Marine Biologist

Marine biology is the study of marine or saltwater organisms. Marine biologists study everything from single-celled bacteria to the blue whale and giant kelp. They are interested in a number of marine features, including the process of marine development, how organisms interact with one another and the ecosystem, and how organisms adapt to their environment. Marine biologists focus on increasing knowledge of the fluid environment and how marine organisms function today in order to predict how ecosystems will cope with large-scale changes such as global warming, overfishing, and pollution.

Woman working on a laptop by the ocean

At a glance

Imagine you are sitting at your lab bench staring through magnifying lenses at a small invertebrate lying in a specimen dish. You are a marine biologist and you found this little guy earlier in the day while diving in a shallow bay off the coast of Vancouver Island. What’s remarkable about this species of mollusc is that its regular habitat is hundreds of kilometres south of this bay, where ocean temperatures are significantly warmer. You have been studying this species of mollusc for 10 months now, making dozens of dives and spending countless hours in the lab gathering data to support your hypothesis that warmer ocean temperatures due to climate change are altering the distribution of this mollusc species. As a marine biologist, you are an expert on the aquatic organisms and fluid environment of this particular bay. You were surprised three years ago when you first spotted this mollusc species so far north and applied for a grant to study how and why it has made its way to Vancouver Island. You’ve hypothesized that climate change has resulted in warmer ocean temperatures in this region, which have made it possible for the mollusc to expand its habitat. A lot of your research has focused on gathering data and mapping trends to determine if local ocean temperatures have changed significantly in recent years, to the point where the coasts of Vancouver Island have become usable habitat for species typically found farther south. On your dives, you collect data on the distribution and abundance of the mollusc inside the bay, as well as gather specimens to take back to the lab. In addition to analyzing water temperature, you study the morphology of your specimens, looking for physiological adaptations that would allow them to survive in colder waters. When published, your research will contribute to the bank of scientific knowledge that records and predicts the effects of climate change on global ecosystems.

Job duties

Duties vary significantly from job to job, but the following list includes typical job duties one might encounter as a marine biologist:
  • Study the behaviour, evolution, distribution, and relationships among organisms in a marine environment.
  • Use electronics and other instruments to measure the physical and chemical properties of water.
  • Examine the biodiversity of benthic and pelagic organisms.
  • Study the structure of marine communities and assist in the rehabilitation of damaged ecosystems.
  • Take samples of marine organisms and conduct laboratory tests using equipment such as electron microscopes.
  • Build mathematical models to estimate the distribution and abundance of marine life in specific places.
  • Develop and implement long-term programs for monitoring environmental pollution, including developing protocols and monitoring environmental compliance.
  • Provide assistance to fisheries management.
  • Write grant proposals to fund research.
  • Write scientific papers to report research findings and present results at conferences.
  • Interact with students and the general public to educate and discuss concerns about marine issues, such as climate change and fishing.

Work environment

Marine biologists work in a variety of locations, including: In the office:
  • Doing paperwork and analyzing data for reporting
  • Drafting plans and models
  • Communicating on the phone and in meetings with clients, colleagues, government departments, and the public, and presenting report findings to clients
  • Writing scientific papers and presenting study results
  • Conducting literature reviews and researching advancements in marine biology, and consulting with other biology professionals
In the field:
  • Deploying equipment from onboard oceanographic research vessels
  • Servicing and testing equipment
  • Conducting field experiments and recording data and observations
  • Collecting organisms for laboratory research
  • Building experimental equipment such as cages and flowmetres
In the lab:
  • Identifying, classifying, and preserving marine organisms
  • Conducting analytical research and laboratory experiments
  • Processing samples

Where to work

There are a number of places marine biologists can find employment. They include:
  • Federal, provincial/territorial, and municipal government departments
  • Colleges, universities, and research institutes
  • Environmental consulting firms
  • Marine science institutions and aquariums
  • Conservation authorities
  • Aquaculture firms, including fish and shellfish farms
  • Private labs
See current job opportunities for Marine Biologists on the ECO Job Board.

Education & requirements

If you are a high school student considering a career as a marine biologist, you should have strong marks or an interest in:
  • Biology
  • Chemistry
  • Physics
  • Mathematics
  • Computer Science
  • English
In most cases, the minimum education requirement to work as a marine biologist is a university undergraduate degree. A graduate degree is required for independent research. If you are a post-secondary student considering a career as a marine biologist, the following programs are most applicable:
  • Marine Biology
  • Ecology
  • Aquatic Biology
  • Oceanography
  • Geology
  • Botany
  • Zoology
  • Environmental Science
Certification is not mandatory in order to work as a marine biologist.


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A marine biologist in an entry level position will make an average of $44,000 per year in Canada. Marine biologists with several years of experience and education will make between $64,000 and $78,000 per year.

Role Model

Shelley Denny

The environment I grew up in really shaped my interest in marine biology. I was raised by my grandmother and lived with her until I went to university. We lived just five minutes from Bras d’Or Lake, ten minutes from the ocean, and a brook ran through our backyard. Not only did all those different types of water surround me, but my grandmother also encouraged my intense curiosity about aquatic life and about nature in general. In other words, I have been interested in marine biology for most of my life—beginning at an age when I didn’t even know that my interest had a name. While high school courses didn’t add much to this interest (I thought my classes were a bit "ho-hum”), I found university to be really fascinating. I went to Acadia University where my major was Biology with a concentration in Marine Biology, and my minors were Chemistry and Psychology. I loved university for the scientific research and enjoyed the mental challenges that it brought. Eventually, my university career presented other challenges as well; in my third year, I had a child. As a single parent, I struggled, but still found ways to put my daughter first and do well in school. I graduated with a Bachelor of Science and am now enrolled at St. Francis Xavier University where I’m working towards my Master’s in Science, with a concentration in fisheries ecology. I plan to complete my Ph.D. after that. My first job was with the Department of Fisheries and Oceans in 1991. In 1992, I landed—without training—in a management position at the Eskasoni Fish & Wildlife Commission. Luckily, I learn quickly, and through experience I’ve come to understand a great deal about the business world. In addition to management, this job has me continuing with various studies on many of the species in the Bras d’Or Lake region. In addition to my work with Eskasoni, I’m also a member of a technical committee that advises the Chiefs of Cape Breton through the Unama’ki Institute of Natural Resources. I am a firm believer that we are responsible for our resources. Whether our people fish for ceremonial or commercial reasons, we need to be responsible for sustaining fish stocks. Education provides us with the opportunity to understand and satisfy that responsibility. It also unlocks doors to the many opportunities for Aboriginal youth in the field of marine biology.