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The increase of The increase of disease in disease in our ocean’s. our ocean’s.

Case study; the Case study; the Pilchard’s Pilchard’s Sardinops Sardinops

sagax sagax of the Southern of the Southern Oceans of Australia.Oceans of Australia.

Andrew G Challingsworth Ph:0439962581aquanet-place@hotmail.com www.aquanetplace.com.au, Deakin University.

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Abstract;Abstract;• A literature review was conducted of ‘Scientific A literature review was conducted of ‘Scientific

journals’.journals’.

• To accurately assess the scientific information, on To accurately assess the scientific information, on the increase of disease in our oceans. the increase of disease in our oceans.

• We can now accurately generalize that disease We can now accurately generalize that disease outbreaks in marine organism have increased in outbreaks in marine organism have increased in recent years.recent years.

• Disease outbreaks correspond to a list of Disease outbreaks correspond to a list of

environmental factors.environmental factors.

• Case study the Australian pilchard Case study the Australian pilchard Sardinops sagax Sardinops sagax and how changing environmental factors resulted in and how changing environmental factors resulted in a disease epidemic.a disease epidemic.

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Introduction;Introduction;• After reviewing the scientific literature. After reviewing the scientific literature.

• We can accurately assess, that disease is more We can accurately assess, that disease is more prominent in the ocean environment. prominent in the ocean environment.

• Environmental factors are increasing disease episodes Environmental factors are increasing disease episodes in our oceans.in our oceans.

• Environmental change can interact with disease in our Environmental change can interact with disease in our oceans in many ways. (Lafferty, Porter & Ford 2004).oceans in many ways. (Lafferty, Porter & Ford 2004).

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• The aquatic environment needs to be thoroughly The aquatic environment needs to be thoroughly understood. understood.

• ‘‘Growth and reproduction of fishes is affected Growth and reproduction of fishes is affected when the environmental parameters of aquatic when the environmental parameters of aquatic environments diverge beyond acceptable limits’.environments diverge beyond acceptable limits’.

• ‘‘This may lead to acute or chronic disease This may lead to acute or chronic disease conditions’. (De Silva et al 2003,Topic one). conditions’. (De Silva et al 2003,Topic one).

Australian Pilchard Sardinops sagax,

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MethodsMethods;;• An accurate study of our environmental An accurate study of our environmental

factors needs to be established. factors needs to be established.

• Environmental factors;Environmental factors;

• Physical factors; i.e. Temperature, Light, Physical factors; i.e. Temperature, Light, Dissolved Gases.Dissolved Gases.

• Anthropomorphic influences/factors; i.e. Anthropomorphic influences/factors; i.e. Pollution from factories, Sewage.Pollution from factories, Sewage.

• Biological factors; i.e. Microorganisms, Biological factors; i.e. Microorganisms, Dinoflagelates, Blue – green algae.Dinoflagelates, Blue – green algae.

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• A biopsy of the Biology of the Australian A biopsy of the Biology of the Australian Pilchard Pilchard Sardinops sagax.Sardinops sagax.

• A biopsy of the disease epidemic; (PHV) A biopsy of the disease epidemic; (PHV) Pilchard Herpes Virus.Pilchard Herpes Virus.

Dead pilchards on a beach in Western Australiaduring the mortality event in 1998.

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Results;Results;• Environmental factors;Environmental factors;

• Physical factors;Physical factors;• Temperature;Temperature; thermal tolerance limits, thermal tolerance limits,

optimum required. optimum required. (De Silva et al 2003,Topic (De Silva et al 2003,Topic one). one).

• Affects resistance to disease. Affects resistance to disease.

Red coral, tolerance limits to temperaturechange, Climate warming.

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• Light;Light;

• Increasing light levels. Increasing light levels.

• Growth in unicellular algae. Growth in unicellular algae.

• Result of climate change. Result of climate change.

A; Increase in harmful algal blooms 1970-1990; A; Increase in harmful algal blooms 1970-1990; ‘‘Climate change’. (Lafferty, Porter & Ford 2004).Climate change’. (Lafferty, Porter & Ford 2004). B; Dinoflagellate.B; Dinoflagellate.

AB

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• Temperature changes solubility of toxic Temperature changes solubility of toxic compounds i.e. crude oil, pesticides. compounds i.e. crude oil, pesticides.

•Crude Oil: Toxicants increase susceptibility to Crude Oil: Toxicants increase susceptibility to disease by impairing defenses i.e. mucus disease by impairing defenses i.e. mucus production. (Lafferty, Porter & Ford 2004).production. (Lafferty, Porter & Ford 2004).

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• Heavy metals also become more toxic. Heavy metals also become more toxic.

(De Silva et al 2003,Topic one). (De Silva et al 2003,Topic one).

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Physical factorsPhysical factors affecting the affecting the aquatic environment;aquatic environment;

• LightLight

• Light and the effects of climate change with Light and the effects of climate change with increasing temperature and light levels can cause increasing temperature and light levels can cause growth in unicellular algae.growth in unicellular algae.

• There has been a notable increase in harmful There has been a notable increase in harmful algal blooms between the periods of 1970-1990 algal blooms between the periods of 1970-1990 corresponding to climate change. (Lafferty, Porter corresponding to climate change. (Lafferty, Porter & Ford 2004).& Ford 2004).

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Physical factors;Physical factors;

•Dissolved GasesDissolved Gases•Excess Carbon dioxide dissolved Excess Carbon dioxide dissolved

in water can depress fish in water can depress fish respiration. Global factors respiration. Global factors include predicted rise in oceanic include predicted rise in oceanic carbon dioxide concentrations. carbon dioxide concentrations. (Lafferty, Porter & Ford 2004).(Lafferty, Porter & Ford 2004).

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Environmental factors;Environmental factors;• Anthropomorphic influencesAnthropomorphic influences

• Pollution from factoriesPollution from factories• Heavy metals;Heavy metals;• In Australia Mercury and Cadmium are In Australia Mercury and Cadmium are

contaminants of fish.contaminants of fish.

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Anthropomorphic Anthropomorphic influencesinfluences• Non-Metals;Non-Metals;• Biodegradation resistant organochlorine Biodegradation resistant organochlorine

compounds are toxic to fish.compounds are toxic to fish.• Can become concentrated in the food chain DDT Can become concentrated in the food chain DDT

and dieldrin as they are highly resistant to and dieldrin as they are highly resistant to degradation.degradation.

• SewageSewage• Discharge reduces water quality causes oxygen Discharge reduces water quality causes oxygen

depletion caused by microbial growth.depletion caused by microbial growth.• Nitrates and phosphates may stimulate excessive Nitrates and phosphates may stimulate excessive

algal blooms and leads to oxygen depletion.algal blooms and leads to oxygen depletion.