Iranian Journal of Fisheries Sciences 17(4) 641-656 2018 DOI: 10.22092/ijfs.2018.116991 Assessing benthic health of hard substratum macrobenthic community using soft bottom indicators and their relationship with environmental condition Mehdipour N.1*; Gerami M.H.2; Nemati H.3 Received: April 2016 Accepted: June 2016 Abstract This study aimed to assess ecological quality status of hard substratum macroinvertebrates communities of the Caspian Sea with three ecological indices and their relationship with environmental factors. For this purpose, benthic communities of the Caspian Sea basin were studied seasonally during 2014 in 8 sampling sites. Temperature, salinity, dissolved oxygen, pH, nitrate, nitrite, silicate and phosphate were measured as environmental factors. The benthic classification indices AMBI (AZTI Marine Biotic Index), M-AMBI (Multivariate AMBI) and BENTIX (BENthic IndeX) were applied to assess the ecological status of the studied area. Results showed low dissimilarity based on species composition and abundance among seasons, while all seasons discriminated clearly based on environmental factors. In addition, AMBI index was more successful to assess ecological health of hard substratum in the Caspian Sea basin than M-AMBI and BENTIX. Furthermore, AMBI showed high sensitivity to environmental variation. Results indicated that temperature, nitrate, silicate, phosphate and nitrite were the most important factors in the composition and abundance fluctuation of hard substratum macroinvertebrates communities, respectively. Keywords: Benthic health, AMBI, M-AMBI, BENTIX, Environmental factors, Caspian Sea 1-Iranian National Institute for Oceanography and Atmospheric Sciences, Iran. 2-Young Researchers and Elite Club, Shiraz Branch, Islamic Azad University, Shiraz, Iran. 3-Faculty of Biological Sciences, Shahid Beheshti University. *Corresponding author's Email: [email protected] 642 Mehdipour et al., Assessing benthic health of hard substratum macrobenthic community using… Introduction stresses (Zubikarai et al., 2014; Hard substratum benthic communities Abbaspour et al., 2017; Ghorbanzadeh in coastal areas, especially those areas Zaferani et al., 2017). Therefore, these that located near or at urban and organisms are considered powerful industrial centers, are highly affected by indicators of environmental pollution. anthropogenic activates. (Fraschetti et The AZTI Marine Biotic Index al., 2001; Zalmon et al., 2011; Spaccesi (AMBI, also referred to as BC) and Rodrigues Capitulo, 2012). developed by Borja et al. (2000) Although these shores support a rich evaluates ecological health condition in biodiversity, but contaminations such as five categories based on the distribution heavy metals and/or bacteria, nutrients of individual abundances in benthic from organic or industrial pollution communities. The species were from diverse sources and from distributed in those groups according to sedimentation seriously affected the their sensitivity to an increasing stress diversity and functioning of these gradient (enrichment of organic matter) ecosystems (Terlizzi et al., 2002; De (Glémarec and Hily, 1981; Hily, 1984). Wolf et al., 2004; Piola and Johnston, M-AMBI (‘Multivariate AMBI’, Bald 2008). et al., 2005; Muxika et al., 2007) is a Hard communities are stressed multivariate index for assessing the environments; due to waste water ecological health and quality status of discharges that is close to the coastline. marine and transitional waters. It is These waters cause deterioration in based on benthic macroinvertebrates water quality and discourage the communities and integrates AMBI, a settlement of several organisms; that biotic index based on species affect these communities thriving in sensitivity/tolerance, with diversity and rocky-shores (Arévalo et al., 2007). richness (Sigovini et al., 2013). It aims Organic and nutrient enrichment due to to integrate the response of species domestic wastes is today one of the richness, the Shannon diversity index main reasons explaining the (Shannon and Weaver, 1949) and the deterioration of marine nearshore biotic index AMBI (Borja et al., 2000). ecosystems (Fletcher, 1996). In Simboura and Zenetos (2002) designed addition, seasonal oscillations in new index based on the AMBI Index environmental conditions dramatically (Borja et al., 2000) with a re- influence the macrobenthic combination of ecological groups that communities in coastal waters assigns different weighting coefficients (Reizopoulou et al., 2014). Benthic and results to the reduction of invertebrates and macroalgae are macrozoobenthic data in three wider sedentary long lives, easy sampling ecological groups (Simboura and organisms that many literatures Argyrou, 2010). published on their distribution in Anthropogenic disturbances and specific environments and on their habitat natural changes are the most response to different environmental important factors in reaction of aquatic Iranian Journal of Fisheries Sciences 17(4) 2018 643 organisms (Nouri et al., 2008; Saghali bottom benthic indices in assessing the et al., 2013). Benthic fauna's structure ecological health in these coastlines. is affected by environmental factors such as temperature, pH, dissolved Materials and methods oxygen and pollution (Sharma and Sampling was performed in 8 sites form Rawat, 2009; Saghali et al., 2013). southwest to southeast shores of the Variation in these factors cause changes Caspian Sea in Iranian waters basin. in rate of supply of organic matter and Sites were located to Astara (S1), consequently affect the composition Anzali (S2), Chamkhaleh (S3), Ramsar and abundance of marine organisms, (S4), Sisangan (S5), Babolsar (S6), such as macrobenthic communities Amirabad (67) and Khajeh Nafas (S8) (Erftemeijer and Herman, 1994; (Fig. 1; Table 1). Sampling was done at Bachelet et al., 2000). the midpoint of each season from spring Assessment of the to winter 2014. Temperature, salinity, macroinvertebrates communities’ health dissolved oxygen and pH were in soft bottom substratum has measured using the portable multi- progressed in recent years (Borja, 2005; meters (HACH 51154, USA) with three Borja, 2006; Kutser et al., 2006; Pinedo replicates in each site. Species area et al., 2007; Borja et al., 2008), but data curve method applied for sampling on hard substratum is limited. The aim from (Browne, 1996). 20×20 cm of this study was to examine the hard- quadrat (0.04 m2) was performed on substratum benthic community rocky substratum from supralittoral organism in 8 sites of the Caspian Sea zone to sample from macrobenthic rocky seawalls under different communities with three replicate and environmental conditions and relate it samples were preserved in 4% formalin. to ecological status indices. Moreover, In the laboratory, the macrofauna were the study explores the applicability of sorted, identified up to species level and three of the most commonly used soft counted (Freeman and Bracegirdle, 1971). Figure 1: Map showing the sampling locations in the southern Caspian Sea (2014). 644 Mehdipour et al., Assessing benthic health of hard substratum macrobenthic community using… Table 1: Geographical coordinates of the stations. Station N E Astara 38°25´59.33” 48°52´52.77” Anzali 37°28´53.00” 49°27´20.55” Chamkhaleh 37°12´57.68” 50°16´33.22” Ramsar 36°55´45.75” 50°40´05.19” Sisangan 36°35´02.49” 51°48´43.41” Babolsar 36°42´52.43” 52°39´35.40” Amirabad 36°51´30.55” 53°23´22.17” Khajeh nafas 36°57´49.43” 54°00´52.51” Surface water samples were collected study; salinity from 0 to 36 ppm for simultaneously from rock pools in all Mediterranean lagoons and 0 to 16 ppm the selected sampling sites for analysis for Caspian Sea in this study; Oxygen the nutrient contents. Water nutrient from 0 to 14 mL L-1 for Mediterranean concentration was measured according lagoons and 0 to 11 mL L-1 for Caspian to photometric methods (Wood et al., Sea in this study; Nitrate from 0.1 to 1967; Strickland and Parsons, 1972). 300 µg L-1 for Mediterranean lagoons Phosphate analyzed by a modified and 0 to 600 µg L-1 for Caspian Sea in ascorbic acid reduction method and this study; pH from 7.5 to 9.8 µg L-1 for silicate assessed based on calorimeter Mediterranean lagoons and 8.3 to 8.9 with formation of molybdic acid µg L-1 for Caspian Sea in this study (Strickland and Parsons, 1972). Nitrite (López and Tomàs, 1989). The determined by colorimetric and ion reference values for M-AMBI were set chromatographic methods and nitrate as: Diversity=0 to 1.62, S=0 to 7 and was measured based on cadmium- AMBI=0.09 to 4, based on AMBI copper reduction to nitrite (Wood et al., calculation. To calculate the BENTIX 1967). (BENthic IndeX) (Add-in v.1.0 version) AMBI, M-AMBI and BENTHIX the software for MS Excel 2007 has biotic indices were calculated by been used downloaded free from: following methods: To calculate the http://www.hcmr.gr/en/articlepage.php? AMBI and M-AMBI, the free software id=141. Diversity indices (Margalef, (http://www.azti.es v.4) along with the Pielou, Shannon and Simpson) and guidelines from the authors (Borja and MDS analyses were carried out using Muxika, 2005) was used in this study. the PRIMER v5 software package, There are no proposed reference values developed in the Plymouth Marine for M-AMBI in the Caspian Sea; Laboratory. Canonical Correlation therefore, due to similarity of the Analysis (CCA) and Canonical Caspian Sea with Mediterranean Discriminant Analysis (CDA) analysis lagoons, (mean average of temperature: was assessed by R statistical