Search results for "macroalgae"

Ocean acidification can mediate biodiversity shifts by changing biogenic habitat

2016

The effects of ocean acidification (OA) on the structure and complexity of coastal marine biogenic habitat have been broadly overlooked. Here we explore how declining pH and carbonate saturation may affect the structural complexity of four major biogenic habitats. Our analyses predict that indirect effects driven by OA on habitat-forming organisms could lead to lower species diversity in coral reefs, mussel beds and some macroalgal habitats, but increases in seagrass and other macroalgal habitats. Available in situ data support the prediction of decreased biodiversity in coral reefs, but not the prediction of seagrass bed gains. Thus, OA-driven habitat loss may exacerbate the direct negativ…

Macroalgal forest vs sea urchin barren: Patterns of macro-zoobenthic diversity in a large-scale Mediterranean study: Macro-zoobenthos of barren and m…

2020

The study aimed at contributing to the knowledge of alternative stable states by evaluating the differences of mobile and sessile macro-zoobenthic assemblages between sea urchin barrens and macroalgal forests in coastal Mediterranean systems considering a large spatial scale. Six sites (100 s km apart) were selected: Croatia, Montenegro, Sicily (Italy), Sardinia (Italy), Tuscany (Italy), and Balearic Islands (Spain). A total of 531 taxa, 404 mobile and 127 sessile macro-invertebrates were recorded. Overall, 496 and 201 taxa were found in macroalgal forests and in barrens, respectively. The results of this large-scale descriptive study have met the expectation of lower macrofauna complexity …

Ocean acidification effects on stable isotope signatures and trophic interactions of polychaete consumers and organic matter sources at a CO2 shallow…

2015

Abstract Stable carbon and nitrogen isotope analysis (SIA) was used to examine trophic interactions in a naturally acidified shallow coastal CO2 area in the Mediterranean Sea. SIA was helpful to determine the potential effects of ocean acidification (OA) on the interactions of organic matter sources and polychaete consumers, which appear to be tolerant to high pCO2. Mesoherbivore consumers, represented by three polychaete species, Platynereis dumerilii (Audouin and Milne Edwards, 1834) (Nereididae), Polyophthalmus pictus (Dujardin, 1839) (Opheliidae) and Syllis prolifera Krohn, 1852 (Syllidae), are abundant in the low pH conditions of the CO2 vents. Samples of consumers and potential organi…

Study of the effects of climate extremes on functioning of intertidal assemblages to design an early warning sensor network

2020

Macroalgal responses to ocean acidification depend on nutrient and light levels. Frontiers in Marine Science

2015

Ocean acidification may benefit algae that are able to capitalize on increased carbon availability for photosynthesis, but it is expected to have adverse effects on calcified algae through dissolution. Shifts in dominance between primary producers will have knock-on effects on marine ecosystems and will likely vary regionally, depending on factors such as irradiance (light vs. shade) and nutrient levels (oligotrophic vs. eutrophic). Thus experiments are needed to evaluate interactive effects of combined stressors in the field. In this study, we investigated the physiological responses of macroalgae near a CO2 seep in oligotrophic waters off Vulcano (Italy). The algae were incubated in situ …

Biological activities of the extracts from macroalgae Carpodesmia crinita, Carpodesmia brachycarpa, Asparagopsis taxiformis

2023

Marine species represent a rich source of biologically active products that can be used in various fields. Among them, marine algae produce numerous secondary metabolites responsible for different biological activities such as: immunomodulatory [1], antioxidant [2], and antimicrobial [3]. The aim of this study was chemically characterizing the extracts of three macroalgae species: Carpodesmia crinite (Duby) Orellana & Sansón, 2019, Carpodesmia brachycarpa (J. Agardh) Orellana & Sansón 2019, Asparagopsis taxiformis (Delile) Trevisan 1845 and evaluate their biological activities. The characterization of the secondary metabolites was performed by HPLC-MS and the results obtained showed…

Algae biomass: characteristics and applications. Towards algae-based products

2018

This book is a compendium of knowledge on the useful properties of algae in the context of application as a useful component of innovative natural products. It presents all aspects of industrial applications of macroalgae biomass derived from the natural environment. Despite many interesting characteristics, algae are still regarded as undervalued raw material, therefore, present in the following chapters are not only environmental benefits arising from the development of excessive algal biomass, but also the distribution and biology of algae in natural conditions in reservoirs, methods of obtaining extracts from biomass of algae for industrial purposes. Furthermore, it also includes topics…

Responses of macroalgal community to environmental changes

2009

Species of Cystoseira (Ochrophyta, Fucales) seem to be sensitive to a variety of environmental changes, as a consequence of which, they are now used in ecological status assessment. On the contrary, invasive species tend to be more resilient to disturbances than Cystoseira species, and thus environmental changes to allow them to out-compete these species. All these evidences lead to consider Cystoseira species, as well as invasive species, as biological indicators of environmental changes. Therefore, the effects of environmental changes can be measured through: (1) the assessment of the current state of the popu- lations of Cystoseira species and of invasive species, (2) the comparison of i…

Selezione dell’habitat in quattro specie ittiche criptobentoniche nell’infralitorale superiore di coste rocciose in Mediterraneo

2010

The seaweeds Fucus vesiculosus and Ascophyllum nodosum are significant contributors to coastal iodine emissions

2013

Based on the results of a pilot study in 2007, which found high mixing ratios of molecular iodine (I2) above the intertidal macroalgae (seaweed) beds at Mweenish Bay (Ireland), we extended the study to nine different locations in the vicinity of Mace Head Atmospheric Research Station on the west coast of Ireland during a field campaign in 2009. The mean values of I2 mixing ratio found above the macroalgae beds at nine different locations ranged from 104 to 393 ppt, implying a high source strength of I2. Such mixing ratios are sufficient to result in photochemically driven coastal new-particle formation events. Mixing ratios above the Ascophyllum nodosum and Fucus vesiculosus beds increased …