Preliminary Environmental Data from a Pilot Marine Protected Area on the Island of Milos, Greece
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PRELIMINARY ENVIRONMENTAL DATA FROM A PILOT MARINE PROTECTED AREA ON THE ISLAND OF MILOS, GREECE Tselentis B.S.1, Kyriakopoulos K.1, Moghaddam-Gholipour K.S.1, Kavvadas P.1, Kourkouli P.2 1Laboratory of Marine Sciences, University of Piraeus, [email protected] 2 Department of Geography, Harokopio University Greece , [email protected] Abstract It is recognized that the creation of Marine Protected Areas is an important tool in the effort to preserve biodiversity, protect and increase fish stocks, prevent further degradation of the marine environment and to protect and restore habitats. It is deemed timely and topical to establish a network of Marine Protected Areas at both national and regional levels in order to mitigate the destruction of sensitive reproduction ecosystems and protected habitats, as well as restrain uncontrolled overexploitation of fish stocks. In this paper the need to gather scientific information on ways to select and map areas that are in need of protection is highlighted and preliminary scientific data on a marine area on the northern part of Milos Island in the Cyclades, is presented. It is also inferred that all efforts within the framework of sustainable management of marine ecosystems and the marine environment in general are not seen as an isolated project, but as a component of the island’s infrastructure as a whole, as well as a factor of social cohesion and local participation in any management schemes applied. Key Words: MPAs, biodiversity, habitat mapping, Cyclades 1. Introduction Scientific evidence has proven that worldwide marine ecosystems are now manifesting severe biodiversity degradation (Rashid et al. 2005). Marine biodiversity loss has been attributed to habitat degradation, anthropogenic pollution, coastal zone mismanagement, overexploitation of fishing stocks, invasive species, climate change (Dulvy et al. 2003). The Mediterranean has been especially affected by all the above, even though it is recognized as one of the world’s most important biodiversity hotspot inhabited by a large number of endemic species (Bianchi & Morri, 2000). Of the total Mediterranean sea surface (2.510.000 km²) only 95.660 km² are protected (3,8%), whereas the percentage of coastal areas protected (9.910 km²) represents 0,4% of the total sea surface (Blue Plan, 2005 and Rashid et al. 2005). Considering the deviation from the target of 10% described in the Barcelona Convention (CBD) (UNEP/MAP/RAC/SPA, ACCOBAMS, IUCN, WWF MedPO, WWF MedPAN, 2008) and the EU habitats and water directives (European Commission, 2006), it is clear that serious steps have to be implemented in order to avert a serious deterioration of the Mediterranean marine ecosystem. In this respect there are now (2007 data) around a hundred MPAs in the Mediterranean, mainly situated on the Northern coast (Abdulla et al. 2008 and references therein). Already there is a move to establish new MPAs in order to supplement existing ones aiming at creating a geographically and ecologically balanced network targeting valuable habitats representing the different Mediterranean ecoregions. The Marine Sciences Laboratory of the University of Piraeus, as far back as 1990, has been involved in studying the marine area of northern Milos (see Maps 1&2) in order to establish a Marine Protected Area (MPA). An extended data base of sound scientific evidence has been created over the years establishing the special characteristics and species in need of protection. The data presented in this paper was accomplished through a funding from the United Nations Environment Programme Mediterranean Action Plan Regional Activity Centre for Specially Protected Areas (Memorandum of Understanding N° 100 RAC/SPA/2009). 2 The area proposed for an MPA covers a marine area of about 13 km , on the northern coast of Milos Island (see Map 2), in which the protected species Posidonia oceanica is extensive and where monk seals and loggerhead sea turtles have been sited (Tselentis, 2010). In respect to these important critically endangered Red List category species, the proposed area is adjacent to one of its most important breeding grounds (islands of Kimolos and Polyaigos) where a minimum of 30 individuals and a breeding activity of 6 -7 pups/year have been reported (RAC/SPA, 2005). Map 1. Geographical region of the Cyclades Islands, Aegean Sea, Greece (arrowed Milos island) Map 2. Location of the pilot MPA north of Milos Island, Cyclades Islands, Aegean Sea, Greece 2. Methodology The area which has been adopted to house the MPA (see Map 2) is not within the NATURA 2000 areas of Milos (GR4220005 Western Milos and GR4220006 Polyaigos island). The MPA area on the north of the island of Milos was proposed by the Laboratory of Marine Sciences of the University of Piraeus and agreed upon by the professional fishermen and Local Government (municipality) of the island of Milos. The Convention for the protection of the Mediterranean Sea against pollution (Barcelona Convention) of 1976, amended in 1995, and the Protocol concerning specially protected areas and biological diversity in the Mediterranean, have adopted common criteria to establish national inventories of natural sites of conservation interest. The tools elaborated by the Regional Activity Centre for Specially Protected Areas (RAC/SPA), including a Standard Data Form (SDF) were used to compile information concerning the site. The reference list of types of habitat and the reference list of species for selecting the sites to be included in the national inventories, elaborated by RAC/SPA were also used. Mapping of marine habitats was performed based on the 3 types of habitats -1120 - P. oceanica meadows, 1170 - reefs and 8330 - caves, highlighted by prior knowledge compiled for the area and the available classification (European reference codes for identification - European Council’s NATURA 2000 and EMERAUDE network of sites to the specific features of the Mediterranean). Supralittoral and mediolittoral biocenoses were not considered. 2.1. HABITAT MAPPING Seagrass meadows are ecologically very important since they form dense and highly productive beds of extreme value to invertebrates and fish, provide protection against coastal erosion, increase dissolved oxygen concentrations in sea water and capture / sequester large quantities of CO2. Pocidonia oceanica meadows are protected at the European level, as a priority habitat (Dir. 92/42 CEE 21/05/92 and 97/62/CE 27/10/1997) and as a strictly protected flora species (Bern Convention, Appendix I). Bottom-trawling is expressly forbidden on seagrass meadows (Fishing regulation 1626/94 and 1967/2006). Due to the above, the methodology used to map habitats in the area under study, was influenced by available and appropriate techniques for mapping seagrasses in areas of different size and water depth. The options available for mapping seagrasses include remotely sensed data from satellites and/or airborne sensors, acoustic remote sensing (side scan sonar), real-time towed video camera, diver observations and grab sampling. In our case the option of mapping the seagrass by remote sensing was not selected mainly because the sea bottom signal is not always distinct and is influenced by the atmosphere (cloud), the condition of the sea-atmosphere interface (waves), the water column and the sea bottom itself. In clear shallow waters with seagrasses occurring on a light, sandy bottom, the contours of the meadows can easily be distinguished in remotely sensed images such as aerial photos. In our situation however, all available aerial photos we could find, were influenced by wave action and could not distinguish seagrass meadows at depths greater than 10 meters max. Satellite pictures, as stated before, are prone to the same confounding factors, plus the fact that they have a high cost to purchase and analyze. It was thus decided to use ground survey techniques, even though they too are often costly and inconvenient for mapping large coastal areas. The ground survey used by our team involved non-destructive techniques involving a fishing vessel of 5.5m in length, real-time towed under water video camera connected to a surface monitor and video recording unit. Data from a GPS plotter (Map 3) and depth echosounder were recorded simultaneously; ground-truthing verification by deployment of a seabed grab (van veen grab sampler) and direct inspection by SCUBA divers were also used. The 0 – 10m zone was surveyed with a smaller craft and a visual examination for habitat mapping was performed using a glass-bottomed bucket. This was very useful at times in conjunction to the surface diving (skin diving) used, since one could cover a larger distance and more importantly have a wider perspective than a surface diver due to the wider angle the transparent surface (d=40cm) produces in the sea. Also the representation of the sea bed is in a continuum (since the boat is moving steadily in one direction) rather than in a patchy manner that a skin diver experiences. Although, at first, it was believed that this visual surveying could cover the 0 to 10m zone, it was clearly realized that this surveying technique was nor reliable beyond a depth of 5m. For depths of up to 10m only skin diving was used. For depths of 10 – 50m a U/W video camera, in a cage attached to a strong rope supporting the umbilical cord as well, was used. This is lowered and moves slowly over the sea surface, its movements observed on a monitor and recorded on tape. Following the echosounder placed afore, one can monitor the depth and by lifting or releasing the rope keep the required distance from the sea bed to have a detailed of a panoramic view. The images from this footage were reviewed and in conjunction to GPS and depth data as well as ground-truthing with SCUBA diving and van veen Grab sampling, were used to clearly map the areas surveyed. In this way it was possible to map (see Map 3) the patchy Posidonia areas.