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Unformatted text preview: Biology 171 Monday June 21, 2010 Lecture 37: Invasive Species & Looking to the Future Announcements
Vicariance (concluded) Global Trade & Invasive Species Importance of Ballast Water as a Vector San Francisco Bay - Massive Global Invasions The Zebra Mussel & Freshwater Ecosystems Purple Loosestrife and Biological Control Threats to Biodiversity - review Hopeful signs: NaLonal efforts in conservaLon Vahatra - Madagascar Health in Harmony Indonesia Discover Life in America Text Reading Lec. 37: none Exam 4: Monday, Dec. 20, 7-9 PM. Covers lectures 28 (viruses) 37 & discussions 9-11 (phylogeny reconstruction, Ant-fungal coevolution, Selection on human populations Exam review: Sunday, Dec 19, 5-6PM, MLB Aud 3 Course Evaluations Available on CTools! 1 Dispersal and Vicariance Both Act to SpaLally ParLLon Previously Intact Biotas Dispersal: A biota expands its range into a new geographic domain; connec6on may be persistent or short-term Vicariance: a preexis6ng biota is split by a new physical barrier Closure of the Isthmus of Panama divided a formerly unitary marine biota, but it also joined two long separated land masses, allowing bio6c exchange of many terrestrial plants and animals. Vicariant Event for Marine Organisms; Dispersal Event For Terrestrial Organisms 2 The Great American Faunal Interchange With the closing of the isthmus of Panama about 3 mya, a number of animal groups migrated from South to North. terror bird opossum giant ground sloth armadillo porcupine 3 The Great American Faunal Interchange Others migrated from North to South muroid rodents elephants (gomphothere) cats ( jaguar) camels (llama) 4 ConLnental DriT The breakup of the southern supercon6nent Gondwana in the Mesozoic era led to specia6on events that gave rise to related lineages on different con6nents. Some of the amphibians and lizards of Madagascar are related to those living in India, sugges6ng vicariance. Other elements of the Madagascar fauna such as the mammals, arrived by over-water dispersal. hSp://www.metacafe.com/watch/2335158/650_million_years_in_1_min_20_sec/ 6 Dispersal opportuni6es among con6nents may also be intermiSent. Many species, such as Caribou (present range shown below), are found in Eurasia and North America due to previous dispersal events facilitated by short-lived land bridges (associated with lowered sea levels during Ice Age Maxima). 7 Bering Strait, 21,000 years ago Ocean waters were about 400 feet lower than they are today 8 Modern humans also took advantage of the last Bering Strait land bridge to colonize the Americas 9 GLOBAL TRADE & INVASIVE SPECIES Modern societies are becoming increasingly globalized with inter-continental trade now making up a large and growing fraction of world economic activity This also has had a huge impact on species distributions..... 10 Introduced Species
A species moved by humans, either intentionally or accidentally, from its native location to a new geographic region; also called an invasive/alien/exotic species. GlobalizaLon of Biotas is an inevitable byproduct of Global Trade 11 Ship Ballast Water as a Vector An inadvertent vector for trans-global marine and freshwater bio6c exchange Ballast Tanks - some submarine designs Filled/Emp6ed with air/water to adjust the ver6cal placement of a craa in the water Water can be taken in in one ocean and flushed out in another 12 Marine Ballast Introduc6ons Ship emptying its ballast tanks while loading cargo 13 14 The Asian clam Potamocorbula amurensis in San Francisco Bay 15 They Come From Everywhere! 16 Un6l recently, con6nental Freshwater Ecosystems were effec6vely isolated from each other by the intervening oceans, e.g., the Great Lakes and the Caspian Sea experienced a very low probability of bio6c exchange 17 Great Lakes Invasions 18 The Most Famous Caspian Import: The Zebra Mussel 19 Since their introduction in the late 1980s, zebra mussels have spread rapidly to all of the Great Lakes and an increasing number of inland waterways throughout North America 20 Zebra mussel life cycle
Zebra mussels release sperm and eggs directly into the surrounding waters for external fertilization. The fertilized egg develops into a pelagic larva that must feed on phytoplankton and grow for 7-30 days (temperature dependent) prior to settlement. During this period, dispersal is passive and dependent on water currents. Females can produce from 30,000 to 1,610,000 eggs each year 21 Zebra Mussels larvae metamorphose onto hard surfaces in huge numbers every summer and each mussel aSaches using mul6ple byssal threads An interconnected mat of mussels typically forms over all exposed hard surfaces - living or dead. 22 Mussel Car 23 Clogged water pipe 24 This pile of zebra mussels was removed from the Number 7 lock and dam along the Mississippi River. Windrows of dead zebra mussel shells on the shores of Lake Erie 25 26 Phytoplankton Density in Western Lake Erie Since zebra mussels became established in Lake Erie, water clarity has increased from 6 inches to 30 feet in some areas. Unfortunately, the material removed from the water consists of other live animals and algae that supply food for larval fish and other invertebrates. In response to this changing food supply, populations of some animals have begun to decline.
27 Coloniza6on of Living Aqua6c Fauna with Hard Exoskeletons Aqua6c Insect Larva - byssal thread aSachments can physically inhibit mol6ng 28 Compe66on with Na6ve Mussels One drastic impact of the zebra mussel invasion is the near extinction of native American unionid musels in Lake St. Clair and in the western basin of Lake Erie. Zebra mussels attach and build colonies on the natives, reducing their ability to move, feed, and breed, eventually leading to death within a couple of years. 29 Purple Loosestrife and Biological Control PreSy but devasta6ng! Purple Loosestrife Lythrum salicaria 30 31 Distribu6on of Purple Loosestrife in the Upper Mid-West Its large ecological impact prompted the search for biological control agents - natural consumers/pathogens of the invasive that (ideally) would be host-specific. 32 33 The Two Leaf Eaters (adults) & their impact Galerucella calmariensis and G. pusilla The Root Eater, Hylobius transversovi4atus & its impact The Flower Eater, Nanophyes marmoratus & its impact 34 Although there was some site heterogeneity; many loca6ons were successfully cleared of purple loosestrife within a few seasons Before (Winona Test Site) Before (St. Paul Test Site) Aaer (Winona Test Site) Aaer (St. Paul Test Site) 35 Final Thoughts: Threats to Biodiversity 36 Final Thoughts: Threats to Biodiversity 37 Final Thoughts: Threats to Biodiversity 38 Final Thoughts: Threats to Biodiversity Land degradation Veracruz, Mexico - 1985 39 Final Thoughts: Threats to Biodiversity Overharvesting Fisheries such as the Atlan6c cod, haddock, capelin, and Atlan6c herring have either collapsed or are harvested at unsustainable levels 40 Final Thoughts: Threats to Biodiversity 41 Final Thoughts: Threats to Biodiversity Overpopulation
Thomas Malthus - 1798 "Essay on the Principle of Popula6on" Food supply 42 Steven M. Goodman Field Ecologist, Field Museum of Natural History: The island of Madagascar fascinates the public and biologists alike with its extraordinary numbers of unique species. In 1989, Steve Goodman launched a survey of the biodiversity of Madagascar which has yet to stop. This research program has spawned discoveries of hundreds of new species of plants and animals, as well as the training of over 80 Malagasy graduate students. The project has recently been turned over to an NGO, known as Vahatra or "grass-roots" in Malagasy, with a trust fund to support long-term conservaLon programs in Madagascar. Dr. Steven Goodman (UM-BS, MS), co-founder of "Vahatra" conserva6on group. hSp://archives.chicagotribune.com/2007/apr/22/magazine/chi-0704210317apr22 43 hSp://www.healthinharmony.org/ 44 Health In Harmony is partnering With Indonesian Interna6onal Rural Agricultural Environmenal Founda6on), a community development project in Indonesia that shares HIH's comprehensive vision. This project is developing health care facili6es in West Kalimantan, Indonesia. The health care work is 6ghtly linked with conserva6on efforts to preserve Gunung Palung Na6onal Park. Antonia Gorog (UM Ph.D.) Fires in southwest Borneo hSp://www.healthinharmony.org/ 45 Paul Super (UM-BS) Director of Science Educa6on for the Great Smoky Mts. Na6onal Park hSp://www.dlia.org 46 What To Do? You can contribute as a scienLst and/or as a ci6zen Halt natural popula6on declines Set up nature reserves Restore degraded systems Prac6ce sustainable development & ac6ve management 47 What To Do? You can contribute as a scien6st and/or as a ciLzen Help to teach others about the threats to, and the importance of, biological diversity Be ac6ve in schools and in the community in conserva6on issues Whatever your chosen career, think about how to live and work in a way that sustains the biological resources of the planet 48 49 Margaret Mead Cultural anthropologist Never doubt that a small group of thoughbul, commiced ciLzens can change the world. Indeed, it is the only thing that ever has. 50 It's your future! Pass it on! 51 ...
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This note was uploaded on 02/13/2012 for the course BIO 171 taught by Professor Josephinekurdziel during the Fall '08 term at University of Michigan.
- Fall '08