MARINE BIOLOGY

MARINE BIOLOGY. Study of life along the seashore, which became known as marine biology by the twentieth century, was first developed and institutionalized in the United States at the end of the nineteenth century. Two distinct traditions contributed to its modern disciplinary form.

First to emerge was marine biology as a summertime educational activity, chiefly designed to instruct teachers of natural history about how to study nature within a natural setting. The notion was first suggested to Louis Agassiz, the Harvard zoologist and geologist, by his student Nathaniel Southgate Shaler. Shaler had conducted highly successful summer field experiences for geology students, and felt that similar experiences could be valuable for biology students. Encouraged by his wife, Elizabeth—a longtime advocate for educational opportunities for the largely female teaching community—Agassiz obtained funding and opened the Anderson School of Natural History in 1873 on Penikese Island, located not too distant from Cape Cod. Following this school, several others offered similar experiences. The Summer School of the Peabody Academy of Sciences (Salem, Massachusetts) sponsored instruction for teachers in marine botany and zoology in 1876, and the Boston Society of natural History, with the support of the Women's Education Association (WEA) of Boston, started its summer station north of Boston at Alpheus Hyatt's vacation home in Annisquam.

The second tradition was European, where several marine stations operated by 1880, most notably the Stazione Zoologica in Naples. This marine biology laboratory was founded by Anton Dohrn in 1872. The "Mecca for marine biology," as Naples was soon known, attracted scholars from throughout the world. Agassiz's son, Alexander Agassiz, imported Dohrn's notion to his summer home near Newport, Rhode Island, offering the latest microscopical tools for researchers. William Keith Brooks, a student of the elder Agassiz, accepted the invitation and completed his doctoral research with the younger Agassiz in 1875. Then, when Brooks obtained a position at America's first graduate university, Johns Hopkins University, one of his first tasks was to create a research laboratory in marine biology. Thus, the Chesapeake Zoological Laboratory was opened in 1878

The first U.S. marine biology laboratory to incorporate both traditions was the Marine Biological Laboratory (MBL), which opened in Woods Hole, Massachusetts, in 1888. It originally offered courses in marine botany and marine zoology for beginning students and teachers. But its original director, C. O. Whitman, had spent time at Naples and, like his colleague Brooks, wanted to create research opportunities in marine biology for more advanced students and researchers. To accomplish the task, Whitman initiated advanced courses in embryology, invertebrate zoology, cytology, and microscopy, all of which began to attract more sophisticated students. By the early twentieth century, the MBL welcomed only advanced students and investigators.

Similar marine biology laboratories were founded on the Pacific Coast. Stanford University established the Hopkins Marine Station in Pacific Grove, California, in 1892. To the north, the University of Washingt on opened a marine station near Friday Harbor (San Juan Islands, Washington) in 1904. Henry Chandler Cowles, an ecologist from the University of Chicago who had done pioneering studies on the sand dunes of Lake Michigan started a course in intertidal ecology, the first such course in the United States.

One additional West Coast laboratory played a critical role in defining the new field of marine biology, albeit by exclusion. William Emerson Ritter, an embryologist from Berkeley, created a laboratory near San Diego, initially named the San Diego Marine Biological Laboratory, in 1903. But Ritter was interested in a more global approach to investigations by the seashore, an approach he never successfully defined. He was successful, however, in attracting the financial resources of the Scripps family, and soon the Scripps Institution for Biological Research was built north of the village of La Jolla. Ritter specifically stated that he had no intention of forming another MBL on the West Coast, preferring to emphasize a comprehensive study of the sea. After he retired, without creating an educational base for the institution similar to the other stations, he was replaced by Thomas Wayland Vaughan in 1924. The La Jolla station was renamed the Scripps Institution of Oceanography, and marine biology disappeared as a focus.

The three major American marine biology stations throughout the twentieth century and into the twenty-first century are the MBL, Hopkins Marine Station, and Friday Harbor Laboratories. By the end of world War I (1914–1918), the stations defined marine biology as the study of life in the littoral zone (also known as the inter-tidal zone), or the area that serves as an interface between the marine and terrestrial environments. Courses at the laboratories helped to divide marine biology into several specialty areas, including invertebrate zoology, ecology, algology, embryology, and invertebrate physiology. Following World War II (1939–1945), this focus shifted somewhat as more research funding was available in the biological sciences, especially in terms of research questions with an application to medicine and to the exciting field of molecular biology. Woods Hole's MBL, for example, has all but abandoned the traditional areas of marine biology for specialized medical and genetic research. Most investigations at the MBL by the end of the twentieth century were laboratory-based studies of cellular and molecular processes, with little fieldwork or studies of marine life. At the same time, largely because the West Coast has a more robust intertidal fauna and flora that is largely unaffected by human intervention, Hopkins and Friday Harbor retain a traditional focus on marine biology.

For the most part, marine biology does not include investigations of the open seas, studies of freshwater marine systems, or inquiries into the country's fisheries. Biological oceanography, a subdiscipline of Oceanography, examines biological questions in the oceans, including studies of marine mammals, marine fisheries, and freshwater sources for the ocean (limnology).

BIBLIOGRAPHY

Benson, Keith R. "Laboratories on the New England Shore: The 'Somewhat Different Direction' of American Marine Biology." New England Quarterly 56 (1988): 53–78.

———. "Summer Camp, Seaside Station, and Marine Laboratory: Marine Biology and Its Institutional Identity." Historical Studies in the Physical and Biological Sciences 32, no. 1 (2001).

Maienschein, Jane. 100 Years Exploring Life, 1888–1988: The Marine Biological Laboratory at Woods Hole. Boston: Jones and Bartlett Publishers, 1989.

Keith R.Benson

See alsoScience Education ; Zoology .

Marine Biology

Sources

Origins of Modern Marine Biology. During the last quarter of the nineteenth century, several leading American biologists became interested in establishing a marine station capable of promoting and sustaining advanced research and instruction in marine biology along the lines of successful and influential European biological stations, such as Anton Dorrn’s marine-biology station in Naples (in which four American universities officially participated) or Henri Lacaze-Duthier’s laboratory at

Banyuls-sur-Mer, France. Louis Agassiz, a Swiss-born zoologist, (1807-1873) mounted the first such endeavor at Penikese Island, Massachusetts, in 1873, and during the same period his students Alpheus Hyatt (1838-1902) and Alpheus Packard (1839-1905) established summer programs at the Massachusetts seaports of Annisquam and Salem, respectively. These programs were all short-lived.

The Woods Hole Laboratory. The most influential early research station was the U.S. Fish Commission laboratory, at Woods Hole, Massachusetts, directed by Spencer Fullerton Baird between 1871 and 1887. Created to survey and study the offshore fish populations and to manage a hatchery, this laboratory contributed to scientific knowledge mainly in the classification of fish species and marine ecology.

The Marine Biology Laboratory. Hoping to expand the scope of his laboratory in concert with a coalition of research-oriented universities, Baird drew up a plan that was the basis for the establishment of the Marine Biological Laboratory (MBL) at Woods Hole in 1888, the year after Baird’s death. Under its first director, Charles O. Whitman (1842-1910), who ran the laboratory until 1908, the MBL established a summer program with instruction in invertebrate zoology in 1888, adding marine botany in 1890, general physiology in 1892, and embryology in 1893. The courses were designed to address problems of marine biology but also employ the specific advantages offered by marine biology in order to push ahead the research perspectives of biology generally. The general-physiology course taught at Woods Hole was the first of its kind in the world. Everywhere else physiology was limited to the study of mammals. At Woods Hole in 1899-1900 German-born physiologist Jacques Loeb (1859-1924), conducted his famous experiments on artificial parthenogenesis of sea-urchin eggs, causing unfertilized eggs to develop into new organisms. Embryology courses at Woods Hole took advantage of the specific characteristics of marine eggs, many of which (including those of the sea urchin) have no outer shell and are transparent.

A Pioneering Institution. By giving the study of marine biology the broadest possible focus, the MBL became a leader in experimental biology. Until universities developed their own research facilities, institutions such as the MBL functioned as centers for scientific research and discovery. Following Dorrn’s model, the MBL allocated benches in its laboratory to participating universities, which sent their most promising students to Woods Hole. In addition to Loeb, the earliest researchers at the MBL included geneticists T. H. Morgan (1866-1945), who won a Nobel Prize in Physiology and Medicine in 1933, and E. B. Wilson (1856-1939)—who, like Morgan, had earlier worked in the U.S. Fish Commission laboratory—as well as embryologist Frank R. Lillie (1870-1947) and geneticist Nettie Stevens (1861-1912).

“THE END OF SCIENCE”

By the time he delivered the Lowell Lectures on Light Waves and Their Uses at Harvard University in 1899, Albert A. Michelson had come to believe that the age of great scientific discoveries had come to an end and that the physicist’s future role would be in the realm of refining previously established laws through precise measurement:

What would be the use of such extreme refinement in the science of measurement? Very briefly and in general terms the answer would be that in this direction the greater part of all future discovery must lie. The more fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote.

Six years after Michelson spoke these words Albert Einstein published his special theory of relativity, overturning all of Michelson’s assumptions about the nature of the universe.

Source: Albert A. Michelson, Light Waves and Their Uses (Chicago: University of Chicago Press, 1903).

Sources

Dean C. Allard, “The Fish Commission Laboratory and Its Influence on the Founding of the Marine Biological Laboratory,” Journal of the History of Biology, 23 (1990): 251-270;

Frank R. Lillie, The Woods Hole Marine Biological Laboratory (Chicago: University of Chicago Press, 1944).

marine biology is the study of all aspects of ecology and life histories of marine organisms. The primary focus is on the organisms and their local interactions with their physical, chemical, and biological environments. Many marine biologists study the natural history of organisms that live in coastal and inshore environments, and so are more readily accessible and can be used in experimental studies. So the scope of marine biology as a scientific discipline overlaps that of biological oceanography. Biological oceanographers tend to be more concerned about large-scale distribution patterns, how substances like carbon flow through the ocean system and how the living communities are responding to the motion of the ocean and different spatial scales. They often use ‘proxies’, for example using the volume of sound back-scattered echo-sounding to track and quantify fish and plankton, and estimating the quantities of the marine plant called phytoplankton in a water sample by measuring the amount of chlorophyll it contains. Marine biologists are much more concerned with the organisms themselves and their responses to other species, and their chemical and physical environment.

Thus, on a rocky beach the seaweeds and their grazers tend to be vertically zoned as a result of their differing abilities to withstand exposure to the air at low tide. The species also vary in their abilities to withstand being battered by waves, so different types of animal and plants are found on beaches that are either sheltered from, or exposed to, heavy surf. Predation and grazing pressures alter the structure of habitats. For example kelp, the straplike seaweeds that grow profusely in places at, and below, the low tide mark on rocky shores, form complex three-dimensional forests. These forests are full of local microhabitats each of which tends to be inhabited by different types of animals ranging from sea anemones to worms and Crustacea. However, echinoderms like sea urchins (Echinus spp.) can graze down these forests and reduce their diversity. Off California the populations of sea urchins are kept in check by one of the most charismatic of marine mammals, the sea otter. When the sea otter populations crashed, because they were over-exploited for their fur, the sea urchins became so abundant they ate down the kelp forests along many shores.

Starfish (asteroids), another group of echinoderms, are active predators that consume many of the snails that graze down the seaweeds on the shore. They often feed selectively on the most abundant species and as a result the less common species are more successful, and the numbers of species able to live on the shore increases. In experimental areas on a rocky shore from which marine biologists removed all starfish, the populations of grazing snails became far less diverse.

Behaviour can be important to those studying marine biology. For example, the crustacean sandhoppers (Talitrus spp.) that are often found feeding in large numbers on the dead seaweed that piles up along the strandline on sandy beaches lay their eggs in the sand. The young hatchlings have to find their way down to the sea, but how do they know which way to hop? The answer seems to be that they navigate according to the patterns of polarized light in the sky, and the correct way down the beach is passed to the egg as chemical information by the female as she is laying. If a polarizing filter is placed over the eggs to that the sky pattern is reversed, the newly hatched youngsters hop inland.

Bibliography

Tait, R., and and Dipper, F. , Elements of Marine Ecology (1998).

M. V. Angel

Marine microbiology

Marine microbiology refers to the study of the microorganisms that inhabit saltwater. Until the past two to three decades, the oceans were regarded as being almost devoid of microorganisms. Now, the importance of microorganisms such as bacteria to the ocean ecosystem and to life on Earth is increasingly being recognized.

Microorganisms such as bacteria that live in the ocean inhabit a harsh environment. Ocean temperatures are generally very cold—approximately 37.4° F (about 3° C) on average—and this temperature tends to remain the cold except in shallow areas. About 75% of the oceans of the world are below 3300 feet (1000 meters) in depth. The pressure on objects like bacteria at increasing depths is enormous.

Some marine bacteria have adapted to the pressure of the ocean depths and require the presence of the extreme pressure in order to function. Such bacteria are barophilic if their requirement for pressure is absolute or barotrophic if they can tolerate both extreme and near-atmospheric pressures. Similarly, many marine bacteria have adapted to the cold growth temperatures. Those which tolerate the temperatures are described as psychrotrophic, while those bacteria that require the cold temperatures are psychrophilic ("cold loving").

Marine waters are elevated in certain ions such as sodium. Not surprisingly, marine microbes like bacteria have an absolute requirement for sodium, as well as for potassium and magnesium ions. The bacteria have also adapted to grow on very low concentrations of nutrients. In the ocean, most of the organic material is located within 300 meters of the surface. Very small amounts of usable nutrients reach the deep ocean. The bacteria that inhabit these depths are in fact inhibited by high concentrations of organic material.

The bacterial communication system known as quorum sensing was first discovered in the marine bacterium Vibrio fischeri. An inhibitor of the quorum sensing mechanism has also been uncovered in a type of marine algae.

Marine microbiology has become the subject of much commercial interest. Compounds with commercial potential as nutritional additives and antimicrobials are being discovered from marine bacteria, actinomycetes and fungi . For example the burgeoning marine nutraceuticals market represents millions of dollars annually, and the industry is still in its infancy. As relatively little is still known of the marine microbial world, as compared to terrestrial microbiology, many more commercial and medically relevant compounds undoubtedly remain to be discovered.

See also Bacterial kingdoms; Bacterial movement; Biodegradable substances; Biogeochemical cycles

Marine Biologist

Marine biology is a field of study encompassing all oceanic life, including representatives from each of the taxonomic kingdoms (plants, animals, blue-green algae, fungus, and single-celled microorganisms called protists). Taxonomy is a system used to name organisms based on their evolutionary relationships. Specializations within this field include ecology , environmentalism, parasitology , reproduction, ocean farming, and anatomy. Many ocean-dwelling organisms have yet to be discovered and assigned a taxonomic nomenclature (scientific name). Other specializations are based on ocean regions, such as coastal, coral reef, deep-sea trench, arctic, and open ocean marine biology. This field is strongly rooted in international research and cooperation because ocean wildlife does not necessarily belong to any one government or country. It necessitates a love of the outdoors, and of the ocean in particular, a willingness to work independently at distant locations, good analytical skills, excellent writing skills, and environmental awareness. Strong swimming skills and certification in scuba (a word derived from the acronym for self-contained underwater breathing apparatus) are also mandatory. Marine biologists may seek employment as a teacher, researcher, resource manager for a governmental agency, field biologist in a consulting company, advocate in an environmental organization, or technician in an aquarium or zoo.

For those who have a strong interest in fishes, marine mammals, marine ecology, or any other related field, it is best to obtain a strong background in basic biology and oceanography. Look for colleges with large marine biology departments, preferably located along the coast of an ocean environment that interests you. Search the Internet for information on the field and make contacts with specialists at other institutions. It is extremely important that you join a research lab or intern at an aquarium or on a research boat during your undergraduate college education. Training marine mammals, for instance at a theme park or for biopsychology or communications research, requires knowledge of psychology and possibly of veterinary science. For a career in academics or college professorship, a doctoral degree from a high-level research institute is necessary. If you wish to work at a zoo or teach high school, a master's degree will suffice.

Rebecca M. Steinberg

Bibliography

Moyle, Peter B., and Joseph J. Cech. Fishes: An Introduction to Ichthyology. Upper Saddle River, NJ: Prentice Hall, 2000.

Nybakken, James Willard. Marine Biology: An Ecological Approach. San Francisco: Benjamin Cummings, 2001.

marine biology study of ocean plants and animals and their ecological relationships. Marine organisms may be classified (according to their mode of life) as nektonic, planktonic, or benthic. Nektonic animals are those that swim and migrate freely, e.g., adult fishes , whales , and squid . Planktonic organisms, usually very small or microscopic, have little or no power of locomotion and merely drift or float in the water. Benthic organisms live on the sea bottom and include sessile forms (e.g., sponges , oysters , and corals ), creeping organisms (e.g., crabs and snails ), and burrowing animals (e.g., many clams and worms ). Seafloor areas called hydrothermal vents , with giant tube worms and many other unusual life forms, have been intensively studied by marine biologists in recent years.

The distribution of marine organisms depends on the chemical and physical properties of seawater (temperature, salinity, and dissolved nutrients), on ocean currents (which carry oxygen to subsurface waters and disperse nutrients, wastes, spores, eggs, larvae, and plankton), and on penetration of light. Photosynthetic organisms (plants, algae, and cyanobacteria), the primary sources of food, exist only in the photic, or euphotic, zone (to a depth of about 300 ft/90 m), where light is sufficient for photosynthesis . Since only about 2% of the ocean floor lies in the photic zone, photosynthetic organisms in the benthos are far less abundant than photosynthetic plankton (phytoplankton), which is distributed near the surface oceanwide. Very abundant phytoplankton include the diatoms and dinoflagellates (see Dinoflagellata ). Heterotrophic plankton (zooplankton) include such protozoans as the foraminiferans ; they are found at all depths but are more numerous near the surface. Bacteria are abundant in upper waters and in bottom deposits.

The scientific study of marine biology dates from the early 19th cent. and now includes laboratory study of organisms for their usefulness to humans and the effects of human activity on marine environments. Important marine biological laboratories include those at Naples, Italy; at Plymouth and Millport in England; and at Woods Hole, Mass., La Jolla, Calif., and Coral Gables, Fla. Research has been furthered by unmanned and manned craft, such as the submersibleAlvin.

See also oceanography .

Bibliography: See R. Carson, The Sea Around Us (rev. ed. 1961); R. Ballard, Exploring Our Living Planet (1983); M. Banks, Ocean Wildlife (1989); W. J. Broad, The Universe Below (1997).

Marine Biologist

A marine biologist is someone who studies plants, animals, and other organisms of the oceans, ranging from large marine mammals to microscopic plankton . Marine biologists study such subjects as animal behavior and ecology, biomedical uses of the sea, the commercial importance of the ocean's natural resources, and methods for preservation of species and habitats.

The need for marine biologists has increased because of growing interest in conservation of the oceans, and many are employed by private and government environmental protection and resource management agencies. For example, marine biologists are needed to determine catch quotas for species of fish in order to prevent a decline in population. In addition to performing basic research, they present information to governments and industries to aid in resource conservation decisions. As land development increases, marine biologists are needed to determine its effects on surrounding habitats and whether an ecosystem can withstand human invasion. Marine biologists also find work worldwide teaching in colleges, universities, and even some high schools. Many work on oceanographic research vessels and in laboratories from polar to tropical settings.

To be well prepared for a career in marine biology, a strong background in mathematics is crucial. One should also take a wide range of science courses in high school and college, such as biology, chemistry, physics, zoology, geology, marine science, oceanography, and atmospheric science. A working knowledge of computers is increasingly necessary for data collection and analysis. Satellite imaging and global information systems (GIS) are common uses of computers in the field.

Summer courses and internships are available worldwide to provide hands-on experience with marine life, the use of field and laboratory equipment, and other aspects of marine research. Employment opportunities are available from the bachelor to the doctorate level, with greater independence, decision-making responsibility, and income at the higher levels.

see also Bony Fish; Cartilaginous Fish; Coral Reef; Crustacean; Estuaries; Ocean Ecosystems; Plankton

Lisa Nicole Saladin and Kenneth S. Saladin

Bibliography

American Fisheries Society Jobs Center Online. <http://www.fisheries.org/jobs.html>.

Castro, Peter, and Michael E. Huber. Marine Biology, 3rd ed. Boston: McGraw-Hill, 2000.

Scripps Institution of Oceanography. <http://www.sio.ucsd.edu/>.

Woods Hole Oceanographic Institution. <http://www.whoi.edu/>.