Biodiversity loss
Safe Drinking Water Act
(1974, 1986, 1996) sets the national standards for safe drinking water. It is responsible for establishing maximum contaminant levels (MCL) for 77 different elements or substances in both surface water and groundwater.
What are the causes of coastal aquatic habitat fragmentation?
*climate change*, *over-irrigation*, *man-made landscape alterations* lead to *decreased freshwater levels*
Describe Bad agricultural practice
-cause of desertification -expansion of cultivated land during rainfall period >>abandonment of land during drought -cultivated land using water from boreholes >>over-irrigation leads to drought & increased soil salinity (salinisation)
Describe habitat fragmentation due to large highways
-construction of large highway leads to *landscape fragmentation* >>isolation of populations& gradual genetic degeneration >>this makes them *prone to changes in diseases & extinction*
Explain the effects of climate change
-extreme weather differences between regions -changes in environmental conditions to act synergistic (one increases the other) -CO2 rise>>increased vegetation density -temperature rise>>increased rate of physiological processes e.g. photosynthesis -distribution of species may be altered by climate change >>could invade endemic species' habitat
What causes the destruction of coral reefs?
-fishing equipment -climate change -disease due to marine pollution
give examples of coastal aquatic ecosystems that are susceptible to fragmentation
-interconnected coastal lagoons, salt marshes, ponds
What other human activities cause habitat loss?
-mining, logging, trawling (fishing net) & urban sprawl -hydroelectric installations flood land -wetlands replaced with agricultural
Describe indirect adverse effects of pollution
-nutrient enrichment of surface waters >>eutrophication >>algal bloom >>mortality of life below due to toxin consumption (that the algal blooms release)
Describe bad farming practice
-overgrazing>>trampling of soils>>no aeration/water penetration>>vegetation disappears, increased vulnerability to erosion
what are the 5 main causes of Biodiversity loss?
1)habitat destruction (degradation, fragmentation) 2) pollution 3)climate change 4)invasive species 5)overharvesting
Clean Water Act
1972) supports the "protection and propagation of fish, shellfish, and wildlife and recreation in and on the water". Issued water quality standards that defined acceptable limits of various pollutants in U.S. waterways.
How much of Brazil's amazon was lost per year in 1990s & 2000's?
1990s = 11.3million hectares 2000s =9.34 million hectares
How much of the Earth's water is freshwater?
2.78%
What percentage of original forests remain, globally?
20%
when could commercial fish/shellfish become extinct?
2048
what is the global desertification rate?
6 million hectares/year
What percentage of coral reefs could disappear by 2030?
60%
describe the main causes of loss of the Amazon rainforest
60% = Pasture 33% = Small cultivations mining,fires, urbanisation = 3% intensive cultivations = 1%
What is the world population predicted to increase to?
8 billion by 2030 -shortages in food, water, energy
percent change equation
= (| original-new | / original) x 100
Sixth mass extinction
Extinction- when there are no longer any of the species in the world. We are currently losing approximately 50,000 species per year. This one is caused by humans!!
IUCN Red List
List of Threatened Species founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species.
septic tank
a tank, typically underground, in which sewage is collected and allowed to decompose through bacterial activity before draining by means of a leaching field.
if overfishing as we are doing is continued, what will happen to fish/shellfish?
all commercial fish/shellfish species predicted to extinct by 2048 (worm 2006)
What group of animals has the highest percentage of threatened or near threatened species?
amphibians
What is the principle cause of habitat destruction?
clearing habitats for *agriculture*
primary sewage treatment
consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment.
nonpoint source pollution
diffuse areas such as an entire farming region that pollutes a waterway.
point source pollution
distinct locations that pump waste into a waterway.
How long do coral reefs take to regenerate?
hundreds of thousands of years (000,000)
secondary sewage treatment
is a treatment process for wastewater (or sewage) to achieve a certain degree of effluent quality by using a sewage treatment plant with physical phase separation to remove settleable solids and a biological process to remove dissolved and suspended organic compounds.
Turbidity
is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air.
Extinct
no known species exist today
Inbreeding
occurs when individuals with similar genotypes, generally relatives, breed with each other.
Endangered Species Act
of 1973 (ESA) was signed on December 28, 1973, and provides for the conservation of species that are endangered or threatened throughout all or a significant portion of their range, and the conservation of the ecosystems on which they depend.
Define desertification
productive land in *arid & semi-arid areas* (low water/vegetation) are transformed into desert mainly due to anthropogenic activities >>caused by *synergistic effects of climate change,resource overexploitation & habitat loss*
Marine Mammal Protection Act
protects all marine mammals, including cetaceans (whales, dolphins, and porpoises), pinnipeds (seals and sea lions), sirenians (manatees and dugongs), sea otters, and polar bears within the waters of the United States.
What can the macroinvertebrate index tell us about water quality?
small spaces found within permeable layers of rock and sediment where water is found.
define Extinct
species not observed for last 50 years
Near-threatened
species that are likely to become threatened in the future
Threatened
species with a high risk of extinction in the future
What is the effect of high population growth on biodiversity?
substantial human-induced environmental changes - usually negative ones >>thus *demographic change is a key component in global biodiversity conservation*
what happens when a population of species falls below a certain critical threshold?
there are not enough individuals to regenerate population & it goes extinct
What is the effect of increased soil salinity?
vegetation disappears as most species cannot tolerate high salinity & seedbank is destroyed
What are the 2 main ways aquatic invasive species spread?
via *shipping* & *aquaculture*
invasive species
when alien species spread rapidly across large areas. Ex- Kudzu Vine, Zebra Mussel, Silver Carp