Distribution Patterns of Meiofauna Assemblages and Their Relationship With Environmental Factors of Deep Sea Adjacent to the Yap Trench, Western Pacific Ocean

Abstract

Sediment samples were collected from 23 sites near the Yap Trench in the Western Pacific Ocean with a depth range of 2896-7837 m. The assemblage composition, spatial distribution, and relationship with environmental variables of meiofauna were studied. A total of 17 meiofaunal taxa were identified, including free-living marine nematodes, benthic copepods, nauplii, ostracods, halacarids, kinorhynchs, cumaceans, turbellarians, cladocerans, polychaetes, oligochaetes, isopods, tanaidaceans, amphipods, tardigrades, gastrotrichs, and pycnogonids. The average abundance of meiofauna was (172.88 ± 149.02) ind•10 cm −2 . Marine nematodes were the most abundant group, with an average abundance of (120.26 ± 102.85) ind•10 cm −2 , accounting for 69.97% of the total meiofauna, followed by benthic copepods (36.13 ± 48.72) ind•10 cm −2 , accounting for 21.04%. The horizontal distribution of meiofauna showed that the high values of meiofaunal abundance were mainly distributed in the northwestern part of the study area and correlated with high sediment organic matter content, which possibly was related to the localized topography, food sources, and hydrodynamics within this area. Vertical distribution showed that meiofauna were mainly distributed in the upper and middle sediment layer (0-6 cm). Results of BIOENV showed that sediment median diameter and pheophorbide content were the most important factors affecting meiofauna community structure. This study provides an insight into relationships of deep-sea meiofauna assemblages with environmental factors in the Western Pacific Ocean.

Macrofauna and Nematode Abundance in the Abyssal and Hadal Zones of Interconnected Deep-Sea Ecosystems in the Kuril Basin (Sea of Okhotsk) and the Kuril-Kamchatka Trench (Pacific Ocean)

“…The increase in the abundance of meiobenthic nematodes (which was maximum on the bottom of the deepest basins of the Kuril-Kamchatka Trench) with depth is probably also associated with the increased organic matter content of bottom sediments of the trench (Schmidt et al, 2019). The increase in the abundance of meiofauna with increasing depth have been repeatedly reported in other studies on eutrophic trenches (George and Higgins, 1979;Shirayama and Kojima, 1994;Danovaro et al, 2002;Leduc et al, 2016;Schmidt et al, 2018;Wang et al, 2019). However, the abundance of large macrobenthic nematodes, unlike meiobenthic ones, on the Kuril-Kamchatka Trench floor was minimum and generally lower than in the abyssal zone of the eutrophic regions of the North Pacific.…”

“…However, the abundance of large macrobenthic nematodes, unlike meiobenthic ones, on the Kuril-Kamchatka Trench floor was minimum and generally lower than in the abyssal zone of the eutrophic regions of the North Pacific. The phenomenon of meiofaunal miniaturization was reported earlier for both oligotrophic and eutrophic deep-sea waters of the world's oceans (Shirayama, 1984;Schewe and Soltwedel, 1999;Danovaro et al, 2002;Wang et al, 2019). After studying the meiofauna of the eutrophic Atacama Trench, Danovaro et al (2002) showed that meiofaunal miniaturization cannot be related to the reduced food availability or to oligotrophic conditions, as previously suggested by Schewe and Soltwedel (1999).…”

“…The box corer was shown to be a much more efficient gear for collecting quantitative samples of deep-sea macrofauna compared to the Petersen and Okean grabs (Hessler and Jumars, 1974;Jumars and Hessler, 1976;Filatova, 1982;Belyaev, 1989). In recent years, the composition, abundance, and distribution of meiofauna in the hadal zone of the world's oceans have been most actively studied on material collected using mainly multicorer (Shirayama and Kojima, 1994;Danovaro et al, 2002;Gambi et al, 2003;Vanhove et al, 2004;Itoh et al, 2011;Kitahashi et al, 2012Kitahashi et al, , 2013Schmidt and Martínez Arbizu, 2015;Leduc et al, 2016;Leduc and Rowden, 2018;Schmidt et al, 2018Schmidt et al, , 2019Wang et al, 2019). Nevertheless, the quantitative distribution of macrofauna in the hadal zone, as before, remains extremely poorly studied due to the major problems associated with collection of quantitative samples using box corer from oceanic trenches with a complex bottom topography, a wide variety of bottom sediments (from very dense with small stones and gravel to "liquid" silts), and great depths (Belyaev, 1989;Jamieson, 2015;Tyler et al, 2016).…”

New Approach for the Evaluation of Ecological Quality in the Mediterranean Coastal Ecosystems, Case Study of Bizerte Lagoon: Marine Nematodes Functional Traits Assessment

“…After generally 30 days, the experiment was conducted adding 4% buffered formalin solution in the experimental plots. Using the Ludox™ centrifugation technique and sieves (40 μm -1 mm), the meiobenthic nematodes were extracted from the sediments and stained for 48 h with Rose Bengal [22]. Afterward, meiofaunal taxa were identified and counted under a stereomicroscope (50×, Wild Heerbrugg M5A Model), and a maximum of 100 nematodes/replicates were randomly collected.…”

Spatial and temporal variations of the subtidal meiobenthic community of the central coast of Venezuela

“…ISSN: 1659-455X • e-ISSN: 1659-407X DOI: http://dx.doi.org/10.15359/revmar.12-2.5 the energy produced by microalgae and bacteria to benthic consumers of higher trophic levels (Moncreiff & Sullivan, 2001;Ansari et al 2012). Meiobenthos modify the physical, chemical, and biological properties of sediments, participating in sediment stabilization, biogeochemical cycles, and waste removal (Wang et al 2019). Additionally, it has been widely used for monitoring environmental quality due to its fast response to changes in the environment, species richness, and short life cycles with 3 to 5 generations per year (Giere, 2009;Ansari et al 2012;Kitahashi et al 2018).…”