scholarly journals Abundance and Summer Distribution of a Local Stock of Black Sea Bottlenose Dolphins, Tursiops truncatus (Cetacea, Delphinidae), in Coastal Waters near Sudak (Ukraine, Crimea)

2016 ◽  
Vol 50 (1) ◽  
pp. 49-56 ◽  
Author(s):  
E. V. Gladilina ◽  
P. E. Gol’din

Abstract The first assessment of abundance of a local population of bottlenose dolphins in the Black Sea (near the Sudak coast) in 2011–2012 has been conducted: the results of a mark-recapture study of photo identified animals were complemented by a vessel line transect survey. The overall abundance of a population was estimated at between 621 ± 198 and 715 ± 267 animals (Chapman and Petersen estimates), and the majority of members of the population were recorded in the surveyed area. The summer range covered the area of a few hundred square kilometers, similar to migrating coastal stocks in other world regions. The greatest density of distribution was observed in August in sea 45–60 m deep; in addition, frequent approaches to the coastline are usual for dolphins of this stock. These trends in distribution may be partly explained by distribution of prey. Interaction with sprat trawling fisheries can be a factor shaping the local population structure. Coastal waters of Sudak and adjoining sea areas are an important habitat for bottlenose dolphins in the northern Black Sea, significant for their conservation.

2020 ◽  
Vol 2020 (19) ◽  
pp. 103-107
Author(s):  
Oksana Savenko ◽  
◽  

Piebaldism is one of three types of hypopigmentation of animals, when some areas on the skin have no pigments. Anomalously white cetaceans are rare, although they have been reported in more than 20 different cetacean species, including the common bottlenose dolphin, which in the Black Sea is recognized as an endangered endemic subspecies — the Black Sea bottlenose dolphin (Tursiops truncatus ponticus Barabash-Nikiforov, 1940). Its main habitat in the north-western Black Sea region is the coastal waters, however, these dolphins also occur offshore. Thirty cases of anomalously white bottlenose dolphins have been reported from the Black Sea, which were unevenly distributed, and only a few sightings have been reported from the north-western Black Sea. Cetacean observations were conducted in the Ukrainian part of the north-western Black Sea waters in April 2017, onboard the research vessel "Auguste Piccard". All encountered cetaceans were photographed, and individual distinctiveness of dorsal fin images was used for their photo-identification. On 13 April 2017, four groups of up to four individuals of bottlenose dolphins were encountered in the same area at a distance of 61 km south of Odesa (34 km from the nearest coast). The depth at the observation site was about 20 m. The initially observed type of dolphins’ behavior was feeding. However, two groups changed their behavior and followed the vessel by 5–6 individuals for approximately 18 minutes. The joint group consisted of adults and one juvenile individual. Among the adults, there was one piebald specimen with white patches on its dorsal fin, peduncle, and tail fluke. The piebald dolphin was photographed and photo-identified. Our research has shown that piebald Black sea bottlenose dolphins occur not only in the coastal waters, but also in offshore waters of the north-western Black Sea. However, the frequency of such hypopigmentation in local populations remains unknown. Further intensive photo-identification and genetic sampling of local stocks of the Black Sea bottlenose dolphins are necessary for the assessment of their population genetic structure and its divergence.


2004 ◽  
Vol 40 (3) ◽  
pp. 42-54 ◽  
Author(s):  
A. D. Gordina ◽  
V. G. Tsytsugina ◽  
Ye. I. Ovsyaniy ◽  
A. S. Romanov ◽  
R.B. Kemp

2013 ◽  
Vol 49 (3) ◽  
pp. 105-111 ◽  
Author(s):  
Ye. B. Mel'nikova ◽  
Yu. N. Tokarev ◽  
N. V. Burmistrova

2019 ◽  
Vol 59 (6) ◽  
pp. 1008-1015
Author(s):  
A. D. Gubanova ◽  
O. A. Garbazey ◽  
D. A. Altukhov ◽  
V. S. Mukhanov ◽  
E. V. Popova

Long-term (20032014) routine observations of zooplankton in Sevastopol Bay (the Black Sea) have allowed the naturalization of the invasive copepod Oithona davisae to be studied in the Black Sea coastal waters. Inter-annual and seasonal variability of the species and their impact on the native copepod community have been analyzed. The invasion of O. davisae and their undoubted dominance in terms of abundance were shown to alter the community structure but, at the same time, the abundances of the native species did not decrease, excepting the Black Sea earlier invader Acartia tonsa. A significant decline in A. tonsa numbers over the stages of O. davisae establishment and naturalization provided evidence of competition between the species. O. davisae have been demonstrated to gain competitive advantage over A. tonsa, that ensured their fast dispersal in the Black Sea, acclimatization in the new habitat and the successful competition over native species.


Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.


Author(s):  
Daniel Cocan ◽  
Vasile Otel ◽  
Calin Latiu ◽  
Vioara Miresan

In August 2015 we managed to capture a specimen of ratan goby (Ponticola ratan) in the Romanian coastal waters of the Black Sea, near the locality of Sf. Gheorghe (Tulcea County). This is the 7-th signaling for this species in Romanian coastal waters. The previous 6 specimens were recorded in the period 1960-1993, between Mangalia (Constanţa County) and Sulina (Tulcea County). The species was identified by means of meristic characters (number of scales on medial line, number of spiny and soft rays), and morphological particularities (cycloid scales on the nape area and pectoral fin joint). Also, the measurements made, confirmed that the ratio between the head length and total length, which was 33% (TL=8.70 cm vs. Head Length=2.61cm). Another morphological character, specific to this species, is the lower jaw, which exceeds in length the upper jaw. Being a Ponto-Caspian endemite, with low population along the Bulgarian and Romanian coastline, we considered it important to point out this new record. Noting that, being known the trend of sporadic migration of this species, would not be excluded that global warming causes a shift from its normal distribution area, from northern and northeastern (Black Sea) to south-west. Therefore, future research may bring more notifications regarding this species in south-western area of the Black Sea


1996 ◽  
Vol 32 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Adriana Cociasu ◽  
Liliana Dorogan ◽  
Christoph Humborg ◽  
Luci Popa

Purpose. To study the state of ichthyofauna in the Zmiinyi Island coastal waters in 2016-2017. Methods. Standard methods of ichthyofauna sampling, determination, abundance and biomass estimation. Results. During the period of studies, 68 species of marine, brackish-water and freshwater fish were found in the Zmiinyi Island area belonging to 18 orders, 41 families and 55 genera. The biggest number of taxa belongs to Perciformes order. The representatives of this order make one-half of all the species found near the island. Indicators of ichthyofauna species diversity in the Zmiinyi Island area were gradually decreasing in the period from 2003 to 2009. In 2015-2016 all those indicators grew significantly. Biodiversity level (Shannon index values calculated coming out of number) in 2016 varied from 0.86 to 3.06 making in the average 2.06; in 2017 – from 2.40 to 2.54 making in the average 2.47. Minimal values of biodiversity indicators were registered in the end of autumn and in winter, maximal – in May-June. In the Zmiinyi Island coastal waters 30.9% of all the fishes registered in the Black Sea were found. The fishes caught near the island belonged to 5 ecological groups. The basis of ichthyofauna in the area was formed by marine fish species – 52 species (76.5 % of the total number of species). Most of species (54 species or 89.4%) were bottom-dwelling or near-bottom. Pelagophylic and protecting species prevailed and their numbers were almost equal (24 species or 35.3% and 23 species or 33.8% respectively). On the type of feeding, predatory (37%) and benthos-eating (33%) species prevailed. Out of 68 species found in the island area, 16 species are included into the Red Book of Ukraine, 22 species – into the Black Sea Red Data Book, 7 species – into the IUCN Red List. More than one-half of the species registered in the area (36 species or 52% of all the species) have a protected status. Сonclusions. Results of analysis of biodiversity, structural characteristics and taxonomic composition of ichthyofauna in the Zmiinyi Island coastal waters have been presented. Seasonal dynamics of its number and biomass has been studied. The results of the analysis of some aspects of ecology and biology of the main mass species of fish are presented. Recommendations are given to improve monitoring of the ichthyofauna of coastal waters. Quality of bottom communities monitoring in the Zmiinyi Island coastal waters can be increased significantly by development and implementation of non-contact low-budget video-monitoring methods to solve the problem of fish stock and biodiversity studying in inaccessible areas. It is anticipated that the method developed will help high precision assess of fish stock in inaccessible shelf areas where application of other methods is connected with technical difficulties, high cost and can lead to unreliable results. Elaboration of the method aimed at development of video materials received computer processing algorithms will significantly simplify the analysis of the data collected.


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