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Lecture 6: Pollution and Disease in the Marine Environment. Pollutants in the Ocean. Sewage Stormwater runoff Oil/petroleum products Industrial pollutants & metals (includes mercury and lead) Persistent Organic Pollutants (POPs) Dumping (of dredge materials and trash) Nutrients.
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Pollutants in the Ocean • Sewage • Stormwater runoff • Oil/petroleum products • Industrial pollutants & metals (includes mercury and lead) • Persistent Organic Pollutants (POPs) • Dumping (of dredge materials and trash) • Nutrients
Sewage • Nutrients • Fecal coliforms, fecal Streptococci, & enterococcus bacteria • Pharmaceuticals (estrogens, antidepressants), caffeine • Suspended particulate matter (increases turbidity) www.seaweb.org
Stormwater Runoff • Sediments • Trash • Nutrients • Oil • Pesticides • Herbicides • Sewage • Animal waste Pinellascounty.org Modmobilian.com
Oil/Petroleum Pollution whoi.edu • Large scale oil spills (Deepwater Horizon, Torrey Canyon, Exxon Valdez) • Small scale spills (spills at oil terminals, groundings of small vessels, routine release of oil from offshore drilling activities) • Vessel operations (illegal tank cleanouts, discharges) • Municipal and industrial effluents • Natural seeps
Threats to Wildlife • Swallowing plastic debris • Entanglement
Persistent Organic Pollutants (POPs) • POP = a substance that possess toxic property and resists degradation • Examples: DDT, lindane, PCBs, dioxins • Stored in the fatty tissue and organs of animals • Can disrupt endocrine system, case cancer or genetic defects, weaken immune systems
Metals • Do not decompose under normal environmental conditions and can accumulate in the environment and in living tissues
Effects of Eutrophication • Algal overgrowth of marine ecosystems • Hypoxia and formation of dead zones • Stimulation of HABs
Disease in the Marine Environment • Affects organisms ranging from coralline algae to manatees • Infectious diseases are transmitted by pathogens • Lack Information on disease processes • Dynamics of host population regulation • Factors that promote disease emergence and outbreak • Mechanisms of pathogen transmission
Causes of Disease • Viruses • Are the most abundant plankton in the sea • Hosts include bacterioplankton and phytoplankton • Have a significant impact on primary production in the sea • Fungi • Slime molds • Bacteria • Protozoans • HABs
Effects of Disease • Changes in community structure • Catastrophic population declines Seaotters.com
Is Disease on the Rise? • Ex. GTFP (green turtle fibropapillomas) www.turtles.org
Role of Climate Change and Humans in Marine Diseases • Two ways climate change and humans can increase the occurrence of marine disease • Increase the rate of contact between novel pathogens and susceptible hosts • Examples: Transmission of canine distemper virus from sled dogs in Antarctica to crab-eater seals; harbor seals infected with influenza virus A (New England) and influenza virus B (Netherlands) • Altering the environment in favor of the pathogen • Examples: Spread of Dermo from warm southern waters to warming waters along Atlantic coast; corals have increased susceptibility to an infectious cyanobacteria during warm water associated bleaching events; polluted habitats increase organisms’ susceptibility to disease
Disease and Biodiversity • Sometimes disease outbreaks can increase biodiversity (Ex. Sea urchins in kelp forests; crown-of-thorns starfish on coral reefs) • Is growing concern that the increase in the frequency and impact of disease outbreaks will negatively affect biodiversity, but hard to predict extent of effects • Disease-mediated extinction is likely to be rare
Marine Disease Research Priorities • Long-term monitoring • Better understanding of disease dynamics • Consideration of diseases in marine reserves
Oyster Disease • Dermo(protozoan parasite, Perkinsusmarinus); MSX haplosporid multinucleated sphere, Haplosporidiumnelsoni)
Seagrass Disease • Wasting disease (marine slime mold-like protistLabyrinthulazosterae) • Responsible for catastrophic (90%) loss of eelgrass along Atlantic coasts of North America and Europe in 1930s. Zostera marina NOAA