The impact assessment of cage aquaculture on benthic communities along the south eastern Black Sea

The present study was conducted to examine the impact of cage aquaculture on benthic communities in coastal areas (depth 25 to 50 m) from fish farming operations located along the southeastern Black Sea (Ordu-Perşembe, Trabzon-Yomra and Rize central). Sampling was conducted seasonally from April 2007 to 2009. Sediment samples were taken using Ekman Grab (box core- 0.04 m2). Temperature, salinity, and water velocity were periodically measured to determine influencing sedimentary organic matter in the sediment, oxygenation, and anoxic conditions. In addition, grain size of sediment, organic carbon content, and distribution of benthic communities were investigated. In order to determine benthic impact of fish farms on the region, Shannon – Wiener diversity index (H’), AMBI (AZTI Marine Biotic Index) and M-AMBI (Multivariate- Marine Biotic Index) indices were used. Results of current study showed that benthic zone ecological quality of stations with number 01, 02, 03, and 04 at Ordu-Perşembefish-farming habitat was found to be very low. In autumn 2008, there were 3 species which belonged to Capitella capitata (844 individuals/m2), Capitella sp. (133 individuals/m2), and Heteromastus filliformis (311 individuals/m2) at OP-01 station. In addition, the impact of Trabzon-Yomra fish-farming activity on benthic communities was low. The degree of exposure for Rize fish-farming area in all seasons was quite low, which was not a significant negative impact

Seasonal changes of invertebrate fauna associated with Cystoseira barbata facies of Southeastern Black Sea Coast

This research was carried out to determine the invertebrate fauna associated with Cystoseira barbata facies distributed in the upper-infralittoral zone of the Southeastern Black Sea coasts and their bioecological features. The investigations were seasonally performed at depths of 0 to 3 m in 5 different stations chosen in the Southeastern Black Sea from July 2005 to May 2006. As a result of the study, a total of 6123 specimens belonging to 38 species and 4 taxonomic groups were identified. Arthropoda was the dominant group in terms of number of species (55.3% of the total of phylum) and number of individuals (83.9% of the number total individuals). With regard to frequency index, 14 species were defined as continious, 8 species of common and 16 species as rare. Idotea metallica is reported for the first time from the Black Sea coast of Turkey in the present study. © 2010 Academic Journals

New records of two species of gnathiid isopods, Paragnathia formica (Hesse, 1864) and Gnathia maxillaris (Montagu, 1804) (isopoda, gnathiidae) from the black sea

During fieldwork on the southeastern Black Sea coast, in October 2009, two gnathiid isopods were found in their free-living stage, Paragnathia formica (Hesse, 1864) and Gnathia maxillaris (Montagu, 1804). These species are herein reported from the Black Sea for the first time.© Koninklijke Brill NV, Leiden, 2011

The Benthic exotic species of the Black Sea: Blood cockle (Anadara inaequivalvis, Bruguiere, 1789: Bivalve) and Rapa whelk (Rapana thomasiana, Crosse, 1861: Mollusc)

The Black Sea is in transition from a freshwater to a marine environment and has a very low biodiversity. Therefore, it appears to be particularly vulnerable and easy target for many exotic species. Anthropogenic introductions of exotic species into the Black Sea began in the 19th century, but accelerated during the second half of the century. There are about 36 kinds of introduced species in Black and Azov seas now and some of them had already severe damage to part or whole ecosystem, while some may have limited or neutral impacts. Current status of two exotic benthic species presented here: Rapa Whelk, Rapana thomasiana and blood-cockle, Anadara inaeguivalvis. Most dramatic changes to benthic ecosystem of the Black Sea has taken place after introduction of predatory gastropod Rapa whelk from Far East (Sea of Japan) to the Black Sea in 1940s and has since spread to the Aegean and Adriatic Seas. The second species blood-cockle is a filtering feeding bivalve introduced 20 years ago, but not so well-known since its invasion ability and impact on ecosystem seems to be not very devastating. Particularly rapid distribution and increased biomass of Rapa Whelk caused severe damage to narrow benthic ecosystem. It has direct (predation on bivalves) and indirect (fishing with dredges) negative impacts on the ecosystem. Annual Rapa. whelk catches from Turkey and Bulgaria reached totally 13,000 ton year-1. This study presents updated information on spatial distribution, habitats preferences, population structures, ecological and economical impacts of two exotic species; Rapa whelk and blood-cockle. © Medwell Journals, 2009

The impact assessment of cage aquaculture on benthic communities along the south eastern Black Sea

The present study was conducted to examine the impact of cage aquaculture on benthic communities in coastal areas (depth 25 to 50 m) from fish farming operations located along the southeastern Black Sea (Ordu-Perembe, Trabzon-Yomra and Rize central). Sampling was conducted seasonally from April 2007 to 2009. Sediment samples were taken using Ekman Grab (box core- 0.04 m2). Temperature, salinity, and water velocity were periodically measured to determine influencing sedimentary organic matter in the sediment, oxygenation, and anoxic conditions. In addition, grain size of sediment, organic carbon content, and distribution of benthic communities were investigated. In order to determine benthic impact of fish farms on the region, Shannon - Wiener diversity index (H'), AMBI (AZTI Marine Biotic Index) and M-AMBI (Multivariate- Marine Biotic Index) indices were used. Results of current study showed that benthic zone ecological quality of stations with number 01, 02, 03, and 04 at Ordu-Perembefish-farming habitat was found to be very low. In autumn 2008, there were 3 species which belonged to Capitella capitata (844 individuals/m2), Capitella sp. (133 individuals/m2), and Heteromastus filliformis (311 individuals/m2) at OP-01 station. In addition, the impact of Trabzon-Yomra fish-farming activity on benthic communities was low. The degree of exposure for Rize fish-farming area in all seasons was quite low, which was not a significant negative impact