Biomarkers for assessing benthic pollution impacts in a subtropical estuary, Mozambique

摘要: This thesis focuses on the marine environment in a subtropical estuary and particularly exploring suite of easy-to-use, cost effective environmentally valid biological response tools (biomarkers). The main driving force is knowledge numerous anthropogenic impacts. Today, only scarce information available Espirito Santo Estuary (ESE) southern Mozambique effects pollutants. Links between behavioural disruption neurological dysfunction, such as acetylcholinesterase (AChE) inhibition has been shown to be most responsive biochemical biomarker at sites influenced by agricultural, urban industrial activities. In Paper I, enzymatic AChE butyrylcholineesterase (BChE) was measured tissues (brain, liver hepatopancreas) from barred mudskipper fish (Periophthalmus argentilineatus), Jarbua (Terapon jarbua), Indian white prawn (Penaeus indicus) clam Meretrix meretrix. general, all species showed significant decrease For M. meretrix BChE evident. water Infulene River, tributary ESE, 12 pesticides were found. Besides contaminants having direct effect burrowing behaviour, they also cause sublethal physiological stress, reducing metabolic activity, growth rate reproduction. II, integrated assays applied using scope for (SFG) method condition index (CI) assessing state ESE Incomati (which used comparison site). Low values SFG (<5 J h g), well low CI (that ranged 0.80 ± 0.02 1.62 0.10) both investigated areas show symptoms stress impact pollution reflected These results that can tool compare bioenergetic responses clams impacts various environmental Locomotion studied behaviour because it links fitness-related parameters, food seeking predator avoidance considered an ecologically valuable individual stress. III, impaired activity signal organismal tested two cross-toxicity (bivalvia, family Veneridae). Metals sediments analysed assess sediment quality according international guidelines human safety consumption and. times different experiments. finding indicated metal contaminated delayed time. Based concentrations metals we concluded northern margin polluted principally Cu, Ni, Cd, Co, Cr, Zn, As Hg. expected, site those contained lower levels these metals. IV presents more relevant aspects adverse pollutants benthic communities nearby estuary. Community indicators, richness abundance association with multivariate analyses assemblage structure status three zones (i.e. upper, middle reaches) ESE. Ecological groups ranking feeding strategies macrofauna bioindicators. clear differences invertebrate density population estuary, while negligible each other. difference estuaries mainly due dominance distinguished macrobenthic groups; polychaetes common bivalves amphipods highly abundant.in It recognized need integrative ecosystem very important scientific point view, but simple pragmatic necessary stakeholders society get useful assessments pressure other coastal ecosystems.