Lecture 11 Biology 5865 Conservation Biology Threats to Biological Diversity - Exotic Species & Invasive Species - Over-exploitation
Time, 21 Feb 2011 Protecting nature can be a profitable corporate priority and a smart business strategy. - Andrew Liveris, CEO Dow Chemical
Coastal Wetland Fish Community Health in the Great Lakes Fish communities are influenced by the plant communities of wetlands and by human-related disturbances Non-native both existing and new are of grave concern Wetlands may provide refuge for native fish species Black Carp Grass Carp Bighead Carp Silver Carp
How do species move? How do they get here? Exotic Species 1. Stowaways e.g., Norway Rat (Rattus norvegicus) and House Mouse (Mus musculus); earthworms - most are exotic; and a variety of weeds - dandelions, plantain, etc. 2. Subsistence - need for familiar food - both plants and animals but many have escaped and are causing problems such as feral pigs (colonization of the South Pacific from Vietnam region based on genetics of pigs) 3. Recreation - Game animals e.g., Ring-necked Pheasant (more common in North America and Europe than it is in its native Asian range) and Hungarian Partridge in Minnesota
Exotic Species continued - 2 4. Fisheries programs in Lake Superior (from Eddy and Underhill, Northern Fishes, 1974, U of Minnesota Press) Brown Trout (European species introduced in Minnesota about 1920) Atlantic Salmon (first introduced in North Shore streams in 1881) Rainbow Trout (Pacific coast - introduced in late 1800's to Lake Superior) Chinook Salmon (Pacific coast, first attempt at introduction in 1876) Coho Salmon (Pacific coast, first introduced in 1965) Pink Salmon (Pacific coast, accidentally introduced, thought to have happened in the process of transplanting fingerlings to a seaplane in Thunder Bay when about 100 escaped into Lake Superior - 1956)
Exotic Species continued - 3 5. Whimsy or aesthetics European Starling (Sturnus vulgaris) - first introduced to New York city in 1890, first appeared in Minnesota in 1929 English or House Sparrow (Passer domesticus) - introduced to Brooklyn, New York in 1850 - unsuccessful, so more reintroduced in 1852; first appeared in Minnesota in 1875 Rock Dove or Domestic Pigeon (Columba livia) - introduced to the US very early during European settlement Of these which have caused problems?
6. Science Exotic Species continued - 4 - gypsy moth escaped from a scientists lab in 1869, the scientist was working on the potential development of a silk industry in New England - today widespread destruction of many forests from Atlantic Coast to the Midwestern US - genetically-modified organisms? 7. Biological control - numerous examples, - Bti widespread use as an insecticide (e.g., mosquito control) - introduction of predators to Australia (red fox), New Zealand (weasels), and Hawaii (mongoose) to control rats and rabbits, profound effects on native species (e.g., ground nesting birds)
Tuesday - Jan. 25, 05 -Gypsy moth introduced in 1869 near Boston, MA -Feeds on hundreds of plant species but most common are oaks and aspen -Natural predators parasitoids and predators (many introduced from Europe over the past 100 yrs) -Also small mammals (at low density) viruses (at high density), and fungus can be effective
Exotic (Invasive) Species continued - 5 8. Habitat change - results in encroachment of species into new portions of their range - Rocky Mountain beetle, coyote, mallard, and brown-headed cowbird - roads - major conduits for the spread of weed-type plants (composites such as asters and grasses)
Mountain pine beetle Dendroctonus ponderosae (Native to North America)
Brown-headed cowbird Lays eggs in nests of other species Feeds almost exclusively in short-grass habitats (80%) and agricultural areas (20%) Breeds in other habitats, including forests Can commute at least 7 km to breeding areas It is not known how food abundance and host abundance interact to attract cowbirds
Overexploitation Intentional or unintentional harvest or persecution Possibly the most direct threat to biodiversity The percentage of Canadian (n = 488) and US (n = 1880) endangered species that are affected by habitat loss, introduced species, overexploitation, and pollution (Venter et al., 2006).
Types of Exploitation 1. Commercial exploitation - Money makes the world go round (Hunter, 2002) Consider American ginseng (Panax quinquefolius) - found from Maine to Georgia, Minnesota to Oklahoma - currently roots are being dug from 20 states - wild variety can command as much as $500 a pound on the black market (25 times more than the cultivated variety) Today there are many regulations for harvest but poaching is widespread; use as a cure for a variety of mental and physical deficiencies - large market in Hong Kong (Asian ginseng has been dug to near extinction)
Overexploitation Causes Collectors pets butterflies tropical fish cacti, orchids marine mollusks -- shells Conch shells Neon tetras
Science Magazine Colombian cashes in on beetle-mania abroad An entrepreneur ships giant, exotic types of the insects by the hundreds each month to Japan and elsewhere. His enterprise is part of his country s belated effort to commercially exploit its stunning variety of plant and animal species. (Note the article also covers concerns over the illegal export of Columbian biodiversity. ) By Chris Kraul - May 21, 2008 http://articles.latimes.com/2008/may/21/world/fg-beetles21
Figure 2. The percentage of Canadian terrestrial (n = 231), freshwater (n = 154), and marine (n = 43) endangered species that are listed by the Committee on the Status of Endangered Wildlife in Canada as threatened by habitat loss, introduced species, overexploitation, pollution, native species interactions, or natural causes. (Venter et al., 2006) Marine species in particular are vulnerable to over-exploitation
Overexploitation Causes Traditional/Natural Medicines 80% of world population are users; especially in Asia Cinchona sp. (used for quinine)
Controlling Overexploitation -- CITES Established in 1973, now 169 countries, Three appendices over 33,000 species protected http://www.cites.org/ - program of UN Environment Program
Types of Exploitation continued 2 2. Subsistence exploitation - need for food, clothing, fuel, etc. - generally does not lead to overexploitation sustainability 3. Incidental exploitation - trawling for shrimp - 90 % of the catch by biomass consists of unwanted species that are dumped overboard dead - the story of Professor Les Watling of University of Maine (Science 287: 1188, 18 February 2000) - rock hopper gear used to scoop up hake had mowed down sponge gardens 4. Recreational exploitation - excessive game fishing, hunting, or as Hunter (2002, pg. 216) points out how bird watchers crushed a black rail in their pursuit to find the species in a marsh
Overexploitation Causes -- Food Many societies use hunting and gathering for subsistence Increasing effects higher human populations increased technology Buffalo skulls in 1890s
The bushmeat crisis 1-4 million tons annually in Central Africa a source of protein
Tomorrow's Habitat for the Wild and Rare -- Minnesota
Controlling Overexploitation Local regulation Bushmeat crisis restrict sale/transport restrict sale of firearms closing roads after logging legal protection to species establishing reserves provide alternate protein sources armed guards other quotas and resource management
Over-exploitation - continued 5. Indirect exploitation - For example, house and feral cat predation - a domestic cat kills about 4 birds per year, there are an estimated 58 million cats in the US alone (100 million plus worldwide) - See www.wisconsinbirds.org/catsbirds.htm - See Lepczyk et al. (Biol. Conservation 115: 191-201, 2003) - On average a cat depredated between 0.7 and 1.4 birds per week - Our results, even taken conservatively, indicate that cat predation most likely plays an important role in fluctuations of bird populations - Study completed in Michigan