scholarly journals Occurrence of Trichodesmium Erythraeum (Cyanophyte) Bloom and Its Effects on the Fish Catch during April 2013, in the Andaman Sea

2015 ◽  
pp. 49-57 ◽  
Author(s):  
Arun Kumar ◽  
Gadi Padmavati ◽  
Hosahalli Pradeep
Keyword(s):  
Surface Temperature ◽  
Growth Phase ◽  
Significant Variation ◽  
Algal Bloom ◽  
Atmospheric Temperature ◽  
Sea Surface ◽  
Andaman Sea ◽  
Fish Populations ◽  
Trichodesmium Erythraeum ◽  
Fish Catch

A highly intense bloom of the nitrogen fixing Cyanobacteria Trichodesmium erythraeum(~7,000 filaments l-1) was observed during April 2013 (for a period of 5 days) in the Andaman Sea, at Lat.10°-13°N and Long. 93°-95°E.This is the first report of this bloom in the open waters of this region. Atmospheric temperature at the time ranged from 27 to 30.5 °C, sea surface temperature ranged from 29 to 34 °C, and salinity values ranged from 32.5 to 34 psu. However, there was no significant variation in pH (8.1-8.3), and DO concentrations ranged from 4.7 to 5.5 mg L-1during the studyperiod. Phosphate values ranged from 0.07 μmol L-1to 0.57 μ mol L-1, silicate values ranged from 1.7 to 2.7 μmol L-1, nitrate levels were very low (0.3-0.57 μmol L-1). At this time, the biomass of Trichodesmium erythraeum was high, indicating the bloom was in a growth phase. An upsurge in water temperature was found to explain the bloom, together with an increase in salinity. The hooking rate of fish ranged from 0 to 0.32%. However, in the study area with the highest density of the bloom, almost zero fish catch was recorded, clearly indicating the harmful impact of this algal bloom on fish populations and their distribution pattern.

Variations in the feeding success and behaviour of Galápagos sperm whales (Physeter macrocephalus) as they relate to oceanographie conditions

1993 ◽  
Vol 71 (10) ◽  
pp. 1991-1996 ◽  
Author(s):  
Sean C. Smith ◽  
Hal Whitehead
Keyword(s):  
Surface Temperature ◽  
Significant Variation ◽  
Foraging Behaviour ◽  
Geographic Area ◽  
Sea Surface ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Feeding Success ◽  
Galapagos Archipelago ◽  
Oceanographic Conditions

The feeding success of sperm whales off the Galápagos Islands, Ecuador, was examined over 5 study years; 1985, 1987, 1988, 1989, and 1991. A total of 160 days were spent following sperm whales at sea. The defaecation rates of sperm whales were used as an indication of feeding success. The recorded acoustic click rates of sperm whales were used as an indication of aggregative and foraging behaviour. Significant variation in feeding success occurred temporally over periods of days, months, and years. Feeding success also varied spatially with geographic area. Feeding success was inversely related to sea surface temperature (SST). The foraging and associative behaviour of sperm whales also varied with feeding success, SST, and by year. Variations in the feeding success and behaviour of Galápagos sperm whales can likely be attributed to changing oceanographic conditions in the waters surrounding the Galápagos archipelago.

scholarly journals RFI and Remote Sensing of the Earth From Space

2019 ◽  
Vol 08 (01) ◽  
pp. 1940001 ◽  
Author(s):  
David M. Le Vine
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
Surface Temperature ◽  
Microwave Remote Sensing ◽  
Atmospheric Temperature ◽  
Passive Microwave ◽  
Sea Surface ◽  
Radio Frequency Interference ◽  
Passive Microwave Remote Sensing ◽  
The Earth

Passive microwave remote sensing of the Earth from space provides information essential for understanding the Earth’s environment and its evolution. Parameters such as soil moisture, sea surface temperature and salinity, and profiles of atmospheric temperature and humidity are measured at frequencies determined by the physics (e.g. sensitivity to changes in desired parameters) and by the availability of suitable spectrum free from interference. Interference from man-made sources (radio frequency interference) is an impediment that in many cases limits the potential for accurate measurements from space. A review is presented here of the frequencies employed in passive microwave remote sensing of the Earth from space and of the associated experience with RFI and contemporary approaches to address the problem.

scholarly journals THE VULNERABILITY STUDY OF LEMURU (SARDINELLA LEMURU) FISH RESOURCES SUSTAINABILITY IN BALI STRAIT IN CORELLATION WITH ENSO AND IOD

2017 ◽  
Vol 11 (2) ◽  
pp. 140
Author(s):  
Candra Saputra ◽  
I Wayan Arthana ◽  
I Gede Hendrawan
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
El Niño ◽  
Strong Influence ◽  
El Nino ◽  
Southern Oscillation ◽  
Sea Surface ◽  
Fish Catch ◽  
The Relationship

The aim of this research is to know the relationship between lemuru fish catch to Sea Surface Temperature (SST), El-Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) phenomenon in Bali Strait. The results showed, that in the period 2007 – 2016. fluctuations of catches lemuru tends to decline. Sea Surface Temperature (SST) distribution with the lowest temperature 25,28oC at 24,53oC - 27,16oC and the highest temperature is 29,31oC in the range of 28,730C – 30,490C. The lowest temperature occurred in July - September while the highest temperature occurred in January - April. Based on the calculation there is a linkage and relationship between catch and SST as shown on the value of determination and correlation reached 50,0% and 70,73%. Most of the catches occurred in the west season and then the transition II, transition I and East Season. The relationship of ENSO phenomenon to the catch during the El-Nino phase of lemuru catch will increase while in the phase of La-Nina the catch of lemuru will decrease, because time of El-Nino phase of the sea surface temperature (SST) relative low which results in the chlorophyll-a mean case which is a food sources of lemuru fish. Based on Trenberth's theory, (1997), the rise and fall of the ENSO Index of less than six months is not stated in ENSO. From the calculation results during the research of 2007 - 2016 happened three times ENSO phenomenon that is in 2009, 2010 and 2015. At the time of the IOD phenomenon, the IOD (+) phase will result in a decrease in catch while the normal IOD phase and (-) will increase the catch. From the results of this study can also be observed, in the year 2007 - 2011 phenomenon ENSO and IOD have a strong influence on the catch while in the year 2012 - 2016 the influence of the phenomenon of ENSO and IOD has no strong influence caused by the quantity of lemuru fish that have been over exploitation that resulted in the current Bali Strait on Over Fishing status.   Keywords : Fish Catch; El-Nino Southern Oscillation (ENSO); Indian Ocean                    Dipole (IOD)

scholarly journals Long-Term Sea Surface Temperature Variability along the U.S. East Coast

2010 ◽  
Vol 40 (5) ◽  
pp. 1004-1017 ◽  
Author(s):  
R. Kipp Shearman ◽  
Steven J. Lentz
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
East Coast ◽  
Atmospheric Temperature ◽  
Coastal Ocean ◽  
Temperature Trend ◽  
Sea Surface ◽  
Temperature Trends ◽  
Cape Hatteras

Abstract Sea surface temperature variations along the entire U.S. East Coast from 1875 to 2007 are characterized using a collection of historical observations from lighthouses and lightships combined with recent buoy and shore-based measurements. Long-term coastal temperature trends are warming in the Gulf of Maine [1.0° ± 0.3°C (100 yr)−1] and Middle Atlantic Bight [0.7° ± 0.3°C (100 yr)−1], whereas trends are weakly cooling or not significant in the South Atlantic Bight [−0.1° ± 0.3°C (100 yr)−1] and off Florida [−0.3° ± 0.2°C (100 yr)−1]. Over the last century, temperatures along the northeastern U.S. coast have warmed at a rate 1.8–2.5 times the regional atmospheric temperature trend but are comparable to warming rates for the Arctic and Labrador, the source of coastal ocean waters north of Cape Hatteras (36°N). South of Cape Hatteras, coastal ocean temperature trends match the regional atmospheric temperature trend. The observations and a simple model show that along-shelf transport, associated with the mean coastal current system running from Labrador to Cape Hatteras, is the mechanism controlling long-term temperature changes for this region and not the local air–sea exchange of heat.

scholarly journals Mangrove Phenology and Environmental Drivers Derived from Remote Sensing in Southern Thailand

2019 ◽  
Vol 11 (8) ◽  
pp. 955 ◽  
Author(s):  
Veeranun Songsom ◽  
Werapong Koedsin ◽  
Raymond J. Ritchie ◽  
Alfredo Huete
Keyword(s):  
Surface Temperature ◽  
Tropical Forests ◽  
Vegetation Index ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Andaman Sea ◽  
Environmental Drivers ◽  
Gulf Of Thailand ◽  
The Gulf Of Thailand ◽  
Study Sites

Vegetation phenology is the annual cycle timing of vegetation growth. Mangrove phenology is a vital component to assess mangrove viability and includes start of season (SOS), end of season (EOS), peak of season (POS), and length of season (LOS). Potential environmental drivers include air temperature (Ta), surface temperature (Ts), sea surface temperature (SST), rainfall, sea surface salinity (SSS), and radiation flux (Ra). The Enhanced vegetation index (EVI) was calculated from Moderate Resolution Imaging Spectroradiometer (MODIS, MOD13Q1) data over five study sites between 2003 and 2012. Four of the mangrove study sites were located on the Malay Peninsula on the Andaman Sea and one site located on the Gulf of Thailand. The goals of this study were to characterize phenology patterns across equatorial Thailand Indo-Malay mangrove forests, identify climatic and aquatic drivers of mangrove seasonality, and compare mangrove phenologies with surrounding upland tropical forests. Our results show the seasonality of mangrove growth was distinctly different from the surrounding land-based tropical forests. The mangrove growth season was approximately 8–9 months duration, starting in April to June, peaking in August to October and ending in January to February of the following year. The 10-year trend analysis revealed significant delaying trends in SOS, POS, and EOS for the Andaman Sea sites but only for EOS at the Gulf of Thailand site. The cumulative rainfall is likely to be the main factor driving later mangrove phenologies.

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