Spatio-temporal variations of macrobenthic fauna in Lake Nasser khors, Egypt

Abstract

Spatial and temporal variations of macrobenthic fauna in Lake Nasser khors, were studied at four subsequent seasons during 2013. Khor Tushka West recorded the highest average number (597 Org./m 2 ). It was decreased at khor Kursku (112 Org./m 2 ) and Kalabsha (105 Org./m 2 ) while it reached the lowest at khor Wadi Abyad (65 Org./m 2 ). The highest average number was recorded during spring (447 Org./m 2 ). It decreased during winter (174 Org./m 2 ) and summer (151 Org./m 2 ), then reached the lowest during autumn (107 Org./m 2 ). Annelida, Arthropoda and Mollusca were the most dominant groups in the lake during the study being 72.65%, 26.09% and 1.35%, respectively. The highest number of species (16) was observed at khor Kalabsha. This may be due to its nature of sandy bottom. Biological indices showed high richness values of all the studies khors except khor Tushka West.These low values of indices may be due to the dominance of Annelids species especially, Limnodrilus spp. and Branchiura sowerbyi. There is a positive correlation between these species and total annelids with all physico-chemical parameters. The analysis of variance between the different khors based on the main macrobenthic groups showed a highly significant value ( p < 0.001). ª 2014 National Institute of Oceanography and Fisheries. Hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Effect of pollution on macrobenthic invertebrates in some localities along the River Nile at Great Cairo, Egypt.

“…The predominance of oligochaetes especially Limnodrilus spp. in water is possibly due to their ability to adapt to various habitats and to their tolerance to low oxygen content in anoxic conditions of the bottom sediment (Mola and Abdel Gawad 2014). Branchiura sowerbyi, Limnodrilus hoffmeisteri, and L. udekemianus considered the most dominant annelid species being 121, 96 and 148 org./m 2 respectively.…”

Struktur Komunitas Dan Distribusi Temporal Gastropoda Di Danau Situ Gintung, Tangerang Selatan, Banten

“…Secara langsung atau tidak langsung, parameter tersebut dipengaruhi oleh perubahan iklim dan perubahan lahan di daratan sekitarnya, termasuk bahan kimia (Carpenter et al, 2011), fisik-kimia perairan, dan perubahan musim (Mola & Gawad, 2014). Sebagai upaya konservasi, studi dampak perubahan fisik-kimia perairan terhadap Gastropoda perlu dilakukan, diantaranya adalah dengan mengetahui data keanekaragaman biota perairan (Strayer & Dudgeon, 2010) dan faktor fisik-kimia perairan (Cai et al, 2011).…”

“…Temperatur perairan danau Situ Gintung di musim hujan dan musim kemarau diduga dipengaruhi oleh temperatur atmosfir yang stabil dengan rata-rata 30-34 °C dan kecerahan (r = 0,700). Temperatur perairan danau mengalami fluktuasi karena pengaruh cahaya matahari, letak geografis (Lewis, 1987), suhu atmosfir (Wetzel, 2001), musim (Alam et al, 2001;Sulastri, 2011;Mola & Gawad, 2014), ketinggian dari permukaan laut (Effendi, 2003), dan kedalaman air (Sarmento et al, 2006;Celik & Ongun, 2007;Feresin et al, 2010;Sinaga et al, 2016).…”

“…Selain temperatur, pengaruh limbah antropogenik seperti fosfor, kalsium, dan alkalinitas (Brylinsky & Mann, 1973), reaksi fotosintesis, nutrien (Morro et al, 2012), serta musim (Mola & Gawad, 2014) dapat menyebabkan perubahan pH di perairan danau.…”

“…Menurut Hakanson (2006) kecerahan berkorelasi positif dengan kedalaman dan partikel terlarut di kolom perairan. Perbedaan kecerahan di ekosistem danau dipengaruhi oleh kekeruhan berupa padatan tersuspensi (Effendi, 2003), kepadatan populasi fitoplankton dan zooplankton, jumlah bahan organik terlarut (Torremorell et al, 2007), serta musim (Mola & Gawad, 2014). Berdasarkan kategori kecerahan perairan (Peeters et al, 2009), danau Situ Gintung tergolong buruk atau memiliki kecerahan rendah.…”