scholarly journals Description of extreme-wave deposits on the northern coast of Bonaire, Netherlands Antilles

2010 ◽  
Author(s):  
Steven G. Watt ◽  
Bruce E. Jaffe ◽  
Robert A. Morton ◽  
Bruce M. Richmond ◽  
Guy Gelfencaum
Keyword(s):  
Northern Coast ◽  
Extreme Wave ◽  
Netherlands Antilles

Assessment of extreme wave flooding from geomorphologic evidence in Bonaire (Netherlands Antilles)

2010 ◽  
Vol 54 (3) ◽  
pp. 219-245 ◽  
Author(s):  
Cosimo Pignatelli ◽  
Anja Scheffers ◽  
Sander Scheffers ◽  
Giuseppe Mastronuzzi
Keyword(s):  
Extreme Wave ◽  
Netherlands Antilles

Extreme wave events recorded in sedimentary archives of the Geropotamos River (north-central Crete, Greece)

2019 ◽  
Vol 62 (2) ◽  
pp. 63-100
Author(s):  
Vera Werner ◽  
Kalliopi Baika ◽  
Anastasia Tzigounaki ◽  
Klaus Reicherter ◽  
Ioannis Papanikolaou ◽  
...  
Keyword(s):  
Bronze Age ◽  
Sedimentary Environment ◽  
River Mouth ◽  
High Energy ◽  
River Valley ◽  
Coarse Grained ◽  
Northern Coast ◽  
Natural Setting ◽  
Extreme Wave ◽  
Cretan Sea

Recent tsunami events have shown that tsunamis may propagate far inland by entering rivers mouths and may cause massive damage along the river banks. However, so far, only a few studies have been conducted such a search for studying tsunami signals in incised valley systems along the Mediterranean coasts although the tsunami hazard is high. The island of Crete is known to have been affected several times by strong tsunamis, e. g., by the AD 365 and the Late Bronze Age (LBA) Santorini tsunamis. The narrow Geropotamos River valley, distinctly incised into local bedrock and located at the northern coast of Crete and fully exposed to the Cretan Sea, was selected as a promising natural setting to search for palaeotsunami signatures in fluvial sedimentary archives. Based on a multi-electrode geoelectrical survey and a set of sediment cores, we investigated the event-geochronostratigraphic record of both the Geropotamos River mouth area and the river valley ca. 1 km upstream by means of sedimentological, geo-chemical, geochronological, geomorphological, and micropalaeontological methods. The sedimentary environment towards the present-day river mouth is dominated by (fluvio-)lagoonal muds since the mid- Holocene. These lagoonal sediments are intersected by six coarse-grained sand layers each representing an extreme wave event (EWE). EWE layers are up to several decimetres thick and are characterized by an allochthonous foraminiferal assemblage comprising shallow marine to open marine species. Also ca. 1 km further upstream, the sedimentary record revealed grain size and microfossil evidence of two high-energy events showing a clear marine imprint. Based on this, we suggest inundation from the seaside that reached minimum 1 km inland and left EWE signatures in a presently inactive external bank position of the Geropotamos River. Considering the sedimentary characteristics, the local wind and wave climate of the Cretan Sea, and the overall geomorphological setting, we interpret these EWE layers as tsunami- related. A major hiatus identified in the Geropotamos River mouth sediments seems to be related to the LBA Santorini tsunami as can be inferred based on local age-depth relations. The LBA tsunami is known to have severely hit the northern coast of Crete. However, the hiatus may also reflect changes in the subsidence rate and the local accommodation space architecture. The youngest EWE signal in the Geropotamos River archive appears to have been caused by the AD 365 tsunami event. Candidate deposits for both tsunami deposits were identified ca. 1 km further inland. Evidence of EWE impact documents channelling and acceleration effects of intruding water masses caused by the narrow and steeply incised Geropotamos River valley in an upstream direction. Further geochronological studies based on OSL dating are necessary for a reliable age control of these EWE candidate layers.

Redescription of Orthopristis ruber and Orthopristis scapularis (Haemulidae: Perciformes), with a hybridization zone off the Atlantic coast of South America

Zootaxa ◽  
2019 ◽  
Vol 4576 (1) ◽  
pp. 109 ◽  
Author(s):  
ALEXANDRE PIRES MARCENIUK ◽  
RODRIGO ANTUNES CAIRES ◽  
LEONARDO MACHADO ◽  
NAJILA NOLIE CATARINE DANTAS CERQUEIRA ◽  
RAYLA ROBERTA M. DE S. SERRA ◽  
...  
Keyword(s):  
South America ◽  
Nuclear Dna ◽  
Atlantic Coast ◽  
Morphological Characteristics ◽  
Distinct Species ◽  
Valid Species ◽  
Brazilian Coast ◽  
Northern Coast ◽  
Western Atlantic ◽  
Coloration Patterns

The genus Orthopristis includes seven valid species, three from the western Atlantic and five from eastern Pacific, while the available identification guides and taxonomic keys incorrectly recognize Orthopristis ruber as the only valid species found on the Atlantic coast of South America. Efforts to expand the inventory of fish species from the northern coast of Brazil led to the identification of two distinct species of Orthopristis from Atlantic South America, based on the analysis of coloration patterns and meristic data, as well as DNA. In the present study, the limits of Orthopristis ruber are reviewed, while Orthopristis scapularis is recognized as a valid species for the northern and northeastern coasts of South America. Based on intermediate morphological characteristics and nuclear DNA markers, a hybrid zone was identified off the state of Espírito Santo, on the eastern Brazilian coast. Additionally, considerations are made on the diversity and biogeography of the coastal marine and estuarine fishes found on the Brazilian coast. 

scholarly journals LC–MS/MS Analysis of Ciguatoxins Revealing the Regional and Species Distinction of Fish in the Tropical Western Pacific

2021 ◽  
Vol 9 (3) ◽  
pp. 299 ◽  
Author(s):  
Naomasa Oshiro ◽  
Takumi Tomikawa ◽  
Kyoko Kuniyoshi ◽  
Akira Ishikawa ◽  
Hajime Toyofuku ◽  
...  
Keyword(s):  
Fish Species ◽  
The Philippines ◽  
Western Pacific ◽  
Tropical Region ◽  
Northern Coast ◽  
Coastal Regions ◽  
Main Island ◽  
Tropical Western Pacific ◽  
The Pacific ◽  
Fish Samples

Ciguatera fish poisoning (CFP) is one of the most frequently reported seafood poisoning diseases. It is endemic to the tropical region and occurs most commonly in the regions around the Pacific Ocean, Indian Ocean, and Caribbean Sea. The principal toxins causing CFP are ciguatoxins (CTXs). In the Pacific region, more than 20 analogs of CTXs have been identified to date. Based on their skeletal structures, they are classified into CTX1B-type and CTX3C-type toxins. We have previously reported species-specific and regional-specific toxin profiles. In this study, the levels and profiles of CTXs in fish present in the tropical western Pacific regions were analyzed using the liquid chromatography–tandem mass spectrometry (LC–MS/MS) technique. Forty-two fish specimens, belonging to the categories of snappers, groupers, Spanish mackerel, and moray eel, were purchased from various places such as Fiji, the Philippines, Thailand, and Taiwan. Only the fish captured from Fijian coastal waters contained detectable amounts of CTXs. The toxin levels in the fish species found along the coastal regions of the Viti Levu Island, the main island in Fiji, and the toxin profiles were significantly different from those of the fish species present in other coastal regions. The toxin levels and profiles varied among the different fish samples collected from different coastal areas. Based on the toxin levels and toxin profiles, the coast was demarcated into three zones. In Zone-1, which covers the northern coast of the main island and the regions of the Malake Island and Korovau, CTXs in fish were below the detection level. In Zone-2, CTX3C-type toxins were present in low levels in the fish. CTX1B-type and CTX3C-type toxins co-occurred in the fish present in Zone-3. The toxin profiles may have reflected the variation in Gambierdiscus spp.

Sign in / Sign up

Export Citation Format

Share Document