Organic matter recycling during a mucilage event and its influence on the surrounding environment (Ligurian Sea, NW Mediterranean)

Meiofauna in sediments colonized by Posidonia oceanica in the Ligurian Sea (NW Mediterranean) was investigated to evaluate its use as an early warning indicator of environmental disturbance. Descriptors commonly used in seagrass health assessment are mainly related to the plant (e.g., phenological parameters) and/or to the meadow (e.g., structural parameters) and are subjected to long-term response times. Conversely, meiofauna is considered a good bioindicator with a rapid response to environmental variations, due to its main features (e.g., short life cycle, scarce mobility, presence/absence of tolerant/sensitive species). Meiofaunal community, sediment characteristics and organic matter descriptors in three meadows located in urbanized coastal areas were contrasted with those observed in three meadows located within Marine Protected Areas. 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 meiofaunal assemblages. The meiofauna and, particularly, the nematode assemblage composition and diversity, highlighted differences among meadows at the end of the summer not detectable by organic matter descriptors and structural parameters of the meadow (e.g. shoot density). Nematodes are, thus, proposed as appropriate biological quality elements (BQEs) able to show early responses to environmental disturbance.

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Organic matter recycling in a shallow coastal zone (NW Mediterranean): The influence of local and global climatic forcing and organic matter lability on hydrolytic enzyme activity

Continental Shelf Research ◽

10.1016/j.csr.2008.09.006 ◽

2008 ◽

Vol 28 (20) ◽

pp. 2725-2735 ◽

Cited By ~ 15

Author(s):

Cristina Misic ◽

Anabella Covazzi Harriague

Keyword(s):

Organic Matter ◽

Enzyme Activity ◽

Coastal Zone ◽

Hydrolytic Enzyme ◽

Climatic Forcing ◽

Nw Mediterranean ◽

Organic Matter Recycling

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Sedimentary organic matter and bacterial community in microtidal mixed beaches of the Ligurian Sea (NW Mediterranean)

Chemistry and Ecology ◽

10.1080/02757540412331280402 ◽

2004 ◽

Vol 20 (6) ◽

pp. 423-435 ◽

Cited By ~ 16

Author(s):

Mauro Fabiano ◽

Valentina Marin ◽

Cristina Misic ◽

Mariapaola Moreno ◽

Vanessa-Sarah Salvo ◽

...

Keyword(s):

Organic Matter ◽

Bacterial Community ◽

Sedimentary Organic Matter ◽

Ligurian Sea ◽

Nw Mediterranean

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

Journal of Marine Science and Engineering ◽

10.3390/jmse8110911 ◽

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.

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