Proceedings of the Second Mediterranean Symposium on Marine
Proceedings of the Second Mediterranean Symposium on Marine
Proceedings of the Second Mediterranean Symposium on Marine
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PROCEEDINGS OF THE SECOND MEDITERRANEAN SYMPOSIUM ON MARINE VEGETATION (ATHENS, 12-13 DECEMBER 2003)<br />
236<br />
MAPPING OF THE POSIDONIA OCEANICA<br />
MEADOW ON THE SLOVENIAN COAST<br />
Tihomir MAKOVEC 1 & Robert TURK 2<br />
1 <strong>Marine</strong> Biology Stati<strong>on</strong> Piran, Nati<strong>on</strong>al Institute <str<strong>on</strong>g>of</str<strong>on</strong>g> Biology, Fornace 41, 6330 Piran, Slovenia<br />
2 Institute <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Republic <str<strong>on</strong>g>of</str<strong>on</strong>g> Slovenia for Nature C<strong>on</strong>servati<strong>on</strong>, Regi<strong>on</strong>al Office Piran, Tartinijev trg 12, 6330 Piran, Slovenia<br />
INTRODUCTION<br />
Mapping <str<strong>on</strong>g>of</str<strong>on</strong>g> seagrass meadows has become an indispensable tool for a proper research<br />
and l<strong>on</strong>g-term m<strong>on</strong>itoring <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> meadows in view <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g>ir management and protecti<strong>on</strong>.<br />
A preliminary investigati<strong>on</strong> <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> size and morphological features <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Posid<strong>on</strong>ia<br />
oceanica (L.) Del. meadow <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> Slovenian coast was carried out by SCUBA divers<br />
already in 1993 (Vukovic & Turk, 1995). More accurate methods were needed in order<br />
to state stability, progressi<strong>on</strong> or regressi<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> meadow and to take proper<br />
c<strong>on</strong>servati<strong>on</strong> measures. A Memorandum <str<strong>on</strong>g>of</str<strong>on</strong>g> Understanding (2002) between <str<strong>on</strong>g>the</str<strong>on</strong>g> Institute<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Republic <str<strong>on</strong>g>of</str<strong>on</strong>g> Slovenia for Nature C<strong>on</strong>servati<strong>on</strong>, <str<strong>on</strong>g>the</str<strong>on</strong>g> Internati<strong>on</strong>al Cooperati<strong>on</strong> for<br />
Envir<strong>on</strong>ment and Development <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Principality <str<strong>on</strong>g>of</str<strong>on</strong>g> M<strong>on</strong>aco and <str<strong>on</strong>g>the</str<strong>on</strong>g> Regi<strong>on</strong>al Activity<br />
Centre for Specially Protected Areas (RAC/SPA) <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Barcel<strong>on</strong>a C<strong>on</strong>venti<strong>on</strong> enabled <str<strong>on</strong>g>the</str<strong>on</strong>g><br />
financing <str<strong>on</strong>g>of</str<strong>on</strong>g> aerial photography and <str<strong>on</strong>g>the</str<strong>on</strong>g> elaborati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> a map <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> meadow.<br />
Study area<br />
The study area is located in <str<strong>on</strong>g>the</str<strong>on</strong>g> Gulf <str<strong>on</strong>g>of</str<strong>on</strong>g> Trieste (nor<str<strong>on</strong>g>the</str<strong>on</strong>g>rn Adriatic), between <str<strong>on</strong>g>the</str<strong>on</strong>g> towns <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
Izola and Koper, with <str<strong>on</strong>g>the</str<strong>on</strong>g> <strong>on</strong>ly site <str<strong>on</strong>g>of</str<strong>on</strong>g> P. oceanica seagrass meadow al<strong>on</strong>g <str<strong>on</strong>g>the</str<strong>on</strong>g> nor<str<strong>on</strong>g>the</str<strong>on</strong>g>rn<br />
and western coasts <str<strong>on</strong>g>of</str<strong>on</strong>g> Istria. The patches <str<strong>on</strong>g>of</str<strong>on</strong>g> Posid<strong>on</strong>ia are situated between st<strong>on</strong>y<br />
coastline and mud bottom, at a depth from 0.5 to 4 m. The area is 1 km l<strong>on</strong>g and 50<br />
m wide. The meadow density varies between 360 and 588 shoots/m 2 . The area is a<br />
known tourist resort with many recreati<strong>on</strong>al activities and has been subjected to some<br />
extent to organic polluti<strong>on</strong> from <str<strong>on</strong>g>the</str<strong>on</strong>g> city <str<strong>on</strong>g>of</str<strong>on</strong>g> Koper.<br />
Mapping and m<strong>on</strong>itoring<br />
A special emphasis was laid <strong>on</strong> underwater mapping <str<strong>on</strong>g>of</str<strong>on</strong>g> different habitat types (Turk<br />
et al., 2002). The underwater inspecti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> area was carried out at five sampling<br />
stati<strong>on</strong>s in <str<strong>on</strong>g>the</str<strong>on</strong>g> years 2000-2001. The diver with camera followed <str<strong>on</strong>g>the</str<strong>on</strong>g> transect rope and<br />
filmed all habitat types. The coverage <str<strong>on</strong>g>of</str<strong>on</strong>g> each habitat type was calculated from <str<strong>on</strong>g>the</str<strong>on</strong>g> habitat<br />
type distributi<strong>on</strong> drawings.<br />
Aerial photography and fur<str<strong>on</strong>g>the</str<strong>on</strong>g>r image processing appears to be a technique which is<br />
particularly suitable in shallow waters (Pasqualini et al., 1998). The aerial photographs <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
<str<strong>on</strong>g>the</str<strong>on</strong>g> meadow were taken during winter 2002/2003, in <str<strong>on</strong>g>the</str<strong>on</strong>g> period <str<strong>on</strong>g>of</str<strong>on</strong>g> greater transparency<br />
<str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> water and when <str<strong>on</strong>g>the</str<strong>on</strong>g> nearby Cymodocea nodosa meadow is not yet grown.The<br />
results were checked out by SCUBA diving in <str<strong>on</strong>g>the</str<strong>on</strong>g> following m<strong>on</strong>ths. Aerial photographs