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Gallo E, Oprandi A, Bianchi CN, Morri C, Azzola A, Montefalcone M. Unexpected slow recovery of seagrass leaf epiphytes after the impact of a summer heat wave and concomitant mucilage bloom. MARINE ENVIRONMENTAL RESEARCH 2023; 189:106034. [PMID: 37290233 DOI: 10.1016/j.marenvres.2023.106034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/20/2023] [Accepted: 05/23/2023] [Indexed: 06/10/2023]
Abstract
The epiphytes of seagrass leaves constitute a peculiar community, comprised of a number of species specialized for this living substrate. Several studies report on the response of epiphytes to different pressures but no information exists about the effects of summer heatwaves, which have become frequent events in the last decades. This paper represents the first attempt to investigate the change in the leaf epiphyte community of the Mediterranean seagrass Posidonia oceanica due to the heatwave occurred in summer 2003. Thanks to a series of data collected seasonally between 2002 and 2006, and punctual data in the summers of 2014 and 2019, we assessed the change over time in the leaf epiphyte community. Temperature data trends were analysed through linear regression, while multivariate analyses (i.e., nMDS and SIMPER) were applied to cover data in order to assess changes over time in the epiphyte community. As a whole, the two most abundant taxa were the crustose coralline alga Hydrolithon and the encrusting bryozoan Electra posidoniae, which displayed the highest average cover values in summer (around 19%) and spring (around 9%), respectively. Epiphytes proved to be sensitive to temperature highs, displaying different effects on cover, biomass, diversity and community composition. Cover and biomass exhibited a dramatic reduction (more than 60%) after the disturbance. In particular, Hydrolithon more than halved, while E. posidoniae dropped sevenfold during summer 2003. While the former recovered comparatively quickly, the latter, as well as the whole community composition, apparently required 16 years to return to a condition similar to that of 2002.
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Affiliation(s)
- Elena Gallo
- SEL (Seascape Ecology Laboratory), DiSTAV (Department of Earth, Environmental and Life Sciences), University of Genoa, Corso Europa 26, I-16132, Genova, Italy
| | - Alice Oprandi
- SEL (Seascape Ecology Laboratory), DiSTAV (Department of Earth, Environmental and Life Sciences), University of Genoa, Corso Europa 26, I-16132, Genova, Italy.
| | - Carlo Nike Bianchi
- SEL (Seascape Ecology Laboratory), DiSTAV (Department of Earth, Environmental and Life Sciences), University of Genoa, Corso Europa 26, I-16132, Genova, Italy; Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn - National Institute of Marine Biology, Ecology and Biotechnology, Genoa Marine Centre (GMC), Villa del Principe, Piazza Principe 4, I-16126, Genova, Italy
| | - Carla Morri
- SEL (Seascape Ecology Laboratory), DiSTAV (Department of Earth, Environmental and Life Sciences), University of Genoa, Corso Europa 26, I-16132, Genova, Italy; Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn - National Institute of Marine Biology, Ecology and Biotechnology, Genoa Marine Centre (GMC), Villa del Principe, Piazza Principe 4, I-16126, Genova, Italy
| | - Annalisa Azzola
- SEL (Seascape Ecology Laboratory), DiSTAV (Department of Earth, Environmental and Life Sciences), University of Genoa, Corso Europa 26, I-16132, Genova, Italy; NBFC, National Biodiversity Future Center, I-90133, Palermo, Italy
| | - Monica Montefalcone
- SEL (Seascape Ecology Laboratory), DiSTAV (Department of Earth, Environmental and Life Sciences), University of Genoa, Corso Europa 26, I-16132, Genova, Italy; NBFC, National Biodiversity Future Center, I-90133, Palermo, Italy
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Plant and Meadow Structure Characterisation of Posidonia oceanica in Its Westernmost Distribution Range. DIVERSITY 2023. [DOI: 10.3390/d15010101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Posidonia oceanica is an endemic seagrass species from the Mediterranean Sea that provides critical ecological services to coastal environments. This species is distributed from the Turkish to the Spanish coast, where its westernmost record was documented in Punta Chullera, Malaga (36°18′36.45′′ N, 5°14′54.31′′ W). Nevertheless, previous studies suggested that its distribution was even further west, although these populations were never described. In this study, we documented and characterised the only known P. oceanica population on the coast of Cadiz, in Cala Sardina (36°18′38.80′′ N, 5°15′15.13′′ W). The newly documented population of P. oceanica presented a fragmented structure, consisting of nine patches found in a rocky shallow area surrounded by the invasive algae Rugulopteryx okamurae, with a total size of 61.14 m2. Shoots had a relatively small size (21.0 ± 2.9 cm) in comparison with centrally-distributed populations. The relatively small size of the plants, alongside the observed low shoot density (437 ± 42 shoots m−2) and leaf area index (4.8 ± 0.7 m2 m−2), may indicate that this meadow could be exposed to sub-optimal environmental conditions for plant development. By contrast, the meadow showed relatively high production rates (0.03 ± 0.01 leaf day−1 shoot−1) in comparison with other Mediterranean populations. The percentage of carbon in plant leaves was 38.73 ± 1.38%, while the nitrogen and C/N were 1.38 ± 0.37% and 29.93 ± 6.57, respectively. The documentation of this meadow extends the distribution of this species to the Mediterranean coast of Cadiz, making this region the place with the highest seagrass biodiversity (four species) in the Iberian Peninsula, and potentially in Europe. This exploratory study provides a baseline to examine the potential effects of climate change, anthropogenic disturbances or the presence of invasive species.
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Cultivable Fungal Endophytes in Roots, Rhizomes and Leaves of Posidonia oceanica (L.) Delile along the Coast of Sicily, Italy. PLANTS 2022; 11:plants11091139. [PMID: 35567139 PMCID: PMC9105210 DOI: 10.3390/plants11091139] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/20/2022] [Accepted: 04/20/2022] [Indexed: 11/24/2022]
Abstract
The presence of endophytic fungi in the roots, rhizomes, and leaves of Posidonia oceanica was evaluated in different localities of the Sicilian coast. Samples of roots, rhizomes, and leaves were submitted to isolation techniques, and the obtained fungal colonies were identified by morphological and molecular (rRNA sequencing) analysis. Fungal endophytes occurred mainly in roots and occasionally in rhizomes and leaves. Lulwoana sp. was the most frequent of the isolated taxa, suggesting a strong interaction with the host. In addition, eight other fungal taxa were isolated. In particular, fungi of the genus Ochroconis and family Xylariaceae were identified as endophytes in healthy plants at all sampling stations, whereas Penicillium glabrum was isolated at only one sampling station. Thus, several organs, especially roots of Posidonia oceanica, harbor endophytic fungi, potentially involved in supporting the living host as ascertained for terrestrial plants.
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De Battisti D, Balestri E, Pardi G, Menicagli V, Lardicci C. Substrate Type Influences the Structure of Epiphyte Communities and the Growth of Posidonia oceanica Seedlings. FRONTIERS IN PLANT SCIENCE 2021; 12:660658. [PMID: 34025699 PMCID: PMC8139341 DOI: 10.3389/fpls.2021.660658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
Epiphytes colonizing adult seagrasses highly contribute to seagrass ecosystem functioning and plant growth. Yet, little information exists on epiphytic communities developing on seagrass seedlings. Moreover, for some species our knowledge about seedling performance is limited to early establishment phases, and the role of substrate type in affecting their growth is still unclear. These are considerable knowledge gaps, as seedlings play an important role in meadow expansion and recovery from disturbance. In this study, seedlings of Posidonia oceanica, a keystone species of the Mediterranean, were grown in a shallow (1.5 m deep) coastal area along the Tuscany coast (Italy). After five years of growth (July 2009), seedlings were collected and, through multivariate analysis, we examined whether the epiphytic communities of leaves (both internal and external side) and rhizomes, as well as the growth characteristics differed between rock and sand substrate. The epiphytic communities of seedlings largely reflected those found on adult shoots. Epiphyte cover was similar between the two leaf sides, and it was higher on seedlings grown on rock than on sand, with encrusting algae dominating the community. No differences in epiphyte cover and community structure on rhizomes were found between substrates. Seedling growth characteristics did not differ between substrates, apart from the number of standing leaves being higher on rock than on sand. No correlation was found among epiphyte communities and seedling growth variables (i.e., leaf area, maximum leaf length, number of leaves, total number of leaves produced, rhizome length, total biomass, and root to shoot biomass ratio). Results indicate that epiphytes successfully colonize P. oceanica seedlings, and the surrounding micro-environment (i.e., substrate type) can influence the leaf epiphytic community. This study provides new valuable insights on the biological interactions occurring in seagrass ecosystems and highlights the need for better understanding the effects of seedling epiphytes and substrate on the formation of new meadows.
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Affiliation(s)
| | | | | | | | - Claudio Lardicci
- Department of Earth Science, University of Pisa, Pisa, Italy
- Centre for Climate Change Impact, University of Pisa, Pisa, Italy
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Alagna A, D'Anna G, Musco L, Vega Fernández T, Gresta M, Pierozzi N, Badalamenti F. Taking advantage of seagrass recovery potential to develop novel and effective meadow rehabilitation methods. MARINE POLLUTION BULLETIN 2019; 149:110578. [PMID: 31550578 DOI: 10.1016/j.marpolbul.2019.110578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 06/10/2023]
Abstract
Seagrasses are among the most threatened biomes worldwide. Until now, seagrass rehabilitation success has reached about 38% overall and more effective approaches to restoration are urgently needed. Here we report a novel method to rehabilitate Posidonia oceanica meadows based on observation of the species' natural recovery after disturbance. Posidonia oceanica rhizomes were transplanted on gabions filled with rocks of selected sizes in order to build a firm substrate with topographic complexity in the relevant scale range to propagules. Five techniques were tested, each involving a different anchoring device. The "slot" technique, which uses a wire-net pocket to retain the cuttings, was the most successful, with survival exceeding 85% after thirty months. Branching allowed final shoot survival to reach 422% of initial planting density. This study shows how an in-depth knowledge of species life history processes provides a suitable foundation for developing effective restoration methods that benefit from species recovery ability.
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Affiliation(s)
- Adriana Alagna
- CNR-IAS, Institute for the study of Anthropic Impacts and Sustainability of the Marine Environment, Via G. da Verrazzano 17, 91014 Castellammare del Golfo, TP, Italy; Stazione Zoologica Anton Dohrn, Integrative Marine Ecology Department, Villa Comunale, 80121 Naples, Italy.
| | - Giovanni D'Anna
- CNR-IAS, Institute for the study of Anthropic Impacts and Sustainability of the Marine Environment, Via G. da Verrazzano 17, 91014 Castellammare del Golfo, TP, Italy
| | - Luigi Musco
- Stazione Zoologica Anton Dohrn, Integrative Marine Ecology Department, Villa Comunale, 80121 Naples, Italy
| | - Tomás Vega Fernández
- Stazione Zoologica Anton Dohrn, Integrative Marine Ecology Department, Villa Comunale, 80121 Naples, Italy
| | - Martina Gresta
- Saipem S.p.A., via Martiri di Cefalonia 67, 20097 San Donato Milanese, MI, Italy
| | - Natalia Pierozzi
- Saipem S.p.A., via Martiri di Cefalonia 67, 20097 San Donato Milanese, MI, Italy
| | - Fabio Badalamenti
- CNR-IAS, Institute for the study of Anthropic Impacts and Sustainability of the Marine Environment, Via G. da Verrazzano 17, 91014 Castellammare del Golfo, TP, Italy; Stazione Zoologica Anton Dohrn, Integrative Marine Ecology Department, Villa Comunale, 80121 Naples, Italy; School of Geosciences, Grant Institute, King's Buildings, University of Edinburgh, Edinburgh, United Kingdom
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6
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Stephens TA, Hughes BB, Kroeker KJ, Hessing-Lewis M, Monteith Z, Morris M, Raymond WW. Between a rock and a soft place: surfgrass colonizes sediments without attachment to rock. Ecology 2019; 100:e02791. [PMID: 31228865 DOI: 10.1002/ecy.2791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/18/2019] [Accepted: 05/28/2019] [Indexed: 11/07/2022]
Affiliation(s)
- Tiffany A Stephens
- University of Alaska Fairbanks, 17101 Point Lena Loop Road, Juneau, Alaska, 99801, USA
| | - Brent B Hughes
- Department of Biology, Sonoma State University, 1801 East Cotati Avenue, Rohnert Park, California, 94928, USA
| | - Kristy J Kroeker
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 113 McAllister Way, Santa Cruz, California, 95064, USA
| | | | - Zachary Monteith
- Hakai Institute, PO Box 30, Heriot Bay, British Columbia, V0P 1H0, Canada
| | - Mary Morris
- Archipelago Marine Research Ltd., 525 Head Street, Victoria, British Columbia, V9A 5S1, Canada
| | - Wendel W Raymond
- University of Alaska Fairbanks, 17101 Point Lena Loop Road, Juneau, Alaska, 99801, USA
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Understanding the sexual recruitment of one of the oldest and largest organisms on Earth, the seagrass Posidonia oceanica. PLoS One 2018; 13:e0207345. [PMID: 30444902 PMCID: PMC6239318 DOI: 10.1371/journal.pone.0207345] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/30/2018] [Indexed: 11/19/2022] Open
Abstract
The seagrass Posidonia oceanica is considered one of the oldest and largest living organisms on Earth. Notwithstanding, given the difficulty of monitoring its fruits and seeds in the field, the development of P. oceanica during its sexual recruitment is not completely understood. We studied the stages of development of P. oceanica seeds from their dispersion in the fruit interior to their settlement in sediment through histological, ultrastructural and mesocosm experiments. P. oceanica sexual recruitment can be divided into three main stages that focus on maximising photosynthesis and anchoring the seedlings to the sediment. In the first stage (fruit dispersion), seeds perform photosynthesis while being transported inside the fruit along the sea surface. In the second stage (seed adhesion), seeds develop adhesive microscopic hairs that cover the primary and secondary roots and favour seed adhesion to the substrate. In the last stage (seedling anchorage), roots attach the seedlings to the substrate by orienting them towards the direction of light to maximise photosynthesis. The adaptations observed in P. oceanica are similar to those in other seagrasses with non-dormant seeds and fruits with membranous pericarps, such as Thalassia sp. and Enhalus sp. These common strategies suggest a convergent evolution in such seagrasses in terms of sexual recruitment. Understanding the sexual recruitment of habitat-forming species such as seagrasses is necessary to adequately manage the ecosystems that they inhabit.
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Vacchi M, Montefalcone M, Schiaffino CF, Parravicini V, Bianchi CN, Morri C, Ferrari M. Towards a predictive model to assess the natural position of the Posidonia oceanica seagrass meadows upper limit. MARINE POLLUTION BULLETIN 2014; 83:458-66. [PMID: 24119311 DOI: 10.1016/j.marpolbul.2013.09.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 09/05/2013] [Accepted: 09/09/2013] [Indexed: 05/15/2023]
Abstract
The upper portion of the meadows of the protected Mediterranean seagrass Posidonia oceanica occurs in the region of the seafloor mostly affected by surf-related effects. Evaluation of its status is part of monitoring programs, but proper conclusions are difficult to draw due to the lack of definite reference conditions. Comparing the position of the meadow upper limit with the beach morphodynamics (i.e. the distinctive type of beach produced by topography and wave climate) provided evidence that the natural landwards extension of meadows can be predicted. An innovative model was therefore developed in order to locate the region of the seafloor where the meadow upper limit should lie in natural conditions (i.e. those governed only by hydrodynamics, in absence of significant anthropogenic impact). This predictive model was validated in additional sites, which showed perfect agreement between predictions and observations. This makes the model a valuable tool for coastal management.
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Affiliation(s)
- Matteo Vacchi
- Aix-Marseille Université, CEREGE CNRS-IRD UMR 34, Aix en Provence, France; SEAMap Ltd., Environmental Consulting, Borghetto Santo Spirito, Italy.
| | - Monica Montefalcone
- Department of Earth, Environmental and Life Sciences, University of Genoa, Italy
| | - Chiara F Schiaffino
- Department of Earth, Environmental and Life Sciences, University of Genoa, Italy; SEAMap Ltd., Environmental Consulting, Borghetto Santo Spirito, Italy
| | - Valeriano Parravicini
- UR 227 - "CoReUs2" IRD - Institut de Recherche pour le Développement, Laboratoire Arago, Banyuls-sur-Mer, France; SEAMap Ltd., Environmental Consulting, Borghetto Santo Spirito, Italy
| | - Carlo Nike Bianchi
- Department of Earth, Environmental and Life Sciences, University of Genoa, Italy
| | - Carla Morri
- Department of Earth, Environmental and Life Sciences, University of Genoa, Italy
| | - Marco Ferrari
- Department of Earth, Environmental and Life Sciences, University of Genoa, Italy
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Personnic S, Boudouresque CF, Astruch P, Ballesteros E, Blouet S, Bellan-Santini D, Bonhomme P, Thibault-Botha D, Feunteun E, Harmelin-Vivien M, Pergent G, Pergent-Martini C, Pastor J, Poggiale JC, Renaud F, Thibaut T, Ruitton S. An ecosystem-based approach to assess the status of a Mediterranean ecosystem, the Posidonia oceanica seagrass meadow. PLoS One 2014; 9:e98994. [PMID: 24933020 PMCID: PMC4059631 DOI: 10.1371/journal.pone.0098994] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 05/09/2014] [Indexed: 11/18/2022] Open
Abstract
Biotic indices, which reflect the quality of the environment, are widely used in the marine realm. Sometimes, key species or ecosystem engineers are selected for this purpose. This is the case of the Mediterranean seagrass Posidonia oceanica, widely used as a biological quality element in the context of the European Union Water Framework Directive (WFD). The good quality of a water body and the apparent health of a species, whether or not an ecosystem engineer such as P. oceanica, is not always indicative of the good structure and functioning of the whole ecosystem. A key point of the recent Marine Strategy Framework Directive (MSFD) is the ecosystem-based approach. Here, on the basis of a simplified conceptual model of the P. oceanica ecosystem, we have proposed an ecosystem-based index of the quality of its functioning, compliant with the MSFD requirements. This index (EBQI) is based upon a set of representative functional compartments, the weighting of these compartments and the assessment of the quality of each compartment by comparison of a supposed baseline. The index well discriminated 17 sites in the north-western Mediterranean (French Riviera, Provence, Corsica, Catalonia and Balearic Islands) covering a wide range of human pressure levels. The strong points of the EBQI are that it is easy to implement, non-destructive, relatively robust, according to the selection of the compartments and to their weighting, and associated with confidence indices that indicate possible weakness and biases and therefore the need for further field data acquisition.
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Affiliation(s)
- Sébastien Personnic
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
- * E-mail:
| | - Charles F. Boudouresque
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
| | - Patrick Astruch
- GIS Posidonie, Pytheas Institute, Aix-Marseille University, Marseille, France
| | | | - Sylvain Blouet
- Aire marine protégée de la côte Agathoise, site natura 2000, Agde, France
| | - Denise Bellan-Santini
- Aix-Marseille University, Institut Méditerranéen de Biodiversité et d'Ecologie (IMBE), UMR 7263, Station Marine d'Endoume, Marseille, France
| | - Patrick Bonhomme
- GIS Posidonie, Pytheas Institute, Aix-Marseille University, Marseille, France
| | - Delphine Thibault-Botha
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
| | - Eric Feunteun
- Museum National d'Histoire Naturelle, UMR 7208, Station Marine de Dinard, France
| | - Mireille Harmelin-Vivien
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
| | - Gérard Pergent
- Equipe Ecosystèmes Littoraux, FRES 3041, University of Corsica, Corte, France
| | | | - Jérémy Pastor
- Université de Perpignan, Via Domitia, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR 5110, Perpignan, France
| | - Jean-Christophe Poggiale
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
| | - Florent Renaud
- Aix-Marseille University, Institut Méditerranéen de Biodiversité et d'Ecologie (IMBE), UMR 7263, Station Marine d'Endoume, Marseille, France
| | - Thierry Thibaut
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
| | - Sandrine Ruitton
- Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Université de Toulon, CNRS/INSU, IRD, UM 110, Marseille, France
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Di Maida G, Tomasello A, Sciandra M, Pirrotta M, Milazzo M, Calvo S. Effect of different substrata on rhizome growth, leaf biometry and shoot density of Posidonia oceanica. MARINE ENVIRONMENTAL RESEARCH 2013; 87-88:96-102. [PMID: 23643476 DOI: 10.1016/j.marenvres.2013.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/29/2013] [Accepted: 04/02/2013] [Indexed: 06/02/2023]
Abstract
The effects of different substratum typologies on Posidonia oceanica growth and morphology were estimated in four Sicilian meadows using Generalized and Linear Mixed Models combined with retrodating and biometric analyses. Substratum exerted a multiple effect, resulting in different biometric features for P. oceanica shoots settled on rock from those growing on sand and matte. On rock, values for growth rate, leaf length and shoot surface were lower than those on other substrata, with 42%, 23% and 32% the highest degree of difference respectively. The present study may have interesting methodological consequences for the comprehensive understanding of the causative variables potentially affecting meadows features and their health status. The importance of substratum in the prediction of likely biometry changes in P. oceanica meadows, means that knowledge of substratum type should receive due attention in the future to derive reliable estimates of meadow status.
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Affiliation(s)
- G Di Maida
- Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università degli Studi di Palermo, Viale delle Scienze Ed. 16, 90128, Palermo, Italy
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11
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Giovannetti E, Montefalcone M, Morri C, Bianchi CN, Albertelli G. Early warning response of Posidonia oceanica epiphyte community to environmental alterations (Ligurian Sea, NW Mediterranean). MARINE POLLUTION BULLETIN 2010; 60:1031-9. [PMID: 20189197 DOI: 10.1016/j.marpolbul.2010.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Revised: 01/27/2010] [Accepted: 01/28/2010] [Indexed: 05/27/2023]
Abstract
The epiphyte community structure of the Posidonia oceanica leaves in three impacted meadows occurring in urbanised coastal areas was contrasted with that observed in three meadows located within Marine Protected Areas in the Ligurian Sea. Samplings were carried out in two distinct periods, at the beginning and at the end of the summer season, in order to individuate early changes in the epiphyte community structure. Differently from the descriptors commonly adopted for evaluating the health status of P. oceanica ecosystem, the epiphyte community structure was able to detect alterations in the water quality already after 4 months. The impacted meadows showed an immature epiphyte community characterised by large development of brown algae. Leaf P. oceanica epiphytes are, thus, proposed as appropriate biological quality elements (BQEs) able to show early responses to environmental alterations and they should be included in the monitoring programs for the conservation and the management of coastal areas.
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Affiliation(s)
- E Giovannetti
- DipTeRis, Department for the study of the Territory and of its Resources, University of Genoa, Corso Europa 26, 16132 Genoa, Italy.
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12
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Montefalcone M, Chiantore M, Lanzone A, Morri C, Albertelli G, Nike Bianchi C. BACI design reveals the decline of the seagrass Posidonia oceanica induced by anchoring. MARINE POLLUTION BULLETIN 2008; 56:1637-45. [PMID: 18603267 DOI: 10.1016/j.marpolbul.2008.05.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 05/08/2008] [Accepted: 05/16/2008] [Indexed: 05/15/2023]
Abstract
The key species Posidonia oceanica is the dominant endemic seagrass in the Mediterranean Sea and its meadows are considered as one of the most important and productive ecosystems in coastal waters. Covering the seabed from the surface down to about 40 m, meadows of P. oceanica are often affected by mechanical direct damages caused by boat anchoring and mooring activities. Negative effects of these activities have been shown to be recorded by P. oceanica at two different levels: the individual level (phenology of the plant) and the population level (structure of the meadow). We investigated the effect of an anchoring chain system on the P. oceanica meadow of Prelo cove (NW Mediterranean Sea) at two different depths (shallow, deep) and at three different situations of P. oceanica bottom cover (high, medium, low). Several standardized descriptors of the meadow health, working either at the individual or at the population level, were analysed in order to quantify the impact of the deployment of the chain system. A symmetrical BACI design was adopted to detect the impact, where multiple disturbed sites were contrasted with multiple controls in two distinct times, i.e. right few days after the chain settling (early) and 4 months later the disturbance (late). The anchoring chain system has been shown to strongly affect the meadow in terms of shoot density decline and rhizome baring, especially in the deep portions and where the cover of the meadow was low. All descriptors working at the population level proved effective in detecting the impact of the anchoring system. In contrast, descriptors working at the individual level did not show a consistent response to the impact. Our results pointed out the imperative necessity to proper regulate the boat anchoring and mooring activities on the P. oceanica meadows and the adoption of seagrass friendly mooring technology is thus recommended.
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Affiliation(s)
- Monica Montefalcone
- DipTeRis, Department for the Study of the Territory and of its Resources, University of Genoa, Genoa, Italy.
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