Diseases in Marine Organisms, October 1st- Quiz: what is the first layer of barrier that organisms have to diseases? Organism’s surface (epidermis), harsh environmental conditions, white bloodcells, or all of the above (the organism’s surface-epidermis)- Quiz: Which of the following is not a type of immune response seen in vertebrate organisms? Adaptive immune response, antibody-mediated immune response, cell-mediated immune response, auto-immune response or all of the above are common to vertebrate organisms (all of the above)- Quiz on podcast: what is causing white pox disease in Elkhorn corals? (Parasitic fungus, bacterium from human fecal waste, a virus that has jumped from marine mammals, or none of the above) a bacterium from human fecal waste- Quiz: we have recently learned what causes most of the diseases in the ocean… now all that is left to do is cure them (false)- What is a necropsy? Studying bacteria, study of viruses, investigating dead animal for cause of death, all of the above (investigating dead animals for cause of death)- Marine vs. terrestrial epidemiologyo Most epidemiological theory developed for terrestrial environmento Questionable how well this applies to marine systemso Marine differs from terrestrial in.. Much more diversity of life forms Different type of life histories Open populations Modes of transmission Human impacts Potential means of control- Implications of higher marine diversityo ~40 animal phyla all found in marine environment only 9 in terrestrial environmentso =higher potential for complexity in interactions between pathogens and hosts in marine environments- Different life historieso Terrestrial environments—direct development common  Means host-parasite interactions are closely coupledo Marine environments—indirect development more common Means host-parasite interactions may not be closely coupled Often intermediate hosts with trophic transfer (trematodes in snails)o Modular colonial life forms (corals) Hosts are genetically identical, so may facilitate more virulent pathogens b/c don’t have to evolve to infect many genetic variantso Parasitic castrators (vs. parasitoids in terrestrial) Stop reproduction, but do not removed from population (diff from parasitoids) so still compete with uninfected individuals- Open populationso Open populations—allows for rapid transfer of disease over large geographical areas So have high rates of epidemic spread (potentially over ocean basins- Modes of transmissiono Terrestrial systems often have vertical transmission (infection from parent to offspring)o Vectors important in terrestrial environment (mosquitoes) Less important in marine-or understudied?- Human impactso Terrestrial=habitat destruction, introduced species, overharvesting, eutrophicationo Marine=overharvesting (decrease fish abundance and thus transmission rates, disease increased in all marine organisms since 1970s except fish, however mariculture introduces pathogen that spread to wild populations), introduced species, eutrophication, habitat destruction possibly underestimated o Climate change could be added to botho Quiz: two ways that humans are influencing diseases in the marine environment- Potential means of controlo Terrestrial—vaccination, controlled breeding, culling, quarantineo Marine—cleaning of symbionts (mariculture)- Why do we care?o Wild sharks, redfish harbor antibiotic-resistant bacteria Every species of fish looked at have drug resistant bacteria We eat the fish that have the drug resistant bacteria, causing vaccines or treatments to possibly not work on us for certain diseaseso Dolphins health shed light on human and ocean health Diseases found in dolphins are similar to human diseases Provide clues into how human health may be influenced by contaminated coastal waters or seafood Serve as model organisms for studying human health Environmental conditions studied off of Georgia coast (superfund site) with high PCB levels, see how it affects dolphins, relate it to humans Dolphins display diabetes-like state but can turn it on or of in order to support a high protein diet (helps us understand the illness) Toxic algae induces epileptic seizures due to domoic acid poisoning Dolphins get papillomavirus (cervical cancer in women) but are not known to get cervical cancer o Sea urchins Have common ancestor to us They are on our evolutionary tree (deuterostomes) Another good model organism, easy to studyo Coral diseases White pox disease: bacterial disease, disease that came from usto corals (only genetically similar to us) Bleaching: global warming affects it, above 75 degrees F, causesbleaching to occur White band disease: acroporid corals, bands of dead tissue thatmove along the coral very quicklyo Other bacterial diseases Withering foot syndrome- Infects abalone- Caused by bacteria, found in California- Attacks digestive track lining and inhibits enzyme production—starves to death, starts digesting itself/the foot, and the foot gets smaller and smaller, doesn’t hang on anymore and the waves wash it off the rock and it starves to death or is eaten by a predator- Influenced by temperature- Virus background Small: 1/100th the size of bacteria DNA or RNA enclosed in protein- DNA replicated in host nucleus- RNA replicated in host cytoplasm- Use machinery of host for reproduction- Beta herpes in….- Symptoms of herpes virus in harbor sealso Highly virulent, mortality within 1-6 days- Canine distemper virus infects seals- Phocine distemper virus (PDV) o Antibodies found in polar bears- HINI discovered in marine mammalso Pandemic virus moving between species o A year after it was in the human population, it was found in elephant seals- Commonality in viruses: began in humans, jump to marine environment- Salmon virus on the moveo Stops the heart from pumping, no oxygen, don’t get energy they need to grow big- Quiz: how could this virus transfer from Norway to Canada and Chile?- Why are viruses on the rise?o Pollution—impaired immune systemo Climate change—facilitates spread of viruses to new populations as species ranges shifto Over fishing—causes mammals to switch prey to new species that may harbor new viruseso Increased human populations also put marine life more frequently into contact with viruses (all these examples for mammals have