Proceedings of the 10th International Conference on Artificial Reefs and Related Aquatic Habitats

[No abstract available

Morphometric relationships and variability of annual body condition of Sea urchin (Paracentrotus lividus - Echinodermata: Echinodermata) at Foca coast in the south Aegean Sea

This study reports about ontogenetic allometry of body components for the most common and abundant echinoderm species (Paracentrotus lividus) in the Aegean Sea (western Turkey). Paracentrotus lividus was collected monthly from the coast of Foca for 12 months and biometric parameters were measured (spine test diameter, spine test height, test diameter, test height and weight); then, indices of body components were calculated. The overall population showed a great concentration within the classes' 3.00-4.50 cm test diameter of lengths. The multiple regression (comparison) of body size and body component wet weight showed high interactions between test diameter and total weight (r = 0.95), test diameter and test height (r = 0.86) test height and total weight (r = 0.87), test diameter and lantern length (r = 0.85) but there was not found any significant interaction between the other traits. Test diameter and total weight, test diameter and test height, test height and total weight, total weight and gonad weight, test diameter and gonad weight interactions showed negative allometries (p5.oo3)=21.503, p<0.00l). © by PSP

Comparison of Isochrysis galbana and Chlorella sp. microalgae on growth and survival rate of European flat oyster (Ostrea edulis, Linnaeus 1758) larvae

Influence of microalgal feeding with Isochrysis galbana and Chlorella sp. on the growth and survival rate of larvae of European flat oyster, Ostrea edulis, was investigated. Larvae were reared with four food regimes: I. galbana, Chlorella sp., mixture of both and unfed for 16 days. After 16 days, it was observed that the larvae reached the umbo stage with a mean size in length 220±4.12 µm and 219±5.76 µm (initial length, 159 µm) (P > 0.05). Larvae were fed on I. galbana and mixture diet. At this stage, survival rate was 30% and 24%, respectively (P > 0.05). Growth and survival rates for the feeding regimes were significantly higher than the Chlorella sp. and unfed groups (P < 0.05)

Two experimental fish aggregating systems (FADs) in the Aegean Sea: Their design and application

Two steel spar buoys were constructed and moored in 50 and 100 m deep of water in the Aegean Sea to support recreational fisheries. The first FAD was deployed at coordinates 38°01'48'N 26°58'02'E and at a distance of 3 nautical miles from the shoreline. The other FAD was moored at 1.1 nautical miles from the shoreline at coordinates 38°03'11'N; 26°59'01'E. An anchor (1.2×1.2×0.8 m3) weighing approximate 2.76 metric ton, made of reinforced concrete, was used to hold a FAD weighing approximate 1.5 metric ton. Hardware and connections of FADs, ropes, mooring calculation and anchor design were made. The interaction between the forces of wave and current and FADs in those waters was investigated. In the experiment, all forces (drag force, buoyancy force etc.) acting on FADs were calculated. It is proposed that the construction of the FADs should take the following design criteria into consideration: wave and current, forces related to the FADs, deployment depth, mooring hardware and ropes. This knowledge provides an important reference for stakeholders performing projects aiming to increase the performance and service life FADs

PRESENZA DI CUBICEPS GRACILIS (NOMEIDAE) NEL MEDITERRANEO ORIENTALE SINTESI

This paper reports an additional record of Cubiceps gracilis (Lowe, 1843) indicating the extension of the species’ distribution into the eastern Mediterranean Sea. On 7 January 2022, a single specimen of C. gracilis was caught by bottom trawl at a depth of about 400 m off Antalya in the southern coasts of Turkey. This oceanic fish is still very rare in the eastern Mediterranean Sea. This is the fourth record of C. gracilis in the eastern Mediterranean Basin, the first after 2006. © 2022, Historical Society of Southern Primorska of Koper. All rights reserved

Preliminary spat settlement of fan mussel Pinna nobilis linnaeus 1758 on a mesh bag collector in Karantina Island (eastern aegean sea, Turkey)

The study regarding the annual pattern of Pinna nobilis settlement in Karantina Island (Izmir Bay, Turkey) was conducted using artificial polyethylene-mesh bag collectors (onion bag). The samples were collected by a SCUBA diver at intervals of 4 weeks, also replacing the collectors during 12 months at 8-m depth. In addition, environmental parameters, such as temperature, salinity, chlorophyll-a, particulate organic matter and particulate inorganic matter in water column, were monthly measured. Fifteen bivalve species were recorded, and among these, Ostrea edulis, Pinctada radiata, Chlamys varia, Chlamys glabra Modiolus barbatus, Mytilus galloprovincialis, Area noae, and Anadara inaequivalvis have a commercial value. P. nobilis represented 0.84% of total amount. Settlement was observed only in August (122 individuals/0.4 m 2) and spat data showed significant variations between outside (8%) and inside (92%) of each mesh bag collector but also the deployed time (P&lt;0.05). Length of spat ranged between 0.3 and 15.3 mm. These results showed that reproduction period of fan mussel was during summer months in Izmir Bay, and fan mussel was collected especially in August from natural area. © by PSP

A new artificial reef design for octopus (Octopus vulgaris cuvier, 1797) in the Aegean Sea and preliminary results

This study was carried out in the Gulf of Izmir in the Aegean Sea between June 2006 and November2008. The purpose was the creation of a new concept of the artificial reef for Octopus vulgaris, witha view to establishing new artificial reef sites to be used in the fisheries management of this species(MPA, NTZ or fishing areas). First, the main characteristics of natural octopus nests were recorded(entrance width, length, etc.) by divers. These characteristics were used in the construction of newoctahedral artificial reef blocks. The blocks were made of reinforced concrete, in a shape like that ofan inverted pyramid, with an upper surface of 100×100×25 cm 3 and a lower one of 60×60 cm 2. Fourcylindrical holes each with two ellipsoidal openings were placed in one face and in the lateral edge ofthe octo-block, to serve as the entrances to the artificial nest. Each nest has a volume of 5000 cm 3.Eighty octo-blocks were deployed as artificial reefs at 10 m from each other at 15 different depths attwo sites by divers with the help of the winch of the R/V EGESUF. These artificial octo-reefs werecensused by direct observation. Twenty-eight octopuses were sampled at the end of 25 dives.Minimum mantle length of the octopuses was 75 mm and the maximum 249 mm, with an average of152.71 mm. The average total length was calculated to be 918.57 mm. The weight of the specimenswas between 244 g and 7140 g with an average of 2335.43 g. The results showed that both sites wereinhabited by octopuses coming from the artificial reefs, which used them as nests. These nests seemto have constituted special places for fisheries management and will permit the assessment of reserveareas or marine protection areas (MPA), thus opening up a new perspective for Turkish fisheries