Acta Adriatica, Vol. 57 No. 2, 2016.
Original scientific paper
The most suitable time and depth to sample Cymodocea nodosa (Ucria) Ascherson meadows in the shallow coastal area. Experiences from the northern Adriatic Sea
Martina ORLANDO-BONACA
; Marine Biology Station, National Institute of Biology, Fornače 41, SI - 6330 Piran, Slovenia
Lovrenc LIPEJ
; Marine Biology Station, National Institute of Biology, Fornače 41, SI - 6330 Piran, Slovenia
Janja FRANCÉ
; Marine Biology Station, National Institute of Biology, Fornače 41, SI - 6330 Piran, Slovenia
Abstract
The Lesser Neptune grass, Cymodocea nodosa, is the most common seagrass species in shallow sheltered to semi-exposed sites along the Mediterranean soft bottom. The MediSkew index was
recently developed as an improvement of the CymSkew index, in order to assess the status of C. nodosa meadows correctly in view of the implementation of three European Directives. The index takes into account the length of the photosynthetic part of C. nodosa leaves, which increases from the less degraded meadow to the most degraded meadow. To adequately assess temporal and spatial trends in the status of C. nodosa meadows, including estimates of the effects of natural disturbances within marine protected areas, the MediSkew index was applied to new samples collected at 3 m and at 6 m of depth, during two months (in July and in September). The analyses are discussed in view of monitoring and conservation of C. nodosa meadows. According to the results of this study, the monitoring programme in the northern Adriatic Sea should be conducted in July, with the collection of samples at 3 m of depth. The presented sampling and assessing methodology proved to be time- and cost-effective for the evaluation of the status of C. nodosa meadows and of human-induced pressures.
Keywords
Cymodocea nodosa; MediSkew index; leaf lengths; sampling time; sampling depth; northern Adriatic Sea
Hrčak ID:
171641
URI
Publication date:
12.12.2016.
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