scholarly journals Long-Term Patterns of Noise From Underwater Explosions and Their Relation to Fisheries in Southern California

2021 ◽  
Vol 8 ◽  
Author(s):  
Anna Krumpel ◽  
Ally Rice ◽  
Kaitlin E. Frasier ◽  
Fairlie Reese ◽  
Jennifer S. Trickey ◽  
...  
Keyword(s):  
Southern California ◽  
Temporal Patterns ◽  
Purse Seine ◽  
Economic Losses ◽  
Negative Effects ◽  
Underwater Explosions ◽  
Marine Life ◽  
Spatio Temporal ◽  
Passive Acoustic

Acoustic deterrents can reduce marine mammal interactions with fisheries and aquacultures, but they contribute to an increasing level of underwater noise. In Southern California, commercially produced explosive deterrents, commonly known as “seal bombs,” are used to protect fishing gear and catch from pinniped predation, which can cause extensive economic losses for the fishing community. Passive acoustic monitoring data collected between 2005 and 2016 at multiple sites within the Southern California Bight and near Monterey Bay revealed high numbers of these small-charge underwater explosions, long-term, spatio-temporal patterns in their occurrence, and their relation to different commercial purse-seine fishing sectors. The vast majority of explosions occurred at nighttime and at many nearshore sites high explosion counts were detected, up to 2,800/day. Received sound exposure levels of up to 189 dB re 1 μPa2-s indicate the potential for negative effects on marine life, especially in combination with the persistence of recurring explosions during periods of peak occurrence. Due to the highly significant correlation and similar spatio-temporal patterns of market squid landings and explosion occurrence at many sites, we conclude that the majority of the recorded explosions come from seal bombs being used by the California market squid purse-seine fishery. Additionally, seal bomb use declined over the years of the study, potentially due to a combination of reduced availability of market squid driven by warm water events in California and regulation enforcement. This study is the first to provide results on the distribution and origin of underwater explosions off Southern California, but there is a substantial need for further research on seal bomb use in more recent years and their effects on marine life, as well as for establishing environmental regulations on their use as a deterrent.

scholarly journals Imaging spatio-temporal patterns of long-term potentiation in mouse hippocampus

2003 ◽  
Vol 358 (1432) ◽  
pp. 689-693 ◽  
Author(s):  
Toshiyuki Hosokawa ◽  
Masaki Ohta ◽  
Takeshi Saito ◽  
Alan Fine
Keyword(s):  
Hippocampal Slices ◽  
Temporal Patterns ◽  
Long Term Potentiation ◽  
Optical Recording ◽  
Stratum Radiatum ◽  
High Frequency Stimulation ◽  
Optical Signals ◽  
Term Potentiation ◽  
Spatio Temporal

Spatio-temporal patterns of neuronal activity before and after the induction of long-term potentiation in mouse hippocampal slices were studied using a real-time high-resolution optical recording system. After staining the slices with voltage-sensitive dye, transmitted light images and extracellular field potentials were recorded in response to stimuli applied to CA1 stratum radiatum. Optical and electrical signals in response to single test pulses were enhanced for at least 30 minutes after brief high-frequency stimulation at the same site. In two-pathway experiments, potentiation was restricted to the tetanized pathway. The optical signals demonstrated that both the amplitude and area of the synaptic response were increased, in patterns not predictable from the initial, pretetanus, pattern of activation. Optical signals will be useful for investigating spatio-temporal patterns of synaptic enhancement underlying information storage in the brain.

scholarly journals Red hind Epinephelus guttatus Vocal Repertoire Characterization, Behavior and Temporal Patterns

2020 ◽  
Vol 31 ◽  
pp. GCFI31-GCFI41
Author(s):  
Carlos M. Zayas Santiago ◽  
Richard S. Appeldoorn ◽  
Michelle T. Schärerer-Umpierre ◽  
Juan J. Cruz-Motta
Keyword(s):  
Low Frequency ◽  
Temporal Patterns ◽  
Spawning Aggregations ◽  
Red Hind ◽  
In Captivity ◽  
In The Wild ◽  
Epinephelus Guttatus ◽  
Spatio Temporal ◽  
Passive Acoustic ◽  
Female Call

Passive acoustic monitoring provides a method for studying grouper courtship associated sounds (CAS). For Red Hind (Epinephelus guttatus), this approach has documented spatio—temporal patterns in their spawning aggregations. This study described vocalizations produced by E. guttatus and their respective behavioral contexts in field and laboratory studies. Five sound types were identified, which included 4 calls recorded in captivity and one sound recorded in the wild, labeled as Chorus. Additionally, the Grunt call type recorded was presumed to be produced by a female. Call types consisted of variations and combinations of low frequency (50—450 Hz) pulses, grunts and tonal sounds in different combinations. Common call types exhibited diel and lunar oscillations during the spawning season, with both field and captive recordings peaking daily at 1800 AST and at 8 days after the full moon.

scholarly journals Spatio-temporal patterns of attacks on human and economic losses from wildlife in Chitwan National Park, Nepal

PLoS ONE ◽  
2018 ◽  
Vol 13 (4) ◽  
pp. e0195373 ◽  
Author(s):  
Babu Ram Lamichhane ◽  
Gerard A. Persoon ◽  
Herwig Leirs ◽  
Shashank Poudel ◽  
Naresh Subedi ◽  
...  
Keyword(s):  
National Park ◽  
Temporal Patterns ◽  
Economic Losses ◽  
Chitwan National Park ◽  
Spatio Temporal

scholarly journals A Spatio-Temporal Analysis of Active Fires over China during 2003–2016

2020 ◽  
Vol 12 (11) ◽  
pp. 1787
Author(s):  
Xikun Wei ◽  
Guojie Wang ◽  
Tiexi Chen ◽  
Daniel Fiifi Tawia Hagan ◽  
Waheed Ullah
Keyword(s):  
Land Cover ◽  
Seasonal Variations ◽  
Urban Areas ◽  
Atmospheric Environment ◽  
Economic Losses ◽  
Change Analysis ◽  
Land Cover Types ◽  
North East ◽  
Spatio Temporal

Fire is a common circumstance in the world. It causes direct casualties and economic losses, and also brings severe negative influences on the atmospheric environment. In the background of climate warming and rising population, it is important to understand the fire responses regarding the spatio-temporal changes. Thus, a long-term change analysis of fires is needed in China. We use the remote sensed MOD14A1/MYD14A1 fire products to analyze the seasonal variations and long-term trends, based on five main land cover types (forest, cropland, grassland, savannas and urban areas). The fires are found to have clear seasonal variations; there are more fires in spring and autumn in vegetated lands, which are related to the amount of dry biomass and temperature. The fire numbers have significantly increased during the study period, especially from spring to autumn, and those have decreased in winter. The long-term fire trends are different when delineated into different land cover types. There are significant increasing fire trends in grasslands and croplands in North, East and Northeast China during the study period. The urban fires also show increasing trends. On the contrary, there are significant decreasing fire trends in forests and savannas in South China where it is most densely vegetated. This study provides an overall analysis of the spatio-temporal fire changes from satellite products, and it may help to understand the fire risk in the changing climate for a better risk management.

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