THE IMPACT OF ORGANIC-CHLORINE ON THE BLACK
SEA DOLPHIN’S LIFE
RESEARCH MOTIVES
The reason why we chose to develop this project is that the Black Sea Mammals are
endangered or already critically endangered.
Apart from humans, marine mammals are the highest life form sustained by the Black
Sea. They depend upon a healthy, unpolluted and diverse Black Sea ecosystem and on the
healthy connection of the Black Sea with the world’s oceans. The message of this project
is a clear one — humans can learn to co-exist with the most sensitive ecosystems in the
Black sea and develop their economic activities. —
THE PURPOSE OF THE PROJECT
To find out the impact of the raised level of organochlorine in the fat tissues of
the stranded dolphins on their life and especially on their echolocation system.
Objectives
- To find out the level of organic chlorine in the fat tissue of stranded dolphins and
the impact to their echo-location system
- To develop skills in team effort during the field activities and special
experimental skills in the laboratory
- To raise the high-school students awareness about the issues of the Black Sea
dolphin’s and to develop among them a positive attitude regarding the endangered
species of the Black Sea
- To involve the young students in voluntary activities in order to solve
environmental issues.
AN OUTLINE OF RESEARCH
Field activity —laboratory activity—in school activity—public information _,..............,
RESEARCH PROCESSES AND RESULTS
Stage one:
1. Field activities - a Coast Watch observation file was filled each covered kilometer, the
eventual pollution sources being able to offer supplementary information about the cause
of the death of the stranded dolphins and for every stranded dolphin found were made
photographs, were made measurements and were taken out samples of their fat tissue.
Results of our expeditions
Several stranded dolphins found on the Romanian Black Sea coast in the last 2 years:
Stage two
2. Laboratory activity - The fat tissue samples we took out from the stranded dolphins
were analyzed for three different organic- chlorine substances (HCH0, HCH and HCHV),
in a laboratory using the gas-chromatographic method AQAC, by a FISIONS device,
connected to a CROMCARD program.
The analytic technique follows 3 main stages:
- The stage of extraction and purification of the fat from the test, which has to be studied.
- The stage of extraction and purification of organochlorine pesticides residues from the
purified fat
- The stage of determination and gas-chromatographic registration
Results and discussions
As a result of our activity and thanks to data, concerning the level of toxic substances,
that was put to our disposal by Mrs. Ligia Dima, researcher at the Natural Science
Museum Complex (see appendix 2), we obtained several graphs (see graphs) that show
the presence and evolution of different polluting substances in the Black Sea and in the
fat tissues of the Black Sea dolphins stranded in last 12 years.
The levels of pesticides found in the fat tissues of the stranded dolphins, for every
species:
The levels of every organochlorine pesticide measured for all the three dolphin species:
Conclusions: For the common dolphin (Delphinus delphis), the level of organochlorine
substances is the lowest (graph 1), fact that could be explained by the pelagic life of this
species. In the case of the two coastal ichthyophagous species there have been found
higher concentrations of organochlorine pesticides. For the harbor porpoise (Phocaena
phocaena) we ascertain that the values are between close limits at all specimens studied
(graph 2). At the bottle-nosed dolphin (Tursiops truncatus) have been recorded the
highest pesticides accumulations (graph 3); also, evident differences between minimum
and maximum limits appeared (7 times higher in the case of DDT and a HCH isomer).
Stage three
3. In school activities — we applied an initial questionnaire to 100 students from our high
school and several teams were formed in order to cover the Black Sea coast and search
for stranded dolphins. There have been organized two expeditions, one in the spring of
2005 and the other, one year later. After the students were informed about the problems
that the mammals have using PowerPoint presentations, posters, flyers and collages, they
had to fill in a final questionnaire. Last step of the project is the interpretation of the
results.
CONCLUSIONS
- Organochlorine pesticides have negative effects over some metabolic parameters of the
living beings populations in the Black Sea. The negative effect is more emphasized, as
the level of organic chlorine is higher.
- As the results show, the level of organic chlorine obtained from the analysis of the
tissues taken from the stranded dolphins remained almost to the same parameters, in the
last few years.
- Pesticides come from different land sources and affect the immunity system of those
mammals.
- Contamination with organic-chlorinate varies according to the degree of habitat
pollution (a higher concentration was established for the mammals living in the coastal
waters).
-The harmful effects depend on the physical and chemical characteristics of each product
and for the same product the effects depend on the species, area, feeding characteristics.
- Bacterial infestations are frequent and are also the results of the pollution of the sea
habitat. So it is essential to take measures everywhere to avoid this destroying. When
dolphins sonar system is perturbed or altered by parasites or electromagnetic interference,
the dolphin can strand.
--As a result of the presentation of the research that we made, the students of our high
school learned a lot of new things and this experience could provide the terms for
developing a more responsible attitude about the Black sea dolphin’s lifes. The students
are also willing to get involved in environmental protection actions.All these things show
us that our students are open-minded and able to develop a good attitude referring to the
environment.
The results of this project have been presented to great industrial companies and also to
the environmental NGO's which helped us start an informing campaign of the population
about the risks of pesticides pollution and its negative effects on Black Sea dolphin's life.