scholarly journals Seagrass meadows of the Moroccan Mediterranean coast: state of research and knowledge

2015 ◽  
Author(s):  
Hocein Bazairi
Keyword(s):  
Zostera Marina ◽  
Posidonia Oceanica ◽  
Mediterranean Coast ◽  
Field Surveys ◽  
Seagrass Meadows ◽  
Halophila Stipulacea ◽  
Depth Study ◽  
The Mediterranean ◽  
State Of Research ◽  
Large Distribution

Seagrass meadows are highly productive and key ecosystems that undergo widespread loss due to ‘climate-related’ and human-mediated stressors as well as natural causes. Therefore, basic information about the distribution, abundance, and characteristics of seagrass meadows and their environment is critical for managers to assess and monitor the resource. Such knowledge is lacking for Morocco and there is a clear need to acquire baseline data for monitoring and protecting these important habitats. The present review summarizes the state of the research and the knowledge on seagrass meadows of the Mediterranean coast of Morocco. Data were assessed using a compilation of historical data compared to recent confirmed observation and field surveys conducted within the framework of several projects (MedMPAnet, Medkeyhabitats, etc.). Of the five species of strictly marine Magnoliophyta found in the Mediterranean Sea, four are also currently identified along the Mediterranean coast of Morocco (Posidonia oceanica, Cymodocea nodosa, Zostera marina and Zostera noltii); the Lessepsian immigrant Halophila stipulacea has not been recorded yet. Apart from C. nodosa, that showed large distribution, the other species remain spatially localized and their distribution has been declining since they have disappeared from many localities. This is the case of Zostera marina that has probably disappeared from many localities (e.g. Cap des Trois Fourches, Marchica lagoon). However, some previous citations, such as the presence of Posidonia oceanica in the Marchica lagoon, seem to be a systematic confusion. Moreover, quantitative data on the characteristics of seagrass meadows are very scarce and many areas of knowledge gaps were identified along the Mediterranean coast of Morocco. An in-depth study of seagrass meadows occurring in Morocco is strongly required and would substantially increase the knowledge on such habitats and help in their conservation.

scholarly journals Seagrass meadows of the Moroccan Mediterranean coast: state of research and knowledge

2015 ◽  
Author(s):  
Hocein Bazairi
Keyword(s):  
Zostera Marina ◽  
Posidonia Oceanica ◽  
Mediterranean Coast ◽  
Field Surveys ◽  
Seagrass Meadows ◽  
Halophila Stipulacea ◽  
Depth Study ◽  
The Mediterranean ◽  
State Of Research ◽  
Large Distribution

Seagrass meadows are highly productive and key ecosystems that undergo widespread loss due to ‘climate-related’ and human-mediated stressors as well as natural causes. Therefore, basic information about the distribution, abundance, and characteristics of seagrass meadows and their environment is critical for managers to assess and monitor the resource. Such knowledge is lacking for Morocco and there is a clear need to acquire baseline data for monitoring and protecting these important habitats. The present review summarizes the state of the research and the knowledge on seagrass meadows of the Mediterranean coast of Morocco. Data were assessed using a compilation of historical data compared to recent confirmed observation and field surveys conducted within the framework of several projects (MedMPAnet, Medkeyhabitats, etc.). Of the five species of strictly marine Magnoliophyta found in the Mediterranean Sea, four are also currently identified along the Mediterranean coast of Morocco (Posidonia oceanica, Cymodocea nodosa, Zostera marina and Zostera noltii); the Lessepsian immigrant Halophila stipulacea has not been recorded yet. Apart from C. nodosa, that showed large distribution, the other species remain spatially localized and their distribution has been declining since they have disappeared from many localities. This is the case of Zostera marina that has probably disappeared from many localities (e.g. Cap des Trois Fourches, Marchica lagoon). However, some previous citations, such as the presence of Posidonia oceanica in the Marchica lagoon, seem to be a systematic confusion. Moreover, quantitative data on the characteristics of seagrass meadows are very scarce and many areas of knowledge gaps were identified along the Mediterranean coast of Morocco. An in-depth study of seagrass meadows occurring in Morocco is strongly required and would substantially increase the knowledge on such habitats and help in their conservation.

scholarly journals Restoration of Seagrass Meadows in the Mediterranean Sea: A Critical Review of Effectiveness and Ethical Issues

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1034
Author(s):  
Charles-François Boudouresque ◽  
Aurélie Blanfuné ◽  
Gérard Pergent ◽  
Thierry Thibaut
Keyword(s):  
Ethical Issues ◽  
Scientific Paper ◽  
Posidonia Oceanica ◽  
Natural Ecosystem ◽  
Seagrass Meadows ◽  
Halophila Stipulacea ◽  
The Mediterranean ◽  
Term Monitoring ◽  
Sea Warming

Some species of seagrasses (e.g., Zostera marina and Posidonia oceanica) have declined in the Mediterranean, at least locally. Others are progressing, helped by sea warming, such as Cymodocea nodosa and the non-native Halophila stipulacea. The decline of one seagrass can favor another seagrass. All in all, the decline of seagrasses could be less extensive and less general than claimed by some authors. Natural recolonization (cuttings and seedlings) has been more rapid and more widespread than was thought in the 20th century; however, it is sometimes insufficient, which justifies transplanting operations. Many techniques have been proposed to restore Mediterranean seagrass meadows. However, setting aside the short-term failure or half-success of experimental operations, long-term monitoring has usually been lacking, suggesting that possible failures were considered not worthy of a scientific paper. Many transplanting operations (e.g., P. oceanica) have been carried out at sites where the species had never previously been present. Replacing the natural ecosystem (e.g., sandy bottoms, sublittoral reefs) with P. oceanica is obviously inappropriate in most cases. This presupposes ignorance of the fact that the diversity of ecosystems is one of the bases of the biodiversity concept. In order to prevent the possibility of seagrass transplanting from being misused as a pretext for further destruction, a guide for the proper conduct of transplanting is proposed.

scholarly journals Posidonia oceanica as a Source of Chromophoric Dissolved Organic Matter for the Oligotrophic NW Mediterranean Coast

2020 ◽  
Vol 8 (11) ◽  
pp. 911
Author(s):  
Francesca Iuculano ◽  
Carlos M. Duarte ◽  
Jaime Otero ◽  
Xosé Antón Álvarez-Salgado ◽  
Susana Agustí
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Rocky Shore ◽  
Posidonia Oceanica ◽  
Mediterranean Coast ◽  
Balearic Islands ◽  
Chromophoric Dissolved Organic Matter ◽  
Absorption Increase ◽  
Seagrass Meadows ◽  
Nw Mediterranean

Posidonia oceanica is a well-recognized source of dissolved organic matter (DOM) derived from exudation and leaching of seagrass leaves, but little is known about its impact on the chromophoric fraction of DOM (CDOM). In this study, we monitored for two years the optical properties of CDOM in two contrasting sites in the Mallorca Coast (Balearic Islands). One site was a rocky shore free of seagrass meadows, and the second site was characterized by the accumulation of non-living seagrass material in the form of banquettes. On average, the integrated color over the 250–600 nm range was almost 6-fold higher in the beach compared with the rocky shore. Furthermore, the shapes of the CDOM spectra in the two sites were also different. A short incubation experiment suggested that the spectral differences were due to leaching from P. oceanica leaf decomposition. Furthermore, occasionally the spectra of P. oceanica was distorted by a marked absorption increase at wavelength < 265 nm, presumably related to the release of hydrogen sulfide (HS−) associated with the anaerobic decomposition of seagrass leaves within the banquettes. Our results provide the first evidence that P. oceanica is a source of CDOM to the surrounding waters.

scholarly journals Seagrasses biodiversity (Posidonia oceanica and Zostera marina) in the Mediterranean Sea

2003 ◽  
Vol 24 ◽  
Author(s):  
Carla Micheli ◽  
Patrizia Paganin ◽  
Massimo Maffucci ◽  
Tania Dolce ◽  
Giuseppe Nascetti ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Zostera Marina ◽  
Posidonia Oceanica ◽  
The Mediterranean

Towards the definition of a standard protocol for the estimation of CO2 fixation by Posidonia oceanica meadows in the Mediterranean Sea (SeaForest Life Project)

2021 ◽  
Author(s):  
Alice Madonia ◽  
Keyword(s):  
Mediterranean Sea ◽  
National Park ◽  
Posidonia Oceanica ◽  
Blue Carbon ◽  
Standard Protocol ◽  
Life Project ◽  
Seagrass Meadows ◽  
Management Plans ◽  
The Mediterranean ◽  
The Impact

&lt;p&gt;&lt;em&gt;Posidonia oceanica &lt;/em&gt;(L.) Delile meadows are considered as the most productive ecosystems of the Mediterranean basin, sequestering and storing significant amount of blue carbon in their rich organic sediments and in their living and non-living biomass and these meadows are identified as a priority habitat type for conservation under the Habitat Directive (Dir 92/43/CEE). Despite the importance of the ecosystem services it provides, this habitat is disappearing at a rate four times as high as that of terrestrial forests, experiencing an alarming reduction due to the impacts of human activities in coastal areas, especially in the north-western side of the Mediterranean Sea. To face this issue, the SeaForest Life project foresees the quantification of carbon deposits and their rate of change related to habitat degradation specifically focusing on the effects caused by boat&amp;#8217;s anchors and moorings. The project is realized in the Archipelago of la Maddalena National Park, the Asinara National Park and the Cilento, Vallo di Diano and Alburni National Park, for which ad hoc management plans of mooring are going to be adopted to reduce the impact of this practice on the seagrass meadows. As a first step, an updating of habitat 1120*&amp;#8217;s cartography in each of the Marine Protected Areas engaged in the project have been fulfilled, using high definition multispectral imagery. Furthermore, monitoring of the areas with the highest attendance of the anchorages was carried out through the use of medium resolution satellite multi-spectral images using the infrared band, to identify and quantify the degradation and the state of conservation of the &lt;em&gt;P.oceanica&lt;/em&gt; meadows present in the investigated areas. The updated cartography has been used to implement the InVEST Coastal Blue Carbon (CBC) which attempts to predict the sequestration, storage and, when degraded, the emissions of carbon by coastal ecosystems, so representing a useful tool for the analysis of the ecological and economic effects of the degradation processes (boats anchoring) and mitigation measures (anchor management plan and eco friendly moorings). Up to now, the InVEST-CBC model has estimated a CO&lt;sub&gt;2&lt;/sub&gt; loss due to boats anchoring equal to 2300 tCO&lt;sub&gt;2&lt;/sub&gt;/year, using stock and flow data in soil and biomass obtained from the results of the Life Blue Natura project and&lt;em&gt; P. oceanica&lt;/em&gt; samples collected in the Cilento National Park. In the future, the results of the model will be improved with data collected in the other two project areas, also through the use of innovative instrumentation. Moreover, the scenarios with the implementation of the mooring management plans will be analyzed in the three study areas. The dataset obtained by the model is being used to define a standard protocol for the estimation of CO&lt;sub&gt;2&lt;/sub&gt; fixation by &lt;em&gt;P. oceanica &lt;/em&gt;meadows in the Mediterranean Sea. Such protocol will be fundamental for the realization of a national IT-based platform for a voluntary based carbon market to sell and acquire the carbon credits generated by the SeaForest Life project activities, to be extended to all the Mediterranean countries and to be scaled up to new protected marine areas.&lt;/p&gt;

scholarly journals Climate change and Mediterranean seagrass meadows: a synopsis for environmental managers

2014 ◽  
Vol 15 (2) ◽  
pp. 462 ◽  
Author(s):  
G. PERGENT ◽  
H. BAZAIRI ◽  
C. N. BIANCHI ◽  
C. F. BOUDOURESQUE ◽  
M. C. BUIA ◽  
...  
Keyword(s):  
Climate Change ◽  
Industrial Revolution ◽  
Net Primary Production ◽  
Global Climate ◽  
Posidonia Oceanica ◽  
Total Carbon ◽  
Anthropogenic Pressures ◽  
Seagrass Meadows ◽  
Mediterranean Countries ◽  
The Mediterranean

This synopsis focuses on the effects of climate change on Mediterranean seagrasses, and associated communities, and on the contribution of the main species, Posidonia oceanica, to the mitigation of climate change effects through its role of sequestering carbon dioxide. Whilst the regression of seagrass meadows is well documented, generally linked to anthropogenic pressures, global warming could be a cause of new significant regressions, notably linked to the introduction of exotic species, the rise of Sea-Surface Temperature (SST), and relative sea level. Seagrass communities could also be affected by climate change through the replacement of seagrass species having high structural complexity by species of lower complexity and even by opportunistic introduced species. Although it is currently very difficult to predict the consequences of these alterations and their cascade effects, two main conflicting trends in the functioning of seagrass ecosystems that could occur are acceleration of the herbivore pathway or of the detritivore pathway. The mean net primary production of the dominant species, Posidonia oceanica, is relatively high and can be estimated to range between 92.5 to 144.7 g C m-2 a-1. Around 27% of the total carbon fixed by this species enters the sedimentary pathway leading to formation, over millennia, of highly organic deposits rich in refractory carbon. At the Mediterranean scale, the sequestration rate might reach 1.09 Tg C a-1. The amount of this stored carbon is estimated to range from 71 to 273 kg C m-2, which when considered at the Mediterranean scale would represent 11 to 42% of the CO2 emissions produced by Mediterranean countries since the beginning of the Industrial Revolution. The greatest value of the P. oceanica ecosystem, in the context of mitigation of global climate change, is linked to this vast long-term carbon stock accumulated over the millennia, and therefore, efforts should be focused on preserving the meadows to keep this reservoir intact.

scholarly journals High Diversity and Abundance of Foraminifera Associated with Mediterranean Benthic Red Algae Mats

Diversity ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 21
Author(s):  
Felix Ivo Rossbach ◽  
Benedikt Merk ◽  
Christian Wild
Keyword(s):  
Mediterranean Sea ◽  
Surface Area ◽  
Red Algae ◽  
Benthic Fauna ◽  
Posidonia Oceanica ◽  
Tyrrhenian Sea ◽  
Pilot Studies ◽  
Seagrass Meadows ◽  
The Mediterranean ◽  
High Diversity

The Mediterranean Sea comprises habitats such as Posidonia oceanica seagrass meadows that exhibit high associated biodiversity of sessile organisms. Recent pilot research indicates that benthic mats formed by the scarcely investigated fleshy red alga Phyllophora crispa also host a high diversity of benthic fauna. Among the key taxa found in these mats in the recent pilot studies are benthic foraminifera that live as epiphytes on the red algae thalli. Knowledge about their abundance and species richness associated with this habitat in relation to reference habitats is missing. We thus carried out a comparative assessment focusing on foraminifera within samples from P. crispa mats and neighboring P. oceanica meadows on five different sampling sites around Giglio Island in the Tuscan Archipelago (Tyrrhenian Sea, Italy). A total of 104 different foraminiferal taxa were identified, of which a total of 85 taxa were found in P. crispa samples (46 exclusively in this habitat). This biodiversity was higher compared to other studies on phytal habitats in the Mediterranean Sea. The number of foraminiferal taxa associated with P. crispa was significantly higher (average 27.5 ± 8.1 taxa) compared to P. oceanica (leaves average 7.0 ± 3.6, shoots average 7.9 ± 3.4 taxa). The abundance of foraminifera (12,000 individuals m−2 surface area of P. crispa mat) was also higher than in the neighboring P. oceanica meadows (7792 individuals m−2 leaf and 8171 individuals m−2 shoot surface area). The most frequently found taxa across habitats were Miniacina miniacea, Lobatula lobatula, and Sejunctella sp. (24%, 20%, and 6% of the total population, respectively). Our results imply that P. crispa mats host an exceptional diversity of associated foraminifera that is even higher than those associated with seagrass meadows. Red algae mats built by P. crispa may thus be considered as potential refuge habitats and biodiversity reservoirs in management and conservation.

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