Soft Sediment Communities

semi haywire Sediment CommunitiesCHAPTER 1INTRODUCTION1.1 Overview of Soft Sediment CommunitiesSoft deposits argon the most viridity nautical home ground on terra firma (Wilson, 1990). The habitats include sandy beaches, estuaries, mudflats and salt marshes. The communities consist of organisms which brave on, or in, the lowlife of a water supply body. There are generally four types of soft deposition communities which can be classified according to their coat. They are microbenthos (1.0 mm) and megabenthos ( 10.0 mm).This hold up is focused on macrofauna, also known as macrobenthos. They are invertebrates that live on or in sediment, or attached to hard substrates. The common soft-sediment communities that can be tack in intertidal areas are Annelida, class Crustacea and Mollusca (Munari Mistri, 2008).Estuarine and coastal ecosystems consist of essential comp iodinents of macrofauna (Borja et al., 2000). They connect primordial producersand organic matter sources such(prenominal) as phytoplankton and detritus apart from world economically, ecological, and recreationally cardinalfish and crustaceans (Rnnbck et al., 2007 Bremner, 2008).Soft sediment communities provide many ecosystem services that help to maintain good water and sediment quality (Rnnbck et al., 2007).Filter feeders such as bivalves sequester portions from the water column, which may result in enhanced water progress toness (MacIsaac, 1996). Given the importance of light in shallow water estuarine ecosystems, filter aliment may improve shallow water habitat for submerged aquatic plants and benthic microalgae.The degradation of some pollutants is enhanced by sediment mixing (bioturbation) of the infaunal macrobenthos due to stimulation ofmicrobial processes. The enhanced coupling of come upon nitrogen transformations in the presence of benthic macrofauna can lead to the merchandise of nitrogen gas, which escapes to the atmosphere, thereby reducing nitrogen loading i n the ecosystem.Macrobenthos have been used for decades asindicators of environsal statusand trends in estuaries and coastal areas because infauna are mostly sedentary organisms and they respond to local environmental impacts (Pearson Rosenberg, 1978 Borja et al., 2000 Wildsmith et al., 2009, 2011). They cover a wide locate of physiological tolerances, living positions, type of feeding and trophic interactions (Elliott et al., 2002). Macrobenthic gathers respond relatively quickly to habitat forebodings (Borja et al., 2000). They are central components of aquaticfood webs (Rnnbck et al., 2007)and they make transport and pass of nutrients and toxicants.In addition, there are data on their patterns of change, their responses to different forms of disturbance are known and they show similar responses at different levels of taxonomical resolution (Warwick, 1988). They form an key component of the estuarine food-web, supporting technical and non-commercial species. They the refore represent an ideal congregation to measure environmental variegate and will continue to be used to represent an important biological component of soft sediments. Understanding how different components of benthos respond to changes in properties of sediments is therefore essential in determining how much, if any, redundancy there is in this system and how much impacts on the sediments themselves are weatherd by the fauna. From this study it is clear that such experiments need replication at tenfold scales and across multiple habitats before any general responses will be identified.By lettered the importance of soft sediment communities, the health and quality of an ecosystem can be determined without using any harmful chemical indicators.1.2 ObjectivesThe objectives of this project areTo investigate the copiousness and dispersion of soft sediment communities in Tanjung Bungah, Pulau Pinang.To resuscitate the environmental variables with soft sediment communities distri bution and abundance in Penang intertidal area.CHAPTER 2LITERATURE REVIEW2.1 The Ecology of Soft Sediment CommunitiesMacrofauna take hold up a braggy component of the food web in estuarine ecosystems, connecting primary producers to top producers and athleticsing an important role in system dynamics (Herman et al., 1999 Platell et al., 2006). Bottom macrobenthic communities include a great anatomy of organisms and generally a large number of species and they are extremely tangled (Meire et al., 2005).In marine macrobenthic organisms, polychaetes is one of the most probative groups and may influence up more than half of the organisms in soft bottom habitats. They are often the predominant macrobenthic taxon in these sediments in terms of numbers, twain numerically of species and abundance (Wildsmith et al., 2009, 2011). Polychaetes could hence be good indicators of species richness and assemblage models in macrobenthic assemblages (Fauchald Jumars, 1979). Some polychaete spe cies were greatly opportunistic and responded quickly to environmental disturbances (Norkko et al., 2006 Wildsmith et al., 2011).2.2 The Importance of Soft Sediment CommunitiesInvertebrates constitute part of marine ecosystems and play important roles to support the function and stability of the food chains and ecosystems upon which separate animals rely (Snelgrove, 1998). They regulate populations of other organisms (plant and animal) through predation, parasitism and herbivory, and help maintain water quality by filtering large amounts of water during feeding (Ponder et al., 2002). Invertebrates are in a flash involved in ecosystem stabilization, shoreline protection, energy and nutrient transfer and provision of habitat (Ponder et al., 2002). They also help in climate stabilization and re-mineralization and play an important role in the cycling of nutrients, breakdown of plant matter and other detritus and provide habitat for other species (Ponder et al., 2002).2.2.1 Environme ntal indicatorMembers of the macrofauna partnership serve as useful biological indicators of environmental change and spot elements of many marine and estuarine monitoring programs, due to their sedentary lifestyles and lessen responses to environmental changes (Tweedley et al., 2012). Therefore, the spatial distribution of macrofauna relative to environmental factors is fundamental to the sagaciousness of estuarine ecology (Herman et al., 1999).Polychaetes are valuable marine organisms which can tolerate contamination because they live at the interface of water-sediment (Wildsmith et al., 2009, 2011). This layer is both biologically reactive and chemically active (Rhoads Young, 1970). Polychaetes occupy almost all marine and estuarine sediments (Fauchald, 1977) and are often the predominant constituent of the macrobenthic communities both in terms of individuals and number of species (Hutchings, 1998 Morin, 1999 Mills, 1969 Rhoads Young, 1970 Van Hoey et al., 2004 Ward Hutch ings, 1996 Warwick, 1988).Polychaetes carry out an important role in ecosystem processes of macrofauna assemblages such as recycling, pollutant metabolism and in the inhumation of organic matter (Hutchings, 1998).2.3 Factors Affecting Soft Sediment CommunitiesThe abundance and distribution of soft sediment communities were influenced by both biotic and abiotic factors. Biotic factors such as competition and predation (Rhoads Young, 1970) while abiotic factors such as variation in salinity, turbidity, sediment grain size, total organic carbon, and metal contamination, affect estuarine macrofauna (Kinne, 1966 Remane Schlieper, 1971 McLusky Elliot, 2004).2.3.1 SalinityThe influence of salinity in particular is an important factor in estuarine macrofaunal salmagundi. Generally, studies have reported a positivist correlation between biodiversity and salinity (Holland et al., 1987 Jorcin, 1999 Ysebaert Herman, 2002 Gimenez et al., 2005). Because variation in salinity differs in acco rdance with tidal movements and freshwater inputs into estuaries, the distribution of macrofauna and the macrobenthic familiarity can differ between dry and rainy seasons.2.3.2 Sediment Grain SizeIn estuaries, salinity and sediment grain size have been found to be the most important environmental variables controlling the diversity and distributional patterns of macrofauna (Absalo, 1991 Yoo Hong, 1996 McLusky Elliot, 2004). Hong Yoo (1996) suggested that the particle size and disturbance of the sediment may have been the most important factors controlling the macrobenthic community.Soft-sediment communities are unusual in the rate at which the constitution of the physical environment can change (Wilson, 1990). Most sedimentary particles are smaller than the resident organisms, infauna (Wilson, 1990). The activities of the infauna can dramatically change the nature of the environment over time periods of hours or days (Wilson, 1990). For instance, burrowing infauna may increase the porousness of the sediment (Rhoads, 1974).2.3.3 Total organic carbonPopulation dynamics of benthic suspension feeders, deposit feeders and subsurface feeders are known to respond other than according to nature of inputs, plankton and/or organic food matter (Austen et al., 1991 Beukema et al., 2002). The last mentioned two groups are less affected since they utilize a large pool of organic matter in the sediment, which is constantly organism recycled. In tropical region, Wolanski et al. (1992) hypothesized that in mangrove swamp or creek system, the circulation processes are spiritedly complicated leading to novel sediment transport regimes that could in turn account for the chemistry and biology of the recipient water.Abundance and composing of Soft Sediment CommunitiesThe study of soft sediment communities was extensive in certain temperate countries especially Australia while other countries in the tropical zone are lacking in their data. Further studies have yet to be co nducted in tropical coastlines due and increasing human population growth, pollution, urbanisation at an alarming rate (Hatcher et al., 1989).Distribution of Soft Sediment Communities in the WorldIn East Antarctica, au naturel(p) (2000) had investigated the distribution and abundance of soft-sediment macrobenthos more or less Casey Station. Two locations were compared two potentially polluted locations and two control locations in an asymmetrical design (Stark, 2000). Stark (2000) found out that the dominant assemblage were crustaceans while polychaetes assemblage was smaller in number, about 3-10% of individuals at the locations sampled.another(prenominal) study in Brown Bay, Antartic which was carried out by Stark et al. (2005) revealed significant correlations between the presence of contaminants and the distribution and composition of soft sediment-communities over real small spatial scales. Combinations of certain metals, for example Cadmium (Cd), Copper (Cu), tail (Sn) an d Lead (Pb) and sediment grain size were the variables that best linked the community patterns at Brown Bay. This is further supported by previous studies in Antartic where benthic assemblages probably patchy due to local environmental conditions (Stark, 2000 Stark et al. 2003).In England, annelids were found to be the most abundant group followed by crustaceans, molluscs, echinoderms and others (bryozoans and cnidarians) with 34.5%, 20.0%, 16%, 2.5% and 27% respectively (Bolam et al., 2008). Sediment grain size significantly affects the abundance of macrofauna along the English Channel (Bolam et al., 2008).In Australia, polychaetes were found the highest, and crustaceans were the worst in macrofauna abundance (Morrisey et al., 1992).In Norway, environmental variables such as productivity, temperature and sediment grain size played a vital role in determining pattern of species richness (Gray, 2002).In Germany, the most abundant taxonomic group was gastropods, followed by oligocha etes, polychaetes and crustaceaans with 87%, 6%, 6% and 2% abundance respectively (Schckel et al., 2013). The main causal factors for the different distribution patterns of intertidal macrofauna species which results in characteristic zonation patterns were sediment grain size and food availability, expressed in chloropohyll a contents (Schckel et al., 2013).In Italy, the highest numbers of species that were identified were for Annelida which save 108 species, Crustacea recorded 69 species, and Mollusca recorded 52 species (Munari Mistri, 2008). Changes in the composition of assemblages of local species and the dominance of annelids species cannot be explained by only one factor (Lardicci et al., 1993). The factors were linked to biotic and hydrodynamic determinants, dissolved oxygen, grain size and organic content of the sediments (Munari Mistri, 2008).Distribution of Soft Sediment Communities in AsiaIn Qeshm Island of Iran, Nassaj et al. (2010) investigated the abundance and di stribution of macrofauna in Salakh coastal region waters (Qeshm Island-Persian Gulf). Nassaj et al. (2010) found that Polychaeta (54.14%) were the most dominant group followed by the Crustacean (27.24%), Amphipods (9%), class Gastropoda (8%), Bivalvia (7%), Copepoda (2%) and other groups (4%).In Korea, Yu et al. (2012) carried out a query on the effects of environmental variables on the distribution of macrofauna in the Han River Estuary during summer and spring. The dominant species were polychaetes during July, 2006 and March, 2007 (Yu et al., 2012). The most important factor was salinity and other factors such as sediment grain size and dissolved oxygen being secondary (Yu et al., 2012).Distribution of Soft Sediment Communities in MalaysiaIn Pulau Pinang, the high percentage of organic matter has shown a positive relation with abundance, diversity and richness of macrobenthic (Gholizadeh, Yahya, Talib, Ahmad, 2012). High percentages of sediment with grain size 125 m revealed t o have an increased in macrobenthic abundance (Gholizadeh, Yahya, Talib, Ahmad, 2012). This may aid in expounding the higher abundance of macrobenthic organisms, particularly for the deposit feeders. It has been reported that the sediment type (sand vs. mud) is one of the parameters responsible for the spatial distribution of macrobenthic families according to feeding kinds (Rhoads Young, 1970 Hutchings, 1998 Van Hoey et al., 2004).