The field of marine biology -- the study of marine organisms, their behaviors, and their interactions with the environment -- is considered one of the most all-encompassing fields of oceanography. To understand marine organisms and their behaviors completely, marine biologists must have a basic understanding of other aspects or "disciplines" of oceanography, such as chemical oceanography, physical oceanography, and geological oceanography. Therefore, marine biologists and biological oceanographers study these other fields throughout their careers, enabling them to take a "big picture" approach to doing research.

Because there are so many topics one could study within the field of marine biology, many researchers select a particular interest and specialize in it. Specializations can be based on a particular species, organism, behavior, technique, or ecosystem. For example, marine biologists may choose to study a single species of clams, or all clams that are native to a climate or region.

One area of specialization, the emerging field of marine biotechnology, offers great opportunity for marine biologists. Marine biotechnology research presents a wide range of possibilities and applications. One focus area is the biomedical field, where scientists develop and test drugs, many of which come from marine organisms. An example of an application of biotechnology research can be seen in industry or defense, where researchers have developed non-toxic coatings that prevent the build-up of fouling organisms, such as barnacles and zebra mussels. Such coatings are useful for ships and intake pipes used in power plants.

Molecular biology is a related area of specialization in this field. Researchers apply molecular approaches and techniques to many environments, from coastal ponds to the deep sea, and many different organisms, from microscopic bacteria, plants, and animals to marine mammals. For example, molecular biology can be used to identify the presence of a specific organism in a water sample through the use of molecular probes. This is very useful when the organism in question is microscopic or similar to other organisms. The study of disease in organisms has also been aided by the use of molecular techniques. Researchers have developed antibodies that are specific to a particular virus, so that when the virus is present in the organism, detection and diagnosis is easier and faster. Likewise, new molecular techniques help scientists identify whether or not an animal has been exposed to pollutants and, in some cases, can determine the source of those pollutants. The field of molecular biology is growing and will continue to see significant advances.

Steven Engstrom
Marine Biologist
Jamie M. Cournane
Fisheries Ecologist
Alejandro "Alex" E. Almario
Biological Science Laboratory and Field Operations Technician
Steven Engstrom
Marine Biologist

Aquaculture, the farming of finfish, shellfish, and seaweeds, is another field that has been aided by marine biotechnology and molecular techniques. Aquaculture is gaining importance in this country as consumer demand for fish and shellfish becomes greater than can be met by traditional commercial fishing. At the same time, technological advances have made aquaculture more economically feasible. In one example, researchers developed a "triploid" oyster, whose meat remains firm and sweet throughout the entire spawning season (May to August). By extending the harvesting and marketing season of the oyster, its economic value increased.

Marine researchers are also experimenting with ways to administer drugs to diseased populations of farm-raised fish. Disease can wipe out an entire crop of farm-raised fish or shellfish due to the confined setting in which they are raised. One technique involves exposing a pen of fish to ultrasound (high frequency sound that cannot be heard by humans). This causes the outer layers of the fish tissues (skin and gills) to become more permeable, making the fish more receptive to a vaccine or antibiotic drug that is released into the water.

Other popular areas within the field of marine biology are environmental biology and toxicology. Both of these areas have direct applications and implications for our society. Examples of specialities in environmental biology and toxicology include water quality research and the study of contaminants or pollutants in the coastal or marine environment. Laws, regulations, and cleanup measures designed to protect the environment will ensure that marine and environmental biologists and consultants continue to play an important role in our society.

Another field of research within marine or aquatic biology involves organisms that have been around for billions of years: protists. Protists are singled-celled organisms that include protozoa and microalgae. They range in size from about two micrometers (.00008 inches) to just under an inch. Their importance as a group lies in the fact that microscopic algae serve as food for animals in aquatic food webs, earning them the title "primary producers." And since primary producers are mostly microscopic species, the organisms that consume them are often single-celled, microscopic species as well. If something happens to somehow alter populations of primary producers, the entire food web could be affected.

Probably the topic most often asked about within marine biology is research involving marine mammals, including cetaceans (whales and dolphins) and pinnipeds (sea lions, seals, and walruses). The reality is that research jobs involving marine mammals are extremely hard to come by for a number of reasons, including the popularity of the field, the fact that working with marine mammals is highly regulated (most research is done using tissue samples of sick, stranded, or dead animals and not on live, healthy animals), and because funding is very competitive.

Two popular fields of research involving marine mammals are bioacoustics and vocalization (the study of marine mammal sounds), and population dynamics (studying marine mammalian behaviors and responses to environmental conditions as they impact population). As for non-research employment options involving marine mammals, most positions would exist at aquaria, museums, and national and international conservation groups, though these are also highly competitive.

© 2009 WHOI Sea Grant Program and NH Sea Grant Program