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 blood cells 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 epidemiology o Most epidemiological theory developed for terrestrial environment o Questionable how well this applies to marine systems o 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 diversity o 40 animal phyla all found in marine environment only 9 in terrestrial environments o higher potential for complexity in interactions between pathogens and hosts in marine environments Different life histories o Terrestrial environments direct development common Means host parasite interactions are closely coupled o 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 variants o Parasitic castrators vs parasitoids in terrestrial Stop reproduction but do not removed from population diff from parasitoids so still compete with uninfected individuals Open populations o 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 transmission o 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 impacts o Terrestrial habitat destruction introduced species overharvesting eutrophication o 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 both o Quiz two ways that humans are influencing diseases in the marine environment Potential means of control o Terrestrial vaccination controlled breeding culling quarantine o 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 diseases o 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 study o Coral diseases White pox disease bacterial disease disease that came from us to corals only genetically similar to us Bleaching global warming affects it above 75 degrees F causes bleaching to occur White band disease acroporid corals bands of dead tissue that move along the coral very quickly o 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 seals o 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 mammals o 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 move o 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 system o Climate change facilitates spread of viruses to new populations as species ranges shift o Over fishing causes mammals to switch prey to new species that may harbor new viruses o Increased human populations also put marine life more frequently into contact with viruses all these examples for mammals have jumped from non marine to marine systems Fungus Atlantic sea turtle population threatened by egg infection infects eggs from human conditions on beach fungus grows on your shower curtain creates blindness in humans causes 100 mortality in turtle eggs if it grows Sea otter recovery o Brain disease toxoplasma