Review of the research on Artificial Reefs in the Mediterranean Sea

Transcription

1 Review of the research on Artificial Reefs in the Mediterranean Sea Giuseppe Scarcella National Research Council (CNR) Institute for Biological Resources and Marine Biotechnologies (IRBIM) Ancona, Italy

2 CONTENTS BRIEF OVERVIEW ON THE MEDITERRANEAN SEA EVOLUTION OF ARS IN THE MEDITERRANEAN SEA ON TIME RESEARCH TOWARD THE UNDERSTANDING OF THE ECOLOGICAL ROLE OF ARS (2 EXAMPLES)

3 The largest (2,969,00 km 2 ) and deepest (average 1,460 m, maximum 5,265 m) enclosed sea on Earth covering 0.7% of the world s ocean area 46,000 km costline Atlantic Ocean Black Sea Bosphorus strait Gibraltar strait Mediterranean Sea 23 Countries 7 EU Member States Suez canal

4 Med is one of the major reservoirs of marine and coastal biodiversity, with 7.5% of the world s marine fauna, 18% of its marine flora and 28% of endemic species MARINE PROTECTED AREAS 1,231 MPAs and OECMs covering 7.14% of the Med 898 marine Natura 2000 sites 186 sites designated nationally 100 sites (at least) are being considered to become MPAs or OECMs From Med/PAN et al., 2016

5 URBANIZATION The population of coastal regions was 215 millions in It is expected to reach 650 millions by 2025 TOURISM More than 320 millions of tourists in 2015 OFFSHORE GAS & OIL PRODUCTION Especially in the Italian continental shelf (~140 offshore platforms), but also in Greece, Spain, Croatia, eastern and southern Med AQUACULTURE ~53% of the EU aquaculture production comes from the Med SHIPPING Intense marine traffic FISHING More than 81,000 fishing vessels in 2015 (FAO, 2016)

6 Small-scale fleet segment generally exceeds 60% of the total fleet size at State level LBN GRC CYP MLT TUR TUN MAR FRA SVN HRV LBY ITA PSE ALB MNE DZA ESP EGY 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Small-scale Other fleet segments Small-scale Trawlers Purse seiners & pelagic trawlers Others and accounts for 55% of the total of people directly employed in fisheries Group of fleet segments Subregions Total vessels % Small-scale % Trawlers % Purse seiners & pelagic trawlers % Others % Western Med Ionian Sea Adriatic Sea Eastern Med From FAO, 2016

7 Most activities interfere each other for spaces and resources.and can contribute to deplete the natural habitats

8 IN THIS CONTEXT ARs can play a relevant role for: protecting sensitive habitats from fishing activities restoring depleted habitats enhancing biodiversity and improving populations of aquatic organisms by providing shelter and available substrates for juvenile and mature individuals as well as for adults during delicate life stages (e.g. moulting season for crustaceans) AS WELL AS for: enhancing professional and recreational fisheries contributing to manage coastal activities and reduce conflicts (MSP)

9 INTERNATIONAL MEDITERRANEAN UNEP-MAP-UN 2008 IMO-UNEP 2009 SPAIN 2008 NATIONAL FAO-GFCM 2015 Mediterranean and Black Sea FRANCE 2009, 2012 & 2015

10 Realized by private Companies, without any scientific support Pavalas-les-Flots (1968) Varazze (1970) Modules: 100 body cars 50 concrete blocks (1 m 3 ) 15 busses 7 tons of tires Modules: 1,300 body cars 2 barges GOAL: to support and develop local fishing by increasing the productivity of the environment GOAL: to prevent trawling and improve recreational fishing in the area

11 PORTO RECANATI AR (Realized by CNR in ) AR Surface: 20 km 2 Modules: 12 pyramids each built with 14 concrete cubic blocks (2x2x2 m) 12 stone piles 2 wood wrecks 285 concrete cubic blocks (2x2x2 m) GOALS to prevent illegal trawling inside the coastal zone to induce finfish re-population to improve biodiversity to redirect the flow of excess nutrients occurring in the Adriatic coastal waters into edible biomass through development of filterfeeders (mussels and oysters) to enhance small-scale fisheries

12 353 ARs

13 Goals Materials

14 The modern concept of ARs was adopted in the Mediterranean Sea in 1960s Initial main scopes were habitat protection & fishery enhancement but in the last decade there has been an increasing interest for: the development of even more innovative and specialized ARs which take into account the ecology of the target species the use of ARs to improve sustainable tourism through the construction of either multipurpose ARs (habitat enhancement, finfish repopulation and tourism) and/or ARs strictly focused on tourism A different approach based on a major involvement of stakeholders Great potential for further use of ARs in MSP often not fully exploited due to a generalized lack of regulation on AR governance

15 Attraction vs Production debate 3rd CARAH Newport, California Two opposing, yet not mutually exclusive models have been proposed to explain increased abundances in proximity of ARs.

16 Attraction vs Production debate Attraction hypothesis: The reefs act purely as fish aggregation devices, providing behavioral cues that exploit the thigmotactic tendencies of fish species.

17 Attraction vs Production debate Production hypothesis: Rather than concentrating existing individuals into a smaller area, ARs provide additional habitat, increasing area s carrying capacity.

18 Growth performance of Scorpaena porcus and Scorpaena notata associated with artificial structures Scorpaena notata Scorpaena porcus

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20 Role of ARs on food web Sciaena umbra Diplodus annularis Lithognathus mormyrus

21 Benthic communities Fishing survey AR substrates Seabed inside AR Seabed outside AR Original seabed Inside AR Open sea Analysis of gut contents

22 Benthic communities Total Richness Abundance

23 S P E C I A L I S T CRUSTACEANS Feeding behaviour CRUSTACEANS MOLLUSCS G E N E R A L I S T CRUSTACEANS HYDROIDS

24 Role of the environment in the trophic behavior original habitat outside AR inside AR not found concrete substrates original habitat outside AR inside AR not found concrete substrates original habitat outside AR concrete substrates inside AR not found

25 Feeding behaviour

26 THANK YOU