Recent Changes in the Black Sea Ecosystem

Source of Aegean Sea harbour porpoises

“…Numbers above branches indicate bootstrap support for the major oceanic clades. Outgroup species used was Phocoena sinus rivers, and increased inputs of organic materials, pollutants, and invasive non-native species have all contributed to the degradation of this unique sea (Bologa 2001). More important perhaps for marine mammals is the change in fish biodiversity and biomass.…”

“…Overfishing has led to a significant decline in many commercially important species. Both anchovy and mackerel stocks have declined significantly, the latter species being at least commercially extinct since the late 1960s (Bologa 2001). It is interesting that Tomilin (1967) reported that Black Sea porpoises once made migrations into the Sea of Azov during the spring following large schools of anchovies.…”

The National Institute for Marine Research and Development „grigore Antipa” Constanța - Historical Highlights

“…However, the reliable data that exist are already sufficient for scientists to draw conclusions about the present state of the Black Sea biota, including the main reasons for the changes that have occurred, the regions of the sea that have been subject to varying degrees of anthropogenic transformation, endangered species, populations and communities, and major gaps in the knowledge of biological diversity. The major biological long-term changes during the last decades could be summarized as follows (Bologa, 1992;Bologa et al, 1995):…”

“…A relatively small number of allogenic (exotic) species have invaded this particular environment in recent decades. Consequently, the Black Sea has faced and continues to be affected by a serious disequilibrium (Hobson and Mee, 1998; Beșiktepe et al, 1999;Bologa, 2001Bologa, , 2011a, due to contamination / pollution both on land and in the air, to which pollution of the marine environment itself (e.g. noise, ballast water, PVC) is added, which can be suggested in the sequence of eutrophication → flowering (phyto-and zooplankton) → hypoxia and anoxia → mortality (plant and animal) → diminished biodiversity and living resources.…”

Length-Weight Relationships for Fourteen Fish Species Collected by Bottom Trawl From the Eastern Black Sea Coast, Turkey

“…The Black Sea is the world's largest land-locked inland sea (Bakan & Büyükgüngör, 2000). It has been exposed to environmental fluctuations and strong anthropogenic stresses (Bologa, 2001). In the Eastern part of the Black sea, the fishing grounds are quite different and the big rivers (Bzyb, Kodori, Inguri of Rio and Çoruh River) flows into the Black Sea from Furthermore, the LWR allows fish condition to be estimated.…”