hand-out 1: ecology for benildeans€¦ · web viewthe hydrosphere is that layer of the planet...

Natural Science 13 De La Salle – College of Saint Benilde

Hand-out 8: The Hydrosphere

Hand-out 8: The HydrosphereLecturer: Mr. Jose Mari Balines Gonzales

M.Sc. in I.T. for Natural Resources Management

Objectives:

To determine the essential role of the hydrosphere in sustaining life here on Earth. To examine how human activities can affect the normal processes of the hydrosphere. To describe the El Niño phenomenon. To examine strategies that sustainably utilizes marine resources.

Introduction

Water is one of the biosphere’s amazing substances. As it constantly moves from the sea to the land and back again, it shapes the earth’s surface and moderates our climate.

Moreover, water is essential for sustaining life here on earth. It is the medium in which all living processes occur. Water dissolves nutrients and distributes them to cells, regulates body temperature, supports structures in our body, and removes waste products. About 60 percent of your body is water. You could survive for weeks

without food, but only a few days without water.Water also is needed for agriculture, industry, transportation, and a host of other

human uses. In short, clean freshwater is one of our most vital natural resources.The hydrosphere is that layer of the planet Earth that makes-up the watery

regions. Ecosystems in the hydrosphere are unique because they are submerged in water. Can human activities affect these kinds of ecosystems too? To answer this question, let us find out what components make-up the hydrosphere, and how each of these components function.

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Class Activity 8: Philippine Coral ReefsThe objective of this film viewing is to examine how marine resources can be utilized

and at the same time be preserved for future use.Instructions:1. Work in groups. Form a group with a maximum of six (6) members. (30 points) 2. View the film Philippine Coral Reefs as a group to examine the highlighted issue and gather

pertinent information for your group output. 3. See Worksheet 6-1 of this handout. Construct a flow chart patterned after the components

illustrated in that worksheet. 4. Be ready to share your output in class.



Hydrosphere

The main component of the hydrosphere is water. But not all water is accessible living organisms. Moreover, not all water on earth can be used (Fig.8-1).The hydrosphere consists of the following structures that are often referred to as bodies of water. They also constitute the varying types of unique ecosystems submerged in water.

A. Freshwater:

Freshwater lakes cover 1.85% of earth’s surface and running freshwater covers 0.3% of earth’s surface (Fig.8-1).

1. Lakes and Ponds- These are areas of standing fresh water.- Ponds: small, shallow lakes.- Marsh: shallow water with floating-leaved and emergent vegetation. Often

occurs as a fringe around lakes.- Lakes: form when there is a source of water and a hole or depression on the

ground that collects it.Ex. 1.) When glaciers retreat.

2.) When a meandering river strengthens3.) When a volcano becomes dormant4.) When caverns collapse

The edge of the lake is richly inhabited by organisms. Plants root at the lake shore and grow up out of the water; other plants float on the surface. Animals include insects, snails and other mollusks, amphibians and reptiles, fish, waterfowl, and small and medium mammals.

The middle of a lake has small, floating algae and larger, deep swimming fish.

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Figure 8-1. Most of the world’s water is found in the ocean. Base from the figure, can you explain why there is a need for mankind to conserve freshwater? – All figures from this handout were downloaded using the Google search engine, 2006.



The bottom of the lake is very cold and has little or no light, mostly bacteria and fungi live there.

- Heat input comes from solar radiation.- Amount of light absorbed depends on depth and clarity of the water.

Therefore, temperature varies with depth (thermal stratification).- Five habit types:

1. Benthos – composed of bottom dwelling organisms2. Penphyton – made-up of microscopic plants and animals3. Plankton – mostly microscopic plans and animals4. Nekton – strongly swimming organisms5. Neuston – occupying the water film

2. Rivers and Streams- These bodies of water continuously flow from a source.- It is characterized by the swiftness of the current, abundance of oxygen and

nutrients; insects and fish requiring cold temperatures and a lot of oxygen are its principal inhabitants.

- 2 basic habitats in streams:1. Riffles - has turbulent water flow.

- oxygen is always high. - mostly have algae attached to rocks. - animals either attach to rocks or avoid the current.

2. Pools - current flow is reduced. - has a point of entry and exit for flowing water.

- River and stream ecosystem have less plankton and more marsh plants.

B. Ocean water:Ocean water has high salinity (saltiness). Ocean water contains about

3.5% salt by weight. The salinity of fresh water, by contrast, is mostly below 0.03%. About 78% of sea salt is sodium chloride (Brewer, 1994). Ocean water covers 97% of the total water we have here on earth (Fig.8-1).

3. Oceans- This hand-out recognizes five major oceans, although some references will

vary from five to three (Fig.8-2). Everything about the ocean is immense (the following information were lifted from discoveryschool.com of Discovery Education).

It has the tallest mountains in the world and the deepest valleys. It covers 72 percent of the Earth’s surface (or 139 million square

miles). It’s deep- 12,460 feet deep on average. That’s 10 Empire State

buildings stacked on top of each other.- Most scientists think life began in the ocean over 3 billion years ago.

Over 1 million known species of plants and animals live in the ocean, and scientists say there may be as many as 9 million species we haven’t discovered yet.

The largest animal in the world: blue whale.

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The tiniest drifting organism in the ocean: plankton. Organism living in the deepest part of the ocean (7,000 feet below the

surface) near sea vents: tube worms.o Within this area the water temperature changes from scalding hot

to icy cold in the space of a few feet.- Life in the ocean depends on energy.

Most ocean animals get their energy by eating plants or other animals. The connection between organisms based on the transfer of energy is called a food chain or a food web. Most food webs start with the conversion of sunlight into food through a process called photosynthesis. This process occurs at the surface of the ocean. But deep within the ocean, at hydrothermal vents, food chains are based on the conversion of chemical energy into food. This process is called chemosynthesis.

- The ocean has an average depth of 4,000 (2 miles).- The ocean life zones (Fig.8-3) consist of the following:

1. Littoral zones – area between the lines of high and low tide.2. Neritic zone – portion of the ocean over the continental shelf (200 m depth)3. Oceanic zone – open ocean.

Coral ReefsThese are the major ecosystems in the ocean.Regarded as marvels of productivity, most diverse of all marine communities and is sustained by complex interdependencies.The living portion of the reef is only a thin skin over bulks of dead skeletons.It is formed by corals. - Corals are colonial animals (coelenterates) that secrete calcium carbonate

skeletons.- develop only in warm water ( 20°C).

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Figure 8-2. Oceans of the world. Can you name each? – Diagram by Mapquest.com, downloaded using the Google search engine, 2006.



The coral reef is rich in carbon, oxygen and dissolved minerals.It provides food and shelter to other marine organisms.The total coral reef of the world: 600,000 km2

The relative elevation of land and sea are responsible for the development of coral reefs.

4. Estuaries- coastal bodies of water connected with the ocean.- high productivity is due to the action of tides.- Have a wide variety of producers, from phyto-plankton to marsh grasses.

Water Pollution

The unwanted alteration of natural chemical processes in a body of water as a direct or indirect result of human activity.Types of pollutants come from varying sources of human activities (Fig.8-4).

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Figure 8-3. The varying zonations of the ocean starting from the shoreline up to the open seas. What reasons are there for life to be less diverse in the open seas? – Illustration by Saunders College Publishing, downloaded using the Google search engine, 2006.



Problem becomes complicated if pollutants enter the watershed.Non-point pollutants can contaminate groundwater.Primary effect of stream pollution by sewage and other organic wastes is providing large amount of food for decomposer organisms, mainly bacteria and fungi.

A large fraction of the pollutants in water come from “non-point” sources, rather than from a pipe:

1. Urban storm-water run-off – oil residues, lead from gasoline, asbestos from brake lining, and chemicals from people’s lawns.

2. Construction – generates erosion hat runs sediments into streams and lakes.3. Forestry – has similar effects with construction, plus heavy inputs of

herbicides and pesticides.4. Mining – produces sediments and may release harmful chemicals from ores.5. Septic systems – (when located near lakes) may run sewage, bacteria, and

household chemicals almost directly into the lake water.6. Atmospheric deposition – source of various highly toxic organic compounds,

such as acids.

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Increased food availability

Biological Indicators

cannot tolerate

Increased respiratory activity

Figure 8-4. The varying sources of water pollutants from human activities show the degree of damage we are inflicting on our water resources. How do you think can we minimize this damage?



7. Agriculture – generates sediments, organic matter, pesticides, herbicides and phosphates and nitrates from fertilizers.

Eutrophication and Algal Bloom

Increasing the availability of nitrate and phosphate in lakes (Fig.8-5).Loss of oxygen in the bottom waters death of animals.This problem is relatively reversible if the water flows out of the lake- dilution.Rivers and streams can dilute organic wastes/materials.Algal bloom refers to the proliferation of algae (blue-green algae) in lakes, streams or ponds because of high amounts of nutrients.- Water body becomes green and smelly.

El Niño Phenomenon

Spanish for “The Christ Child” named by South American fishermen because it occurs at Christmas (birth of the Christ Child).What happens when this phenomenon occurs (Fig.8-6)?

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Figure 8-5. A summary of how eutrophication may take place in a lake or pond. What do you think will be the impacts? – Diagram downloaded using the Google search engine, 2006.



Effects of the El Niño phenomenon on the marine ecosystems:1. Decline in fish catch near South America.2. Coral bleaching.

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Figure 8-6. Examine the diagram above. Why do droughts occur during the period of El Niño? – Diagrams downloaded using the Google search engine, 2006.



Coral Reef Destruction

Economic importance is due to high species diversity:

Primary causes of rapid degradation:1. Rapidly increasing human population.2. Greed.

Coral reef destruction leads to loss of habitats, decline of species diversity and poverty for people living along the coastline.

E N D

References:

Bush, M.B. 1997. Ecology of A Changing Planet. Prentice Hall, Upper Saddle River, New Jersey, USA.Brewer, R. 1994. The Science of Ecology, 2nd Ed. Saunders College Publishing, USA.Cunningham, W.P. and Cunningham, M.A. 2006. Principles of Environmental Science, 3rd Edition. McGraw-Hill Companies. New York, USA.Enger, E. and Smith B. 2006. Environmental Science: A Study of Interrelationships, Tenth Edition. McGraw-Hill Companies, Inc. New York, USA.

Web sites:

http://school.discovery.com/schooladventures/planetocean/ocean.html

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FOOD

MEDICINE AESTHEIC PURPOSES

LIVELIHOOD

CORAL

REEFS

http://school.discovery.com/schooladventures/planetocean/ocean.html



Worksheet 6-1Finding Sustainable Solutions

Name: ______________________________ Section: ________ Date: _____________

After viewing the film Philippine Coral Reefs discuss vital information and insights with your group members. Construct a flowchart that will illustrate ways to address the problem of illegal fishing here in the Philippines. Follow the instructions below and the accompanying flowchart.

1. Identify human activities in the coastal regions of the Philippines that threaten marine resources using references from the Web and LRC-Extension.

2. Formulate realistic solutions for the Philippines that will minimize coral reef destructions. A sustainable solution pertains to a solution that will work in favor of the communities, the national/local economy and the environment.

3. Identify the group of people that should be involved in formulating/developing solutions to this kind of problem.

4. Describe the strategy needed to put your proposed solution into action by specifying key steps.

1. Human Activities- What are the various human activities in the coastal regions of the Philippines that

pose threats to the coral reefs?

4. Strategy- What steps will be taken to put the solution into action?

2. Sustainable Solution(s)- Formulate a balance solution that

will favor social, economic and environmental components.

3. Stakeholders- Who should be involved in

finding the solution?

Act 1

Act 2Etc.

Act 3

Solution 1

Solution 2 Etc.

Strategy

Stakeholders

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hand-out 1: ecology for benildeans€¦ · web viewthe hydrosphere is that layer of the planet...

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