The Science of Marine Biology Chapter One The Science of Marine Biology Copyright © 2016 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education.

What is Marine Biology? Marine biology - the study of organisms that live in the sea, including all water that has some degree of salinity, like the estuaries at river mouths Marine biology is not a separate science. It is an applied field of biology and incorporates many other sciences such as: Geology Chemistry (organic and inorganic; Biochemistry) Physics Meteorology Zoology, Botany

A Marine Biologist is not exactly the same as an Oceanographer Marine Biologists study the organisms that inhabit the sea Oceanographers mainly study the physical (non-living) aspects of the ocean including tides, currents, waves, and the chemical make-up of seawater

Why Study Marine Biology? 1. Since life is believed to have arisen in the sea, studying marine life can provide clues about early life on earth. 2. Many products come from the sea including food, medicines derived from marine species, food resources, and other items used for human use.

Why Study Marine Biology? 3. Marine organisms produce oxygen used by all kinds of organisms, including humans. 4. The marine environment provides recreation and support tourism worldwide.

Why Study Marine Biology? 5. The oceans help regulate climate. Water is slow to change in temperature, keeping coastal land masses more stable year-round

History of Marine Biology Clam shells, which are approximately 165,000 years old, have been discovered in a cave previously inhabited by humans in South Africa 110,000-year-old shell harpoons and fishhooks have also been found This shows that humans have been using the sea since early times

History of Marine Biology Early explorations were made by Pacific Islanders as well as the Phoenicians, who extensively sailed the Mediterranean and adjacent seas Ancient Greeks also had extensive knowledge of the Mediterranean Sea. Aristotle, the Greek philosopher, described many marine forms

History of Marine Biology Captain James Cook and his crew, which included naturalists, sailed around the world beginning in 1768, and were the first Europeans to view the Antarctic ice fields and land on Hawaii, Tahiti and many other Pacific islands. His crew did extensive mapping and brought back many specimens.

History of Marine Biology Charles Darwin Sailed on the HMS Beagle from 1831-1836 as a naturalist. While the primary goal of the expedition was to map coastlines, Darwin observed, collected, and wrote detailed written descriptions of the organisms he observed. His observations led him to formulate his principle of natural selection and evolution.

History of Marine Biology Edward Forbes Extensively studied the seafloor around the British Isles, Aegean Sea, and other locations in 1840’s and 1850’s. He discovered that species on the seafloor vary greatly depending on depth, a fundamental principle of marine biology.

History of Marine Biology Challenger Expedition (1872-1876) First major exploration devoted to the study of marine organisms. The crew discovered thousands of species previously undescribed and published 50 volumes of information from the data collected over the next 19 years.

Challenger Expedition

Modern Marine Biology Many marine biology research stations exist in locations around the world. Several facilities in the United States are considered among the most famous: Woods Hole Oceanographic Institution and Marine Biological Laboratory, Massachusetts Scripps Institution - La Jolla, California Friday Harbor Laboratories, Washington state

Important Tools in Modern Marine Biology Remote sensing – Satellites are used to study large expanses of the ocean surface Sonar – Used to map seafloor depths and formations SCUBA – Used for the study of the marine environment for longer periods and at depths otherwise unavailable to humans Remotely operated vehicles (ROVs) – Allows for direct exploration of the marine environment when scuba is not an option.

Important Tools in Modern Marine Biology Research vessels – These floating laboratories allow oceanographers and marine biologists to explore the marine environments for weeks, months, or even years without returning to a land-based facility. Many types of electronic devices and other gear are currently used to study the marine environment and its inhabitants (see Box 1.1 “Observing the Ocean”).

The Scientific Method is Used to Perform All Scientific Research, Including Research in Marine Biology The scientific method is a systematic way of testing ideas. At the heart of the method is the need to OBSERVE nature.

The Scientific Method Begins with a hypothesis, a testable statement constructed from observations as well as reasoning, both induction and deduction. The hypothesis must be worded so that it is testable by scientific means. See Fig. 1.19 for the “steps” followed in the scientific method

The Scientific Method One important aspect of science and the scientific method is that you can’t prove a hypothesis. You can only disprove hypotheses based on the evidence you have. Hypotheses that have been tested repeatedly and not disproved are considered to be true based on the available evidence.

Considerations in Scientific Research A researcher must look at only one factor at a time: these factors are the variables. If a researcher wants to study the effects of temperature on mussels, they could, for example, acquire similar specimens of mussels from different locations.

Considerations in Scientific Research If only temperature is being tested, all other factors must be kept constant (amount of food given, age and size of mussels, oxygen concentration, salinity, etc.). If two tanks with mussels are kept at different salinities and different temperatures, for example, a researcher cannot attribute altered growth rates to only temperature. The results could be the combination of temperature and salinity.

What is a Theory? In everyday language, a theory can be likened to a “hunch.” In this everyday use, it just means that it is what you suspect to be true. In scientific language, a scientific theory is a hypothesis that has been tested repetitively over time by many people and has not been disproven. If there is ample evidence to support the theory, it is then regarded as true in the scientific community.

Limitations of Scientific Method Due to the requirements for direct observations or measurements and a testable hypothesis, not all questions can be answered. Science can offer no answers on values, feelings, and beliefs. These are beyond the scope of the scientific method.