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Aquatics Macroinvertebrate Diversity and Bio-Assessment of the Quality of the Middle Wadi Oum Er-Rbia (Morocco)

Ilham Saad, Amal Abou Elghayt, El Mahdi Hbaiz, El Hassania Saad, Sanae Rezouki, Allal Douira, Mohamed Fadli

Ecological Engineering & Environmental Technology

2022

Vol. 23, iss. 6

53--60

The Oum Er Rbia river in Morocco is particularly threatened by lack of appropriate management. It is in this context, this study of the biological diversity of benthic macroinvertebrates in the middle zone of Oum Er Rbia river and the evaluation of the biological quality of water at this level, during a campaign carried out in April 2018. The results show that the stations upstream of the two sources of agricultural and industrial pollution represented by the stations (S1, S3, S4, S5 and S6), the biodiversity is important and the water is of good quality. So that the discharge of wastewater from the city of Kasba Tadla (S2) and Dar Ouled Zaidouh correspond to the station S7 has caused a reduction in diversity and a degradation of water quality of Oum Er Rbia river. We also noted a significant improvement in water quality away from Dar Ouled Zaidouh by 5 km from sources of pollution, which demonstrates the purifying power of the water of the Oum Er Rbia river.

The benthic macrofauna from the Lower Maastrichtian chalk of Kronsmoor (northern Germany, Saturn quarry): taxonomic outline and palaeoecologic implications

Engelke J., Esser K. J. K., Linnert C., Mutterlose J., Wilmsen M.

Acta Geologica Polonica

2016

Vol. 66, no. 4

671--694

The benthic macroinvertebrates of the Lower Maastrichtian chalk of Saturn quarry at Kronsmoor (northern Germany)been studied taxonomically based on more than 1,000 specimens. Two successive benthic macrofossil assemblages were recognised: the lower interval in the upper part of the Kronsmoor Formation (Belemnella obtusa Zone) is characterized by low abundances of macroinvertebrates while the upper interval in the uppermost Kronsmoor and lowermost Hemmoor formations (lower to middle Belemnella sumensis Zone) shows a high macroinvertebrate abundance (eight times more than in the B. obtusa Zone) and a conspicuous dominance of brachiopods. The palaeoecological analysis of these two assemblages indicates the presence of eight different guilds, of which epifaunal suspension feeders (fixo-sessile and libero-sessile guilds), comprising approximately half of the trophic nucleus of the lower interval, increased to a dominant 86% in the upper interval, including a considerable proportion of rhynchonelliform brachiopods. It is tempting to relate this shift from the lower to the upper interval to an increase in nutrient supply and/or a shallowing of the depositional environment but further data including geochemical proxies are needed to fully understand the macrofossil distribution patterns in the Lower Maastrichtian of Kronsmoor.

Effects of trophic conditions on benthic macrofauna in the vicinity of the River Swina mouth (Pomeranian Bay; southern Baltic Sea)

Masłowski J.

Oceanologia

2003

No. 45 (1)

41-52

The export of phytal material from the eutrophic Szczecin Lagoon into the Pomeranian Bay creates excellent trophic conditions for the local benthic fauna in the vicinity of the mouth of the river Swina, where the bottom macrofauna is abundant but highly variable. The changes in the bottom macrofauna biomass of selected taxa, chlorophyll a and nutrient concentrations were tested for associations. The biomasses of selected taxa varied in significant concordance, which suggests that these changes have common causes. Despite the importance of trophic enrichment to faunal abundance, no relationships between faunal biomass and chlorophyll a concentration changes were established. The presence of organic matter enables macrofauna to attain a high biomass, but population fluctuations are controlled by numerous factors. The significant relationship between the changes in the annual average phosphate levels and chlorophyll a concentrations in the Szczecin Lagoon indicates the importance of this nutrient to primary production processes in the Lagoon and to the trophic conditions for benthic macrofauna in the vicinity of the Swina mouth.