мая 25 2001

Some Remarks About The Impacts Of Human Activities

Опубликовано в 22:23 в категории Без рубрики

Some remarks about the impacts of human activities

on the Romanian Black Sea coastal ecosystems

M.-T. Gomoiu, N. Panin

National R&D Institute for Marine Geology

and Geoecology – GeoEcoMar, Romania

It is well known that the Black Sea Strategic Action Plan represents a joint statement of commitment by Governments of Bulgaria, Georgia, Romania, Russian Federation, Turkey and Ukraine, who are convinced of the need to protect and restore the environment.

This important document realized with international support from the Global Environment Facility, GEF, through the Black Sea Environmental Programme and adopted at the Ministerial conference held in the City of Istanbul, Turkey on 30-31 October 1996, triggered intense activities supported by a great diversity of participants such as governmental representatives, scientific people and many other actors enrolled in NGOs.

It is worth mentioning that in most Black Sea countries facing the difficulties of their economy in transition, especially the extremely limited financial support for scientific research, there have been preoccupations to solve the problems concerning the study, rehabilitation and protection of the Black Sea.

We would like to make a few remarks about two major problems tackled at the National Institute of Marine Geology and Geoecology – GeoEcoMar and "Ovidius" University in Constanta, namely:

1. the problem of the erosion processes at the Romanian littoral; and

2. the problem of changing the specific biodiversity of the Black Sea in general and at the Romanian littoral in particular by introducing alien species.

The erosion processes at the Romanian littoral

On the basis of up-to-date researches, performed by dedicated institutions (GeoEcoMar, National Institute of Marine Research and Development, National Institute for Environmental Research, Aquaproiect, Apele Romane – Romanian Waters etc.), the approximately 243 km long Romanian littoral of the Black Sea is in an intense and continuous degradation

by marine erosion (Fig.1). The shore line retreats with yearly rates varying from a few meters to 15-20 m for the Delta littoral (between Sulina and Cape Midia) and on the littoral belts south of Cape Midia and with app. 0.2 – 0.5 m for the cliffs littoral (the Constanta – Vama Veche sector). Simultaneously with the erosion are profoundly affected the coastal zone ecosystems, its general ecological state, the economic activities (especially tourism, balneology, fisheries, safety of marine works etc.) and the health state of the population.

The causes of degradation by erosion. The processes of littoral erosion have both natural (such as global climatic changes and sea level variations, subsidence phenomena etc.) and especially anthropic causes (Fig.1). Among the anthropic activities with an especially important impact on the littoral environmental state one may mention the hydrotechnical works on the Danube and its main tributaries, harbour works and others coastal engineering works. The hydrotechnical works achieved on the Danube and on its main tributaries have significantly decreased (30-50 %) the Danube sediment discharge in the littoral zone. Thus has been created a great sedimentary unbalance in the coastal zone, determining an intensification of the erosion process. The harbour and other coastal engineering works such as the defence breakwaters of the Sulina shipping canal (Fig. 2), the defence piers of Midia, South Constanta and Mangalia harbours (Fig. 3), the littoral protection works, also determine great environmental disturbances in the coastal zone.

Tendencies. Considering the global climatic changes and the general sea level rising as well as the geoecological regional conditions characterising the Danube – Danube Delta – littoral zone – Black Sea geo-ecosystem, one may predict on a medium term that the erosion process of Romanian littoral will be at least as active as for the last two decades. The long term prediction emphasises an intensification of the beach erosion, especially because of the continuing decrease of the Danube sandy material discharge in the littoral zone, of the continuing rising of the sea level as well as a continuously rising energetic level of the hydro-meteorological factors, which may be associated with the global climatic changes.

Face to face with this situation, the National Institute for Marine Geology and Geoecology – GeoEcoMar considers that the integrated management of the coastal zone and prevention of littoral erosion represents a problem of national importance and the National Program for Protection and Integrated Management of the Littoral Zone represents the scientific ground for the implementation of the protection and rehabilitation system of the Black Sea coastal zone. Assessing its capability, activity and potential, GeoEcoMar put forward to Ministry of Water, Forest and Environmental Protection and other interested forums proposals concerning a National Integrated Programme for the protection and management of the Romanian coastal zone, which in fact consists of two interconnected parts:

1. the program for protection and rehabilitation against the erosion of the Romanian littoral, or in short "Littoral Protection Program", and

2. the coastal zone integrated management program.

At the moment we refer only to the program for littoral protection, which should include chain-activities: research → designing → modelling → building → management including monitoring, aiming at the following objectives:

– updating knowledge of the geoecological state of the coastal zone;

– establishing new technologies for protection against erosion;

– defending the Romanian littoral against erosion;

– monitoring the geoecological state of the coastal zone;

– developing a GIS system for the sustainable management in the area;

– setting-up the legislative and normative ground.

The program structure comprises three interconnected sub-programs (Fig.4):

A. Multidisciplinary researches to obtain the scientific ground necessary to realise the littoral protection having in view the following objectives:

A1. Oceanographic and meteorological studies to assess the dynamic factors affecting the littoral zone;

A2. Sedimentological, geomorphological and geological studies for the knowledge of the relief, nature and dynamics of the littoral sedimentary substratum;

A3. Studies for the knowledge of the anthropic factors influence on the littoral zone evolution.

B. The subprogram for designing protection measures against erosion represents integration of the data obtained from subprogram A aiming at:

B1. Modelling of littoral evolution;

B2. Tracing the perimeters most affected by erosion – hierarchisation;

B3. Selecting engineering works for specific protection and sustainable use;

B4. Testing alternative scenarios on models;

B5. Choosing and designing the most adequate solutions for each zone.

C. The subprogram for the realisation of activities to protect the littoral against erosion and its geoecological monitoring; focussing the sustainable management of resources this subprogram is based on the following objectives:

C1. Building engineering works for protection against erosion;

C2. Multidisciplinary (oceanological and geoecological) monitoring and integrated management of the Black Sea Romanian littoral;

C3. Creating a normative and legislative ground for sustainable and integrated administration of the coastal zone, correlated with the similar legislation from EU and the Black Sea riparian countries.

What effects do we expect from this program ?

Scientific effects

– new information

– realisation of the informational management system

– improvement of the monitoring system

– guaranteeing the international information exchange

Socio-economic effects

– providing the ground for the integrated management of the coastal zone

– sustainable development of the zone, including tourism development

– maintaining the ecological balance

– revival of economic activities

– creation of new working places

– identification of new, potentially utilisable resources

Political effects

– technical and scientific competitiveness of Romania in the field

– development of international co-operation

– alignment of Romania to EU by the realisation and implementation of a sustainable and efficient system for the integrated management of the coastal zone.

The project proposed by GeoEcoMar was submitted to the Romanian Scientific Community and stakeholders for analysis, observation and suggestions. Now the Project is waiting for partners from other institutions and much more expects the understanding of national, regional and local administration for financing and starting the work.

On the new species accidentally penetrated into the Black Sea

As it is well known today, in the last decades in the Black Sea have come some marine species originating beyond the Mediterranean Sea, from Far East Seas or from the Atlantic Ocean. The immigrants are quite well studied and they are still under observations. However, our knowledge on the alien or exotic species is limited; usually our attention was only for the large body size forms. We do not know very much what is happening with microflora or microfauna and surprises can appear in the future.

Some immigrants have produced major disturbances in the structure and functioning of ecosystems; there are known facts more or less understood.      The most common hypotheses regarding the causes of accidentall penetration of alien species imply naval transport. This way is mentioned also for the Ponto-Caspian species, largely distributed today in other aquatic basins. The development of maritime transport, a very important economic sector, comprises numerous activities forming a complex network of causes with consequences ending in two directions: loss of native species, accompanied by appearance of new, free, empty ecological niches, and increasing of the potential of alien species penetration.

What we want to underline is the possibility that the Black Sea gate for exotic organisms was permanently opened; along the time, when the Black Sea was in a healthy ecological state, all the niches were occupied and the chances for new comers to develop in the Black Sea sustainable populations were at minimum. When the ecological conditions were drastically damaged as a consequence of pollution/eutrophication processes, the empty niches were ready to absorb new populations.

Based on the dynamics of alien species accumulation into the Black Sea (Fig.6), we consider that the process could continue quite rapidly (after the linear or exponential tendencies), or could slow down (after the polynomial tendency) (Fig.7); anyway, a more attentive checking is absolutely necessary.

The scientific problems of alien species in the Black Sea are still open.

Which are the lessons we have learned form the stories of the Black Sea as a receptor for new exotic species ? This could be discussed in detail, but now we will summarise only as follows:

– the process of penetration is still open - attention to the toxic and harmful species;

– the impact of alien species is complex and unpredictable;

– species biodiversity monitoring is absolutely necessary, a special attention must be directed mostly to the proper monitoring of microflora and microfauna;

– there are necessary legal measures and regulations for limiting the penetration of immigrants;

– training human resources in biological taxonomy and systematics is of high priority; the old generation of marine botanists and zoologists is getting reduced and to understand correctly the Black Sea ecosystems and what must be done for its protection, we have to know deeper their biota only through young educated specialists – marine biologist.

Fig. 1 – Diagram of geoecological chain changes at the Romanian Black Sea Coast

Fig. 2 – Impacts of building jetties at the Sulina branch mouth of the Danube River

Fig. 3 – Impact of building harbours on the marine ecosystems at the Romanian coast of the Black Sea

Fig. 4 – GeoEcoMar Proposal for a Littoral Protection Program – Subprograms Interconnection

Fig.5 – Main ecological chains triggered by the development of maritime transport

Нет пока ответов

Комментарии закрыты.