Taxonomic composition of phytoplankton in Black Sea area in front of the Cape Galata (2008-2016)

D. Klisarova, D. Gerdzhikov

Institute of Fish Resources, 9000 Varna, Bulgaria
(Manuscript received 13 August 2017; accepted for publication 3 October 2017)

Abstract. In this article have been investigated the taxonomic structure of the phytoplankton communities developing in the Black Sea area in front of the Cape Galata. For the period 2008 – 2016, relatively high species diversity was found (161 species). Throughout the most of the year dominated class Dinophyceae (up to 54.17%). The number of phytoplankton species decreased with distance from the shore, but the percentage participation of the group of peridineas and diatoms in the general taxonomic composition grew. Only in class Prymnesiophyceae increased biodiversity was registered in the high seas

Investigation of the biota of Burgas Bay, Black Sea

D. Klisarova*, E. Petrova, D. Gerdzhikov, S. Stoykov

Institute of Fish Resources, 4 Primorski, 9000 Varna, Bulgaria
(Manuscript received 23 March 2016; accepted for publication 30 May 2016)

Abstract. Burgas Bay is the largest one on the Bulgarian Black Sea coast. Industrial plants along the coast as well as ports for liquid and solid cargoes create conditions of anthropogenic pressure on hydrobionts in that area. Macrozoobenthos and phytoplankton samples were collected under a specific scheme in connection with the construction of the Burgas-Alexandroupolis oil pipeline, at stations located around the designated places for unloading tankers. During the study period (2009 – 2010), 88 phytoplankton species distributed in 13 classes were identified and over 50 species of benthic species distributed in four main groups: Polychaeta, Mollusca, Crustacea and the mixed group Diversa.


Egg quality traits in layers from different production types

H. Lukanov

Abstract. Egg quality traits have been investigated in chickens from different production types, namely egg-laying breeds or breeds interesting from the point of view of genetic diversity maintenance. In this research, studied eggs were produced by 50-week-old layers from the following breeds: Rhode Island Red, Rhode Island White, Starozagorska Red, Schijndelaar, White Leghorn and Black Shumen chicken. The studied egg traits were egg weight (g), egg shape index, albumen index, Haugh units, yolk index, yolk colour (Roche), eggshell weight (g) and average eggshell thickness (μm). Among the tested breeds, the eggs of Rhode Island White line D were with the highest weight: 63.3±0.77 g. White Leghorn eggs were with the highest albumen index: 9.07±0.23 and Haugh units: 83.13±0.98. The greatest eggshell thickness had eggs of Rhode Island White line D (422.98±6.26 μm).


Blue-green coloured eggs in Gallus gallus domesticus

H. Lukanov
Abstract. Chicken eggs with blue-green coloured eggshells have been known for centuries. The pigmentation is due to deposition of biliverdin IX and biliverdin zinc chelate in eggshell and underlying membranes during their formation. The deposition of pigment is determined by a dominant autosomal gene, marked with О. According to most recent research, the gene responsible for this mutation is SLCO1B3. In the world, there are some breeds and breed groups of chickens that lay eggs with blue-green eggshells. During the last two decades there has been an increasing interest in non-traditionally coloured eggs in West Europe, North America and Japan. Consequently, some egg-laying chicken strains laying blue-green eggs have been created. All non-purebred and hybrid layers producing blue-green eggs are collectively called Easter Eggers and contribute to the maintenance of biological diversity in domestic chickens.


Environmental studies of the macrozoobenthos in the nearby coastal zone along the Bulgarian Black Sea coast

E. Petrova, S. Stoykov
Abstract. The interest in studies of the nearby coastal zone of the Black Sea is great because it is the most productive section of the basin. The variety of habitats, water aeration, good temperature and density of nutrients coming from the nearest land and littoral contribute to the development of intensive life in it. In this area there are representatives of almost all groups of benthic organisms with the exception of some deep species. At the same time proximity to the coast makes it the most polluted part of the sea. Following the EU requirements pollutants are greatly reduced, which affects favourably biodiversity in the Black Sea ecosystem. 77 taxa of macrozoobenthos species were established, divided into four main groups: Polychaeta, Mollusca, Crustacea and “Diversa”. The ecological status is calculated on the Index of species diversity (H’), marine biotic index (AMBI) and multivariate Marine Biotic Index (M-AMBI). The results of the studies of macrozoobenthos from north to south in the nearby coastal area tend to improve the ecological situation in comparison with previous periods.