scholarly journals An analysis of the macroalgal δ<sup>13</sup>C variability in the Gulf of California

2021 ◽  
Author(s):  
Roberto Velázquez-Ochoa ◽  
María Julia Ochoa-Izaguirre ◽  
Martín F. Soto-Jiménez
Keyword(s):  
Environmental Conditions ◽  
Gulf Of California ◽  
Life Form ◽  
Inorganic Carbon ◽  
Subtidal Zone ◽  
Terrestrial Plants ◽  
Shallow Marine ◽  
Habitat Features ◽  
Marine Habitats ◽  
Inorganic Carbon Source

Abstract. The C isotopic composition in macroalgae (δ13C) is highly variable, and its prediction is very complex relative to terrestrial plants. To contribute to the knowledge on the variations and determinants of δ13C-macroalgal, we analyzed a large stock of specimens varying in taxa and morphology and inhabiting shallow marine habitats from the Gulf of California (GC) featured by distinctive environmental conditions. A large δ13C variability (−34.61 ‰ to −2.19 ‰) was observed, mostly explained on the life form (taxonomy, morphology, and structural organization), and modulated by the interaction between habitat features and environmental conditions. The intertidal zone specimens had less negative δ13C values than in the subtidal zone. Except for pH, environmental conditions of the seawater do not contribute to the δ13C variability. Specimens of the same taxa showed δ13C similar patterns, to increase or decrease, with latitude (21º–30° N). δ13C-macroalgal provides information on the inorganic carbon source used for photosynthesis (CO2 diffusive entry vs HCO3− active uptake). Most species showed a δ13C belong into a range that indicates a mix of CO2 and HCO3− uptake; the HCO3− uptake by active transport is widespread among GC macroalgae. About 20–34 % of species showed the presence of carbon concentrating mechanism (CCM). Ochrophyta presented a high number of species with δ13C > −10 ‰, suggesting widespread HCO3− use by non-diffusive mechanisms. Few species belonging to Rhodophyta relied on CO2 diffusive entry (δ13C 

scholarly journals An analysis of the variability in <i>δ</i><sup>13</sup>C in macroalgae from the Gulf of California: indicative of carbon concentration mechanisms and isotope discrimination during carbon assimilation

2022 ◽  
Vol 19 (1) ◽  
pp. 1-27
Author(s):  
Roberto Velázquez-Ochoa ◽  
María Julia Ochoa-Izaguirre ◽  
Martín Federico Soto-Jiménez
Keyword(s):  
Environmental Conditions ◽  
Gulf Of California ◽  
Carbon Assimilation ◽  
Life Forms ◽  
Isotopic Signature ◽  
Terrestrial Plants ◽  
Isotope Discrimination ◽  
Marine Habitats ◽  
Complementary Techniques ◽  
Species Specific

Abstract. The isotopic composition of carbon in macroalgae (δ13C) is highly variable, and its prediction is complex concerning terrestrial plants. The determinants of δ13C macroalgal variations were analyzed in a large stock of specimens that vary in taxa and morphology and were collected in shallow marine habitats in the Gulf of California (GC) with distinctive environmental conditions. A large δ13C variability (−34.6 ‰ to −2.2 ‰) was observed. Life-forms (taxonomy 57 %, morphology and structural organization 34 %) explain the variability related to carbon use physiology. Environmental conditions influenced the δ13C macroalgal values but did not change the physiology, which is most likely inherently species-specific. Values of δ13C were used as indicators of the presence or absence of carbon concentrating mechanisms (CCMs) and as integrative values of the isotope discrimination during carbon assimilation in the life cycle macroalgae. Based on δ13C signals, macroalgae were classified in three strategies relative to the capacity of CCM: (1) HCO3- uptake (δ13C > −10 ‰), (2) using a mix of CO2 and HCO3- uptake (-10<δ13C > −30 ‰), and (3) CO2 diffusive entry (δ13C < −30 ‰). Most species showed a δ13C that indicates a CCM using a mix of CO2 and HCO3- uptake. HCO3- uptake is also widespread among GC macroalgae, with many Ochrophyta species. Few species belonging to Rhodophyta relied on CO2 diffusive entry exclusively, while calcifying macroalgae species using HCO3- included only Amphiroa and Jania. The isotopic signature evidenced the activity of CCM, but it was inconclusive about the preferential uptake of HCO3- and CO2 in photosynthesis and the CCM type expressed in macroalgae. In the study of carbon use strategies, diverse, species-specific, and complementary techniques to the isotopic tools are required.

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

Strategies and adaptations to aquatic life at high altitude

2017 ◽  
Author(s):  
Dean Jacobsen ◽  
Olivier Dangles
Keyword(s):  
High Altitude ◽  
Environmental Conditions ◽  
Low Temperatures ◽  
Cold Adaptation ◽  
Inorganic Carbon ◽  
Direct Result ◽  
Aquatic Life ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Regulatory Capacity

Chapter 5 is focused on how organisms cope with the environmental conditions that are a direct result of high altitude. Organisms reveal a number of fascinating ways of dealing with a life at high altitude; for example, avoidance and pigmentation as protection against damaging high levels of ultraviolet radiation, accumulation of antifreeze proteins, and metabolic cold adaptation among species encountering low temperatures with the risk of freezing, oxy-regulatory capacity in animals due to low availability of oxygen, and root uptake from the sediment of inorganic carbon by plants living in waters poor in dissolved carbon dioxide. These and more adaptations are carefully described through a number of examples from famous flagship species in addition to the less well-known ones. Harsh environmental conditions work as an environmental filter that only allows the well-adapted species to slip through to colonize high altitude waters.

scholarly journals Breeding Ecology of the Red-Billed TropicbirdPhaethon aethereusUnder Contrasting Environmental Conditions in the Gulf of California

Ardea ◽  
2011 ◽  
Vol 99 (1) ◽  
pp. 61-71 ◽  
Author(s):  
José Alfredo Castillo-Guerrero ◽  
Miguel A. Guevara-Medina ◽  
Eric Mellink
Keyword(s):  
Environmental Conditions ◽  
Gulf Of California ◽  
Breeding Ecology

Trace Fossils in Quaternary, Bahamian-Style Carbonate Environments: The Modern to Fossil Transition

1992 ◽  
Vol 5 ◽  
pp. 105-120 ◽  
Author(s):  
H. Allen Curran
Keyword(s):  
Fossil Record ◽  
Trace Fossils ◽  
Subtidal Zone ◽  
Carbonate Sediments ◽  
Shallow Marine ◽  
Shallow Subtidal ◽  
Dominant Process ◽  
Burrowing Activity

Tracemaking organisms are common and diverse components of the fauna and flora of tropical, shallow-marine and coastal carbonate environments. In the shallow subtidal zone, the burrowing activity of callianassid shrimp commonly is the dominant process in the modification of original depositional fabrics (Tudhope and Scoffin, 1984; Tedesco and Wanless, 1991). Both borers and burrowers have great potential to leave their mark in tropical carbonate sediments and rocks and to become part of the fossil record.

scholarly journals Evidence for medieval salt-making by burning Eel-grass (Zostera marina L.) in the Netherlands

2005 ◽  
Vol 84 (1) ◽  
pp. 43-49 ◽  
Author(s):  
B. van Geel ◽  
G.J. Borger
Keyword(s):  
The Netherlands ◽  
Zostera Marina ◽  
Starting Material ◽  
Northwestern Part ◽  
Land Area ◽  
Archaeological Evidence ◽  
Shallow Marine ◽  
Salt Production ◽  
Marine Habitats ◽  
Peat Deposits

AbstractFrom the 8th/9th centuries onwards the former peat land area in the northwestern part of the Netherlands was drained and reclaimed. Drainage, peat digging and marine erosion of peat deposits created an extension of shallow marine habitats into which Zostera marina (Eel-grass) expanded. Modern publications do not note the use of Eel-grass as starting material for salt-making. Archaeological evidence, however, indicates salt-making activities by using Zostera in medieval times. We postulate that, after salt-containing peat had become difficult to obtain, Eel-grass was used for salt production.

scholarly journals Effect of bicarbonate on growth of the oleaginous microalga Botryococcus braunii

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Giovanna Salbitani ◽  
Carmela M.A. Barone ◽  
Simona Carfagna
Keyword(s):  
Inorganic Carbon ◽  
Algal Growth ◽  
Botryococcus Braunii ◽  
Final Concentration ◽  
Time Intervals ◽  
Experimental Conditions ◽  
Co2 Gas ◽  
Inorganic Carbon Source ◽  
Doubling Times

The effect of bicarbonate, produced by the enzymatic hydration of CO2 from postcombustion fumes, was investigated on Botryococcus braunii growth. The NaHCO3, supplied to cultures in the role of inorganic carbon source is proposed as a more eco-sustainable alternative to gaseous CO2. The salt was provided to the cultures at the final concentration of 0.5-1.5-2.5 g L- 1. The growth rate was considered for specific time intervals (T0-T5, T5-T10 and T0- T10) showing values significantly higher in the culture supplemented with 2.5 g L-1 bicarbonate. The doubling times were also considered in all experimental cultures showing a faster doubling for the period T0÷T5. The increase in pH drives the increase in growth in the experimental conditions in which the salt was added. The results suggest that bicarbonate is able to promote the algal growth, therefore it can be considered a valid alternative to CO2 gas.

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