Luiza Florea


THE COMPARATIVE ANALYSIS OF FISH RESOURCES IN THE DANUBE NEAR BRAILA, WITHIN THE PERIODS 1972-1986 AND 2006-2008

Luiza Florea

Abstract
The purpose of this paper is to propose a new indicators for assessing the health of fish population in the Danube River, near Braila. In this way we analyzed the available data sets provided by industrial fishing from this area, for two different periods: present period (2006-2008) and previous period (1972-1986). Between 1972-1986 the environmental conditions in the Danube River were highly affected by direct and indirect anthropogenic activities. In 2006-2008 the human impact on fish populations was diminished because fishing was banned in floodplain areas, economic activities decreased and new legislation on environmental protection came into force. The proposed indicators describing the status of the freshwater fish community from the Danube River, near Braila are: (1) the total capture (TC, tonnes/year); (2) the total capture per unit area (TCA, tonnes/year x km2); (3) the total number of fish species (TNF, number of species/year); (4) the number of valuable fish species (NVF, number of species/year); (5) the number of ruling fish species (NRF, number of species/year); (6) the abundance of flow preference guilds (AFPG , % / guild). This comparative analysis highlights a highly unbalanced structure of the fish community in both periods, but in 2006-2008 the fish community structure come out to be in a changing process due to increase of rheophilic species.

Key words: Danube, fish, captures, present, past

ANALIZA COMPARATIVA A RESURSEI DE PESTE DIN DUNARE, ZONA BRAILA, ĪN PERIOADELE 1972-1986 SI 2006-2008

Luiza Florea

Rezumat
Scopul acestei lucrari este de a propune introducerea unor noi indicatori pentru evaluarea starii populatiilor de pesti din Dunare, zona Braila. Pentru aceasta s-au analizat datele furnizate de pescuitul industrial din aceasta zona īn doua perioade diferite: perioada actuala (2006-2008) si perioada trecuta (1972-1986). Īn perioada 1972-1986 conditiile de mediu din Dunare au fost puternic afectate de interventiile directe si indirecte ale omului. Īn perioada 2006-2008, impactul direct al activitatilor umane asupra populatiilor de pesti a fost diminuat deoarece īn zona inundabila activitatea de pescuit industrial a fost interzisa, activitatile economice s-au restrans si noile reglementari de mediu au īnceput sa se aplice. Indicatorii propusi a fi analizati īn vederea descrierii starii populatiilor de pesti de apa dulce din Dunare, zona Braila, sunt: (1) captura totala (CT, tone/an); (2) captura totala pe unitate de suprafata (CTS, tone/an x km2); (3) numarul total de specii de pesti (NTP, numar de specii/ an); (4) numarul de specii cu valoare economica (NPV, numar specii/an); (5) numarul de specii dominante īn capturi (NPD, numar specii/an); (6) abundenta ghildelor ecologice dupa preferinta fata de curentul apei (AGPC %/ghilda). Aceasta analiza comparativa pune īn evidenta o structura dezechilibrata a comunitatii de pesti de apa dulce pentru ambele perioade, īn schimb pentru a doua perioada, 2006-2008, structura populatiilor de pesti este īntr-un proces de schimbare datorita cresterii speciilor reofile.

Cuvinte cheie: Dunare, peste, capturi, prezent, trecut