scholarly journals The Occurrence and Distribution of Benthic Foraminifera in Tropical Waters Along the Strait of Malacca

2021 ◽  
Vol 8 ◽  
Author(s):  
Fatin Izzati Minhat ◽  
Suresh M. Ghandhi ◽  
Nurul Syahirah Mohd Ahzan ◽  
Norizmaira Abdul Haq ◽  
Omar Abdul Rahman Abdul Manaf ◽  
...  

Foraminifera are shelled single-celled protists that are found in all marine environments. Benthic foraminifera either live in sediments or attach to surfaces on the seafloor. Understanding the distribution and ecological response of benthic foraminifera is crucial, as they can indicate past and current ocean conditions. However, the benthic foraminifera distribution along the busy Strait of Malacca, which connects the Indian Ocean (north) to the Java Sea (south), is undersampled. In this study, we collected 24 surface samples from the northern Strait of Malacca to understand the distribution of foraminifera assemblages in shallow tropical waters. A total of 49 species of benthic foraminifera were identified. Calcareous hyaline species dominated the assemblages, with an extremely low occurrence of calcareous porcelaneous species. The common calcareous hyaline taxa were Asterorotalia pulchella, Pseudorotalia schroeteriana, Discorbinella bertheloti, Ammonia tepida, and Heterolepa praecincta. Cluster analysis categorised the foraminiferal assemblages into three major groups. The first cluster (Group A) consisted of a more diverse assemblage of hyaline and agglutinated species that inhabited a mean water depth of 45 m. The second cluster represented a population that inhabited deeper water environments (average water depth of 59 m). Finally, the third cluster (Group C) consisted of a foraminifera assemblage that inhabited shallow coastal environments (average depth of 22 m) with higher organic matter enrichment. The multivariate canonical correspondence analysis (CCA) showed that the foraminiferal assemblages reflected the shallow to deep water transition in the Malacca Strait. Water depth, which defines the depositional environment, had a greater influence on foraminifera distribution here than organic matter and salinity.

2020 ◽  
Vol 50 (1) ◽  
pp. 89-96
Author(s):  
Nazihah Azmi ◽  
Fatin Izzati Minhat ◽  
Sanatul Salwa Hasan ◽  
Omar Abdul Rahman Abdul Manaf ◽  
Aishah Norashikin Abdul A'ziz ◽  
...  

Abstract We investigated the distribution of modern benthic foraminifera from Kelantan waters in the western part of the Sunda Shelf, South China Sea. Twenty-nine benthic foraminiferal species were identified from seven samples collected along a ∼250 km-long transect perpendicular to the Kelantan coastline. Calcareous hyaline species made up 57% of the overall assemblages collected in the study area, followed by calcareous porcelaneous (23%) and agglutinated (20%) species. Cluster analysis recognised two distinctive groups. Group A represented the shallow inner-shelf area (19–35 m water depth) with a coarse sand-dominated substrate where Amphistegina papillosa (13.37%) and Assilina ammonoides (11.04%) were highly abundant. Group A had lowest diversity with no agglutinated species. Group B, occurred at 40–60 m water depth, had higher foraminiferal diversity and was characterised by a very fine sand substrate. The foraminiferal assemblages here were dominated by calcareous hyaline species in group B followed by calcareous porcelaneous and agglutinated species. Group B was characterised by Assilina ammoinodes (11.04%), Heterolepa dutemplei (10.29%), and Discorbinella bertheloti (10.03%). The dominant agglutinated species in Group B were Textularia agglutinans (4.93%) and Cylindroclavulina bradyi (3.55%). Shallow-water species, such as Amphistegina spp., were absent from Group B. Our study shows that the distribution of benthic foraminiferal assemblages from the western Sunda shelf off Kelantan, is closely associated with changes in seafloor sediment, distance from the shore, and water depth.


2016 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Nazar Nurdin ◽  
Imelda R. Silalahi

Perairan Aceh termasuk Pulau Weh, Pulau Breuh dan Pulau Penasi merupakan area terluar di sisi barat Kepulauan Indonesia yang menghadap ke Samudera Hindia. Wilayah ini sangat menarik bagi para peneliti terutama setelah kejadian tsunami pada tahun 2004. Tujuan dari penelitian adalah untuk mengetahui distribusi foraminifera sebagai organisme yang sensitif terhadap perubahan lingkungan. Sebanyak 32 contoh sedimen diambil pada kedalaman 7- 170 meter dan terpilih 11 contoh untuk studi foraminifera. Hasil penelitian menunjukkan bahwa ada 45 spesies foraminifera bentik yang sangat berlimpah, terdiri atas 28 spesies anggota Subordo Rotaliina, Miliolina (7 spesies) dan Textulariina (10 spesies). Amphistegina papilosa dijumpai dalam jumlah sangat berlimpah dan tersebar merata yang memberi indikasi kondisi lingkungan terumbu karang baik. Ammonia tepida sangat dominan (47%) di sebelah utara Pulau Weh (S30) dibandingkan dengan spesies lain. Di bagian Timur Pulau Penasi, ditemukan cangkang foraminifera dalam kondisi rusak dalam jumlah berlimpah yang dapat dikaitkan dengan arus kuat di lokasi ini. Kata kunci : foraminifera bentik, distribusi, perairan Aceh The Aceh waters including Weh, Breuh and Penasi islands are the outer parts of northwestern Indonesia that facing the Indian Ocean. This area is interested for many scientists especially after tsunami in 2004. The purpose of this study is to establish the distribution of benthic foraminifera as a sensitive indicator of environmental changes. Thirty two (32) surface sediment samples were collected at the water depth of 7-170 m and eleven samples were selected for foraminiferal study. The results show 45 species of benthic foraminifera very abundantly and consists of 28 species belong to Suborder Rotaliina, Miliolina (7 species) and Textularia (10 species). Amphistegina papilosa is found abundantly and widely distribution that provide an indication of good reef environments. Ammonia tepida is very dominant(47%) in the northern part of Weh island compared with other species. Abnormal shells of foraminifera were found abundantly in the eastern part of Penasi Island that related to strong current in this area. Keywords: benthic foraminifera, distribution, Aceh waters


2013 ◽  
Vol 10 (5) ◽  
pp. 2945-2957 ◽  
Author(s):  
A. Dell'Anno ◽  
A. Pusceddu ◽  
C. Corinaldesi ◽  
M. Canals ◽  
S. Heussner ◽  
...  

Abstract. The bioavailability of organic matter in benthic deep-sea ecosystems, commonly used to define their trophic state, can greatly influence key ecological processes such as biomass production and nutrient cycling. Here, we assess the trophic state of deep-sea sediments from open slopes and canyons of the Catalan (NW Mediterranean) and Portuguese (NE Atlantic) continental margins, offshore east and west Iberia, respectively, by using a biomimetic approach based on enzymatic digestion of protein and carbohydrate pools. Patterns of sediment trophic state were analyzed in relation to increasing water depth, including repeated samplings over a 3 yr period in the Catalan margin. Two out of the three sampling periods occurred a few months after dense shelf water cascading events. The benthic deep-sea ecosystems investigated in this study were characterized by high amounts of bioavailable organic matter when compared to other deep-sea sediments. Bioavailable organic matter and its nutritional value were significantly higher in the Portuguese margin than in the Catalan margin, thus reflecting differences in primary productivity of surface waters reported for the two regions. Similarly, sediments of the Catalan margin were characterized by significantly higher food quantity and quality in spring, when the phytoplankton bloom occurs in surface waters, than in summer and autumn. Differences in the benthic trophic state of canyons against open slopes were more evident in the Portuguese than in the Catalan margin. In both continental margins, bioavailable organic C concentrations did not vary or increase with increasing water depth. Overall, our findings suggest that the intensity of primary production processes along with the lateral transfer of organic particles, even amplified by episodic events, can have a role in controlling the quantity and distribution of bioavailable organic detritus and its nutritional value along these continental margin ecosystems.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jacquelyn N. Cresswell ◽  
Peter J. van Hengstum

Karst subterranean estuaries (KSEs) are created from the two- and three-way mixing of saline groundwater, rain, and oceanic water in the subsurface on carbonate landscapes, and this hydrographic framework promotes unique physical processes, biogeochemical cycling, and biological communities. Here we provide evidence that the source and quantity of particulate organic matter (POM) that is delivered to the benthos strongly correlates to benthic habitat partitioning in the oxygenated marine sectors of KSEs. A dataset of benthic foraminifera at 128 different locations from several large flooded cave systems in Bermuda were compiled and evaluated against common environmental characteristics (e.g., tidal exposure, substrate particle size, bulk organic matter, C:N, total organic carbon, and δ13Corg). Benthic areas receiving more carbon isotopically depleted organic matter sources (mean δ13Corg values < −23.2‰, C:N ratios >11), most likely from the terrestrial surface and some marine plankton, were dominated by Trochammina inflata, Bolivina spp., and Helenina anderseni. In contrast, benthic areas receiving more carbon isotopically enriched organic matter sources (mean δ13Corg values > −21.6‰, C:N ratios <10), most likely from marine plankton transported through marine cave openings cave from adjacent coastal waters, were dominated by Spirophthalmidium emaciatum, Spirillina vivipara, Patellina corrugata, and Rotaliella arctica. The benthic foraminifera most distal from any cave entrances were dominated by taxa also known from the deep-sea (e.g., Rotaliella, Spirophthalmidium) in sediment with the lowest bulk organic matter content (mean: 6%), or taxa that prefer hard substrates and are potentially living attached to cave walls (Patellina, Spirillina). While physical groundwater characteristics (e.g., salinity, dissolved oxygen) are expected drivers of benthic ecosystems in KSEs, these results suggest that POM source, quantity, and delivery mechanisms (e.g., groundwater-seawater circulation mechanisms, terrestrial flux) play an important role in benthic habitat partitioning and the spatial variability of biogeochemical cycles in the oxygenated marine sector of KSEs.


MethodsX ◽  
2017 ◽  
Vol 4 ◽  
pp. 55-62 ◽  
Author(s):  
G. Sreenivasulu ◽  
N. Jayaraju ◽  
B.C. Sundara Raja Reddy ◽  
T. Lakshmi Prasad ◽  
K. Nagalakshmi ◽  
...  

2013 ◽  
Vol 10 (2) ◽  
pp. 1131-1141 ◽  
Author(s):  
K. A. Koho ◽  
K. G. J. Nierop ◽  
L. Moodley ◽  
J. J. Middelburg ◽  
L. Pozzato ◽  
...  

Abstract. Burial of organic matter (OM) plays an important role in marine sediments, linking the short-term, biological carbon cycle with the long-term, geological subsurface cycle. It is well established that low-oxygen conditions promote organic carbon burial in marine sediments. However, the mechanism remains enigmatic. Here we report biochemical quality, microbial degradability, OM preservation and accumulation along an oxygen gradient in the Indian Ocean. Our results show that more OM, with biochemically higher quality, accumulates under low oxygen conditions. Nevertheless, microbial degradability does not correlate with the biochemical quality of OM. This decoupling of OM biochemical quality and microbial degradability, or bioavailability, violates the ruling paradigm that higher quality implies higher microbial processing. The inhibition of bacterial OM remineralisation may play an important role in the burial of organic matter in marine sediments and formation of oil source rocks.


2016 ◽  
Vol 67 (12) ◽  
pp. 1826 ◽  
Author(s):  
Libe Solagaistua ◽  
Maite Arroita ◽  
Ibon Aristi ◽  
Aitor Larrañaga ◽  
Arturo Elosegi

Discharge fluctuations modify water depth and velocity in streams and this can affect leaf litter breakdown, which is an important ecosystem function. Both during droughts, when parts of the surface dry out, and during floods, which scour the benthic surface, macroinvertebrates can seek refuge in the subsurface. Therefore, as an important part of them depend on organic matter, the effects of discharge fluctuations on leaf breakdown might be greater on the surface than in the subsurface of lotic ecosystems. To test this hypothesis, we measured microbial and total breakdown rates of alder (Alnus glutinosa (L.) Gaertner) both on the surface and in the subsurface in two areas of a stream, namely, the permanently wet channel and the parafluvial areas. Reduced discharge dried out only the surface of the parafluvial areas, and thus, breakdown rates were reduced only in this habitat. In contrast, breakdown rates were similar in both habitats of the permanently wet channel, but also in the subsurface of the parafluvial area. The subsurface can mitigate the effects of discharge alterations on the breakdown of organic matter in streams, which might be critical for the productivity of these ecosystems under increased drought frequencies.


2013 ◽  
Vol 87 (6) ◽  
pp. 1160-1185 ◽  
Author(s):  
Hiroyuki Takata ◽  
Ritsuo Nomura ◽  
Akira Tsujimoto ◽  
Boo-Keun Khim ◽  
Ik Kyo Chung

We report on the faunal transition of benthic foraminifera during the middle Eocene at Site U1333 (4862 m water depth, 3,560–3,720 m paleo-water depth) of Integrated Ocean Drilling Program Expedition 320 in the eastern equatorial Pacific Ocean. During the period ∼41.5–40.7 Ma, which includes carbonate accumulation event 3 (CAE-3), the benthic foraminiferal accumulation rate (BFAR) increased gradually and then it declined rapidly. In contrast, BFAR was considerably lower during ∼40.7–39.4 Ma, corresponding to the middle Eocene climatic optimum (MECO), and then it increased during ∼39.3–38.4 Ma, including CAE-4. Diversity (E [S200]) was slightly lower in the upper part of the study interval than in the lower part. The most common benthic foraminifera were Nuttallides truempyi, Oridorsalis umbonatus, and Gyroidinoides spp. in association with Globocassidulina globosa and Cibicidoides grimsdalei during the period studied. Quadrimorphina profunda occurred abundantly with N. truempyi, O. umbonatus, and G. globosa during ∼39.4–38.4 Ma, including CAE-4, although this species was also relatively common in the lower part of the study interval. Virgulinopsis navarroanus and Fursenkoina sp. A, morphologically infaunal taxa, were common during ∼38.8–38.4 Ma, corresponding to the late stage of CAE-4. Based on Q-mode cluster analysis, four sample clusters were recognized and their stratigraphic distributions were generally discriminated in the lower and upper parts of the study interval. Thus, there was only a small faunal transition in the abyssal eastern equatorial Pacific during the middle to late-middle Eocene. The faunal transition recognized in this study may be related to recovery processes following intense carbonate corrosiveness in the eastern equatorial Pacific during MECO.


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