[The Effect Of Zncl2 And Different Ranges Of Ph (Zncl2 Alone And/Or With Ph) On Neries Succinea]

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Abstract

The population of harbour ragworms, Nereis diversicolor, inhabiting the upper reaches of Restronguet Creek in the Fal Ria, UK, are known to be resistant to the acute, toxic effects of copper, zinc and cadmium. This research aimed to establish whether metabolic and reproductive performance costs were associated with the resistance phenomenon and what the biochemical mechanisms of resistance were, by comparing animals from the Creek with two comparable study sites in the South West of England: Froe Creek and the Teign estuary. There was a significant metabolic cost, measured as a reduction in Scope for Growth, associated with the resistance phenomenon. As no differences in energy intake or uptake were found between resistant and non-resistant animals it was concluded that this cost was covered by demand-side regulation of energetics. A reduction in the amount of biochemical energy reserves in the form of lipids and sugars was also observed in resistant animals suggesting that resource allocation had been shifted away from this endpoint and towards maintenance and activity. The perturbed metabolism and physiology of resistant N. diversicolor is shown to have detrimental consequences for their life-history. Sexually mature, resistant females were significantly smaller than non-resistant ones, indicating that they had either matured at a younger age or grown more slowly. Both total fecundity and mass-specific fecundity were significantly reduced in resistant females, likely as a direct result of the metabolic costs of resistance reducing the resources available to fuel gametogenesis. No differences were found in the energetic reserves stocked within each gamete by resistant and non-resistant animals, suggesting that this trait is heavily selected for. Synthesis of reduced glutathione [GSH] in resistant animals' tissues appeared to be elevated. Glutathione peroxidase activity was also increased, likely to remediate the effects of Reactive Chemical Species [RCS] that result from the inevitably incomplete binding of intracellular metals. As GSH functions in metal detoxification to covalently binding metals entering resistant animals' cells, preventing their involvement in toxic interactions and their catalysis of the production of RCS, it is proposed that together there two phenomena comprise the fundamental mechanism of resistance to metal toxicity.

TABLE OF CONTENTS

Chapter 1: Introduction And Historical Review6

Introduction6

Industrial Countries and Aquatic Pollution6

The High Toxicity of ZnCl2 to Aquatic Organisms7

Polychaetes9

Microfluidic chip or Lab-on-a-chip Technology13

The Role of Different Types of Oil15

Types of Fabricate Microfluidic Chip15

The Advantages of Droplet-Based Designs in Microfluidics15

Aims and Objectives16

Chapter 2: The Accumulation Of Zn And Ca (Calcium) In The Sea Water, Sediment And Nereis Tissue19

Introduction19

Materials and Methods20

Experimental Site20

Experimental Design20

Sampling Of Pore Water And Sediment23

Analysis Of Pore Water, Sediment, And Plant Tissue25

What environmental problems can arise due to water contamination with cadmium?26

What are the health effects of cadmium in the water?28

Which water purification technologies can be used to remove cadmium?29

Statistical Methods30

Results30

Cadmium in Pore Water31

Partitioning of Cd in The Sediment32

Changes In Percentage Of Dry Matter In Plants36

Adsorbed Cd in H2O-Washed Plants36

Cadmium Accumulation in TiCl3-Washed Plants37

Discussion38

Chapter 3: The Biochemical And Physiological Costs (Homeostasis) Of Nereis As A Result ...