Arabian Sea Coast Research Articles

Biogeography of the coastal fishes of the Socotra Archipelago: Challenging current ecoregional concepts.

The Socotra Archipelago, located in the eastern Gulf of Aden, has a unique marine environment, which combines tropical and ‘pseudo-temperate’ elements. An updated species inventory recently considered its coastal fish diversity the highest among Arabian ecoregions, necessitating to re-assess the ichthyogeographic position of the island group. The main aim of this study is to describe the distributional biogeography of its coastal fish fauna in relation to contemporary ichthyogeographic and ecoregional concepts. Inferences are drawn with regard to the marine biogeographic arrangement and ecoregional partitioning of the Arabian region. The main datasets comprise eight and twenty selected families including 404 and 898 species, respectively, from Arabian ecoregions. The Socotra Archipelago has close affinities to a putative ecoregion in the eastern Gulf of Aden that extends to southern Oman. It is more closely related to the Arabian Sea coast of Oman than to ecoregions in the Red Sea and a putative ecoregion in the western Gulf of Aden. The Gulf of Aden does not represent a consistent ecoregion in ichthyogeographic terms, because its eastern and western parts are less closely related to one another than to other ecoregions. The Socotra Archipelago and the eastern Gulf of Aden should therefore not be assigned to a joined province with Red Sea ecoregions. The coastal fish faunas of the southern Red Sea have close affinities with those of the western Gulf of Aden. The Arabian/Persian Gulf is least related to the other Arabian ecoregions. The authors posit the Socotra Archipelago as a distinct ecoregion, either on its own or in combination with affiliated mainland areas. This best reflects the ichthyogeographic data and the exceptionally high levels of fish and overall marine diversity. Two alternative ecoregional delineations are proposed, serving as working hypotheses for onward research.

GEOGRAPHIC, HISTORIC, POLITICAL, RIPARIAN, AND SOCIO-ECONOMIC FACTORS THAT LEAD TO PAKISTAN AS A LAND OF PENTA MESOPOTAMIA

The research aims to investigate Pakistan’s geographic, historic, political, riparian, and socio-economic factors that lead to Pakistan as a Land of Penta Mesopotamia. Pakistan is situated in South Asia along the coast of Arabian Sea, bordering Afghanistan in west, China in north, Iran in southwest, Arabian Sea in South and Hindustan (India) lies in the east. Historically, the land of Pakistan has been the host of Neolithic period’s South Asian multi Indus valley civilization (IVC) that includes Gandhara, Harappan, Mehrgarh, Mohenjo-Daro, Takht-i-Bahi and Texila civilizations that emerged during 3,300 BCE to 1300 BCE. Muslim Civilizations emerged from 712 to 1857 and British colonial culture also developed from 1857-1947 in this area. The Indus valley civilization flourished parallel to the Mesopotamian civilizations. Mesopotamian civilization includes the Assyrian and Babylonian Civilization that emerged in Iraq in between the two rivers of Euphrates and Tigris from 3,100 B.C. to 332 B.C. and is referred to the “Cradle of Civilizations”. Since Mesopotamian civilization attracted all the ancient civilizations in West Asia to nourish because of its friendly ecological environments, fertile land and rich alluvium soils. Pakistan’s geography also attracted the Indus valley civilizations that emerged in the confluence of seven perennial rivers i.e. Sutlej, Ravi, Chenab, Jhelum, Indus, Swat and Kabul rivers, credited as the “Cradle of South Asian Indus valley Civilizations”. Pakistan’s strategic location in the region, her favorable ecosystem for biodiversity, favorable multi seasons, fertile land, friendly ecological conditions, rich agricultural environment, rich alluvium soils, strategic multiple riparian potentials that originate from Himalayan, Karakorum, and Hindu-Kush mountain ranges, remained lucrative for South Asian Indus valley civilizations. Pakistan’s geography also remained very attractive to the sub regions of Asia i.e. Central, South and West Asia because it has provided and has been providing the Mesopotamians agrarian transit economy to landlocked countries of Afghanistan and Central Asian States from the shortest possible sea route of Arabian Sea and visa-vi to oil rich states of Middle East via China Pakistan Economic Corridor (CPEC). Mesopotamian’s cultural, ecological, geographic, historic, riparian, socio-economic, socio-political equilibrium and similar factors are founded in the Indus valley civilizations that erect the sufficient evidence to prove that “Pakistan is a Land of Penta Mesopotamia”. Keywords: Civilizations, Confluence, Fertile land, Mesopotamia, Riparian potentials.

Sentinel-1A for monitoring land subsidence of coastal city of Pakistan using Persistent Scatterers In-SAR technique

Karachi is located in the southern part of Pakistan along the Arabian Sea coast. Relevant institutions are concerned about the possibility of ground subsidence in the city, contributing to the comparative sea-level rise. So yet, no direct measurement of the subsidence rate and its relation to city submergence danger has been made. SAR (Synthetic Aperture Radar) interferometry is a powerful method for obtaining millimeter-accurate surface displacement measurements. The Sentinel-1 satellite data provide extensive geographical coverage, regular acquisitions, and open access. This research used the persistent scatterer interferometry synthetic aperture radar (PS-InSAR) technology with Sentinel-1 SAR images to monitor ground subsidence in Karachi, Pakistan. The SARPROZ software was used to analyze a series of Sentinel-1A images taken from November 2019 to December 2020 along ascending and descending orbit paths to assess land subsidence in Karachi. The cumulative deformation in Line of Sight (LOS) ranged from − 68.91 to 76.06 mm/year, whereas the vertical deformation in LOS ranged from − 67.66 to 74.68 mm/year. The data reveal a considerable rise in subsidence from 2019 to 2020. The general pattern of subsidence indicated very high values in the city center, whereas locations outside the city center saw minimal subsidence. Overall, the proposed technique effectively maps, identifies, and monitors land areas susceptible to subsidence. This will allow for more efficient planning, construction of surface infrastructure, and control of subsidence-induced risks.

Ecological assessment of heavy metals accumulation in sediments and leaves of Avicennia marina along the Diu coast of the northeast Arabian Sea

The Coastal region of Diu is the natural habitat dominated by Avicennia marina mangrove species at the southeast coast of Saurashtra in Gujarat state of India. However, Diu being a famous industrial and tourism place survival of these mangrove species is threatened due to anthropogenic activities. In present studies, sediment and leaf samples of A. marina were collected from the Diu coast to evaluate the ecological threat of heavy metals accumulation in the marine habitat. There was remarkable presence of heavy metals such as copper, nickel, cadmium, chromium and lead in sediments and leaf samples of A. marina. The values of Biological concentration factors (BCFs) of heavy metals in leaf samples were high for cadmium, chromium and lead which suggest chelation of these heavy metals with biomolecules. The geo-accumulation index suggested that Site-4 and Site-5 were heavily contaminated with copper and nickel. The ecological risk index suggested that there is no significant effect of heavy metals on growth of plants in the mangrove ecosystem. Principal component analysis revealed that the samples collected from the natural habitats (Site-4 and Site-5) near the fishing and industrial areas were the main sources of heavy metal contamination. Hence, it was concluded that the concentration of heavy metals in the studied ecosystem had limited impact on growth of plants at Site-1, Site-2 and Site-3. However, growth of plants at Site-4 and Site-5 were threatened due to the toxic effect of copper and nickel present in its sediments.

Reviews and syntheses: Physical and biogeochemical processes associated with upwelling in the Indian Ocean

Reviews and syntheses: Physical and biogeochemical processes associated with upwelling in the Indian Ocean

Sultanate of Oman, Dhofar Governorate, Arabian Sea Coast

Sultanate of Oman, Dhofar Governorate, Arabian Sea Coast

Pakistan, Balochistan Province, Arabian Sea Coast

Pakistan, Balochistan Province, Arabian Sea Coast

Genetic characterization of Kiddi shrimp, Parapenaeopsis stylifera (H. Milne Edwards, 1837) along the Indian coast using microsatellite markers

Parapenaeopsis stylifera (H. Milne Edwards, 1837), popularly known as Kiddi shrimp, constitutes an important fishery resources along the Indian coast with wide geographical distribution. Despite its economic importance, the genetic stock structure of the species is not investigated so far. Knowledge on genetic structure is essential for formulating sustainable management and conservation measures. Present study is carried out to characterize the five geographically isolated stocks of P. stylifera along the Indian coast using microsatellite markers. Eleven polymorphic microsatellites were developed in P. stylifera and used for genetic stock characterization. Including all the stocks, a total of 174 alleles were observed with a mean of 15.81 alleles per locus. Mean observed (Ho) and expected (He) heterozygosity values ranged from 0.641 to 0.692 and 0.710–0.743, respectively. Six loci shown deviation from Hardy-Weinberg equilibrium and no significant linkage disequilibrium between loci pairs were detected. Pair-wise FST, AMOVA and Structure analyses indicated low genetic structure between the stocks of east (Bay of Bengal) and west (Arabian Sea) coasts of India. Based on the present study, P. stylifera stocks of east and west coast of India can be proposed as single management units (MUs), which require single monitoring and management practices.

Umman'ın Arap Denizi Kıyılarından Argyropelecus gigas Norman, 1930 ve Conocara fiolenti Sazonov & Ivanov, 1979'un için yeni kayıtlar

Two specimens of Argyropelecus gigas and Conocara fiolenti were collected from off the city of Salalah on the Arabian Sea coasts of Oman. The specimens represent the first confirmed record of the species from the northwestern quadrat of the Indian Ocean. Meristic and morphometric characters match those described for these species.

Preliminary Study on Abundance of Microplastic in Sediments and Water Samples Along the Coast of Pakistan (Sindh and Balochistan)-Northern Arabian Sea

Plastic material dominates our life and accordingly, it dominates the environment as a pollutant. Pakistan coasts are facing with plastic pollution problem like the rest of the world. The number and types of microplastics found in sea water and sediment samples from 25 locations along the Arabian Sea coast of Pakistan were explored in this study. The results of the present study show that the region is under a high pollution from microplastics. Microplastic abundance in seawater was found as mean 582.12±246.14 particle. L-1 and in sediment samples was mean 987.40±617.06 particle.kg-1 dry sediment. Microplastic concentration was maximum in Manora both seawater and sediment samples. Fibers were major contribution to total microplastics, up to 99% of all samples both seawater and sediment samples.

New insights into human occupation through rock art at Khatm al Melaha archaeological site (Sharjah, United Arab Emirates)

This paper is an approach to the study and documentation of a quite large group of rock art boulders at Khatm al Melaha (Sharjah, United Arab Emirates). More than 150 decorated stone blocks, with almost 400 motifs, have been identified on a hill close to the Arabian Sea coast, highlighting its importance as a control point for communicating the coast and the hinterland. Although a domestic human occupation of the area has not yet been documented, the symbolic significance of this place is reinforced not only by rock art but also by the presence of several dry-stone tombs. Despite the limited studied area, our contribution outlines a preliminary approach to a previously very little studied territory, providing a local chrono-stylistic proposal for those figurative (humans, animals) and non-figurative (signs) engravings attending to different stylistic conventions, techniques, subject matters and varnish colour. Different digital documentation techniques (digital tracings, terrestrial and aerial photogrammetry, web mapping) have been applied in order to create an updated and accurate data corpus allowing future analysis. The ongoing research will try to find new evidence of symbolic occupation of the territory in relation to human settlements and their relationship within a wider landscape.

First report on the diet and reproductive biology of red-toothed triggerfishOdonus niger(Ruppell, 1836) from the south-eastern Arabian Sea

AbstractThe feeding habits and reproductive biology of red-toothed triggerfishOdonus niger(Ruppell, 1836) was analysed from 449 specimens collected from the Karnataka coast of the south-eastern Arabian Sea. Of the total stomachs examined, only 54 (12%) were empty and 395 contained food remains. The diet comprised crustacean remains (48.0%), zooplankton (21.4%), algae (16.5%), fish remains (6.1%) and cephalopod remains (5.3%) along with partially digested matter (2.3%) and detritus (0.4%). The species was found to be a generalist feeder and an omnivore. The overall sex ratio between males and females (1: 0.44) was significantly (P< 0.05) different. Histological examination of the ovaries indicated asynchronous ovarian development in females, with males maturing earlier than females. The gonadosomatic index (GSI) patterns of males and females, and the presence of ripe ovaries and spermatozoids suggested that April–May is the peak spawning period. The absolute and relative fecundity estimates ranged from 16,464–312,420 eggs and 251–2812 eggs g−1respectively. Fecundity was positively correlated with total length and body weight. The biological information on diet composition and reproductive traits provided for the first time in this study can facilitate conservation, management and sustainable exploitation of this species in the study area.

First Records of Xanthochromism in Four Marine Fish Species Collected from the Arabian Sea Coasts of Pakistan

First Records of Xanthochromism in Four Marine Fish Species Collected from the Arabian Sea Coasts of Pakistan

Sailfin velifer, Velifer hypselopterus Bleeker, 1879 (Perciformes, Veliferidae) in Oman waters: a new substantiated record from the Arabian Sea coast of Oman

The first substantiated records of Sailfin velifer, Velifer hypselopterus Bleeker, 1879 in Omani waters are reported based on 10 specimens ranging in total length 300-430 mm, which have been collected by gill net on the coast of Al-Ashkharah City, 319 km south of Muscat City, Arabian Sea, Oman. Morphometric and meristic data are provided and compared with those of several specimens of this species from other parts of the world. This study reports on the largest specimen of this species ever being collected.

Distribution and characterization of microplastics in beach sediments from Karnataka (India) coastal environments

The presence of microplastic particles from five different beach locations (Arabian Sea coast) in the Indian state of Karnataka was assessed. The sieving and density separation method was modified to enhance the yield of microplastics. Three different techniques were used to characterize isolated microplastics, such as optical fluorescence microscopy, Raman spectroscopy, and FESEM-EDX. Microplastic concentrations ranged from 264 ± 62 n/kg to 1002 ± 174 n/kg of dry sand in beach sediments, and the average abundance of the five beaches was 664 ± 114 n/kg. The majority of the microplastics were fragmented, <1 mm in size, white and transparent in color. FESEM images of microplastics show the roughness, cracks, mechanical and oxidative weathering, indicating their continuous exposure in the environment. EDX spectra provide the presence of various elements on the microplastic surface.

Assessment of variation in water quality at Right Bank Outfall Drain, including Manchar lake, Sindh, Pakistan

ABSTRACT Right Bank Outfall Drain (RBOD) is a drainage canal being built on the right side of river Indus, Sindh Pakistan and will carry saline water from Balochistan and Northern Sindh to Arabian Sea coast. It is still at different stages for completion. Thirteen samples were collected from RBOD III and RBOD I (Hairdin Pumping Stations, Balochistan to Sehwan, Manchar lake, Sindh), and a reference sample was collected from river Indus at Kotri Barrage. The sampling scheme was repeated three times in 2009 and 11 samples were collected from RBOD I during 2018. The water samples were analysed for about 27–41 different parameters, including physicochemical, cations, anions, trace metals and the presence of microbiological organisms. The variation in the water quality was examined pre- and post-monsoon season and flows of water at Kotri Barrage. A significant variation was observed in quality of water pre and post monsoon. Higher concentrations were reported during pre-monsoon season. The water quality index (WQI) indicated that most of the samples were within poor water category for both drinking and irrigation purposes. Gibb’s diagrams demonstrated that evaporation was dominant (85.7%) on the hydrochemistry of the water samples. The Cd, Pb, Ni, Cr and As crossed the permissible limits at a number of sampling stations. The water samples were also examined for multivariate analysis including principal component analysis (PCA), cluster analysis, piper diagrams and coefficient of variation. Chloride (Cl−) and sodium were dominant, followed by calcium, magnesium, sulphate and bicarbonate. The average values of analyses (n = 4) indicated RSD within 4.0%. The samples were examined for possible use for irrigation and 53–92% samples collected from RBOD (n = 14) were within unsuitable category for irrigation.

Incidence of microplastics in gastrointestinal tract of golden anchovy (Coilia dussumieri) from north east coast of Arabian Sea: The ecological perspective

Anthropogenic marine litters or microplastics (MPs) accumulation in marine organisms is an emerging environmental threat. In this background, the gastrointestinal tract of Coilia dussumieri (n = 150) was studied in the samples collected from the fishing grounds of the north east coast of Arabian Sea through experimental fishing. Out of the total 150 specimens collected, all showed the incidence of microplastic particulates in the guts. The average abundance of MPs was found to be 6.98 ± 2.73 items/individual whereas gastrointestinal tract recorded with an average number of 28.84 ± 10.13 MPs/g in the gut material. The dominant MPs were found in the size range of 100–250 μm and of fibers type mostly blue in color. The prevalence of MPs in Coilia dussumieri is a matter of serious concern due to its ecological consequences due to trophic transfer in the connected food chains and probable threats to the health of human beings consuming the fish.

Impact of climate change on the fishery of Indian mackerel (Rastrelliger kanagurta) along the Kerala coast off the southeastern Arabian Sea

Climate change impact varies at regional as well as species level and accordingly research needs to be focused on exploring the region-wise influence of oceanographic variations on key marine species. The present study depicts the annual and decadal fluctuations in Indian mackerel fishery along Kerala coast of southeastern Arabian Sea over a time period of 31 years (1985–2016), its relationship between four major oceanographic variables (SST, Pr, SSS and SSC) and future predictions under two Representative Concentration Pathways (RCPs). Coast specific changes of these oceanographic variables since 1960 provide a baseline status of the existing climatic conditions of the marine ecosystem of the SEAS whereas, the RCP projections till 2100 provide an insight to the future conditions. Generalized Additive Models (GAMs) has been used to comprehend the relation among the Weighted CPUE (cpue) and Relative effort (Effort) of Indian mackerel and the four major oceanographic variables. The GAM model could explain 68.9 % and 71.1 % deviance of cpue and Effort respectively. The significance of the most influential oceanographic variables on the cpue of Indian mackerel were in the order SST > Pr > SSC > SSS and for Effort were in the order Pr > SST > SSS > SSC. The projected cpue and Effort of Indian mackerel exhibits varying trends under the RCP 4.5 and RCP 6.0 scenarios. The future catch potential of Indian mackerel predicted under both RCP scenarios for the period 2020–2100 also show reduction, with the latter exhibiting a more drastic reduction. The study implies that for sustainable long-term fishery and to reduce the impact of climate change on Indian mackerel, the fishing pressure has to be maintained at low and healthy level.

Skeletal lesion assessment of a Neolithic fishing community: Osteological data from Area 43 of Ra’s al Hamra 5, Oman

We assess the state of health of individuals recovered from the Neolithic fishing community of Ra’s al Hamra 5 (RH5). The archaeological site is located by the Oman gulf on the Arabian Seacoast near the suburb of Qurum; located near the Omani capital city Muscat. The graveyard dates from 3800 BCE to 3300 BCE. We recorded lesions specific to degenerative joint disease, vertebral osteoarthritis, periostitis, dental and oral defects, and cranial pitting from Area 43 of the graveyard. Lesions are scored simply as presence or absence. Intra-site (Area 43) comparison is done by age groupings (sub-adult and adult). Comparison is also made between the findings of dietary lesions, oral defects and DJD from the 77 burials from Area 43 and 182 non-Area 43 burials of the RH5 site. No differences in these lesion frequencies are found between the two parts of the RH5 graveyard. Critically, we found that most of the sub-adults in Area 43 lacked skeletal indicators of illness, suggesting acute origins for their untimely deaths. A comparison is also made with other Neolithic sites for example, a comparison with the contemporary pastoral community of Jebel al-Buhais 18 revealed no statistically significant differences in most skeletal lesion frequencies, except for DJD, antemortem tooth loss and osteoarthritis. A comparison with several Neolithic farming communities instead documented statistically higher rates of lesions compared to the RH5 fishing community. Both comparisons suggest that a fishing economic strategy provided the RH5 inhabitants with an adequate diet and less stressors than other Neolithic economic strategies.

Observing a severe flooding over southern part of India in monsoon season of 2019

Kerala is one of the most flood prone states of India due to its geographical location and topography. In recent decades, the frequency and intensity of flood has significantly increased in Kerala. Floods that occurred in the year 2007, 2009, 2014 and 2018 resulted in heavy damage in the form of lives and properties. This research focuses on exploring a recent flood event of Kerala in July–August 2019 using observations from space. Enhanced convective activities over Kerala were resulted due to movement of a low-pressure system westwards from Bay of Bengal towards coastal Arabian Sea under favourable conditions. Results report that excess cumulative rainfall resulting from multi-day extreme precipitation events due to enhanced convection during July and August resulted in catastrophic flood events over various parts of Kerala. Kannur, Wayanad, Kozhikode and Palakkad districts of north Kerala were affected more as compared to other region. Kannur district received a cumulative rainfall of about 1300 mm from multiple rainy spells during July and August of 2019. Peak rainfall was recorded on August 08, 2019. A peak hourly rainfall of about 60 mm/h was recorded at 1230 UTC on August 08 over Kannur district. These multiple heavy to very heavy rainfall episodes led to severe flooding over Kerala resulting in huge damage. Present research emphasizes on the importance of space-borne satellite remote sensing in monitoring of flood events in order to envisage preparedness and mitigation in flood scenarios.