Long-term changes and community structure of macrobenthic Arthropoda and mollusca in Bardawill lagoon
Abstract
En
Lagoons are among the most productive aquatic ecosystems which for thousands of years have been exploited by man. Bardawil Lagoon is a small, hyper saline lagoon in an arid area located in the middle of Sinai’s Mediterranean coast. Long-term changes,community structure, biodiversity, biomass and abundance of Arthropoda and Mollusca were studied. Orchestia gammarella, Chironomidae larvae and Balanus perfera were recorded as dominant taxa within 15 identified Arthropoda species. The western area of the lagoon maintained the highest standing crop as a result of the flourishing of Chironomidae larvae. Arthropoda are weakly represented in the middle and eastern areas. The standing crop of the total Arthropoda shows an obvious increase from 253 and 298 indiv.m-2 during 1984 and 1986 to 711 indiv.m-2 during the present study.Branchiodonta variabilis was the dominant of 9 molluscan species. Spatially there was a tendency towards a decrease in abundance westwards. The population density of Mollusca had highly reduced from 1028 indiv.m-2 in 1984 to 671 indiv.m-2 during the present study.The present study shows that Arthropoda and Mollusca assemblages undergo dramatic changes. There is no sign of presence of 20 previously listed species in the lagoon.On the other hand, 9 species have been recorded for the first time.
Lagoons are among the most productive aquatic ecosystems which for thousands of years have been exploited by man. Bardawil Lagoon is a small, hyper saline lagoon in an arid area located in the middle of Sinai’s Mediterranean coast. Long-term changes,community structure, biodiversity, biomass and abundance of Arthropoda and Mollusca were studied. Orchestia gammarella, Chironomidae larvae and Balanus perfera were recorded as dominant taxa within 15 identified Arthropoda species. The western area of the lagoon maintained the highest standing crop as a result of the flourishing of Chironomidae larvae. Arthropoda are weakly represented in the middle and eastern areas. The standing crop of the total Arthropoda shows an obvious increase from 253 and 298 indiv.m-2 during 1984 and 1986 to 711 indiv.m-2 during the present study.Branchiodonta variabilis was the dominant of 9 molluscan species. Spatially there was a tendency towards a decrease in abundance westwards. The population density of Mollusca had highly reduced from 1028 indiv.m-2 in 1984 to 671 indiv.m-2 during the present study.The present study shows that Arthropoda and Mollusca assemblages undergo dramatic changes. There is no sign of presence of 20 previously listed species in the lagoon.On the other hand, 9 species have been recorded for the first time.
DOI Code:
10.1285/i15910725v28p17
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