Abstract
Confluence of anthropogenic influences is common in coastal areas (e.g., disposal of different pollutants like industrial and domestic sewage, brine, etc.). In this study we assessed whether the combined disposal of domestic sewage and brine altered patterns in the abundance and assemblage structure of subtidal meiofauna inhabiting sandy seabeds. Samples were collected in May 2008 and January 2009 at varying distances (0, 15, and 30 m) from the discharge point. Meiofaunal abundances were consistently larger at 0 m (1663.05 ± 1076.86 ind 10 cm–2, mean ± standard error) than at 15 m (471.21 ± 307.97 ind 10 cm–2) and 30 m (316.50 ± 256.85 ind 10 cm–2) from the discharge outfall. This pattern was particularly accentuated for nematodes. Proximity to the discharge point also altered patterns in meiofaunal assemblage structure, though temporal shifts in the sedimentary composition also contributed to explain differences in the meiofaunal assemblage structure. As a result, meiofauna may be a reliable tool for monitoring studies of the combined disposal of sewage and brine as long as potential confounding factors (here temporal changes in grain size composition) are considered.
Highlights
In coastal environments, sewage discharge is a common source of human disturbance
Overall meiofaunal abundance was affected by proximity to the discharge outfall: abundances at 0 m (1663.05 ± 1076.86 ind 10 cm–2) were larger than at 15 and 30 m from the discharge point (15 m: 471.21 ± 307.97 ind 10 cm–2; 30 m: 316.50 ± 256.85 ind 10 cm–2) consistently between surveys (Distance × Year, P = 0.658, table 3)
We observed a significant increase in meiofaunal abundances immediately adjacent to the combined sewage and brine outfall
Summary
Detailed studies have been conducted on the effects of sewage on several marine assemblages, such as fishes (Azzurro et al 2010) and sessile organisms on rocky substrates (Terlizzi et al 2002), and diverse ecosystems, including coral reefs (Reopanichkul et al 2009), seagrass meadows (Balestri et al 2004), and sandy unvegetated substrates (Smith and Shackley 2006). Sewage discharges alter the organic content and biochemical composition of sediments (Cotano and Villate 2006), as well as the biochemical properties of the water column (Oviatt et al 1987), affecting biological assemblages through blooms of nitrogen-consuming algae (Thornberg et al 2008); high concentrations of pathogens and bacteria that may enter the food chain (Korajkic et al 2010); reef erosion by mechanical, chemical, and biological processes (Pastorok and Bilyard 1985); changes in protein synthesis and growth (Houlihan et al 1994); changes in feeding and respiration rates (Butler et al 1990); and inhibition of germination (Burridge et al 1996)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
