From October 6 to 13, with the financial support of the Swiss organization OceanCare, a fifth expedition in the last three years was conducted to study the population densities of the three Black Sea marine mammal species - the bottlenose dolphin, the common dolphin and the porpoise.
A team of Green Balkans experts and volunteers for a week have been collecting data on the presence of cetaceans in Bulgarian territorial waters during the autumn season. Transects with total length of 409.5 km have been covered by vessel. Unfortunately, the initial results show extremely low numbers of all three marine species during this season - a total of 54 observations, which is the lowest result for all expeditions conducted so far. According to the data collected, the ratio of the species during this autumn season is no different from that in the same period last year: most often were encountered the common dolphins - 23 sightings, followed by the bottlenose dolphins - 18, and the harbour porpoises have been the rarest with only 10. In three of the sightings species was not identified. This illustrates very well the seasonal dynamics in the distribution of the three species. In fact, during this season the harbour porpoise undertakes a long migration to its wintering grounds in the Southeastern part of Black Sea, off the coast of Georgia and Eastern Turkey. In general it can be said that the population density of all three cetacean species provides information about the dynamics of fish stocks, which it is directly dependent on.
In fact the dolphin species, located at the top of the Black Sea food chain, are ideal indicators of the state of the entire ecosystem and the balance between all the species, environment and conditions that has coevolved for millennia. This balance provides us with the resources we rely on, the livelihoods that nourish us and the cultural appearance of coastal towns. A balance that has "learned" to survive in the face of a variety of extreme events that have occurred throughout the history of the sea, relying on each of its constituents, working in perfect synchrony as a whole.
This is precisely the main aim of our work and the research we strive to conduct on a regular basis - to know at any moment what is the status of this important ecosystem for our society, especially when, whether and what kind of measures are necessary, to continue its support for us.
For additional information:
Dimitar Popov, e-mail: dpopov@greenbalkans.org
A team of Green Balkans experts and volunteers for a week have been collecting data on the presence of cetaceans in Bulgarian territorial waters during the autumn season. Transects with total length of 409.5 km have been covered by vessel. Unfortunately, the initial results show extremely low numbers of all three marine species during this season - a total of 54 observations, which is the lowest result for all expeditions conducted so far. According to the data collected, the ratio of the species during this autumn season is no different from that in the same period last year: most often were encountered the common dolphins - 23 sightings, followed by the bottlenose dolphins - 18, and the harbour porpoises have been the rarest with only 10. In three of the sightings species was not identified. This illustrates very well the seasonal dynamics in the distribution of the three species. In fact, during this season the harbour porpoise undertakes a long migration to its wintering grounds in the Southeastern part of Black Sea, off the coast of Georgia and Eastern Turkey. In general it can be said that the population density of all three cetacean species provides information about the dynamics of fish stocks, which it is directly dependent on.
In fact the dolphin species, located at the top of the Black Sea food chain, are ideal indicators of the state of the entire ecosystem and the balance between all the species, environment and conditions that has coevolved for millennia. This balance provides us with the resources we rely on, the livelihoods that nourish us and the cultural appearance of coastal towns. A balance that has "learned" to survive in the face of a variety of extreme events that have occurred throughout the history of the sea, relying on each of its constituents, working in perfect synchrony as a whole.
This is precisely the main aim of our work and the research we strive to conduct on a regular basis - to know at any moment what is the status of this important ecosystem for our society, especially when, whether and what kind of measures are necessary, to continue its support for us.
For additional information:
Dimitar Popov, e-mail: dpopov@greenbalkans.org
