Online Class: Marine Biology 101

In this course, you will learn about life in the ocean depths, at the Polar extremes, in coral reefs, estuaries, and in the open sea. You will learn about plants large and small, marine birds, reptiles, invertebrates and fish. You will learn how all these organisms connect with each other in the marine biome, and what threats are facing these ecosystems.

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  • 9
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Course Description

Dive into the Depths: Exploring the World of Marine Biology

Spanning over 70% of our planet's surface, the oceans are a vast, mysterious, and captivating realm teeming with life. Marine biology isn't just about understanding saltwater ecosystems, but unraveling the intricate tapestry of life that resides, thrives, and even orchestrates planetary processes within them. From the shimmering surface to the abyssal depths, every droplet of seawater holds a story of evolution, adaptation, and survival.

The genesis of life, according to scientists, took place in these saline expanses. Over epochs, life forms diversified and migrated to terra firma. Yet, some, like dolphins and whales, made a prodigious journey back into the marine embrace. One of the lesser-known marvels of our oceans is the microscopic phytoplankton. Despite their diminutive size, they play a colossal role in maintaining planetary health by producing a significant portion of the oxygen we breathe while also acting as a natural sink for carbon dioxide.

Oceans are the planet's lifeblood, with currents acting as arteries, transporting warmth and nutrients. Their dynamic nature, with evaporation and precipitation, orchestrates the global climate and weather patterns. The oceans' profound impact on global systems underscores the importance of understanding them.

Our meticulously designed course will take you on an enlightening journey:

  • Lesson 1: Oceanography Essentials: Set sail with a foundational understanding of the marine world.
  • Lesson 2: The Bedrock Beneath: Delve deep into marine geology and the oceans' underlying structures.
  • Lesson 3: Riding the Waves: Navigate the fascinating realm of marine currents and tides.
  • Lesson 4: Nomenclature Navigations: Discover the taxonomy of marine species.
  • Lesson 5 & 6: A classification voyage through invertebrates and vertebrates.
  • Lesson 7 & 8: Meet the fascinating marine fish and mammals that reign the oceans.
  • Lessons 9-11: Ecosystem Expeditions - Dive into diverse habitats, from coral kingdoms to serene estuaries.
  • Lessons 12 & 13: Coral Chronicles - Unravel the biology and ecosystems of coral reefs.
  • Lessons 14-16: Journey from the frigid polar oceans to the open seas and the dark, mysterious abyss.
  • Lesson 17: Heeding the Sirens: Address the contemporary challenges facing our oceans and the ways to safeguard their future.

You will encounter a plethora of life forms, from soaring marine birds and elusive reptiles to the myriad of fish that glide and dart through the oceanic expanses. Uncover the relationships, symbioses, and ecological intricacies that bind these creatures together in the vast marine biome. More importantly, become aware of the mounting threats these delicate ecosystems face.

Embark on this immersive odyssey and uncover the stories, secrets, and science of the oceans. Dive deep, for the tales of the seas are as boundless as the waters themselves. Join us, and let the waves of knowledge guide your voyage into the world of marine biology.

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Course Motivation

The Ocean Environment
Over millions of years, water running off the land dissolved salt from rocks and carried it downstream into the ocean. Salt also poured out of volcanic vents deep under the ocean. The sun and heat went to work and evaporated the water into the atmosphere, and the salt stayed behind in the sea. Today, the average salt level, or salinity, in the ocean is 35 parts per thousand, or ppt. Some oceans, like the Black Sea, are less salty and some, like the Dead Sea, are even more salty than average. The higher the salinity of the water, the denser the water is (higher density or specific gravity). In the Dead Sea, the water is so salty and dense that people can float on top of the water effortlessly, like a cork. 

Not all organisms can live in a high salinity environment. People, for example, can't survive in saltwater. Since you have no special adaptations to remove salt, if you drink too much seawater, your kidneys will try to flush the excess salt out as quickly as possible through urine, and you would lose more water than you originally drank, leaving you dehydrated. If you didn't correct the situation by replacing fluids with fresh (non salty) water, your organs would eventually shut down and you would die. 

Living in the ocean requires special adaptations, like a tolerance for salt or a way to remove the excess effectively, the ability to move through the water, find food, hide from predators, and locate a mate.  

On land, we tend to think that ecosystems develop in certain geographical areas, but in the ocean, distance doesn't matter as much as depth. The ocean environment changes as you move deeper into the water. It becomes colder and darker. The pressure is higher and there is less oxygen dissolved in the water. The living conditions are so different at different depths that plants, bacteria and animals can usually only live in certain zones. Scientists call this vertical stratification.

Science and Marine Biology
Scientists generally agree that all life, from algae to whales, all descended from the same original ancestor. This one ancestor reproduced, and its offspring reproduced.  

According to the theory of evolution, as generations passed, the descendants changed, or evolved, until they did not resemble one another at all. Once these distant relatives weren't able to reproduce with one another, they became entirely different species. Scientists study all the different organisms existing today and analyze the traits that they have in common to group them into families. Although scientists argue about how evolution happens and how long the process takes, they do agree that change is constant and that it's going on right now. Species which did not change, or adapt, to changing circumstances eventually died out and became extinct. 

An adaptation is a successful change that provides an organism with an advantage for living in its environment. The theory of evolution argues that organisms that are best adapted to their environment have the best chance of surviving long enough to reproduce. When organisms don't have to work as hard to get food or fight predators, they have more energy for reproduction, which means they can have more offspring. Over time, the descendants of well adapted organisms will increase and multiply while less successfully adapted organisms spend more time just trying to survive, and will eventually die out. This process is called natural selection.
What is Ecology?
Ecology is the study of relationships between living organisms and their environment. Instead of looking specifically at one type of plant or fish, ecologists look at the big picture. For example, if one type of fish usually eats a lot of algae, but the fish suddenly disappears from its ecosystem, the algae might grow out of control. It could cloud the water and keep the plants below from being able to use the sun for energy. Lower plants might die off, and other fish that used the plants for food and shelter would suffer.

Understanding the relationships between species has helped scientists derive useful medicines from natural sources, like a substance in horseshoe crabs that is now used in leukemia treatments. 

  • Completely Online
  • Self-Paced
  • 6 Months to Complete
  • 24/7 Availability
  • Start Anytime
  • PC & Mac Compatible
  • Android & iOS Friendly
  • Accredited CEUs
Universal Class is an IACET Accredited Provider

Course Lessons

Average Lesson Rating:
4.5 / 5 Stars (Average Rating)
"Extraordinarily Helpful"
(4,361 votes)

Lesson 1: Introduction

Marine biology is the science of saltwater and everything that lives, moves, and filters through it. 15 Total Points
  • Lesson 1 Video
  • Lesson discussions: Marine Biology; Reasons for Taking this Course
  • Complete Assignment: An Introduction
  • Assessment: Lesson 1: Introduction

Lesson 2: Geology and the Ocean

The area where old crust is sinking under another slab of crust is called a subduction zone. Subduction zones create such deep trenches that they are all below sea level. 10 Total Points
  • Lesson 2 Video
  • Assessment: Lesson 2: Geology and the Ocean

Lesson 3: Currents and Tides

The term current refers to the motion of water. On land, the motion of water is usually driven by gravity: rain falls from clouds and then runs downhill toward lakes and to the ocean. Additional lesson topics: Waves, Tides and Currents 10 Total Points
  • Lesson 3 Video
  • Assessment: Lesson 3: Currents and Tides

Lesson 4: What's in a Name?

A species is a group of organisms that are able to successfully reproduce with one another. Additional lesson topics: Marine Taxonomy; The Classification of Living Things 10 Total Points
  • Lesson 4 Video
  • Assessment: Lesson 4: What's in a Name?

Lesson 5: Invertebrates

The jellyfish, for example, contracts its umbrella shaped body to propel itself through water. Other invertebrates use water pressure, shell, or cups to support themselves. Additional lesson topics: Marine Invertebrates; The Several Types of Invertebrates 35 Total Points
  • Lesson 5 Video
  • Complete: Lesson 5 Assignment
  • Assessment: Lesson 5: Invertebrates

Lesson 6: Vertebrates

There are seven main classes and superclasses of vertebrates that include fish, reptiles, amphibians, birds and mammals. 10 Total Points
  • Lesson 6 Video
  • Assessment: Lesson 6: Vertebrates

Lesson 7: Marine Fish

The study of fish is called ichthyology, and ichthyologists have grouped all fish into three main categories: jawless, cartilaginous, and bony. 10 Total Points
  • Lesson 7 Video
  • Assessment: Lesson 7: Marine Fishes

Lesson 8: Marine Mammals

Mammals, whether they live on the land or in the sea, are all vertebrates (meaning they have a backbone and a brain). Additional lesson topics: List of Marine Mammals 35 Total Points
  • Lesson 8 Video
  • Complete: Lesson 8 Assignment
  • Assessment: Lesson 8: Marine Mammals

Lesson 9: Marine Ecosystems

A biome is a large geographical area that contains several different ecosystems. All the plants, animals and other organisms that live in a biome are adapted to that environment. 10 Total Points
  • Lesson 9 Video
  • Assessment: Lesson 9: Marine Ecosystems

Lesson 10: Life at the Shore

The intertidal zone (also called the foreshore, seashore and the littoral zone) is the area that is exposed to air at low tide and underwater at high tide. Additional lesson topics: Tide Pools 9 Total Points
  • Lesson 10 Video
  • Lesson discussions: Tide Pools
  • Assessment: Lesson 10: Life at the Shore

Lesson 11: Estuaries

An estuary is one type of intertidal zone, where a river meets the sea: freshwater meets saltwater in a bay, lagoon, sound, or slough. 10 Total Points
  • Lesson 11 Video
  • Assessment: Lesson 11: Estuaries

Lesson 12: Coral Reef Biology

Coral reefs are usually found in the tropics, and although corals make up a big part of the reef, they are just one component of an enormous community. Additional lesson topics: Coral Reef Biology 10 Total Points
  • Lesson 12 Video
  • Assessment: Lesson 12: Coral Reef Biology

Lesson 13: Coral Reef Ecosystems

Many marine scientists think that most reefs start out as fringe reefs, and over time, the coral grows out and away from land. As it gets farther from land, the reef's diameter expands and a large lagoon forms. Additional lesson topics: Reef Ecosystems 10 Total Points
  • Lesson 13 Video
  • Assessment: Lesson 13: Coral Reef Ecosystems

Lesson 14: Life in the Polar Oceans

Although the two poles have a lot of similarities, like very cold weather and extreme living conditions, life in the two regions was shaped by a different series of circumstances. 35 Total Points
  • Lesson 14 Video
  • Complete: Lesson 14 Assignment
  • Assessment: Lesson 14: Life in the Polar Oceans

Lesson 15: The Open Sea

The open ocean is the largest biome in the world by volume, but in terms of the quantity of life, the Pelagic resembles the most enormous desert ever known. 10 Total Points
  • Lesson 15 Video
  • Assessment: Lesson 15: The Open Sea

Lesson 16: Life in the Ocean's Depth

The Benthic Zonerefers to the sea floor, which extends from the tidal areas all the way down to the deepest trenches on the planet. 10 Total Points
  • Lesson 16 Video
  • Lesson discussions: Marine Organisms
  • Assessment: Lesson 16: Life in the Ocean's Depth

Lesson 17: Oceans in Jeopardy

Some of the major threats facing the oceans include climate change, pollution, nutrient runoff, garbage dumping, overfishing, and ship strikes. Additional lesson topics: 7 Biggest Problems Facing Oceans; The Ocean's Problems 85 Total Points
  • Lesson 17 Video
  • Lesson discussions: Ocean Challenges; Program Evaluation Follow-up Survey (End of Course); Course Comments
  • Assessment: Lesson 17: Oceans in Jeopardy
  • Assessment: The Final Exam
Total Course Points

Learning Outcomes

By successfully completing this course, students will be able to:
  • Define what marine biology is and why it is important to study.
  • Describe geology and the ocean, currents and tides.
  • Understanding the nomenclature of marine biology
  • Identify invertebrates of the marine environment.
  • Identify vertebrates of the marine environment.
  • Identify marine fish.
  • Identify marine mammals.
  • Describe marine ecosystems.
  • Summarize what estuaries are and why they are important.
  • Summarize coral reef biology and ecosystems.
  • Describe life in the polar oceans and the open sea.
  • Describe life in the ocean's depth and its future with the human race.
  • Demonstrate mastery of lesson content at levels of 70% or higher.

Additional Course Information

Online CEU Certificate
  • Document Your Lifelong Learning Achievements
  • Earn an Official Certificate Documenting Course Hours and CEUs
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Document Your CEUs on Your Resume
Course Title: Marine Biology 101
Course Number: 8900066
Lessons Rating: 4.5 / 5 Stars (4,361 votes)
Languages: English - United States, Canada and other English speaking countries
Availability: This course is online and available in all 50 states including: California, Florida, Georgia, Illinois, New York, Pennsylvania, Ohio, Texas, and Washington.
Last Updated: September 2023
Course Type: Self-Paced, Online Class
CEU Value: 0.9 IACET CEUs (Continuing Education Units)
CE Accreditation: Universal Class, Inc. has been accredited as an Authorized Provider by the International Association for Continuing Education and Training (IACET).
Grading Policy: Earn a final grade of 70% or higher to receive an online/downloadable CEU Certification documenting CEUs earned.
Assessment Method: Lesson assignments and review exams
Instructor: UniversalClass Instructional Team
Syllabus: View Syllabus
Course Fee: $120.00 U.S. dollars

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Student Testimonials

  • "I thoroughly enjoyed the course and I have learned a lot. I will most definitely recommend the course to all of my friends that want to improve their knowledge on marine biology or just want to learn more about our oceans." -- Carmen T.
  • "The Instructor was very responsive and prompt with feedback. The study material was detailed and well-organized. As a senior citizen (age 76) I really welcomed a challenge. I have studied Ecology, Chemistry, and Geology with this instructor." -- Judith J.
  • "The instructor was prompt and the course was challenging and interesting." -- Abby H.
  • "Love the course material and the instructor was also helpful and fast to grade." -- Francinne A.
  • "I thoroughly enjoyed all the information that was presented in the course." -- Kathy W.
  • "Outstanding course. I really enjoyed taking it." -- Matthew G.
  • "Really enjoyed the course and learnt a lot." -- Ann R.
  • "VERY good instructor and course." -- Ruth M.
  • "Great instructor!" -- Melanie H.
  • "This was a very interesting course. I enjoyed learning about marine biology. I would sit at dinner with my husband and children and tell them an interesting fact I had learned that day." -- Victoria L.