Aquatic Resources & Problems

Part 1: Problems

Ocean Problems

Marine PollutionGlobal WarmingOver HarvestingEndangered SpeciesWetland CrisisSubsidence

Pollutants

Natural Man-made

Heavy Metals Hg, Pb, Ag, Ni Volcanoes Cities, industry

Hydrocarbons Oil, Coal SeepsShipping,

runoff

NutrientsNitrogen & Phosphorus

UpwellingCities,

Agriculture

RadioactiveUraniun,

PlutoniumVolcanoes

Power plants, weapons, hospitals, industry

Particulate Matter

Silts, Clay River currents Cities

SourcesType Example

Effects of Pollutants

Heavymetals/radioactives: foodchain problems, biological magnification

Excess nutrients: plankton blooms resulting in a decrease in the fish population

Debris: organisms die from consumption or entanglement

Particulate matter: increases turbidity which can reduce photosynthesis

Effects of Pollutants cont’d.

Thermal Pollution: Hot waste from power plants, etcDecreases dissolved oxygen Increases organisms’ metabolic ratesCan be used in aquaculture

Oil Pollution

Major source of marine pollutionTransportation is the greatest contributor Most accidents occur in shallow water

Oil Pollution Cont’d

Crude Oil (unrefined oil mix) spill Some evaporate

Gasoline & kerosine

Some sink Asphalt Coats bottom dwellers

Some dissolves into food chain Biological magnification Some float

Prevents photosynthesis Harms plantonic and nektonic organisms Harms birds

Oil Spill Clean Up

In the water:Skimmers, booms, dispersants, absorbants

On shore:High pressure hoses, hot water, absorbant

towelsNew technology

Bioremediation using oil eating bacteria

Global Warming

Greenhouse effect raises global temperatures

Glaciers meltSea level rises causing coastal floodingGreenhouse effect is due to greenhouse

gases Trap radiant (heat) energy from the sun in

our atmosphere

Global Warming Cont’d: Greenhouse Gases

Carbon Dioxide: produced by burning fossil fuels

Nitrous Oxide: produced from excessive use of nitrogen fertilizers and the burning of hydrocarbons in combustion engines

Methane: produced from decomposition of organic material in cattlelots, rice paddies, landfills, sewage treatment plants

Chlorofluorocarbons: from industrial processes as in producing plastic foam, refrigerants, and solvents

Acid Rain

Air pollutants mix with atmospheric waterOrigin of air pollutantsPower plants (sulfur dioxide)Motor vehicles (nitrogen oxide)Effects: harms plants, erodes different

types of statuary and building features

Overharvesting

Reduces population numbers because of overcollecting (Tragedy of the Commons Lab)

Difficult recoveryAdults are harvested before they can

reproduceJuvenilles harvested before maturing and

being able to reproduce

Endangered Species

Definition: organisms are in danger of becoming extinct because population numbers are too low to recover

CausesLoss of habitatOverharvesting Introduction of non-native species

Wetland Crisis Threats

Pollution Sources from watersheds, septic systems, sewage

treatment plants, cars, boats, yards, farms, industry Effects

Harm or kill marine organisms, health risk to seafood, closures of beaches

Habitat Loss Increasing human populations

Development Subsidence Rise in sea level

Importance of Wetlands

Nursery grounds for our food Filter pollutants Protect shorelines by buffering from erosion

and flooding Recreation

Fishing, boating, swimming

Food & habitat for ecosystem Commercial activities

ports, marinas

Subsidence Causes

Land lowers due to fine grain sediments compacting

Pumping of underground without recharge

Oil and gas withdrawalUnderground mining operationsDrainage of marshlands

Subsidence Effects

Changes in elevation, slope of streams, canals and drains

Damage to bridge, roads, railroads, storm drains, sewers, canals, levees

Damage to buildingsFailure of well casingsTides moving to low lying areas

Aquatic Resources & Problems

Part 2: Resources

Ocean Resources: Types

RenewableReplaced yearlyPlants & animalsBiological

Non-renewable In fixed amounts

Example: mineralsCannot be replenished

Biological Resources

Controlled by sunlight & nutrients Dependent upon plant productivity Productivity ratings:

1. Upwellings & estuaries

2. Shallow water/continental shelves

3. Arctic & Antarctic

4. Open ocean/deep ocean Biological desert

Mineral Resources Types

Elements in solution: salt, bromine, magnesium are most profitable

Minerals in bedrock: phosphorites (for fertilizers), precipitates (upwelling areas)

On ocean bottom: oil & gas (most valued), sand & gravel, sulfur

Other uses of the ocean

DesalinizationDrinking water

Nuclear waste disposalEnergy

Harness Wave energy (buoys)Harness tide energy