Impact of altered coastal features on Macrobenthos of two beaches of Mumbai, Maharashtra, India

摘要

Ecosystems are productive and efficient when there is sufficient Biodiversity. Each form of lifernworks together with the surrounding environment to help recycle the waste, maintainrnecosystem and provide services to be used by others. Coastal waters all over the worldrnincluding India are exploited for various purposes. This results in to ecological deterioration ofrncoastal ecosystems. Extensive coastal pollution, over fishing, and developmental activitiesrnhave detrimental effect on marine biodiversity.rnMarine waters of the world have been extensively studied for its water quality and benthicrnmacrofauna. Indian waters including west coast of India are also studied for their level ofrnpollution and benthic diversity. Marine species diversity, with an application to benthic faunarnof Norwegian continental shelf was measured by Gray (2000). Ingole et al. (2002) studiedrnMacrobenthic communities of the coastal waters of dabhol, west coast of India. Balan et alrn(2003) reported changes in benthic communities along presumed pollution gradient inrnVancouver harbour, while Khade et al (2009) studied the diversity of gastropod molluscs onrnRaigad coast of Maharashtra. Co-existance of macroalgae and benthic macrofauna in thernintertidal zone along Dahanu and Colaba coast was noted by Mandal et al. (2009).rnThus there appears to be a gap as far as study of relationship between effect of alteredrncoastal features and biodiversity. Present study is conducted at two beaches of Mumbairnnamely, Dadar (19o1'N Latitude and 72o 49'E Longitude.) and Khardanda (19o 4'N Latitudernand 72o 49'E Longitude). Visits were planned at regular interval between October 2007 tornSeptember 2009 covering all the seasons of the year. The sediment and surface waterrnsamples from mid littoral zone were collected from both the beaches, each having two fixedrnstations. During each visit representative species were collected, occasionally from local fisherrnfolk. Macrobenthos observed at both the beaches include macroalgae, coelenterates,rncrustaceans and molluscs.rnWhen compared with previous records, it is observed that the macrobenthos diversity of thernstudy area is affected in terms of quality and quantity. Noticeable ecological modificationrnassociated with faunal abundance and diversity is related to deteriorating marine waterrnquality due to anthropogenic activity. This effect can be attributed to the altered physicalrnfeatures of Dadar and Khardanda beach with respect to water quality and sediment analysis.