اسم المؤلف:
رغد زيدان خلف
اسم المشرف:
هيفاء علي حمزة
مرتضى يوسف العباد
المستخلص:
The present study aimed macrobenthic invertebrats communites in three different aquatic environments southern Iraq. Eight stations were chosen for this purpose, Four of them distinction by being with running water and affected with the tide of Arabian Gulf,these include two stations on each of Shatt Al - Arab River (Al - Mohamadiat and Al - Salihia) and east part of Al - Hammar marsh (Al - Burgah and multaqaa Al - Mashab and Al - Sallal).the other four stations were not affected with the tide and located on the central marshes, two stations on each of Aum Al - Showaich marsh (Al - Sibitia and Al - Badria) and Al - Chebaeish marsh (Abu Sobat and Al - Sihaqee).The samples of water and sediment were collected monthly during the period from April 2014 to March 2015.Some environmental factors for each station were measured these include air and water temperatures, pH ,electrical conductivity, turbidity, dissolved oxygen, biological oxygen demand, total dissolved soild, total hardness, Calcium, nitrate , reactive phosphate, sulphate, total organic carbon and soil texture. The macrobenthic invertebrates samples which collected by Three replicates monthly for each station were isolated and identified,then densities and relative abundance were calculated.Some ecological indices such as diversity, richness, evenness, dominance, beta diversity and similarity indices(qualitative and numerical) were studied. Canonical correspondence analysis was adopted to evaluate the effect of the measured environmental factors on the occurrence and density of the studied macrobenthic invertebrates.The results showed that the variables of the stations were ranged as below : Air temperature (12 - 44)C̊ ,while the water temperatures (10.6 - 35)C̊ , PH (7.5 - 9.1), EC (2.07 - 13.7) mS /cm, Turbidity (4.2 - 199) NTU, DO (5 - 11.5) mg/l , BOD5 (0.3 - 3.5)mg/l , TDS(1245 - 10220)mg/l , TH (531 - 2928) mg/l , Ca+2 (80.2 - 320)mg/l , NO3 - (0.26 - 15.25) mg/l , PO4 - 3 (0.032 - 2.9) mg/l , SO4 - 2 (250 - 910)mg/l , and for sediments : TOC (9.3 - 22.5)% and soil texture ranged between sandy silt to muddy silt.The total number of recorded taxes were 80,representing by 16 species belonging to Annalida, 36 genus to the Aquatic insects (28 genus of them were first record in the middle wetlands), 16 species to Crustacea and 12 species to Mullosca. The species Pomacea canaliculata was recorded for the first time from Shatt Al - Arab river. The recorded taxes were classified according to its occurrence periods into four classes : dominant, fluctuated, less abundant and rare.The monthly density of each taxa of macrobenthic invertebrate and for each main macrobenthic invertebrate group in all stations was calculated. The results revealed that the densities were ranged from( 0 - 7115, 0 - 485 , 0 - 703 and 0 - 1199) ind/m2 for the groups of annelid, aquatic insect, crustacean and mollusca respectively. While the total density of all macrobenthic invertebrate groups was ranged between( 0 - 7367) ind/m2.The results of annual relative abundance for each main macrobenthic invertebrate group in all study stations referred that the value 66.3% was recorded for the annelids, while the lowest one 6.1% was recorded for the aquatic insects. On the other hand, the annual relative abundance for each main group in each station was investigated, and was ranged between (0.9 - 68)% recorded in Shatt Al - Arab river stations for the groups of aquatic insects and annelids respectively,( 0.4 - 67)% recorded in east Hammar marsh stations for groups of water insects and mollusks respectively, and (1 - 82)% recorded in Middle marshes stations for the annelids. The annual relative abundance for total macrobenthic invertebrate group in all stations was ranged from (2 - 27)% recorded in Al - Sibitia and Al - Sihaqee stations respectively. The annual relative abundance for the species and genus which recorded during our study revealedthat all highest values (94, 96.58 and 100)% were recorded for the species Limnodrilus hoffmeisteri in stations of Shatt Al - Arab River, east Hammar marsh, and Middle marshes respectively.The monthly relative abundance for main macrobenthic invertebrate groups in all station was studied. The highest value which recorded from Shatt Al - Arab river stations (Al - Salihia station) was reached 95.8% and recorded for the annelids, while reached 100% either in east Hammar marsh stations(Al - Burgah) for the mollusks and in Middle marshes stations (Al - Sibitia) for the crustaceans.Some ecological indices for each for each main macrobenthic invertebrate group from all stations totally were calculated. About the spatial diversity the range of Shannon - Wiener diversity index were between 0 - 0.6674 for annelids, 0.8718 - 1.92 for aquatic insects,0.5404 - 1.917 for crustaceans and 0.3035 - 1.15 for mollusks, while were 1.076 - 2.085 for all the benthic groups totally.The values of Richness index were from 0 - 1.127 for annelids,0.778 - 3.683 for aquatic insects, 0.5212 - 2.104 for crustaceans and 0.2543 - 1.277 for mollusks, while were 2.321 - 5.225 for all the benthic groups totally. The values of Evenness index were ranged between 0 - 0.9629 for annelids,0.4649 - 0.7419 for aquatic insects ,0.3016 - 0.8327 for crustaceans, and were 0.2189 - 0.8974 for mollusks, while were 0.3121 - 0.77 for all benthic groups totally. The values of Dominance index were ranged from 0.6129 - 1 for annelids, 0.343 - 0.7736 for aquatic insects ,0.2991 - 0.8772 for crustaceans,0.5075 - 0.9845 for mollusks while were 0.2638 - 0.7762 for all benthic groups totally.About the temporal diversity the values of Shannon - Wiener diversity index were between 0 - 0.99 for annelids, 0 - 2.01 for aquatic insects, 0 - 1.5 for crustaceans and 0 - 1.637 for mollusks, while were 0 - 1.981 for all benthic groups totally. The values of Richness index were from 0 - 0.969 for annelids, 0 - 2.717 for aquatic insects, 0 - 1.314 for crustaceans and 0 - 731 for mollusks, whilewere 0 - 3.047 for all the benthic groups totally. The values of Evenness index were ranged between 0 - 1 for each of annelids, aquatic insects and crustaceans, and were 0 - 0.992 for mollusks, while were 0 - 971 for all benthic groups totally. The values of Dominance index were ranged from 0 - 1 for each of four benthic groups, while were 0.3 - 1 for all benthic groups totally.Whittaker Beta index between the three different aquatic habitats for each main macrobenthic invertebrate group was calculated. The lowest value 1.14 was recorded for the mollusks between the middle marsh of um Al - Shoowaich and Al - Chebaeish, and highest value 1.66 was recorded for the aquatic insects between the east Hammar marsh and marsh of Al - Chebaeish, while the index values for all groups of macrobenthic invertebrate totally were ranged from 1.33 between the Shatt Al - Arab river and east Hammar marsh to 1.54 between the Shatt Al - Arab river and marsh of Al - Chebaeish.Jaccard Similarity index for each main macrobenthic invertebrate group for each stations was calculated.The values of index for annelids were ranged from( 0 - 89)% the lowest value recorded between Al - Burgah and Al - Sibitia stations and the highest value between Al - Salihia and Multaqaa of Al - Mashab and Al - Sallal stations, for the aquatic insects the values of index between (8.3 - 46.7)% the lowest value between Al - Salihia and Al - Sibitia and the highest value between Al - Mohammediat and Al - Badria stations, for the crustaeceans values ranged(14.3 - 77.8)% the lowest value between Al - Mohammediat and Al - Badria stations while the highest value between Al - Sibitia and Al - Badria,and for mollusks were between(18 - 80)% the lowest value between Al - Mohammediat and Al - Burgah stations while the highest value between Multaqaa of Al - Mashab and Al - Sallal and Abo Sobat stations.The index for all macrobenthic invertebrate groups totally also calculated and its values were from (15 - 58.5)% recorded between Al - Mohammediat with Al - Sibitia stations and between Al - Mohammediat with Al - Salihia stations respectively.Bray - Curtis index was calculated monthly for each main macrobenthic invertebrate group in each stations .Also the Bray - Curtis index was calculated annually between stations and the results refer that the highest values as the following : 0.993 for the annelids between Al - Badria and Al - Sihaqee stations, 1 for the crustaceans between Al - Salihia and Al - Sibitia stations, and 0.96 for the mollusks between Al - Sibitia and Abo Sobat stations.The highest value for all benthic group totally was 0.983 between Al - Salihia and Abo Sobat stations.On other hand Bray - Curtis index was calculated for all macrobenthic invertebrate groups totally between the three aquatic habitats and the values were ranged from 0.5 recorded between the wetlands of um Al - Shoowaich and Al - Chebaeish to 0.875 recorded between the east Hammar marsh and wetlands of um Al - Shoowaich.The Canonical Correspondence Analysis (CCA) by using Canoco application revealed the clear effect of different ecological factors on numbers of the individuals and species of each group of macrobenthic invertebrate in all stations during the study period.
