stream invertebrates report

stream invertebrates report

A Sample Answer For the Assignment: stream invertebrates report

Title: stream invertebrates report

stream invertebrates report

Environmental impact assessment of Cedar Creek, Trexler Park, Lehigh County, Allentown, PA using benthic macroinvertebrates Introduction Freshwater ecosystems are among the most degraded ecosystems on Earth. The Great Lakes, the Black Sea, and the Danube and Yangtze rivers are examples of major systems that have been severely affected by human impact. Many factors contribute to the degradation of freshwater systems, including overfishing, direct alterations of the system, such as dams, and pollution from surrounding human altered landscapes. Unfortunately, major systems are not the only systems that have been impacted. The health of small, local systems are also of concern. In this study, we will focus on a small, local stream, Cedar Creek, to determine whether an artificial !duck pond” that the creek runs through affects the health (i.e., water quality) of the creek. To do this, we will conduct a survey of the diversity of benthic macroinvertebrates in the creek. Methods This study will take place over three weeks. We will do our fieldwork in the first week. Identification of benthic macroinvertebrates will take place in the second week. And data analysis will be done in the third week. We will conduct our sampling upstream of the duck pond and and downstream of the duck. Each lab section will survey one site. WEEK 1 Benthic Macroinvertebrate Survey Before starting the survey, you will discuss and develop the hypothesis and predictions that we will be testing. In order to get an unbiased assessment of benthic macroinvertebrate diversity, we will sample along a 20m transect tape placed in the middle of the stream from upstream to downstream. Do this by having one person hold onto the end of the tape (0m mark) while another person pulls the tape downstream while holding onto the handle, stopping just beyond the 20m mark. Put the handle on the bottom of the steam and use rocks if necessary to keep it in place. Make sure the tape is stretched out and is sitting on the bottom. Use rocks if needed to keep the tape down. We will sample along the transect every 5m starting at the 0m mark, alternating sides as you move along the transect. Start on the left side (as you face downstream) of the transect at the 0m mark. To make sure that every participates in the project, the class will be broken up into groups and each group will sample at least one site along the transect. Follow the following steps to collect samples at each location. 1. Place the kick net on the bottom of the stream with the opening of the net facing upstream (so that water flows into the net) and manually disturb the substrate in front of the net by “kicking” so that you scrape off sediment and organisms off the sediment in a 1m2 area in front of the net. Kick for 30 seconds. Lift the net out of the water using a slight forward motion to make sure that you do not lose any of the sample. 2. Wash down the sides of the net to collect the material at the end of the net by repeatedly dipping the net a few times in the creek while shaking the net with your hand. 3. On land, add a few centimeters stream water into deep-sided tray. Transfer the material from the net into the bucket by carefully turning the net inside out and dipping it into a the water in the bucket. Make sure to agitate the bottom of the net to dislodge all of the material from the net 4. If any large objects were capture in the net (e.g., sticks, rocks), wash them in the bucket and discard. 5. Gently mix up the contents of the tray (including and sediment) using your hand in stirring motion and carefully pour the contents of the bucket through the mesh sieve. Pour a little at a time and mixed up the contents of the bucket between pours. We are not collecting the water so you can drain the water onto the ground or into the stream. 6. If there is sediment in the tray, be careful not to pour the sediment into the sieve. Stop pouring when you cannot pour anymore water without adding the sediment to the sieve. 7. Place the sieve upside down into the tray and rinse the sieve using a squirt bottle, using as little water as possible to minimize dilution of the alcohol that will be used to preserve the samples. Gently pour the contents of the tray into a 1 L wide-neck, labeled sample-bottle. Make sure you use the correct bottle (Upstream, Downstream). All samples from the same location will be poured into the same bottle. 8. Lastly, fill the bottle 3/4 of the way with the 95% ETOH. Cap the bottle and gently invert the bottle several times to mix the contents with the ETOH. Then fill the bottle completely with ETOH and cap. The bottle will then be brought to the lab for identification in Week 2. WEEK 2 Identification of Benthic Macroinvertebrates You will work in groups to identify and count the benthic macroinvertebrates collected from the streams. 1. Choose a sample bottle and gently swirl it to suspend the contents. Be sure to note which location (upstream, downstream). Using a turkey baster, remove enough of the contents to cover the bottom of the sampling tray. Add an equal amount of water to suspend the organisms and to dilute the ETOH. 2. Fill each compartment in the ice cube tray halfway with water. Sort organisms by morphology by placing organisms that look alike together in the same compartment of a plastic ice cube tray. Use a forceps to move the organisms to the ice cube tray. 3. When you have sorted all the organisms in your sampling tray, rinse out the tray with tap water and start a new sample (from the same bottle) 4. Continue this until all organisms from that bottle have been sorted by the class. Add water to the ice cube tray as needed to keep the organisms wet. 5. Use the identification guide to identify the benthic macroinvertebrates the lowest taxonomic rank on the identification guide and record the number of individuals of each taxon in your notebook (e.g., the number of individuals of the Order Ephemeroptera; Appendix I). Alternatively, you could ID the organisms as you see them and then sort them. WEEK 3 Data Analysis Pollution Tolerance Index Benthic macroinvertebrates can be categorized by how tolerant they are to pollution (Table 1). Category 1 organisms are pollution intolerant organisms. That is, they cannot survive in any water that is even minimally polluted. Category 2 organisms are intermediate in tolerance. They can survive in a wide range of water quality. Category 3 organisms are pollution tolerant. They can survive in fairly polluted water, as well as clean water. To calculate the Pollution Tolerance Index (PTI), you need to determine the taxa richness (not abundance) of each category and then multiply each by appropriate index value. For example, if there are six Category 1 taxa (pollution intolerant), two Category 2 taxa (intermediate tolerance), and eight Category 3 taxa (pollution tolerant), the PTI = (6*3)+(2*2)+(8*1)=30. The PTI is then compared to Table 6 to determine water quality. Table 1. Benthic macroinvertebrates categorized by pollution tolerance used to calculate Pollution Tolerance Index. The index values for each category is in parentheses. Category 1: Pollution intolerant (3) Category 2: Intermediate tolerance (2) Category 3: Pollution tolerant (1) Order Ephemeroptera (mayflies) Order Odonata (dragonflies, damselflies) Family Chironomidae (nonbiting midge) Order Plecoptera (stoneflies) Order Isopoda (sowbug) Family Simuliidae (black fly) Order Trichoptera (caddisflies) Order Amphipoda (scuds) Class Turbellaria (flatworms) Order Megaloptera (dobsonflies, alderflies) Family Tipulidae (crane flye) Class Hirudinea (leeches) Order Coleoptera (beetles) Class Bivalivia (clams, mussels) Class Oligochaeta (aquatic worms) Class Gastropoda (righthanded snails) Order Decapoda (crayfish) Class Gastropoda (left-handed lung snails) Order Diptera, Family Athericidae (Watersnipe fly) Family Hydropsychidae (Netspinning caddisflies ) Family Psephenidae (Water pennies) Order Hemiptera (true bugs) Class Collembola (springtails) Order Trombidiformes (water mites) As you can see, our example has excellent water quality. Remember, the PTI is based on the number of different kinds (taxa) of macroinvertebrates collected, rather than the number of individuals collected. Table 3. Pollution Tolerance Index water quality values. PTI Quality >22 Excellent 17-21 Good 11-16 Fair Diptera (24.7%) > Decapoda (24.03%). The number of taxa was least for station 2 (14) and was highest (23) for station 4, with highest population density recorded for station 1 (211 individuals). The heterogeneity indices revealed higher values for evenness across the stations except, for station 1 (0.3574). Meanwhile, PTI values showed moderate water quality with range of values from 7 to 16. Keywords: Macroinvertebrate, Biological Diversity, Tolerance Index, Aquatic regimes. 1. Introduction In the last few decades, aquatic ecologists have focused more on water quality, resources management and sustainable utilization. Research in aquatic ecology becomes more challenging when coupled with climate change phenomena. Inundation, siltation, agriculture and deforestation outside industrialization and urbanization, pose greater challenges to aquatic regimes. The use of benthic macroinvertebrates to ascertain the overall health status of aquatic environments remains the most suitable, reliable, and the most widely acclaimed method globally. In this study, we attempt to define pollution tolerance index (PTI) as a method of measuring the overall health status of aquatic bodies through the use of macrobenthic invertebrates. Macrobenthic invertebrates are useful bio-indicators in understanding the ecological health of an aquatic ecosystem, rather than using chemical and microbiological data, which at least give short-term fluctuations (Ravera, 2000; Ikomi et al., 2005; George et al., 2009). Odiete (1999) discussed the use of benthic macroinvertebrates in the assessment of freshwater bodies. Benthic invertebrates were used as bio* Corresponding author. e-mail: [email protected]. indicators for studies of impact of environmental perturbations on the aquatic ecosystems (Lenat et al., 1981; Victor and Ogbeibu, 1985). They are considered important because they reflect the cumulative effects of the present and past conditions; also they have low mobility (i.e. are sedentary or sessile or nearly) and life cycles of several weeks and or years. Biomonitoring studies and the use of macroinvertebrates to rate the quality of water bodies which include both lotic and lentic types have been widely reviewed elsewhere (Ogbeibu and Oribhabor, 2002; Imoobe and Ohiozebau, 2009; Omoigberale and Ogbeibu, 2010; and Olomukoro and Dirisu, 2012). Macroinvertebrates, which were utilized in aquatic pollution studies, included: Mayflies (Ephemeroptera), caddisflies (Trichoptera), stoneflies (Plecoptera), beetles (Coleoptera), crayfish and amphipods (Crustaceans), aquatic snails (Mollusca), biting midges (Chironomids) and leeches (Hirudinea) in Nigeria, North America and Europe. Existing works on the benthic fauna of Agbede wetlands are quite scanty and included: Olomukoro and Dirisu (2012) who dealt with the macroinvertebrate community of a post lindane treated stream with a 20 © 2014 Jordan Journal of Biological Sciences. All rights reserved – Volume 7, Number 1 record of 43 taxa comprising 532 individuals, and Olomukoro et al. (2013) on the ecological survey of macrobenthic invertebrates of selected ponds in Agbede flood plain, where they encountered 10 groups and 1,031 individuals. The purpose of this study is, firstly, to present a general account of the benthic macroinvertebrates species composition and diversity as well as determining the water quality using the benthic fauna, and, secondly, to establish the pollution tolerance index (PTI) for the water bodies. So this study would hopefully be a reference archive for future studies of the water bodies in the subject area. 2. Materials and Methods 2.1. Study Area Agbede wetlands are situated within a derived savannah ecozone that lies between 06o16.3E, 06o 18.7E and 06o52.2N, 06o55.4N. The climate of Agbede and its environs is not stable. It is comparatively like that of Benin and its environs as a rhythm of rainfall occurs in conjunction with the movement of the Southern-West monsoon wind across the Atlantic Ocean and the timing of this movement varies from year to year. There are two distinct annual seasons associated with this region: the rainy season which begins in April and terminates in October, and the dry season which starts from November and terminates in March. Rainfall for 2010, ranged from 158.4 – 608.7mm with the lowest recorded in the month of May (158.4mm) and the peak recorded in the month of September (608.7mm). The mean rainfall value was (356.76mm). Figure 1. Map of the study area. Station 1: This station (06o55.4N and 06o16.4E) is directly located on the Benin and Auchi/Abuja high way by Edion River bridge. There was an occasional inundation of the surrounding banks in the months of July, August, and September. The station is surrounded by a number of ponds on its banks as well as settlements. It is subjected to all forms of human activities. The velocity of flow was determined to be 0.372m/s and the average depth 76cm. Lemna pausicostata (duckweed) was found floating here. Stations 2: This station (06o55.4N and 06o16.4E) is located about 1,050m downstream of the same river Edion. There are lots of aquatic macrophytes (Lemna pausicostata) and algae (Chlorophyta sp.) here. There is vegetation of shrubs and trees like Bambusa bambusa and Anacadium occidentalis on the banks. Cattle dung is commonly associated with this station. The velocity of flow was 0.24m/s and the depth was 82cm. Station 3: This station (06o52.2N and 06o16.8E) is the upstream of River Omodo at Odighie community, by Ewora-Idegun Road. It is surrounded by Bambusa bambusa tickets. Macrophytes are rare here. Velocity of flow was 0.27m/s and the depth was less than 35cm. In dry season, it flows in South–North direction. Human activities in this station include washing, bathing, fishing and fermentation of starch (cassava). It is the only source of domestic water to the immediate communities. Station 4: This station (06o52.2N and 06o18.7E) is located about 840m downstream of stations 3. Here, features and human activities are similar to those in station 3 except the fermentation of starch activities. Current velocity was equally high here (0.29m/s) and the water depth did not exceeded 35cm. 21 © 2014 Jordan Journal of Biological Sciences. All rights reserved – Volume 7, Number 1 2.2. Benthic Fauna Macrobenthic fauna were collected by sampling the rivers substratum using an Ekman grab (made by Hydrobios, West Germany) as recommended for sand and silt (Hynes, 1961) as well as on the Bank-roots and Macrophytes (Olomukoro and Dirisu, 2012). Contents trapped by the grab were processed as described by Olomukoro and Ezemonye (2000). For the bank-roots and macrophytes, benthos was collected using a hand net made of mesh bolting silk of 100µM. The sediment was collected in a plastic container of 15 liters volume; water was added and stirred vigorously while the floating fauna were sieved using 150, 250 and 500 micron sieve sizes and the unfloated fauna were handpicked. The benthic macroinvertebrates were identified using the literature (Olomukoro, 1996). 2.3. Determination of Pollution Tolerance Index (PTI) Pollution tolerance Index (PTI) was determined and computed by utilizing the methods earlier used by Klemm et al. (1990) and Izaak Walton League of America (1994). Three groups of macroinvertebrates were chosen and assigned a multiplication factor of 3 for the pollution sensitive group (Ephemeroptera, Trichoptera and Coleoptera), 2 was assigned to the facultative or somewhat tolerant group (Anisoptera, Zygoptera and Decapoda) and 1 to the pollution tolerant group (Pond snails, Oligochaetes and Leech) as utilized in this study after which they were sum to get the PTI values for the four stations and the same was done for the monthly, and spatial variations. Values obtained were thereafter compared with established standard values. Unpolluted water had values between 23 and above, excellent, 17-22 good. Polluted water had 11-16 fair and < 10 poor. The water quality of stations 2, 3 and 4 had different results. Although station 1 had a PTI value of 16; PTI values of stations 2 and 3 were 7 for each; station 4 had 10. 2.4. Statistical Analysis Biological indices, such as taxa richness, evenness (E) and Shannon-Weiner diversity, were computed using paleontological statistics software (PAST). The graphs were plotted with MS-Word Excel. 3. Results 3.1. The Macrobenthic Fauna A total of 33 macroinvertebrate taxa composed of 1 species each of Oligochaeta, and Decapoda (crab), 3 species of Crustaceans (shrimps), 6 species of Ephemeroptera, 3 species of Anisoptera and 3 species of Zygoptera. Others include; Coleoptera 1 species, Trichoptera 3 species, Ceratopogonidae (Diptera) 1 species, Chironomidae (Diptera) 8 species, Cullicidae (Diptera) 2 species, Mollusca 2 species. The relative percentage composition of the taxonomic groups collected from the four stations were: Oligochaeta (0.972%), Decapoda (24.027%), Ephemeroptera (45.420%), Odonata (3.611%), Coleoptera (0.139%), Trichoptera (0.833%) Diptera (24.722%) and Mollusca (0.277%). (Table1 and 2). Table 1. Summary of macrobenthic invertebrate communities present in Edion and Omodo Rivers of Agbede Wetlands, Edo State (March to October, 2010). Stations Taxa STN1 STN2 STN3 STN4 Total OLIGOCHAETA Nais sp. DECAPODA 7 1 Unidentified crab larva – – – 2 2 Caridina africana Caridina gabonensis 14 14 15 17 40 8 21 14 90 53 Desmocaris trispinosa 17 8 2 1 28 EPHEMEROPTERA Adenophlebiodes sp. Baetis sp. Centroptilum sp. Cloeon sp. Cloeon bellum Ephemerella ignita ODONATA 1 45 10 84 2 2 31 14 49 2 32 2 21 1 – 16 6 6 2 1 3 124 32 160 3 5 1 1 1 5 3 3 4 4 6 9 7 1 1 1 2 1 Anisoptera Aeschna sp Libellula sp. Aphylla sp Zygoptera Coenagrion sp. Enallagma sp. Lestes sp. COLEOPTERA Dytiscus marginalis TRICHOPTERA Hydroptila sp. Limnophilus sp. Unidentified larva 1 1 1 1 1 2 DIPTERA Anopheles sp. Ceratopogonidae Palpomyia sp. 1 2 1 1 3 10 1 11 2 2 Chironomidae Chironomus fractilobus 6 4 18 22 50 Chironomus travalensis 6 Chironomus sp. 1 5 8 17 4 32 19 54 5 13 12 5 25 7 3 1 7 4 1 Tanypus sp. Tanytarsus sp. Clinotanypus sp. Pentaneura sp. Insect larva MOLLUSCA Hydrobia sp. 1 1 Planorbis crista 1 1 1 Total no. of individuals 211 160 179 170 Total no. of species 20 14 16 23 Pollution Tolerance Index (PTI) 7 4 3 5 720 22 © 2014 Jordan Journal of Biological Sciences. All rights reserved – Volume 7, Number 1 Table 2. Relative percentage composition of taxonomic groups including; the dominant and subdominant, in the study area. While polluted water would have 11 –16 fair and < 10 poor. The water quality of stations 2, 3 and 4, had different results. Although station 1 had a PTI value of 16, stations 2 and 3, PTI values of 7 each and station 4 had 10. Groups Taxa (%) Number of Individuals % Occurrence Oligochaeta 3.03 7 0.972 Decapoda 12.12 173 24.027 Ephemeroptera 18.18 327 45.420 Table 4. Summary of the overall health status of the water quality in the wetlands Odonata 18.18 26 3.611 Rivers/Stations PTI Coleoptera 3.03 1 0.139 Water Quality Status Tricoptera 9.09 6 0.833 Edion 1 (Upstream) 16 Fair 2 (Downstream) 7 Poor 7 Poor 10 Poor Diptera 30.30 178 24.722 Mollusca 6.061 2 0.277 Total 33 720 100 Omodo 3 (Upstream) 4 (Downstream) A total of 720 individuals belonging to 33 species were recorded during this study. At station 1, the total numbers of taxa were 20, and the number of individuals was 211. At station 2, the numbers of taxa and individuals were 14 and 160, respectively. While, at stations 3 and 4, the numbers of taxa and individuals were 16 and 179, and 23 and 170, respectively. (Table 3) 3.2. Diversity Indices Diversity indices were applied to the macroinvertebrates using the computer software package tool called PAST (Palaeontological Statistics) to determine taxa richness, evenness, Shannon diversity, dominance index and Margelef index (Table 3). At stations 2, 3 and 4, the pollution tolerance Index values were low, indicating a poor water quality status (Table 5). This is an indication that organisms such Odonata (Zygoptera and Anisoptera), Oligochaeta, Chironomids among others were dominant. The monthly pollution tolerance indices (Figure 2) for all the stations generally recorded low water quality values. But, PTI values were generally higher in the month of September throughout the sampling period and generally lowest in the month of March. Meanwhile the PTI value (11) was highest at station 1 (Edion River), in the month of June and least in March. At station 4, PTI (9) was highest in the month of September. Table 3. Diversity of the macroinvertebrate community of the selected rivers, in Agbede Wetlands Description Station Station Station Station (Indices) 1 2 3 4 Number of samples 16 16 16 16 Number of Taxa 20 14 16 23 Number of Individuals 211 160 187 170 Taxa Richness (d) 0.2236 0.1675 0.1170 0.0965 Shannon diversity (H) 1.967 2.082 2.414 2.625 Evenness (E) 0.3574 0.5729 0.6210 0.6003 Dominance Index (C) 0.7764 0.8325 0.8830 0.9035 Taxa richness was highest in station 1 (0.2236) and least in station 4 (0.0965). Station 2 and 3 had very close values. There was a gradual decrease from station 1 to 4. Station 4 had the highest general diversity value (2.625), while, station 1 recorded the least value (1.967). An increasing order from station 1 to 4 was observed here. The evenness of these species was fairly low across the stations. The values were < 1 in each station. However, it was lowest in station 1 (0.3574). Station 4 had the highest value (0.9035) for dominance when compared with station 1 (0.7764). 3.3. Pollution Tolerance Index (PTI) PTI was utilized to assess the overall health status of the study stretch to ascertain the extent of human impact on rivers (Table 4). Unpolluted water would have values between 23 and above, excellent, 17 – 22, good. Figure 2. Monthly fluctuation of pollution tolerance index at the stations. 4. Discussion All the organisms found in this study have been variously reported elsewhere in Africa and in the tropics at large (Green, 1979; Olomukoro and Ezemonye, 2000; Imoobe and Ohiozebau, 2009; and Olomukoro and Dirisu, 2012). Oligochaeta were very poorly represented (3.030% by taxa and 0.972% by individual). Olomukoro (1996) recorded several species of Oligochaetes in Warri River including Nais sp. It was reported that the abundance of Oligochaeta was due to the richness of the immediate substrate in organic matter. This may be due to their feeding habits as they are deposit feeders and they are © 2014 Jordan Journal of Biological Sciences. All rights reserved – Volume 7, Number 1 tolerant to silting, decomposition and flow rate than other macrobenthic groups. Among the Decapoda, a high abundance of shrimps was recorded. Three species of shrimps (Caridina gabonensis, Caridina africana, and Desmocaris trispinosa) were recorded. The diversity and high population density of shrimps have been widely reported in Nigeria (Ogbeibu and Victor, 1989; Olomukoro, 2002; and Omoigberale and Ogbeibu, 2010). Ephemeroptera showed relatively high diversity. Three families (Leptophlebiidae, Baetidae and Ephemiridae) and six species which include Ademophleboides sp., Baetis sp., Centroptillum sp., Cloeon sp., Cloeon bellum and Ephemerella ignita were recorded. The abundance of these species is an indication of good water quality and may be due to habitat preference and availability of food. Odonata are known to be facultative animals as they are mostly associated with moderately polluted waters. A total of six species of Odonata was recorded. The diversity of Odonata has been utilized in biomonitoring of fresh water bodies. Generally, the diversity was poor except in station 3 where, Aeschna, Libellula and Aphylla sp. (members of the suborder Anisoptera) had a little higher numbers and in station 4, respectively. Only one species of Coleoptera (Dytiscus marginalis) was represented in this group. Coleoptera are known to be mostly associated with lentic water bodies such as ponds and lakes. They are sheltered by macrophytes. Only two species of Trichoptera were recorded in the month of June and high density is indicative of good water quality. The density was very low when compared with the work of Imoobe and Ohiozebau, (2009) for Okhuo River in Benin City. This may be as a result of the fact that they are mostly present in well oxygenated and fast running waters. Diptera was the second largest group after Ephemeroptera. Three families (Ceratopogonidae (1 species), Chironomidae (8 species) and Culicidae (1 species)) were recorded throughout the study. Chironomus sp., Chironomus fractilobus and Chironomus travalensis were dorminant with the highest occurrence in stations 3 and 4, respectively. Tanypus sp., Pentaneura sp., Clinotarnypus sp. and unidentified insect larva recorded a low density and were restricted to stations 3 and 4 only. The relative abundance of these taxa has been emphasized by Wallace and Hynes (1981). They may have been so favored by the conditions of the immediate substrates, which include the alkaline pH in the study area. Mollusca were poorly represented with two species (Hydrobia sp and Planorbis crista). The younger life forms inhabit polluted environment, hence their great importance in monitoring pollution stress of wetlands. The two species and two individuals Mollusca recorded were restricted to station 1 only. Molluscs are mostly associated with lentic ecosystems, so that the restriction may be attributed to sampled station type, with an element of backwaters during the dry season months. The diversity of the macroinvertebrates fauna was low when compared with the number of taxa recorded in some other water bodies. Victor and Ogbeibu (1985) 23 recorded 55 taxa in Ikpoba River, Olomukoro and Egborge (2003) recorded 138 taxa in Warri River, and Omoigberale and Ogbeibu (2010) recorded 57 taxa in Osse River. The low taxa and the total number of individuals recorded for these two Rivers in Agbede – wetlands may be very surprising. This is in contrast with the report of Victor and Victor (1992) who stated that brackish water are known to record low number of taxa. However, the low number of taxa may be due to the choice of sampling stations such that the activities impacting such habitats are colossal, and hence, do not support the ecology of benthos. The use of pollution tolerance index was subject to problems of the inherent variations in the nature of the aquatic communities in the study area and it was observed that the list of groups of organisms had different degrees of tolerance to their environments. A high pollution tolerance index of 16 was recorded for station 1 (upstream of Edion River) in the wetlands, where organisms, such as Ephemeroptera, Coleoptera and Trichoptera, which are least tolerant to pollution, were represented in a variety of species. It obviously indicated that the waters at station 1 were of low pollution (fair), which could be described as Oligosaprobic in quality. Pollution sensitive organisms such as Trichoptera and Coleoptera had no species recorded outside station 1 and Ephemeroptera density was lower. However, Odonata and Decapoda had relatively high abundance and high species diversity; and densities in stations 2, 3 and 4. The high density of Chironomidae in these stations 2, 3 and 4 was an indication that the waters were relatively polluted or mesosaprobic in quality. The relatively high diversities of Ephemeroptera, Coleoptera and Trichoptera as utilized in this study may be due to habitat preference resulting from presence of very low pollutants/contaminants levels, as directly impacted into the immediate substrates. Trichoptera are mostly present in uplands streams or rivers which are well oxygenated when compared to low land fresh waters like in this case. In conclusion, organisms, which are most sensitive to pollution, such as Coleoptera and Trichoptera as utilized in this study, were completely absent in stations 2, 3 and 4, an indication that the waters were relatively poor in the above stations, considering the PTI values (7, 7 and 10). Thus, the density of the families of the Ephemeroptera group in stations 2, 3, and 4 dropped when compared with that at station 1. One peculiar observation is that some of the insects like Ephemeroptera prefer slow running water environment with macrophytes, which support their ecology. We strongly advocate that organic farming should be encouraged and practiced as run-off from agricultural sites contains lots of contaminants; and washing of all kinds and channeling of industrial effluence be discouraged. Nomadic agriculture should be restricted to designated sections along the rivers catchment. The need for long-term hydrobiological investigation, with elaborate emphasis on water quality monitoring and the ecology of macrobenthic fauna is so much 24 © 2014 Jordan Journal of Biological Sciences. All rights reserved – Volume 7, Number 1 recommended for the safety and conservative use of our fresh water bodies and the resources. Ogbeibu AE and Victor R. 1989. The effect of road and bridge construction on the bank root macrobenthic invertebrates of a southern Nigeria stream. Environ Pollution, 58: 85 – 100. References Olomukoro JO. 1996. Macrobenthic fauna of Warri River in Delta State – Nigeria. (Ph.D Thesis) University of Benin, Benin City, Nigeria. 205pp. George ADI, Abowei JFN and Alfred-Ockiya JF. 2009. The Distribution, Abundance and Seasonality of Benthic Macroinvertebrate in Okpoka Creek Sediment, Niger Delta, Nigeria. Res J Applied Sci Engineer Technol., 2(1): 11 – 18. Green J. 1979. The Fauna of Lake Sofon, Sierra Leone. J Zool Lond., 187: 113 – 133. Hynes HBM. 1961. The Invertebrate fauna at Welsh Mountain Stream. Arch Hydrobiol., 57: 344 – 388. Ikomi RB, Arimoro FO and Odihirin OK. 2005. Composition, distribution and abundance of macroinvertebrates of the upper reaches of River Ethiope Delta State, Nigeria. The Zoologist, 3: 68 – 81. Imoobe TOT and Ohiozebau E. 2009. Pollution status of a tropical forest river, using aquatic insects as indicator. African J Ecol., 48: 232 – 238. Izaak Wlaton League of American, 1994. Creek Connections Aquatic Life Module – Aquatic Macroinvertebrate Sampling. (Adapted from Volunteer Stream Monitoring: Methods Manual, United States Environmental Protection Agency, Office of Water, Draft Document #EPA 841-B-97-003, November, 1996). Klemm DJ, Philip AL, Florence and Lozoreckak 1990. Macro invertebrate field and laboratory method for evaluating the biology integrity of surface water. U.S.EPA, EPA/600/4-90.030 Xii 256pp. Lenat DR, Penrose DLS and Eagleson KW. 1981. Variable effects of Sediment addition on stream benthos. Hydrobiologia, 79: 187 – 194. Odiete WO. 1999. Environmental physiology of animals and pollution. Diversified Resources, Lagos, Nigeria, pp: 220-246. Ogbeibu AE and Oribhabor BJ. 2002. Ecological impact of river impoundment using benthic macroinvertebrates as indicators. Water Res., 36: 2427 – 2436. Olomukoro JO and Dirisu AR. 2012. Macroinvertebrate Community of a Post Lindane Treated Stream Flowing Through a Derived Savannah in Southern Nigeria, Tropical freshwater Biol., 21(1): 67 – 82. Olomukoro JO and Egboge ABM. 2003. Hydrobiological studies of Warri River, Nigeria. Part 1: The composition, distribution and diversity of macrobenthic fauna. Bios Res. Commun., 15: 279 – 294. Olomukoro JO and Ezemonye LIN. 2000. Studies of the macrobenthic fauna of Eruvbi Stream, Benin City, Nigeria. Trop Environ. Res., 2(1&2): 125 – 136. Olomukoro JO, Osamuyiamen IM and Dirisu AR. 2013. Ecological Survey of Macrobenthic Invertebrates of Selected Ponds in Agbede Flood Plain, Southern Nigeria. J Biol, Agriculture and Healthcare, 3(10): 23 – 29. Omoigberale MO and Ogbeibu AE. 2010. Environmental Impacts of Oil exploration and production on the invertebrate fauna of Osse River, Southern Nigeria. Res J Environ Sci., 4: 101 – 114. Ravera O. 2000. Ecological monitoring for water body management. Proceedings of monitoring Tailor made III. International Workshop on Information for Sustainable Water Management, Pp 157 – 167. Victor R and Ogbeibu AE. 1985. Macro benthic invertebrates of a stream flowing through farmland in Southern Nigeria. Environ Poll. (Series A). 39: 339 – 349. Victor R and Victor J. 1992. Some aspects of the Ecology of Littoral invertebrates in a coastal Lagoon of Southern Oman. J Arid Environ., 37: 33 – 44. Wallace RB and Hynes HBN. 1981. The effect of chemical treatment against black fly larvae on the fauna of running waters. In: Laird M (Eds.), Black Flies, The Future For Biological Methods In Integrated Control, Academic Press, London, pp 327 – 358. water Article Benthic Macroinvertebrate Diversity as Affected by the Construction of Inland Waterways along Montane Stretches of Two Rivers in China Peng Dou 1,2 , Xuan Wang 1 , Yan Lan 3 , Baoshan Cui 1 , Junhong Bai 1 and Tian Xie 1, * 1 2 3 *



 Citation: Dou, P.; Wang, X.; Lan, Y.; Cui, B.; Bai, J.; Xie, T. Benthic Macroinvertebrate Diversity as State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; [email protected] (P.D.); [email protected] (X.W.); [email protected] (B.C.); [email protected] (J.B.) Department of Water Environment, Beijing Water Science and Technology Institute, Beijing 100048, China Foreign Environmental Cooperation Center, Ministry of Ecology and Environment, Beijing 100035, China; [email protected] Correspondence: [email protected] Abstract: Building inland waterways affects the natural structure, formation, and extent of the riverbed and riparian zone. It alters the hydrology and sediment deposition conditions and hence damages the aquatic ecosystem. To address the effects of the construction of inland waterways on the riverine biome, benthic macroinvertebrate communities were compared at different building stages of inland waterways along a gradient of shipping traffic density at two montane rivers in China. The Shannon–Wiener diversity index of the benthic macroinvertebrate communities ranged from 0.4 to 1.6; the lowest value was recorded in the completed inland waterway, while the highest value was recorded in the unaffected stretch. Principal component analysis and canonical correlation analysis showed the communities in the inland waterways to be distinct from those in the natural riparian habitats. Our results suggest that benthic macroinvertebrate communities can reflect the damage done by the hydromorphological modifications caused by building inland waterways. Benthic macroinvertebrate diversity and abundance should therefore be included when assessing the impact of building and operating inland waterways. Affected by the Construction of Inland Waterways along Montane Stretches of Two Rivers in China. Keywords: benthic macroinvertebrate communities; waterway construction; riparian ecosystems; shipping traffic; Shannon–Wiener diversity Water 2022, 14, 1080. https:// doi.org/10.3390/w14071080 Academic Editor: Arantza Iriarte 1. Introduction Received: 26 January 2022 Accepted: 26 March 2022 Published: 29 March 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Building inland waterways affects many components of river ecosystems [1,2] because of the inevitable anthropogenic interventions, such as regulating river channels, constructing dams, dredging channels, and building wharves [3–6]. Stream channels and riparian zones are affected by building and operating inland waterways [7,8], resulting in changes in dissolved and suspended nutrients, substrate composition, sediment deposition, and the abundance of aquatic organisms within specific stretches of the rivers [9,10]. Habitats within natural riparian zones are also heavily impacted when inland waterways are built in mountainous regions [11–14]. Natural riverbanks are land–water interfaces that affect the hydrological regime, river morphology, and fauna within rivers. In particular, benthic macroinvertebrates, which are typically larger than 0.5 mm or 1 mm and therefore visible to the naked eye, at the bottom of a water body in the riparian zone include the most ubiquitous species and perform many indispensable ecological functions in the riparian ecosystem [15–17]. Benthic macroinvertebrate species are found in the bottom sediment layer in rivers during spawning, reproduction, and feeding [18,19], and any disturbance to that bottom layer, inevitable during waterway construction and shipping, is bound to influence the abundance, composition, and diversity of those benthic macroinvertebrate assemblages [20]. Water 2022, 14, 1080. https://doi.org/10.3390/w14071080 https://www.mdpi.com/journal/water Water 2022, 14, 1080 2 of 13 Changes to hydrological conditions and the loss of riparian habitats caused by waterway construction significantly reduce the biomass (and therefore the abundance) and the diversity of aquatic organisms along the river [21,22], and ship traffic along inland waterways has been proposed as the key factor limiting the survival of benthic macroinvertebrate species [23,24]. Some characteristics of benthic macroinvertebrates can be used as bioindicators to evaluate the quality of riparian habitats [25–27], and benthic macroinvertebrate diversity and abundance can therefore be included in the criteria for assessing the likely environmental impact of building inland waterways before their construction is initiated. The availability of habitats within a riparian zone is altered by the construction of river channels and the density of shipping traffic in ways that threaten the survival of a number of benthic macroinvertebrate species [28]. Additionally, the altered hydrologic regimes affect the structure of riparian habitats significantly, and the stability of a riverbank is affected by changes in the flow of discharge, the hydrological cycle, waves generated as a result of shipping traffic, and periods of inundation. Loss of suitable riparian habitats is a primary factor affecting the distribution of benthic macroinvertebrate species [29–31], and some studies have shown how benthic macroinvertebrates respond to the deterioration of riparian habitats [32,33] and how they are adversely affected by the construction and operation of river channels [34]. The species diversity and abundance of benthic macroinvertebrates decreased after inland waterways were built, especially following changes in riparian habitats [35,36]. Such changes may prevent benthic macroinvertebrates from colonizing specific stretches of a river and thus hasten the deterioration of benthic macroinvertebrate communities [37]. Earlier studies have only partly confirmed that construction of waterways and the subsequent traffic affect the composition of benthic macroinvertebrate communities significantly. Research on benthic macroinvertebrate diversity in riparian zones has focused on the relationship between benthic macroinvertebrate communities and environmental variables but ignored the different phases of inland waterway construction and the effects of traffic [38,39]. The effects of traffic and the presence of hydro-engineering structures in waterways could lead to permanent hydrological changes, resulting in loss of habitats, including riparian wetlands. Consequently, the riparian flora and fauna become less widely distributed. Furthermore, shipping traffic disturbs the deposition of sediment on the river bottom in the riparian zone, which may have even greater effects on the benthic macroinvertebrate communities than those caused by other environmental parameters. Once the construction of an inland waterway is complete, the ecosystem biodiversity begins its recovery, starting from sites in the riparian zone adjacent to the riverbed. Given a large stretch of diverse habitats, riparian benthic macroinvertebrate populations can survive the period of inland waterway construction and then recolonize the river ecosystem. Changes in streambed substratum habitats, improvement of the river water quality, regulation of the waterway operation intensity, and even optimization of the river’s hydrological regime have been proposed as measures for the restoration of benthic macroinvertebrate populations, but the effectiveness of these measures is difficult to evaluate because there is little information addressing the mechanism of human disturbance of benthic macroinvertebrate communities [4]. More research is required into the dynamics of benthic macroinvertebrate populations as influenced by such construction and by shipping traffic in inland rivers. The present study is an effort to address the influence of the construction of inland waterways on the benthic macroinvertebrate communities. We examined the differences in the response of benthic macroinvertebrate communities to construction at different building stages of inland waterways. Using the method of multivariate analysis, we tested the relationship between the diversity and the abundance of macroinvertebrate communities with the water quality factors and the density of traffic. We propose two hypotheses, namely: (1) benthic macroinvertebrate populations within a stretch of a river vary during different periods or phases of constructing a waterway along the river; and (2) once the waterway is operational, the density of traffic affects the abundance and the diversity of benthic macroinvertebrate populations in that ecosystem. Water 2022, 14, 1080 namely: (1) benthic macroinvertebrate populations within a stretch of a river vary during different periods or phases of constructing a waterway along the river; and (2) once the waterway is operational, the density of traffic affects the abundance and the diversity of 3 of 13 benthic macroinvertebrate populations in that ecosystem. 2. Materials and Methods 2. Materials 2.1. Study Areaand Methods 2.1. Study Area The study was carried out in the mountainous stretches of two rivers in southwest studythe was carried out in the stretches of two rivers in southwest China,The namely Zhangjiang river andmountainous the Wuyang river, via repeated sampling in 2015 China, namely the Zhangjiang river and the Wuyang river, via repeated sampling in 2015 and 2016. Both the Zhangjiang river and the Wuyang river are part of the same hydrologand 2016. Both the Zhangjiang river and the Wuyang river are part of the same hydrological ical catchment (Xijiang river basin), with similar hydrogeological conditions, including catchment river basin),substrate. with similar hydrogeological conditions, width, width, flow (Xijiang flux, and riverside There is very little vegetation inincluding the bedrock or flow flux, and riverside substrate. An There is very little vegetation in the bedrock or gravelly gravelly substrate of the riverside. inland waterway project was under construction in substrate of the riverside. An inland waterway project was under construction in the upper the upper and middle reaches of the Zhangjiang river during the study period. The and middle of the Zhangjiang river during the study period. Wuyang Wuyang riverreaches waterway had been in operation for nearly 3 years prior The to the study. river The waterway had been in operation for nearly 3 years prior to the study. The total length of total length of the Zhangjiang river is 100.6 km, and its average annual discharge is 28.8 3 /s. The total the Zhangjiang river is 100.6 km, and its average annual discharge is 28.8 m m3/s. The total length of the Wuyang river is 258.4 km, and its average annual discharge is 258.4 sites km, and itsestablished average annual discharge is 31.22 m2river /s. A islength 31.22 of m2the /s. AWuyang total of river 24 sampling were (17 along the Zhangjiang total of 24 sampling sites were established (17 along the Zhangjiang river and 7 along the and 7 along the Wuyang river) (Figure 1). Discrete samples were collected (see Section 2.2 Wuyang river) (Figure 1). Discrete samples were collected (see Section 2.2 for details) from for details) from sites within similar niches (similar in terms of vegetation, land use, river sites within similar niches (similar in terms of vegetation, land use, river width, and flow width, and flow velocity). In September 2015 and 2016, the sampling sites were divided velocity). In September 2015 and 2016, the sampling sites were divided into three groups: into three groups: Group A comprised seven sites (numbered A1 to A7) along a developed Group A comprised seven sites (numbered A1 to A7) along a developed inland waterway in inland waterway in the Wuyang river; Group B comprised nine sites (B1–B9) representing the Wuyang river; Group B comprised nine sites (B1–B9) representing an inland waterway an inland waterway under construction as part of the Zhangjiang river; and Group C comunder construction as part of the Zhangjiang river; and Group C comprised eight sites prised eight sites (C1–C8) representing a natural stretch of the Zhangjiang river (Figure (C1–C8) representing a natural stretch of the Zhangjiang river (Figure 1). Traffic density 1). Traffic density along these stretches was estimated by observing and recording the along these stretches was estimated by observing and recording the number of ships number of ships passing a fixed point within a unit of time over ten consecutive days. passing a fixed point within a unit of time over ten consecutive days. Figure 1. Sampling sites (red circles) along the Wuyang (a) and Zhangjiang (b) rivers in southwestern Figure 1. Sampling sites (red circles) along the Wuyang (a) and Zhangjiang (b) rivers in southwestChina. Sites A1A1 to to A7A7 represent a developed inland waterway in in thethe Wuyang river; sites B1B1 to to B9 ern China. Sites represent a developed inland waterway Wuyang river; sites represent a stretch of inland waterway under construction along the Zhangjiang river; and sites C1 B9 represent a stretch of inland waterway under construction along the Zhangjiang river; and sitesto C8torepresent an undisturbed stretch of theofZhangjiang river.river. C1 C8 represent an undisturbed stretch the Zhangjiang 2.2. Benthic Macroinvertebrate Sampling Benthic macroinvertebrate populations were sampled from parts of the riverbank in contact with river water. From each sampling site in the riparian zone, three samples were collected as three replications using a Surber net (at a depth of 15 cm), each from an area 40 cm × 40 cm in size. The samples were filtered through a 2 mm sieve, and the residue was preserved in 5% (v/v) formaldehyde in plastic vials. The macroinvertebrates in the residue were handpicked using a dissection microscope at 10× magnification and preserved in 70% alcohol. Water 2022, 14, 1080 4 of 13 The subsequent classification and identification of the taxa or morphotaxa were conducted in the laboratory. The macroinvertebrates retained for identification were identified at the species level (few were identified at the family level), and the abundance of each species is expressed as the unit ind/m2 . The diversity of macroinvertebrates was calculated by the Shannon–Wiener diversity index H’. S Ni N ln i N N i =1 H0 = − ∑ (1) where S is the total number of species in a sample plot, Ni is the number of individual species i, and N is the number of all species in the sample plots. 2.3. Analyses of Environmental Factors From each sampling site, we collected three water samples (10 L each). The physical and chemical properties of the water, including temperature (TEM), pH, dissolved oxygen (DO), total dissolved solids (TDS), and suspended solids (SS), were recorded using portable electrochemical meters (WTW Multi3320 multi-probes and WTW Turb 430T turbidity meter, Xylem Analytics Germany Sales GmbH & Co. KG., Weilheim, Germany). Water velocity (VEL) was measured using a portable flow meter (HD-DPF420 Doppler current meter, Haydn Technology Co., LTD, Chongqing, China). All the …