Download CHAP - Jessamine County Schools

CHAP. 12 NOTES
APES
STATS
- about 50% of the human population depends on seas for primary
source of food.
- about 90% of fish spawn in the world’s coral reefs, mangrove swamps,
coastal wetland or rivers.
- coral reefs have the greatest biodiversity.
- about 1 % of Earth’s surface is made of freshwater systems.
MAJOR CAUSES OF SPECIES LOSS IN MARINE ECOSYSTEMS
- habitat destruction
- pollution
- erosion
- alien species - caused over half of fish extinctions of last century in US
- overfishing - lowers size of fish populations
- decreases marine keystone species
REASONS WHY PROTECTING AQUATIC BIODIVERSITY IS
ESPECIALLY DIFFICULT
1) expanding human ecological footprint
2) most of the ocean area lies outside political jurisdiction of any one
country
3) damage to oceans is not visible to most people
4) many view the ocean as an inexaustible resource
MAJOR COMMERCIAL FISHING METHODS - p. 254-255
-trawl fishing - involves dragging weighted, funnel-shaped net along
ocean floor in order to catch shellfish, flounder, etc.
- most destructive form to ocean floor.
- purse seine - practice used to capture schooling fish (tuna).
- surrounds and encloses with a net.
-drift net - uses hanging vertical nets in the water column with buoys to
catch fish by gills.
-longline fishing - involves putting out lines hung with thousands of
baited hooks.
-Deep sea aquaculture cage - form a “fish farming”.
- these strains of fish are usually weaker
than the “wild” form of the species. If
weaker strains escape into the wild, could
weaken wild population.
-by-catch - non-target species that are caught and killed
LEGISLATION - p, 255
1) 1975 Convention on International Trade in Endangered Species
(CITES)
2) 1979 Global Treaty on Migratory Species
3) US Marine Mammal Protection Act of 1972
4) US Endangered Species Act of 1973
5) US Whale Conservation & Protection Act of 1976
6)1995 International Convention on Biological Diversity
International Whaling Commission
- established by the International Convention for the Regulation of
Whaling in 1946.
-Eskimos are allowed to continue hunting whales.
- Japan, Norway and Iceland kill about 1300 whales/yr. for “scientific
purposes”.
- Japan more than doubled whaling catch in 2005.
In 2006, President George W. Bush created the world’s largest marine
reserve in Hawaii.
Solutions for managing global fisheries more sustainably and protecting
marine biodiversity - p. 261
Maximum sustained yield (MSY) - model to project the maximum # of
fish that can be harvested annually from a fish stock without causing a
population drop.
Optimum sustained yield (OSY) - takes into account interactions with
other species and provides more room for error.
COASTAL WETLANDS
1) serve as buffers against storms
2) trap sediments and filter water
3) act as nurseries for fish, shellfish and birds
4) more than half of the coastal wetlands have disappeared
-largest wetlands restoration project is in the Everglades.
-US Army Corps of Engineers - federal agency responsible for undoing
development (dredging canals, levees) in Everglades. Ironically, this
agency oversaw the development of the Everglades since the 1940s.
Best long-range strategy to reduce beach erosion:
-prevent development on beach areas or allow development only behind
protective dunes.
DAMS AND RESERVOIRS
1) may kill young salmon as they pass through turbines.
2) slow downstream migration, exposing juvenile salmon to more
predation.
3) may prevent upstream migration of mature salmon.
Ecosystem rehabilitation and salmon restoration on the Columbia River:
includes
1) building new hatcheries upstream of the dams
2) putting 40,000 miles of stream off limits to hydropower development.
3) reducing runoff of silt from logging roads.
Runoff of nitrates and phosphates into waterways cause
1) increase in algae blooms
2) large fish die off
3) eutrophication
4) increase in B. O. D. (biological oxygen demand)
National Wild & Scenic Rivers System
- offers protection to rivers or segments of rivers with
1) cultural & historical value
2) wildlife & scenic value
3) recreational value
- allows activities such as
1) camping
2) canoeing
3) kayaking
4) fishing
NOT motor boating