Analysis of the spatio-temporal distribution of chlorophyll-a in the eastern Indian Ocean near the time of the 2004 South Asian tsunami

Fauziah A, Bengen DG, Kawaroe M, Effendi H, Krisanti M. 2019. Spatio-temporal distribution of microalgae producing chlorophyll and carotenoid pigments in Bali Strait, Indonesia. Biodiversitas 20: 61-67. The Bali Strait waters become a place for various development activities that connect Java Island and Bali Island so that it is thought to have an impact in the life of microalgae that play an important role in the wealth of their water resources. This study aims to explore the spatiotemporal distribution of marine microalgae, which has the potential to produce chlorophyll and carotenoid pigments, as well as their relationship with the environmental characteristics of the Bali Strait waters. The research was conducted at the 5 stations in the morning, midday and afternoon. The data obtained were analyzed using Principal component analysis (PCA) and Correspondence analysis (CA). The results showed that chlorophyll-a, chlorophyll-b and carotenoid were mostly contained by the species Chaetoceros gracilis, Tripos lunula at station 5 (Pang-pang Bay) in the morning, midday and afternoon, and contained by the species Fragilariopsis cylindrus, Thalassiothrix fravenfeldii at station 3 (Ketapang-Gilimanuk ferriage) in the midday and afternoon. Spatially, salinity, ammonia, nitrate, and chlorophyll-a have significantly different values between stations, while temporally the content of chlorophyll-b and carotenoid are influenced by time (in the morning, midday and afternoon).

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VARIABILITY OF SEA SURFACE TEMPERATURE (SST) AND CHLOROPHYLL-A (CHL-A) CONCENTRATIONS IN THE EASTERN INDIAN OCEAN DURING THE PERIOD 2002–2017

International Journal of Remote Sensing and Earth Sciences (IJReSES) ◽

10.30536/j.ijreses.2019.v16.a3147 ◽

2019 ◽

Vol 16 (1) ◽

pp. 55

Author(s):

Michelia Mashita ◽

Jonson Lumban-Gaol

Keyword(s):

Indian Ocean ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Chlorophyll A ◽

Sea Surface ◽

Asia Pacific ◽

Eastern Indian Ocean ◽

Positive Anomaly ◽

Chl A ◽

Annual Variability

We analysed the variability of sea surface temperature (SST) and chlorophyll-a concentration (Chl-a) in the eastern Indian Ocean (EIO). We used monthly mean Chl-a and SST data with a 4-km spatial resolution derived from Level-3 Aqua Moderate-resolution Imaging Spectroradiometer (MODIS) distributed by the Asia-Pacific Data-Research Center (APDRC) for the period 2002–2017. Wavelet analysis shows the annual and interannual variability of SST and Chl-a concentration in the EIO. The annual variability of SST and Chl-a is influenced by monsoon systems. During a southeast monsoon, SST falls while Chl-a increases due to upwelling. The annual variability of SST and Chl-a is also influenced by the Indian Ocean Dipole (IOD). During positive phases of the IOD (2006, 2012 and 2015), there was more intense upwelling in the EIO caused by the negative anomaly of SST and the positive anomaly of Chl-a concentration.

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Estimating Fishing Effort and Spatio-Temporal Distribution of Longline Vessels in the Indian Ocean

Frontiers in Marine Science ◽

10.3389/fmars.2021.671036 ◽

2021 ◽

Vol 8 ◽

Author(s):

Febrianto W. Utama ◽

Xavier Hoenner ◽

Britta Denise Hardesty ◽

David Peel ◽

Jessica H. Ford ◽

...

Keyword(s):

Indian Ocean ◽

Temporal Distribution ◽

Fishing Effort ◽

Fishing Activity ◽

Widespread Occurrence ◽

Fisheries Resources ◽

Spatial Shift ◽

Landing Sites ◽

The Indian Ocean ◽

Spatio Temporal

Protein from fish is essential for feeding the world’s population and is increasingly recognized as critical for food security. To ensure that fisheries resources can be sustainably maintained, fisheries management must be appropriately implemented. When logbook and landing records data are not complete or are incorrect, it is challenging to have an accurate understanding of catch volume. Focusing on Indonesian longline vessels operating in the Indian Ocean from 2012–2019 (n = 1124 vessels), our aims were to (1) assess compliance through identification of landing sites and potentially illicit behavior inferred by interruptions in VMS transmission, and (2) understand how the fishery operates along with quantifying the spatio-temporal distribution of fishing intensity by applying a Hidden Markov Model, which automatically classified each VMS position as fishing, steaming and anchoring. We found vessel compliance gaps in 90% of vessels in the dataset. Compliance was questionable due both to the widespread occurrence of long intermissions in relaying VMS positions (mean = 17.8 h, n = 973 vessels) and the use of unauthorized landing sites. We also observed substantial changes in fishing effort locations among years. The introduction of regulatory measures during the study period banning transshipment and foreign vessels may be responsible for the spatial shift in fishing activity we observed, from encompassing nearly the whole Indian Ocean to more recent intense efforts off western Sumatra and northern Australia.

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Spatio-temporal distribution of chlorophyll-a in relation to physico-chemical parameters in coastal waters of the northwestern Bay of Bengal

Environmental Monitoring and Assessment ◽

10.1007/s10661-015-4660-x ◽

2015 ◽

Vol 187 (7) ◽

Cited By ~ 13

Author(s):

S. K. Baliarsingh ◽

Aneesh A. Lotliker ◽

K. C. Sahu ◽

T. Sinivasa Kumar

Keyword(s):

Chlorophyll A ◽

Bay Of Bengal ◽

Coastal Waters ◽

Temporal Distribution ◽

Chemical Parameters ◽

Physico Chemical ◽

Spatio Temporal

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The Horizontal Distribution of Siliceous Planktonic Radiolarian Community in the Eastern Indian Ocean

Water ◽

10.3390/w12123502 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3502

Author(s):

Sonia Munir ◽

John Rogers ◽

Xiaodong Zhang ◽

Changling Ding ◽

Jun Sun

Keyword(s):

Indian Ocean ◽

Chlorophyll A ◽

Mixed Layer ◽

Diversity Index ◽

Horizontal Distribution ◽

Eastern Indian Ocean ◽

Entire Area ◽

Factors Affecting ◽

Major Factors ◽

First Time

The plankton radiolarian community was investigated in the spring season during the two-month cruise ‘Shiyan1’ (10 April–13 May 2014) in the Eastern Indian Ocean. This is the first comprehensive plankton tow study to be carried out from 44 sampling stations across the entire area (80.00°–96.10° E, 10.08° N–6.00° S) of the Eastern Indian Ocean. The plankton tow samples were collected from a vertical haul from a depth 200 m to the surface. During the cruise, conductivity–temperature–depth (CTD) measurements were taken of temperature, salinity and chlorophyll a from the surface to 200 m depth. Shannon–Wiener’s diversity index (H’) and the dominance index (Y) were used to analyze community structure. There was a total of 168 plankton species, composed of Acantharia, Phaeodaria, Polycystina, Collodaria and Taxopodida (monospecific—Sticholonche zanclea, Hertwig is the only recognized species). Hence, it included both celestine-based and siliceous organisms, which are also described here for the first time from this region. Total radiolarians ranged from 5 to 5500 ind/m−3, dominated by co-occurrences of Sphaerozoum punctatum and Stichonche zanclea species at the south-equator zone (SEQ)-transect 80° E and equator zone (EQ)-transect Lati-0. The possible environmental variables were tested through RDA analysis; although no result was obtained for the full species dataset, the samples from the equatorial transect related strongly to mixed-layer chlorophyll a concentration and those of a north–south transect to surface silicate concentrations or mixed-layer nitrate were significantly correlated (p < 0.01) to the radiolarian community. Our results indicate that the silicate and chlorophyll-a concentrations are the two major factors affecting the radiolarian distribution along two of the investigated transects (southern equator and equator) in the study area.

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