 107-2221-E-236-002. Mangrove and seagrass ecosystems are widespread coastal and estuarine environments found in tropical and subtropical latitudes. To maintain tidal mudflats, mangrove seedlings were removed from the Hong Kong Mai Po Ramsar Site; the result was elevated biodiversity (WWF Hong Kong, 2006). Field experiments were approved by the Environmental Protection Administration, R.O.C. The results of EVI are consistent with those of NDVI. Because of the continuous spreading of the mangrove in the coastal areas, the effects seen included habitat singularity, decline of species abundance, decline of biodiversity, infilling of estuaries, flooding, and small black mosquito breeding. Sediment cores and epifaunal counts in impacted and non-impacted areas. Of these, clear-felling, aquaculture and over-exploitation of fisheries in mangroves are expected to be the greatest threats to mangrove species over the next 10–15 years  . The species diversity was largest in October 2015 and smallest in January 2016. To calculate the area of mangrove cover, NDVI and EVI were used. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The annual market of capture fisheries has been conservatively estimated at between US $750 and $16,750 per ha, which illustrates the potential support value of mangroves (Rönnbäck, 1999). After mangrove removal, the composition of the sediment changed from a muddy to a sandier habitat, and clams began to appear (Young, 2013). However, these biological habitats are sensitive and fragile; after a coastal environment has been destroyed, it can be restored or rehabilitated only with great difficulty. This area is also known as the Siangshan Wetland (Fig. Five habitats in the cleared and undisturbed areas were sampled:
6. 7). Mangrove forests are among the world's most vulnerable subtropical and tropical habitats. Species density of bivalve species at A1, B1, A5 and B5 in October 2015 (A); species density of bivalve species at A1, B1, A5 and B5 in February 2016 (B); species density of bivalve species at A1, B1, A5 and B5 in June 2016 (C); species density of bivalve species at A1, B1, A5 and B5 in August 2016 (D). The study also provides useful ecological data for coastal managers and other officials interested in controlling mangrove spread. 2. Based on projected rates, mangrove trees could lose their race against rising water within the next 30 years. Thus, the question of whether natural coast ecological habitats are preferable to artificially constructed coasts is important in coastal management. You can also choose to receive updates via daily or weekly email digests. Those losses are critical to society because mangroves filter terrestrial contaminants, protecting coral reefs from eutrophication, sedimentation, and resulting degradation. Several small-scale mangrove-removal projects, ranging from 1 to 14 ha, were implemented from 2007 to 2014. Journal Reference Areas where mangroves have been removed also need regular maintenance to keep mangrove seeds from re-establishing—an annual cost that can range from $1000 to $5000 per hectare for seedling removal and disposal. The invading mangroves changed the structure and functions of the habitat for benthic organisms and caused infilling of estuaries, flooding, and invasions of the small black mosquito (Forcipomyia taiwana). Mangrove forests are among the world's most vulnerable subtropical and tropical habitats. The expansion of mangroves often blocks the waterways. Climate change also affects their survival. no more than one email per day or week based on your preferences. Root material was weighed wet and again after drying to constant weight at 60°C. This region could shed light on such synergistic effects when studied at the latitudinal boundary of mangrove extent in south Australia and north New Zealand. Mangrove presence increases the residence time of water, especially in flat, wide mangroves with complex waterways (Wolanski & Ridd 1986). After mangrove removal, the species returned to their original habitats. Nonetheless, once a fence is built its effects are long lasting. Few studies have investigated the negative biological effects of mangroves. A large-scale mangrove-removal project was undertaken by the Hsinchu City Government from October 2015 to March 2016. After mangrove removal, species returned to their original habitats and noteworthy biological values significantly increased in the mangrove regions. In this project, the mangrove forest was divided into two dense regions and a scattered region; a mechanical removal method was applied in the dense regions and manual removal in the scattered region. Yu-Chi Chen conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, prepared figures and/or tables, authored or reviewed drafts of the paper, approved the final draft. The number of species within the mangrove regions increased after mangrove removal. • Five replicate bulked sediment samples were collected from the top 20 mm of
Abstract. This study clearly evidences the beneficial effects of mangrove removal on benthic organisms in the Siangshan Wetland in Hsinchu, Taiwan. To test this hypothesis, radiotracer experiments were performed to evaluate zinc (65Zn) and cadmium (109Cd) removal kinetics by redeposited mangrove sediments. Many rehabilitation projects are conducted by planting full-grown mangroves or seedlings. 3). The results indicate that mangrove removal can be an appropriate habitat rehabilitation strategy for benthic organisms. First, flow conditions affect decomposition rates and may be modified by the fishpond walls. Subhanil (2016) reported that the NDVI index provided satisfactory results in distinguishing various types of vegetation coverage. The results indicate that the benthic communities at the cleared sites have not recovered within the observation period (2005 – 2008). Analysis of the 2005 samples was reported by Felsing (2006) and a comparison of the 2005 and 2006 results was discussed in a report by Stokes (2008). Satellite imagery has informed several studies (Ramirez-Garcia, Lopez-Blanco & Ocana, 1998; Murray et al., 2003; Matsushita et al., 2007; Lee & Yeh, 2009; Shih et al., 2011a; Shih et al., 2011b; George et al., 2018) that have examined the reach of wetland vegetation and have assessed the relationship between mangrove distribution and coastal changes (Allison & Lee, 2004; Fromard et al., 2004; Nakamura et al., 2004; Shih et al., 2011a; Shih et al., 2011b; Lonard et al., 2017). The benthic biomass was significantly different at periods before and after mangrove removal (one-way ANOVA, F = 5.571, p = 0.022). This provides the small juvenile fishes benign physical environment to settle. Core stratigraphy revealed silty sands to depths below 12 cm at all cleared sites,
The following information was supplied regarding data availability: The raw data are provided in a Supplemental File. 11 p. In subtropical estuarine wetlands, fishes, crabs, gastropods, prawns, and other megafauna require mudflats to serve as critical habitats. Mangroves areas produce and support a multitude of land- and water-dwelling organisms (Nagelkerken et al., 2008). These water diversions alter the natural flow of water that maintains the health of surrounding mangroves as well as ecosystems farther inland and offshore. Spreading mangroves: a New Zealand phenomenon or a global trend? Mangroves cover a wide latitudinal range in Australia and New Zealand, so it is difficult to summarize the potential synergistic effects of climate change stressors for the entire region. The results showed that both the Shannon–Wiener index (H′) and Pielou’s evenness index (J) increased, indicating an increase in biodiversity after mangrove removal. "Following" is like subscribing to any updates related to a publication. The types of mangroves, bare land, and water were analyzed using Erdas Imagine Software. fresh and detrital organic matter; Peterson et al., 1… Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand. Based on projected rates, mangrove trees could lose their race against rising water within the next 30 years. Author(s) : Alfaro, A. C. Author Affiliation : Faculty of Health and Environmental Sciences, School of Applied Sciences, Auckland University of Technology, Private Bag 92006, Auckland 1020, New Zealand. Rehabilitation and restoration differ in their meaning: the latter refers to partly or completely replacing the structure or functional aspects of an affected ecosystem, whereas the former attempts to return the ecosystem to its original characteristics (Field, 1999). 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