scholarly journals Complex yet fauna-deficient seagrass ecosystems at risk in southern Myanmar

2018 ◽  
Vol 61 (3) ◽  
pp. 193-203 ◽  
Author(s):  
Benjamin L. Jones ◽  
Leanne C. Cullen-Unsworth ◽  
Robert Howard ◽  
Richard K.F. Unsworth

AbstractDependence on seafood across Southeast Asia is extensive. Myanmar is no exception, but the country’s provisioning marine ecosystems are threatened. Seagrass is one habitat that is frequently overlooked in management as an important fisheries resource, despite its nursery function. In Myanmar, research on seagrass habitats is particularly sparse, and as a result, our understanding of seagrass exploitation remains limited. In this study, we provide a baseline assessment of the seagrass-associated fish assemblages at four locations in the Myeik Archipelago in southern Myanmar using mono Baited Remote Underwater Video systems. Across the sites surveyed only 12 taxa of motile fauna were recorded. Relative to other regional and global studies, this figure is meagre. Our data adds to a growing literature suggesting that the marine ecosystems of Myanmar are in a worrying state. Despite the lack of recorded seagrass associated fauna, our study revealed minimal impacts to seagrass meadows from eutrophication or sedimentation, and the meadows included appeared to be healthy. The sites with the highest number of motile fauna were within Myanmar’s only National Marine Park offering some optimism for the effectiveness of protection, but further assessments are required to allow targeted management of Myanmar’s seagrass meadows.

2017 ◽  
Vol 68 (7) ◽  
pp. 1391 ◽  
Author(s):  
D. Harasti ◽  
K. A. Lee ◽  
R. Laird ◽  
R. Bradford ◽  
B. Bruce

Stereo baited remote underwater video systems (stereo-BRUVs) are commonly used to assess fish assemblages and, more recently, to record the localised abundance and size of sharks. The present study investigated the occurrence and size of white sharks (Carcharodon carcharias) in the near-shore environment off Bennett’s Beach, part of a known nursery area for the species in central New South Wales, Australia. Six stereo-BRUV units were deployed approximately fortnightly between August and December 2015 for periods of 5h in depths of 7–14m. Stereo-BRUVs successfully recorded 34 separate sightings of 22 individual white sharks. The highest number of individuals detected during a single day survey was eight. All C. carcharias observed on stereo-BRUVs were juveniles ranging in size from 1.50 to 2.46-m total length (mean±s.e., 1.91±0.05m; n=22). The time to first appearance ranged from 15 to 299min (mean±s.e., 148±15min). This study demonstrates that the use of stereo-BRUVs is a viable, non-destructive method to obtain estimates of the size and presence of white sharks, and may be useful in estimating relative abundance in near-shore environments where white sharks are known to frequent.


2017 ◽  
Vol 68 (3) ◽  
pp. 568 ◽  
Author(s):  
Aidan T. Walsh ◽  
Neville Barrett ◽  
Nicole Hill

Cool-temperate reef fish assemblages are often poorly described below 20m because of depth limitations of conventional diver-based visual census. The recent development of baited remote underwater video systems (BRUVs) provide an alternative quantitative sampling method. Despite being used in warmer temperate and tropical waters and cool-temperate waters in Victoria, initial trials of vertical BRUVs in Tasmania, Australia, provided poor results. Our study explored possible reasons for this, including using horizontal BRUVs and various baits across a depth gradient. We examined the fish fauna in, and adjacent to, a small, but long-established, no-take marine reserve to assess the potential for BRUVs to enhance monitoring programs in exposed coastal environments. Significant differences in the fish assemblage were described relating to location, depth and bait type, with pilchards being an effective bait type. Fish abundance and species richness increased with depth. The research validated BRUVs for monitoring deep-reef systems in Tasmania, reinforced the importance of depth in structuring fish assemblages and identified the range of observable species in this region that may not be fully captured with diver-based surveys alone. Power analyses were conducted using the data generated here to inform the amount of replication needed to detect biologically meaningful differences in targeted fish assemblages in subsequent studies examining the response of no-take marine reserves to protection. This facilitates future assessments of the effectiveness of Tasmanian no-take reserves and allows for more broad-scale studies that can address a range of ecological and conservation questions.


2018 ◽  
Vol 588 ◽  
pp. 179-189 ◽  
Author(s):  
BL Gilby ◽  
AD Olds ◽  
RM Connolly ◽  
PS Maxwell ◽  
CJ Henderson ◽  
...  

2020 ◽  
Vol 7 (4) ◽  
pp. 169-174
Author(s):  
Chatragadda Ramesh ◽  
Raju Mohanraju

Seagrasses are unique marine flowering plants that play an important ecological role by yielding primary production and carbon sequestration to the marine environment. Seagrass ecosystems are rich in organic matter, supporting the growth of bio-medically important epi and endophytic microorganisms and harbor rich marine biodiversity. They are an essential food source for endangered Andaman state animal Dugongs. Seagrasses are very sensitive to water quality changes, and therefore they serve as ecological bio-indicators for environmental changes. The benthic components in and around the seagrass beds support a significant food chain for other Micro and organisms apart from fishery resources. The epiphytic bacterial communities of the leaf blades support the sustenance against the diseases. Recent reports have shown that the loss of seagrass beds in tropical and temperate regions emphasizes the depletion of these resources, and proper management of seagrass is urgent. The decline of seagrass will impact primary production, biodiversity, and adjacent ecosystems, such as reefs. Therefore, restoring the seagrass meadows could be possible with effective implementing management programs, including seagrass meadows in marine protected areas, restoration projects, seagrass transplantation, implementation of legislative rules, monitoring coastal water quality and human activities in the coastal zone. Lacunas on the seagrass ecosystem management in Andaman & Nicobar Islands are addressed.


2018 ◽  
Vol 12 (2) ◽  
pp. 35-44
Author(s):  
Sania Prisilia ◽  
Wahyu Adi ◽  
Arief Febrianto

Seagrass beds have a variety of roles in fish life, which can be used as nurseries, as a place for feeding ground, and for areas to seek protection. This study aims to analyze the structure of fish communities and seagrass communities and analyze the relationship of fish abundance with seagrass ecosystems. This research was conducted in March 2018 on the beach of Puding Air Banten II, Pasir Putih Village, Tukak Sadai District, Bangka Selatan Regency. Line transect method for seagrass data collection and fish data retrieval using fixed gill nets (gill net). The results of the study found that the total number of individual fish as much as 409 ind / m2 consisted of 25 species. The highest abundance of fish found in Station I with Ambassis interrupta species as many as 241 ind / m2. There were six types of seagrass found on the coast of Puding, namely Enhalus acoroides, Thalassia hemprichii, Halodule uninervis, Halophila spinulosa, Halophila decipiens and Cymodocea serrulata. The highest seagrass density was found at Station I with the seagrass Halodule uninervis species of 2541 ind / m2. Correlation coefficient analysis shows that the abundance of fish with seagrass density has a significant value of 0.956 which is classified as having a very strong relationship. Fish have higher abundance with seagrass meadows which vegetate with mangroves


2020 ◽  
Vol 4 (1) ◽  
pp. 6-13
Author(s):  
Sing Lui Lo ◽  
Tzuen Kiat Yap ◽  
Cheng Ann Chen ◽  
Teruaki Yoshida

A comparison of zooplankton abundance and community in the seagrass and non-seagrass areas of Limau-limauan and Bak- Bak waters within the newly established Tun Mustapha Marine Park was made during 15-17 May 2017. Samples were collected via horizontal tow of a 140 μm plankton net. Environmental variables (temperature, salinity, DO, pH, turbidity) showed no significant differences among the study sites. However, zooplankton showed increasing abundance from non-seagrass, seagrass edge, to seagrass areas at Limau-limauan, while abundance values were comparable among the stations at Bak-bak. Overall zooplankton abundance was significantly higher at the seagrass areas relative to the non-seagrass station at Limau-limauan (p < 0.005), while no statistical difference was found at Bak-Bak (p < 0.21). Mean canopy height was 3-fold higher (p < 0.001) at Limau-limauan than Bak-Bak, suggesting the importance of seagrass bed structural complexity in habitat preference for zooplankton. Cluster analysis revealed the zooplankton community from the seagrass area at Limau-limauan was different from that at seagrass edge and non-seagrass areas, which may be attributed to the influence of seagrass meadows in forming characteristic zooplankton compositions. Marked differences in zooplankton composition and abundance even in close vicinity of sites suggest the importance of local small-scale variations in seagrass habitats in shaping the zooplankton community.


2018 ◽  
Vol 61 (5) ◽  
pp. 429-440 ◽  
Author(s):  
Milica Stankovic ◽  
Naruemon Tantipisanuh ◽  
Anchana Prathep

Abstract Seagrass ecosystems are important contributors to mitigation of climate change, since they are responsible for large carbon sinks. However, there is limited knowledge regarding the importance of variability of carbon storage in various ecosystems. In this study, we estimated carbon storage in several structurally different seagrass meadows along the west coast of Thailand and determined whether degree of exposure, human disturbance, and meadow type influenced carbon storage within these meadows. Carbon content within the living vegetation was on average 3±2.7 Mg ha−1, whilst average storage of carbon in the sediment was 122±35.3 Mg ha−1. Meadow type and disturbance had a significant influence on total carbon storage in the ecosystem, while the degree of exposure of the bay did not show great differences. Uniform meadows had a higher average total carbon storage than mixed meadows (133±36.2 and 110±41.3 Mg ha−1, respectively). Undisturbed meadows had a higher average total carbon storage than disturbed ones (140±36.5 and 103±34.8 Mg ha−1, respectively). The results obtained contribute to our understanding of carbon storage on an ecosystem scale and can provide a baseline for proper management, conservation, and climate change studies in the region.


2019 ◽  
Vol 70 (6) ◽  
pp. 870 ◽  
Author(s):  
Thomas M. Clarke ◽  
Sasha K. Whitmarsh ◽  
Peter G. Fairweather ◽  
Charlie Huveneers

Baited remote underwater video stations (BRUVS) are increasing in popularity as non-invasive and fishery-independent tools for assessing fish assemblages. Although most BRUVS studies have focused on benthic fish communities, recent studies also use BRUVS to examine the comparatively undersampled pelagic communities. However, the propensities of benthic BRUVS to detect pelagic fishes and, likewise, pelagic BRUVS to detect demersal fishes are unknown. This study simultaneously used benthic and pelagic BRUVS deployed either separately (single) or in combination to determine assemblages of demersal and pelagic species at three contrasting sites within temperate South Australia. Assemblages observed by benthic v. pelagic BRUVS differed significantly at all sites, including one as shallow as 7m deep, but there were no significant differences in assemblages observed between BRUVS of the same position (i.e. pelagic or benthic) when BRUVS were deployed as single units or in combination. This study reveals the limitations of using only benthic or pelagic BRUVS, and highlights the necessity for both BRUVS positions to be used together to ensure that a comprehensive representation of entire fish assemblages throughout the water column can be obtained.


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