scholarly journals New record of the Red scorpionfish, Scorpaena scrofa (Actinopterygii: Scorpaeniformes: Scorpaenidae) from deep waters off Israel, Gulf of Aqaba, Red Sea

2020 ◽  
Vol 50 (3) ◽  
pp. 357-362
Author(s):  
Ronald Fricke ◽  
Daniel Golani ◽  
Brenda Appelbaum-Golani ◽  
Uwe Zajonz
Keyword(s):  
Red Sea ◽  
New Record ◽  
Gulf Of Aqaba ◽  
Deep Waters ◽  
Scorpaena Scrofa

scholarly journals Modelling the biogeochemical effects of heterotrophic and autotrophic N<sub>2</sub> fixation in the Gulf of Aqaba (Israel), Red Sea

2018 ◽  
Vol 15 (24) ◽  
pp. 7379-7401 ◽  
Author(s):  
Angela M. Kuhn ◽  
Katja Fennel ◽  
Ilana Berman-Frank
Keyword(s):  
Water Column ◽  
Red Sea ◽  
N2 Fixation ◽  
Large Scale ◽  
Gulf Of Aqaba ◽  
Nutrient Concentrations ◽  
Nutrient Ratios ◽  
Biogeochemical Models ◽  
Deep Waters ◽  
Direct Measurements

Abstract. Recent studies demonstrate that marine N2 fixation can be carried out without light by heterotrophic N2 fixers (diazotrophs). However, direct measurements of N2 fixation in aphotic environments are relatively scarce. Heterotrophic as well as unicellular and colonial photoautotrophic diazotrophs are present in the oligotrophic Gulf of Aqaba (northern Red Sea). This study evaluates the relative importance of these different diazotrophs by combining biogeochemical models with time series measurements at a 700 m deep monitoring station in the Gulf of Aqaba. At this location, an excess of nitrate, relative to phosphate, is present throughout most of the water column and especially in deep waters during stratified conditions. A relative excess of phosphate occurs only at the water surface during nutrient-starved conditions in summer. We show that a model without N2 fixation can replicate the observed surface chlorophyll but fails to accurately simulate inorganic nutrient concentrations throughout the water column. Models with N2 fixation improve simulated deep nitrate by enriching sinking organic matter in nitrogen, suggesting that N2 fixation is necessary to explain the observations. The observed vertical structure of nutrient ratios and oxygen is reproduced best with a model that includes heterotrophic as well as colonial and unicellular autotrophic diazotrophs. These results suggest that heterotrophic N2 fixation contributes to the observed excess nitrogen in deep water at this location. If heterotrophic diazotrophs are generally present in oligotrophic ocean regions, their consideration would increase current estimates of global N2 fixation and may require explicit representation in large-scale models.

scholarly journals Biogeochemical evidence of heterotrophic N<sub>2</sub> fixation in the Gulf of Aqaba (Israel), Red Sea

2018 ◽  
Author(s):  
Angela M. Kuhn ◽  
Katja Fennel ◽  
Ilana Berman-Frank
Keyword(s):  
Water Column ◽  
Red Sea ◽  
N2 Fixation ◽  
Large Scale ◽  
Gulf Of Aqaba ◽  
Nutrient Ratios ◽  
Biogeochemical Models ◽  
Deep Waters ◽  
Direct Measurements ◽  
Scale Models

Abstract. Recent studies demonstrate that marine N2 fixation can be carried out without light by heterotrophic N2-fixers (diazotrophs). However, direct measurements of N2 fixation in aphotic environments are relatively scarce. Heterotrophic, as well as unicellular and colonial photoautotrophic diazotrophs, are present in the oligotrophic Gulf of Aqaba (northern Red Sea). This study evaluates the relative importance of these different diazotrophs by combining biogeochemical models with time series measurements at a 700 m-deep monitoring station in the Gulf of Aqaba. At this location, an excess of nitrate is present throughout most of the water column, especially in deep waters during stratified conditions. An excess of phosphate occurs only at the surface during nutrient-starved conditions in summer. We show that a model without N2 fixation can replicate the observed surface chlorophyll, but fails to accurately simulate inorganic nutrient ratios throughout the water column. Models with N2 fixation improve simulated deep nitrate by enriching sinking organic matter in nitrogen, suggesting that N2 fixation is necessary to explain the observations. The observed vertical structure of nutrient ratios and oxygen is reproduced best with a model that includes heterotrophic, and colonial and unicellular autotrophic diazotrophs. These results suggest that heterotrophic N2 fixation explains the observed excess nitrogen in deep water at this location. If heterotrophic diazotrophs are generally present in oligotrophic ocean regions, their consideration would increase current estimates of global N2 fixation and may require explicit representation in large-scale models.

Shrimp-gobies in the southern Gulf of Aqaba (Red Sea)

2012 ◽  
Vol 55 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Mario Freinschlag ◽  
Robert A. Patzner
Keyword(s):  
Red Sea ◽  
Gulf Of Aqaba

Iron and sulphur speciation and cycling in the sediments of marine systems located in the arid environment: Case of the northern Red Sea

2021 ◽  
pp. jgs2021-027
Author(s):  
Valeria Boyko ◽  
Jürgen Pätzold ◽  
Alexey Kamyshny
Keyword(s):  
Red Sea ◽  
Water Depth ◽  
Iron Content ◽  
Gulf Of Aqaba ◽  
Earth System ◽  
Content Type ◽  
Reactive Iron ◽  
The Earth ◽  
Sulphur Cycle ◽  
Supplementary Material

High fluxes of iron minerals associated with aeolian dry deposition may result in anomalously high reactive iron content and fast reoxidation of hydrogen sulphide in the sediments that prevents pyrite formation and results in “cryptic” sulphur cycle. In this work, we studied cycling of iron and sulphur in the deep-water (> 800 m water depth) sediments of the Red Sea and its northern extension, Gulf of Aqaba. We found that reactive iron content in the surface sediments of the Gulf of Aqaba and the Red Sea is high, while the content of sulphur-bound iron is very low and decreases with water depth. The presence of pyrite traces and zero-valent sulfur as well as isotopic compositions of sulphate and pyrite, which are consistent with sulphate reduction under substrate-limiting conditions, suggest that cryptic sulfur cycling is likely to be a result of fast reoxidation of hydrogen sulfide rather than microbial sulfate reduction suppression. In the sediments of Shaban Deep, which are overlain with hyper-saline hydrothermal brine, low reactive iron and high organic carbon contents result in a non-cryptic sulphur cycle characterized by preservation of pyrite in the sediments.Thematic collection: This article is part of the Sulfur in the Earth system collection available at: https://www.lyellcollection.org/cc/sulfur-in-the-earth-systemSupplementary material:https://doi.org/10.6084/m9.figshare.c.5508155

Checklist of the Red Sea Fishes with delineation of the Gulf of Suez, Gulf of Aqaba, endemism and Lessepsian migrants

Zootaxa ◽  
2018 ◽  
Vol 4509 (1) ◽  
pp. 1 ◽  
Author(s):  
DANIEL GOLANI ◽  
RONALD FRICKE
Keyword(s):  
Red Sea ◽  
Endemic Species ◽  
Gulf Of Aqaba ◽  
Gulf Of Suez ◽  
Actual Number ◽  
Suez Gulf ◽  
Number Of Species ◽  
Main Basin ◽  
Lessepsian Migrants ◽  
Current List

The current checklist provides for each species of the Red Sea its records in the Gulf of Suez, Gulf of Aqaba, Red Sea main basin and its general distribution.This new checklist of Red Sea fishes enumerates 1207 species, representing 164 families. Of these, 797 species were recorded from the Gulf of Aqaba and 339 from the Gulf of Suez. The number of species from the Gulf of Suez is evidently lower than the actual number not including 27 Lessepsian (Red Sea) migrants to the Mediterranean that most likely occur in the Gulf. The current list includes 73 species that were newly described for science since the last checklist of 2010. The most specious Osteichthyes families are: Gobiidae (134 species), Labridae (66), Apogonidae (59), Serranidae (including Anthiadinae) (44), Blenniidae (42), Carangidae (38), Muraenidae (36), Pomacentridae (35), Syngnathidae (34), Scorpaenidae (24) and Lutjanidae (23). Among the families of Chondrichthyes, the most specious families are the Carcharhinidae (18 species) and Dasyatidae (11). The total number of endemic species in the Red Sea is 174 species, of these, 34 species are endemic to the Gulf of Aqaba and 8 to the Gulf of Suez. 

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