Developing a rapid method for undertaking the World Ocean Assessment in data-poor regions – A case study using the South China Sea Large Marine Ecosystem

Abstract The genus Xanthocalanus inhabits the intermediate and deep waters of the world ocean. The present study records and describes the first female individual of Xanthocalanus agilis Giesbrecht, 1893, collected in the South China Sea (13°0.21′N 113°0.21′E) at depths of 500-800 m. This species was identified by the following morphological characteristics: (i) rostrum with 2 slender filaments; (ii) posterolateral corners of fifth thoracic somite protuberant and triangular, reaching the posterior margin of genital somite; (iii) first segment of fifth pereiopod (P5) with a list of inner marginal spinules, distal segment short with 3 robust terminal spines. This finding expands the known global and vertical distribution of X. agilis.

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Condominium Arrangements as a Legal Mechanism for the Conservation of the South China Sea Large Marine Ecosystem

Asia-Pacific Journal of Ocean Law and Policy ◽

10.1163/24519391-00201005 ◽

2017 ◽

Vol 2 (1) ◽

pp. 52-87 ◽

Cited By ~ 1

Author(s):

Michelle Lim ◽

Nengye Liu

Keyword(s):

South China Sea ◽

South China ◽

Marine Ecosystem ◽

The South China Sea ◽

Collaborative Management ◽

Marine Biodiversity ◽

The South ◽

Governance Arrangement ◽

China Sea ◽

Large Marine Ecosystem

The South China Sea Large Marine Ecosystem is one of the world’s richest marine biodiversity areas. The sea area is however the site of increasing tensions between its ten coastal States, six of which have competing claims in the South China Sea. The expanding populations and economies of the coastal States have also resulted in the growing depletion of the Sea’s rich marine resources. Coordinated approaches are needed to protect the unique biodiversity and natural resources of the South China Sea at the appropriate ecological scale. The continuation of sovereignty disputes are detrimental to all coastal states as well as international economic interests of non-claimant states which arise as a result of the Sea’s status as a globally important trade route. This paper urges coastal states to adopt a far-sighted outlook which ensures long-term sustainable ecosystems, livelihoods and economies of the region. To do this, a shift in approach which emphasises collaborative management of marine ecosystems is required instead of a scramble for sovereignty to exclusively exploit living and non-living resources. This paper therefore explores how the shared governance arrangement of a condominium could facilitate the exercise of sovereignty for the shared benefit of all coastal States. The paper argues that the condominium approach would enable State parties to put aside thorny sovereignty disputes in favour of collaboration to protect the area’s important and unique biodiversity.

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Correlations among seabed mega pockmark size, water depth, and gas volumes suggest formation by depressurization: A case study of the Reed Basin in the South China Sea

10.5194/egusphere-egu2020-1769 ◽

2020 ◽

Author(s):

Ziyin Wu ◽

Dineng Zhao ◽

Jieqiong Zhou ◽

Xiaowen Luo ◽

Jihong Shang

Keyword(s):

South China Sea ◽

South China ◽

The South China Sea ◽

The South ◽

Submarine Canyons ◽

China Sea ◽

Bathymetric Data ◽

The World ◽

Gas Explosions

<p>Pockmarks are relict seafloor geomorphological features formed by seepage of gas or fluid from the seabed. While seafloor pockmarks are widely distributed around the world, mega pockmarks with diameters > 1 km are rare, and their formation and maintenance mechanisms remain enigmatic. Using high-resolution multi-beam bathymetric data, this paper systematically identified mega pockmark groups in the southern depression of the Reed Basin in the South China Sea. Mega pockmarks of various shapes occur in groups in the Reed Basin, primarily along the sides of submarine canyons. Observed geomorphologic characteristics differ significantly from features reported in the published literature. Based on the collected data, the average ratio of pockmark depth to pockmark radius (d/r) is evaluated as ~0.3, which is consistent with analyses of additional pockmarks in 21 regions around the world. Our observations also agree with the previously reported generalization that small pockmarks are developed in shallow water and large pockmarks in deep water. We propose that pockmarks in the Reed Basin are formed by seafloor gas explosions. Widely developed carbonates store buried gas that continuously seeps along NE-SW trending faults. Cap layers are undercut by submarine canyons forming lines of mechanical weakness. During periods of rapid sea level fall, depressurization causes buried gas to be rapidly ejected along these lines, forming large pockmark groups. Because these results correlate easily observed bathymetric features to the presence of buried gas deposits, they have important implications for the exploration and research of deep-sea gas resources.</p><p></p>

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