scholarly journals Underlying environmental factors and geomagnetic fields linked to 45 pilot whales Globicephala macrorhynchus stranding in Modung white beach, Indonesian coast on 19th February 2021

2021 ◽  
Author(s):  
Andri A Wibowo
Keyword(s):  
Environmental Factors ◽  
Geomagnetic Field ◽  
Algal Blooms ◽  
Sediment Load ◽  
Underwater Noise ◽  
Pilot Whale ◽  
Geomagnetic Fields ◽  
Magnetic Field Change ◽  
Pilot Whales ◽  
Sentinel 2

The reason whale and dolphin stranding is not fully understood and it is not linked to a standalone variable. Theories assume intertwined factors including sickness, underwater noise, navigational error, geographical features, the presence of predators, poisoning from pollution or algal blooms, geomagnetic field, and extreme weather are responsible to whale stranding. On 19th February 2021, a pod consists of 45 pilot whales Globicephala macrorhynchus was stranded in a remote 7050 m2 Modung white beach of Indonesian coast. This paper aims to assess the environmental factors that may be can explain and link to this stranding cases. Those factors include bathymetry, plankton cell density measured using MODIS, water sediment load measured using Sentinel 2 Bands 4,3,1, vessel traffic, precipitation (inch) and thunder (CAPE index J/kg), water salinity and temperature, and geomagnetic field (nT). The results show the water near stranding sites were shallow, has sediment load, high plankton density, warmer, receiving torrential rain prior stranding, having weak geomagnetic field and high total magnetic field change/year. The combination of those environmental covariates may influence the behavior, navigation, and echolocation of the said stranded pilot whale.

scholarly journals Hindcast and Near Real-Time Monitoring of Green Macroalgae Blooms in Shallow Coral Reef Lagoons Using Sentinel-2: A New-Caledonia Case Study

2021 ◽  
Vol 13 (2) ◽  
pp. 211
Author(s):  
Maële Brisset ◽  
Simon Van Wynsberge ◽  
Serge Andréfouët ◽  
Claude Payri ◽  
Benoît Soulard ◽  
...  
Keyword(s):  
Green Algae ◽  
Algal Blooms ◽  
New Caledonia ◽  
Spectral Indices ◽  
Green Macroalgae ◽  
Spectral Bands ◽  
Algae Blooms ◽  
Trade Offs ◽  
Sentinel 2

Despite the necessary trade-offs between spatial and temporal resolution, remote sensing is an effective approach to monitor macroalgae blooms, understand their origins and anticipate their developments. Monitoring of small tropical lagoons is challenging because they require high resolutions. Since 2017, the Sentinel-2 satellites has provided new perspectives, and the feasibility of monitoring green algae blooms was investigated in this study. In the Poé-Gouaro-Déva lagoon, New Caledonia, recent Ulva blooms are the cause of significant nuisances when beaching. Spectral indices using the blue and green spectral bands were confronted with field observations of algal abundances using images concurrent with fieldwork. Depending on seabed compositions and types of correction applied to reflectance data, the spectral indices explained between 1 and 64.9% of variance. The models providing the best statistical fit were used to revisit the algal dynamics using Sentinel-2 data from January 2017 to December 2019, through two image segmentation approaches: unsupervised and supervised. The latter accurately reproduced the two algal blooms that occurred in the area in 2018. This paper demonstrates that Sentinel-2 data can be an effective source to hindcast and monitor the dynamics of green algae in shallow lagoons.

scholarly journals Comparison of <i>H</i> component geomagnetic field time series obtained at different sites over South America

2018 ◽  
Vol 36 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Maurício J. A. Bolzan ◽  
Clezio M. Denardini ◽  
Alexandre Tardelli
Keyword(s):  
South America ◽  
Geomagnetic Field ◽  
Phase Coherence ◽  
South American ◽  
Data Set ◽  
Geomagnetism And Paleomagnetism ◽  
Strong Phase ◽  
Geomagnetic Fields ◽  
Time Variations ◽  
Physical Phenomena

Abstract. The geomagnetic field in the Brazilian sector is influenced by the South American Magnetic Anomaly (SAMA) that causes a decrease in the magnitude of the local geomagnetic field when compared to other regions in the world. Thus, the magnetometer network and data set of space weather over Brazil led by Embrace are important tools for promoting the understanding of geomagnetic fields over Brazil. In this sense, in this work we used the H component of geomagnetic fields obtained at different sites in South America in order to compare results from the phase coherence obtained from wavelet transform (WT). Results from comparison between Cachoeira Paulista (CXP) and Eusébio (EUS), and Cachoeira Paulista and São Luis (SLZ), indicated that there exist some phenomena that occur simultaneously in both locations, putting them in the same phase coherence. However, there are other phenomena putting both locations in a strong phase difference as observed between CXP and Rio Grande, Argentina (RGA). This study was done for a specific moderate geomagnetic storm that occurred in March 2003. The results are explained in terms of nonlinear interaction between physical phenomena acting in distinct geographic locations and at different times and scales. Keywords. Geomagnetism and paleomagnetism (time variations – diurnal to secular)

scholarly journals Love-iathan, the meat-whale and hidden people: ordering Faroese pilot whaling

2016 ◽  
Vol 23 (1) ◽  
pp. 26 ◽  
Author(s):  
Benedict E. Singleton
Keyword(s):  
News Item ◽  
Faroe Islands ◽  
Political Ontology ◽  
Pilot Whale ◽  
Environmental Dispute ◽  
Pilot Whales ◽  
Ocean Environment

A key question in any environmental dispute is the nature of what is under discussion. 'Cosmopolitics' – political battles over the form of reality – are a feature of many environmental clashes. This article focuses on one such clash: during the summer of 2014, grindadráp – the iconic practice of driving pilot whales for meat – was the big news item in the Faroe Islands. More accurately, a conservation campaign by the controversial group Sea Shepherd Conservation Society (SSCS), Operation Grindstop 2014, garnered most attention. Aiming to stop or at least disrupt the 'barbaric' and 'sadistic' grindadráp, SSCS were involved in several confrontations with Faroese authorities and publicly engaged with Faroese pro-whaling advocates in several discussions that were seemingly fruitless. Based on 3 months fieldwork during the campaign, this article describes a 'political ontology' of Grindstop 2014. What emerged was a 'hybrid' born of a clash between two fundamentally dissonant systems of ordering, which structured and were reinforced by various practices, both discursive and material. Activists on both sides were engaged in a cosmopolitical struggle to decisively enact their orderings, creating alternative stories of whales, Faroese whaling, the ocean environment and modernity. The aim is to understand what happened when these orderings met. This article argues that throughout the summer these two orderings moved apart, consequently hiding the diversity of opinion and discussion within Faroese society around grindadráp. As such, alternative orderings of grindadráp were suppressed, notably those voiced by Faroese activists arguing that the practice should cease because of the high levels of toxins in pilot whale meat.Key words: Faroe Islands, whaling, political ontology, cosmopolitics

scholarly journals Influence of Seasonal Environmental Variables on the Distribution of Presumptive Fecal Coliforms around an Antarctic Research Station

2003 ◽  
Vol 69 (8) ◽  
pp. 4884-4891 ◽  
Author(s):  
Kevin A. Hughes
Keyword(s):  
Environmental Factors ◽  
Solar Radiation ◽  
Sea Ice ◽  
Fecal Coliform ◽  
Algal Blooms ◽  
Austral Summer ◽  
Fecal Coliforms ◽  
Late Winter ◽  
Research Station ◽  
The Antarctic

ABSTRACT Factors affecting fecal microorganism survival and distribution in the Antarctic marine environment include solar radiation, water salinity, temperature, sea ice conditions, and fecal input by humans and local wildlife populations. This study assessed the influence of these factors on the distribution of presumptive fecal coliforms around Rothera Point, Adelaide Island, Antarctic Peninsula during the austral summer and winter of February 1999 to September 1999. Each factor had a different degree of influence depending on the time of year. In summer (February), although the station population was high, presumptive fecal coliform concentrations were low, probably due to the biologically damaging effects of solar radiation. However, summer algal blooms reduced penetration of solar radiation into the water column. By early winter (April), fecal coliform concentrations were high, due to increased fecal input by migrant wildlife, while solar radiation doses were low. By late winter (September), fecal coliform concentrations were high near the station sewage outfall, as sea ice formation limited solar radiation penetration into the sea and prevented wind-driven water circulation near the outfall. During this study, environmental factors masked the effect of station population numbers on sewage plume size. If sewage production increases throughout the Antarctic, environmental factors may become less significant and effective sewage waste management will become increasingly important. These findings highlight the need for year-round monitoring of fecal coliform distribution in Antarctic waters near research stations to produce realistic evaluations of sewage pollution persistence and dispersal.

AN ANALYTICAL SOLUTION OF THE COSMIC RAYS TRANSPORT EQUATION IN THE PRESENCE OF THE GEOMAGNETIC FIELD

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1645-1653
Author(s):  
MARINA GIBILISCO
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Analytical Solution ◽  
Transport Equation ◽  
Geomagnetic Field ◽  
The Earth ◽  
Factorization Technique ◽  
Diffusion Motion ◽  
Geomagnetic Fields ◽  
The Magnetic Field

In this work, I study the propagation of cosmic rays inside the magnetic field of the Earth, at distances d ≤ 500 Km from its surface; at these distances, the geomagnetic field deeply influences the diffusion motion of the particles. I compare the different effects of the interplanetary and of the geomagnetic fields, by also discussing their role inside the cosmic rays transport equation; finally, I present an analytical method to solve such an equation through a factorization technique.

Viewpoints of Dominant Environmental Factors Influencing Algal Blooms

2011 ◽  
Vol 66-68 ◽  
pp. 155-159
Author(s):  
Di Guan ◽  
Da Wen Gao ◽  
Nan Qi Ren ◽  
Yi Fan Li
Keyword(s):  
Environmental Factors ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Meteorological Factors ◽  
Chlorophyll Concentration ◽  
Phytoplankton Growth ◽  
High Biomass ◽  
Coupling Effects ◽  
Factors Influencing

Harmful algal blooms (HABs) are generally known as excessive phytoplankton growth or rapidly concentrate to high biomass. This study summarized the situation of HABs in China, and discussed possible dominant factors stimulating algal blooms by analyzing several actual HABs cases. It was manifested nutrients may affect algae concentration principally, but such impact tended to decease with degradation of background water. Meanwhile the hydrological and meteorological factors expressed greater correlation to chlorophyll concentration under multiple coupling effects of complex environmental factors. For the complex mechanisms, the determination of principle factors which stimulate excessive algal blooms effectively still need further researches, which are suggested to conduct under overall considerations on 3 scales: macro dimension, medium dimension and micro dimension.

Electrophoretic differentiation among local populations of the long-finned pilot whale, Globicephala melaena, at the Faroe Islands

1988 ◽  
Vol 66 (8) ◽  
pp. 1884-1892 ◽  
Author(s):  
Liselotte Wesley Andersen
Keyword(s):  
Reproductive Isolation ◽  
Muscle Tissue ◽  
Gel Electrophoresis ◽  
Faroe Islands ◽  
Starch Gel Electrophoresis ◽  
Pilot Whale ◽  
Local Populations ◽  
Starch Gel ◽  
Pilot Whales ◽  
Polymorphic Enzymes

Enzyme variation within and between nine schools of long-finned pilot whales, Globicephala melaena, caught at the Faroe Islands, was examined by starch gel electrophoresis. Twenty-seven enzymes were investigated, representing 41 loci, of which three were polymorphic. The polymorphic enzymes were analyzed in either liver or muscle tissue from 628 specimens. No heterogeneity within the schools was observed, while significant differences in allele frequencies between schools were detected by a multilocus G-test. This result indicated some degree of reproductive isolation.

The Analysis of the Deep Sea Geomagnetic Measurement Platform Rotation's Impact on the Measurement Results

2013 ◽  
Vol 367 ◽  
pp. 322-326
Author(s):  
Dan Wang ◽  
Cheng Chi ◽  
Wei Zhen Chen
Keyword(s):  
Magnetic Field ◽  
Deep Sea ◽  
Geomagnetic Field ◽  
Field Detection ◽  
Measurement Results ◽  
The World ◽  
Magnetic Model ◽  
Geomagnetic Fields ◽  
Geomagnetic Measurement ◽  
Three Components

The deep sea magnetic field detection is influenced by the environment of marine and the platform, the influence of the platform is mainly caused by platform rotation. The variation of the geomagnetic fields three-components caused by different directions of the platform rotation are compared by using the World Magnetic Model WMM2010.The results show that the changes of the three-components of the Earth's magnetic field caused by the platform rotation can not be ignored. So the measured results of the deep sea geomagnetic field detection should be compensated. The conclusion can be used for automatic correction of the deep sea magnetic field observation platform.

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