Macro Benthic Invertebrates Assemblage in Different Anthropogenic Activities Zone in Badagry Creek, South Western Nigeria

Macro-invertebrates’ species (benthos) are important ecosystem component within the ecosystem-based approach, due to their sessile, sedentary and relatively long life which are considered as important factors to be suitable and sensitive indicators of natural and anthropogenic variations Pearson [1]. A good indicator of temporal and chronic disturbances that has been proven is macro benthos Dauer [2]. Therefore, the assessment of the condition of benthic habitat is one of the evaluation criteria both ARTICLE INFO ABSTRACT

in biological quality element, biodiversity, and sea floor integrity.
Habitat transformation and pollution are problems encumbered by estuaries worldwide with serve risks to their ecological resilience Lotze, et al. [3]. The increasing pollution threaten the ecological services provided by estuaries, especially near urban centers where there is poor management of multiple impacts. Estuaries are priority areas for conservation and to be managed as marine reserves, despite their low environment quality. The sedimentary organic matter and pollutants on estuaries are important drivers of ecological changes observed on benthic assemblages. Urbanization and population growth are associated with pollution pressures that Nigerian aquatic systems are subjected to Edokpayi, et al. [4].
The seasonal distribution of rainfall, the lagoon and creeks experience seasonal flooding which introduces a lot of detritus, nutrients, as well as other land-based pollutants Ogunwenmo [5,6].
An assessment procedure for determining the condition of softsediment benthic habitats require the following aspects: i. Habitat assignation of the samples (habitat approach), ii. Reference or target conditions for the benthic parameters (reference approach) and iii. The selection of indicator tools to assess the relative quality status (indicator approach).
A number of research works on benthic macro invertebrates community of lagoon systems of Southern Nigeria has been documented the hydrochemistry and macro benthic fauna characteristics of Ogbe creek Edopkayi, et al. [7] Benthic macrofauna of Epe Lagoon Uwadaie 2010, which has assisted in the taxonomic study and species identification in these lagoons. However, Badagry creek presents environmental gradients and considerable habitat heterogeneity resulting from human disturbance and natural environmental conditions, thereby providing an ideal testing ground to explore benthic assemblages and physiochemistry in their different structuring variation and biological communities.
The present study aimed to assess the physicochemical parameters and microbenthic invertebrate assemblages across the different anthropogenic site in Badagry creek.

Study Area
Lagos State is located in South-Western Nigeria. Badagry creek

Macroinvertebrate Sampling
Benthic macroinvertebrates were obtained from three quantitative replicates using a Van Veen grab (sampling surface area: 0.1m²) of which the contents were sieved over 1mm mesh sieve (prior to fixation). Invertebrates were preserved in 5% formaldehyde, mixed with Rose Bengal for further analysis.
After sieving all organisms were identified to the lowest possible taxonomic level (species level).

Sampling Stations
Badagry creek was divided into three zones based on geographic locations and logistical characteristics, upper, middle, and lower zones Southwood [8,9]. In each of the zones, three stations were randomly selected and chosen as replicates, thus giving a total of nine stations. The nine stations were further grouped into five ecological sites, classifying sites based on comprehensive environmental disturbance score which was modified from Weigel [10].
Gastropoda were tolerant to all disturbance which may be due to their biological characteristics, filter feeder , this report supported the findings of Ajao [13], that stated that Gastropoda

Conclusion
The variances in the number of species and numerical abundance are largely due to physical variability of the study area, the depth of investigation, and the predominant ecological conditions, including the level of contamination from anthropogenic sources of the study area at the time of the surveys. The study revealed that most of the microbenthic fauna occurred seasonal in the water body and the creek could be said to support a wide range of microbenthic invertebrates' species exhibiting different diversity patterns across the anthropogenic zones. This result generated will serve as a checklist data on the seasonal occurrence, composition, and abundance, which will be useful in developing framework for sustainable management of the creek.