Chapter 10 Flashcards
What is extinction?
complete loss of a species
What is Extirpation?
local extinction of a species, with extant populations elsewhere
Can extinction disrupt food webs?
Yes
It may result in the loss of ecosystem services
How many prehistoric extinctions did Earth Experience? What were the potential causes?
5:
Ordovician -Silurian
Devonian
Permian-Triassic
Triassic - Jurassic
Tertiary-Boundary
Causes:
Asteroid impact
Volcanic activity
Ocean anoxia
Glaciation
Etc.
What are the two names for the current extinction era we are in?
Anthropocene
Homogenocene
What does Anthropogenic mean?
of, relating to, or resulting from the influence of human beings on nature
What are the effects human did on the environment?
Anthropogenic extinctions and reduced diversity
Spread of non-native species
Habitat loss and modification
Alteration of natural geochemical cycles, such as increased emissions of greenhouse gasses
What are the 6 major causes of extinction?
Invasive species
Habitat destruction
Overharvesting
Pesticides
Natural disasters?
Climate Change?
Why are islands highly prone to extinction?
Due to it being an island, species within are limited based upon:
Land
Are endemic or have ecological niches
Can live long with low biotic potential (low offspring production)
Easy prey
High economic value
Migrate dependent for habitats
Move in flocks for resource aggregation or breeding
What does the Homogenocene era refers to?
Species have been introduced to new areas since the dawn of human migration
Modern modes of transport and shipping have provided affected vehicles to spread species
What are examples of deliberate introductions for species?
Plants for food and as ornamentals
Livestocks/poultry
Pets
Biological control
What are accidental introductions to species?
Hitchhickers
Are introduced species a significant threat to an island’s ecosystem?
Yes
Regardless of their mode of introduction, species may become a pest
Species that harm people or things people value
Sometimes our view of a pest is subjective
Is tanan-tangan a pest?
Is ailing a pest?
What are the four factors that allow species to be considered pests onto an island?
Ecological release
Niches Available
Competitively dominant
Effective predator
What is Ecological Release?
from predators and competitors
- Islands may be free of species that regulated its population size in native range
- Have predators that don’t know how to kill the pests
What is Niches Available?
on an island that are unoccupied
- Resources may be available for exploitation or are underutilized by native species
What is Competitively dominant?
over native species
- May use resources more effectively than native spp.
- May have adaptation that inhibit competitors
What is Effective Predator?
on native species
- Islands species may have lost or lack effective adaptations against novel predators
What species is a classic example of an ecological effect for an introduced species?
Brown Tree Snake
- Its uses the factors of Ecological Release, Niches Available, and Effective Predator
- When arriving on Guam during WWII, it took dominated many of Guam’s bird species and other species, causing many of them to go extinct.
What are other animals that were introduced to the islands but caused some damages?
Ungulates (hoofed animals) on islands
- Goats, deer, pigs, and cattle
- Goats are efficient herbivores on native vegetation
- Pigs uproot plants and dig wallows
- Secondary effects include dispersing seeds of non-native plants in ungulate-distributed forests
- As abundance of native trees declines, the canopy may open and favor introduced pioneer species
What are the three ways of controlling invasive species?
Biological Control
Pesticides
Integrated Pest Management
What is Biological control?
Use of a natural predator or diseases to control pests population
Modern biocontrol seeks specialists on pests or with narrow preference for host
However, biocontrols may switch hosts and then prey or infect native species
- Biocontrol may thus become pests itself
What is Pesticides?
Chemicals that kill pests and decrease growth rate
Often over-applies or misapplied
Good at removing species but have a lot of problems for others
What is Integrated Pest Management?
Typically used in agricultural systems, uses natural predators and pest-deterrent plants to reduce pest abundance in a crop
- Acknowledge that complete eradication is not likely or feasible
Pesticides are applied only sparingly, as needed
However, difficult to apply towards pests in natural systems
What is a Persistent Organic Pollutant (POP)?
do not easily break down in the environment because they are synthetic, carbon-based molecules (such as DDT and PCBs)
- Stays in the soil for a long time
- Gets into the water, gets to mosquitoes and other water organisms that live there
- Zooplankton eaten by fish, fish by bigger fish, bigger fish by birds and us.
What is eggshell thinning?
caused the eggshell of big birds to be thin and easily destroyable due to DDT or POP
What is genotoxicity?
the ability of chemicals to damage the genetic information within a cell resulting in mutations, which may lead to malignancies.
What is Bioaccumulation/Biomagnification?
refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organisms
Low level of toxin get amplified as it gets higher on the pyramid, becoming highly toxic at the top
What does the phrase, “As mad as a hatter” refer to?
mercury poisoning
What is Ciguatera?
Food poisoning that comes from eating reef fish
Ciguatera toxins (ciguatoxins) accumulates in an organisms tissues
Most obvious symptom is hot = cold, cold = hot
Gambierdiscus toxicans is the main dinoflagellate (algae) that produces a toxin to discourage herbivores
Made by how a natural toxin bioaccumulates or builds up within the fishes.
- 10 small fishes eaten by 1 big fish has a higher rate of toxin than one small fish.
What are the symptoms of Ciguatera?
Begins six to eat hours after eating.
Symptoms include:
Nausea
Vomiting
Diarrhea
Muscle pain
Numbness
Tingling
Abdominal pain
Dizziness
Vertigo
_____________ is caused by several dinoflagellates (algae) that live on seaweed. Some of these toxins accumulate through biological magnification to make fish toxic.
Ciguatera
Are red tides/ciguatera toxic?
Yes
naturally produces toxins can also bioaccumulate
What is Red Tides?
Red dinoflagellates (Gonyaulax) that multiply rapidly.
Due to their large numbers, the sea appears red in colour.
They release large amounts of toxins in water that can cause death of a large number of fishes.
Does low level of toxin get amplified as it gets higher on the pyramid?
Yes
What is the Endangered Species Act of 1973?
Species that are under threat of extinction may receive protection
The Endangered Species Act of 1973 provides a framework to conserve and protect endangered and threatened species and their habitats both domestically and abroad.
EX. If a habitat holds that endangered species, then the owner of the plot can’t affect the endangered animals land/terrain
What is the Marine Mammal (Protection) Act?
Prohibits killing or injuring marine mammals, except under certain circumstances.
This program provides an annual exemption for the incidental mortality or injury of marine mammals that occurs during commercial fishing.
What is the Convention on International Trade in Endangered Species of Fauna and Flora (CITES)?
Trade of endangered species is restricted
Tries to solve the problem of illegal taking of endangered species at the source, not just to monitor the trade
An international agreement, signed by 184 parties in 1973, designed to ensure that international trade in animals and plants does not threaten their survival in the wild.
EX. Control the product of the an endangered species and protects them
______________ also afford protection, but protected species lists often must be renewed periodically
Local Laws
A common approach is to also protect the species’ …
Critical habitat
Designation prevents federal government agencies from modifying the habitat of the Endangered species.
What are pests?
Plants, animals, and microorganisms (diseases) harm people or things that are valued such as crops and landscapes.
Rapidly populate
Spread and multiply
Accidentally introduced
They “escape” cultivation and begin to invade the native landscape.
What is Endangered species?
These are those whose populations have declined so low that they are in danger of becoming extinct.
Several characteristics of islands promote _____________ but also make _____________ vulnerable to extinction.
endemism, endemics
Isolation promotes endemism because the number of new arrivals tends to be slower than species divergence.
Why do endemic species on islands are more prone to being extinct or extirpated?
Island populations tend to be small
Island populations are isolated and often endemic
Endemic populations often evolved with minimal competition, predators, or disease
Many endemic species on islands have low reproductive rates and the populations are less able to recover from catastrophe
What is Mass Extinctions?
An event when species vanish much faster than they are replaced.
What is a habitat?
Both physical AND chemical conditions in a place and the range of those conditions in which each species can thrive.
What is pollution?
The addition of harmful materials or heat to natural ecosystems.
Ex. Plastic, carbon dioxide, DDT, etc.
What is point source pollution?
Pollution comes from one single source.
- When pollution comes from major identifiable sources or outfalls, such as a factory or sewer outfalls.
What is Non-Point source pollution?
Pollution comes from multiple small sources.
- If there are a great many small points or undefined places of entry into the environment
What waste is the most pressing environmental concern for the Pacific Islands? Which animal is the most common source of contaminated animal waste?
Human domestic wastes and animal wastes
- causes health problems and affects marine communities
Pigs
What is Primary Treatment?
Involves screening the raw sewage and allowing some of the solids to settle out. Sedimentation, where solids separate from the water through several different tanks.
- The wastewater is generally chlorinated to disinfect it before it is discharged. The sludge can be heat-sterilized and used as an agricultural manure as long as it does not have toxic compounds in it.
- In most cities, sewage is given only PRIMARY TREATMENT before it is piped into the ocean.
What is secondary treatment?
Uses decomposer microbes to break down the very small particles of organic matter.
Used when waste go into rivers that serve as drinking water.
What is tertiary treatment?
Take dissolved nutrients out of the water, to prevent eutrophication.
Eliminating non-biodegradable pollutants. It follows primary and secondary treatment. This technique allows the removal of phosphorus and nitrogen contained in the water to refine it. It is based on the use of chemical and physical processes.
What is eutrophication?
Additions of nutrients, such as nitrogen and phosphorus, to aquatic ecosystems. This often results in explosive growth of plants that then affects the entire ecosystem.
What is indicator bacteria?
Used to measure the potential presence of fecal material and associated pathogens in water and soil
What is Sanitary Landfills?
An engineered method of disposing of solid waste on land in a manner that protects the environment, by spreading the waste in thin layers, compacting it to the smallest practical volume, and covering it with compacted soil by the end of each working day or at more frequent intervals if necessary.
What are the layers on top of the landfill?
Grass
Topsoil
Sand
Clay
Trash
What are layers on the bottom of the landfill?
Trash
Sand
Synthetic Liner
Sand
Clay
Subsoil
What is recycling?
Collected waste into raw material, then manufacturing new products from it. It is not the same as reusing products, which is also a useful method for saving waste.
- The best way to reduce the problem of trash disposal is to produce less trash (source reduction)
What is leachate?
Rainwater that percolate through the garbage and leach out chemicals on its way to rivers or the ocean.
