Environmental Engineering Reference
In-Depth Information
sels, in canned form, were exported to Mediterranean markets. Today Odessa
shops advertise foreign canned mussels, but not local mollusks. The reason of
such a conversion of an exporter into an importer are not only the successful
free-market relations in the Ukraine, but the drastic fall in commercial stocks
of mussels on the NWS caused by deoxygenation of bottom water, which has
been produced by man-made eutrophication.
The ecological situation in other shelf areas of the Black Sea, out of zones
of strong impact of the river runoff, is better, but the largest NWS area, is a key
zone in terms of biological resources of the Black Sea and their reproduction.
This is the most productive area of the Black Sea regarding benthic and pelagic
species. Until recently, this area produced more than 95% of all the standing
stock of the red algae
Phyllphora nervosa
and
P. brodiaei
, the seagrasses
Zostera marina
and
Z. noltii
and the blue mussel
Mytilus galloprovincialis
;
more than 90% of the turbot
Psetta maeotica
, the flounder
Platichthys flesus
luscus
, and the mackerel
Scomber scombrus
; about 70% of the spiny dogfish
Squalus acanthias
, the thornback ray
Raja clavata
, the sprat
Sprattus sprattus
phalericus
, the Black Sea shad
Alosa kessleri pontica
, the whiting
Merlangius
merlangus euxinus
, and gobies (species of Gobiidae family); about 60% of the
anchovy
Engraulis incrasicholus ponticus
and the horse mackerel
Trachurus
mediterraneus ponticus
; and other fish, including sturgeons (Acipenseridae)
were concentrated in this area. Therefore the NWS was an area for traditional
harvesting of fish, marine mammals, mussels,
Phyllophora
and other biological
resources.
In the late 1990s, some signs of recovery of the NWS and Black Sea ecosys-
tems were observed. Some species of invertebrate and fish, considered to be rare
or even extinct and inscribed into Black Sea Red Data Book [1], became quite
common. According to author's observations, among them there are hermit
crab (
Diogenes pugilator
), crabs
(Carcinus aestuarii
and
Pilumnus hirtellus
),
bottom fishes, sole (
Solea nasuta
), dragonet (
Callionymus belenus
), sea horse
(
Hippocampus ramulosus
), turbot (
Psetta maeotica
) and some other species.
In September-October 2003, during an international cruise of RV “Acad-
emic”, in the frame of the UNDP-GEF Black Sea Ecosystem Recovery Project,
comprehensive investigations of bottom organisms on the North-western and
Western Black Sea shelves, under the guidance of the well-known specialist
of the bottom fauna, Professor M.T. Gomoiu, were carried out. According to
preliminary assessments, obvious evidences of a mass mortality of benthic
organisms in this year were not registered (Prof. L.V. Vorobyova, personal
communication).
