Chapter 1 Science and Marine Biology Karleskint Small Turner

Key Concepts Marine and terrestrial environments are interrelated, interactive, and interdependent. The ocean is an important source of food and other resources for humans. Marine biology is the study of the sea’s diverse inhabitants and their relationships to each other and their environment.

Key Concepts The history of marine biology is one of changing perspectives that have shaped the modern science and its applications. Marine laboratories play an important role in education, conservation, and biological research.

Key Concepts It is important to study marine biology in order to make informed decisions about how the oceans and their resources should be used and managed. Scientists use an organized approach called the scientific method to investigate natural phenomena.

Importance of the Oceans and Marine Organisms World ocean covers nearly 71% of earth’s surface Oceans interacting with the atmosphere affect weather patterns on a global scale

Importance of the Oceans and Marine Organisms Marine Organisms: –provide substantial part of human food supply -are used as subjects of scientific study for many areas of research -are useful to medicine and industry providing jobs for many people worldwide

Study of the Sea and Its Inhabitants Oceanography –study of the oceans and their phenomena, such as waves, currents and tides Marine biology –study of the living organisms that inhabit the seas and their interactions with each other and their environment Knowledge of these disciplines will promote marine conservation.

Marine Biology: A History of Changing Perspectives Early studies of marine organisms - traced back to ancient Greeks and Romans - Aristotle and the “ladder of life”, a scheme of classification Renewed interest in marine organisms –voyage of the HMS Beagle and Charles Darwin’s On the Origin of Species, theory on evolution through natural selection –discovery of deep sea organisms on retrieved transatlantic telegraph cable

Marine Biology: A History of Changing Perspectives Beginnings of modern marine science –Challenger expedition exploring world’s oceans 4,700 new species collected and described significance of plankton receives attention marine studies in the United States expeditions of Alexander Agassiz funding of the first marine biology laboratory: Anderson Summer School of Natural History, predecessor of the Marine Biological Laboratory at Woods Hole forerunner of other U.S. marine laboratories

Marine Biology: A History of Changing Perspectives Marine biology in the twentieth century –Fridtjof Nansen’s Arctic expedition –Sir Alistair Hardy’s Antarctic expedition –impact of human activities on marine environment gains attention Marine biology today –deep-sea submersibles –discovering ties between terrestrial and marine environments –information sharing via the Internet

Process of Science Hypothesis –explanations that can be tested by experiments Scientific method – an orderly pattern of gathering and analyzing information

Steps in the Scientific Method Making observations (Step 1) Using inductive reasoning to form a hypothesis (Step 2) Using deductive reasoning to design experiments (Step 3) –experimental variable –experimental set –control set

Steps in the Scientific Method Gathering results (Step 4) Drawing conclusions (Step 5) –theory versus hypothesis EXAMPLE: Plant growth in a salt marsh: a case study of the scientific method –observation of growth patterns and analysis of soil samples –experiment to test hypothesis –analysis of results of the experiment

Availability of nitrogen is a major limiting factor on the growth of salt marsh plants *Hypothesis is confirmed 7) Draw Conclusions IF nitrogen is added to the soil, THEN marsh grass will grow larger or faster or both 3) Use deductive reasoning to make a prediction based on the hypothesis Small increases in size, mass, and growth rate Large increases in size, mass, and growth rate 5) Gather Results Similar results 6) Repeat Experiments and Test More Plots Use inductive reasoning 2) Formulate a Hypothesis Growth of marsh grass is limited by nitrogen availability Tall grass Plot 1 Low nutrient input Short grass Why do salt marsh plants in some areas grow larger? 1) Make Observations and Ask Questions Soil sample has high nitrogen Soil sample has low nitrogen Plot 2 High nutrient input 4) Design Experiments and Do Them Add fertilizer lacking nitrogen All plants are initially the same height Experimental plot 2 Area 2 Add nitrogen-containing fertilizer Control plot 1 Area 1 Control plot 2 Area 2 Experimental plot 1 Area 1 Fig. 1-11, p. 11 Stepped Art

Process of Science Alternative methods of science –experimentation is not always possible –observational science – observation alone must be used to support or deny the hypothesis “The science of Marine Biology” –Introduction to Marine Biology 3rd edition contains “Science of Marine Biology” features to illustrate the application of the scientific method in studying marine organisms