STUDYING OCEAN LIFE
For a long time studying sea life meant throwing nes and traps overboard from a ship and examining them after they had been hauled on the deck and examining dead creatures to make inferences about the living.
Censuses are taken in coastal waters and reefs by scuba divers who measures out a an area on the ocean floor and count the numbers and estimate the size of different species they observe and record the numbers with a pencil on waterproof paper. In the past scientists have traditionally relied catch numbers from fishermen to determines the health and population size of marine species. The Census of Marine Life is an ambitious $650 million, 10-year study to determine numbers and diversity of marine life. See Marine Life
Cheryl Lyn Dybas wrote in Natural History magazine: “Along the United States West Coast, oceanographers are finding new ways of looking beneath research vessels that ply the Pacific. They’re getting a fish’s eye view of the deep by placing electronic tags on predators such as blue whales and California sea lions, yellowfin tuna and white sharks. [Source: Cheryl Lyn Dybas, Natural History magazine, September-October 2012]
In 2006, the Canadian government announced the launching of a project called the Ocean Tracking Network, which aims to track fish stocks and marine mammals with low-cost electronic tags similar to bar codes imbedded in salmon, whales, polar bears, penguins and others marine creatures to collect data on fish and animals migrations and water temperature and salinity — and pick up the data using acoustic receivers in the sea floor and satellites.
See Separate Article DEVICES, TECHNOLOGY AND MEASUREMENTS USED IN OCEANOGRAPHY
Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; “Introduction to Physical Oceanography” by Robert Stewart , Texas A&M University, 2008 uv.es/hegigui/Kasper ; Fishbase fishbase.se ; Encyclopedia of Life eol.org ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Woods Hole Oceanographic Institute whoi.edu ; Cousteau Society cousteau.org ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures
Marine biogeography is the study of marine species, the geographic distribution of their habitats, and the relationships between living organisms and the environment. By mapping benthic habitats, studying what occurs on the bottom of a body of water, and assessing the relationships between the environment and the organisms that live there, biogeographers provide useful information to protect and conserve marine resources. [Source: NOAA]
Marine biogeographers often use Geographic Information Systems, or GIS, to aid in their research of marine animals, plants, and habitats. Scientists and GIS specialists develop map-based data that describe the distribution and ecology of living marine resources and their connections to human communities. State and federal planners can apply these tools and information to position aquaculture sites and alternative energy facilities, and to protect fisheries and coral spawning areas. Information from biogeographers allows planners to consider possible scenarios, such as new development, that may, or may not, impact the environment.
Creating a habitat ecosystem map of the seafloor — a key component of marine biogeography — is a tricky process. NOAA's National Centers for Coastal Ocean Science conducts research on the distribution and ecology of marine plants and animals to predict future trends. Tools such as surveys, maps, and reports provide specific information to assess ecosystem conditions, anticipate changes in the environment, and evaluate how people's social and economic needs can be met.
Marine telemetry uses devices attached to animals to gather data. These telemetry devices, called tags, are attached to a wide range of marine species, from tiny salmon smolts to giant 150-ton whales. Tags are attached to the outside of an animal with clips, straps, or glue, and are sometimes surgically inserted in an animal's body. Signals from the tags are received by research vessels, buoys, and satellites. Telemetry tags don’t just report the animal’s movements; they can also also record information about the animal (temperature, heart rate, oxygen levels), its behavior (vocalizations, breathing, tail beats), and its environment (sound, temperature, salinity, light). [Source: NOAA]
These observations significantly improve our understanding of animals’ locations and how they respond to climate change and human-made disturbances. Telemetry data also improves population estimates and aids implementation of the Endangered Species Act and other conservation laws and policies. Marine telemetry can also provide data at relatively low cost and in areas that are difficult to study, such as the Arctic.
As the Earth’s climate continues to change, data collected by telemetry tags can tell scientists the effect of warmer ocean water on animal behavior, their migration patterns, and the availability of their food sources. For example, during an unusual influx of warm water along the West Coast in 2005, telemetry showed that sea lions traveled farther than normal from the shore. Data from the tags showed the sea lions made these trips to find the fish species in the region that make up much of their diet. The data from telemetry tags helped scientists understand more not only about the sea lions, but also about their preferred prey.
Census of Marine Life
The Census of Marine Life was an ambitious $650 million, 10-year study to determine the diversity, distribution, and abundance of life in the ocean. It was launched in 2000 and has involved 2,700 marine biologist from 80 countries. Over 13,000 new species were found in 2004 alone. Most were species of zooplankton. In one 1.5-kilometer-deep area of water off of Australia scientists found a shrimp that was supposed to have been extinct for 50 million years. Among the technology utilized were laser-based radar, deep sea robots and sonar that is so sensitive it can track fish 150 kilometers away.
The census included 540 marine expeditions. Scientists combined information collected over centuries, with new data obtained during the census and created a list of species in 25 regions, from the Antarctic to the Arctic, through temperate and tropical seas. A key reason for compiling this marine life inventory was to catalog species which are endangered.
The Census resulted in the International Ocean Biogeographic Information System (iOBIS) database. The U.S. component of this database, Ocean Biogeographic Information System (OBIS)-USA, allows users to search and download biodiversity data from marine waters of the United States. The data and information collected by the Census — 30 million records and 2,600 papers contributed to the scientific literature — will serve as a baseline in the coming years, as researchers strive to measure changes to ocean habitats due to sea level rise and climate change, extreme weather events, hazardous spills, and other factors. [Source: NOAA]
As a partner in the Census, NOAA's Office of National Marine Sanctuaries played a leading role on the U.S. National Committee for the Census of Marine Life, published reviews on biodiversity and the OBIS-USA database, and contributed a chapter to the book Biota of the Gulf of Mexico.Data from the sanctuaries were incorporated into the OBIS database, so that biodiversity of these special ocean areas could be documented. The long time-series of data incorporated into the Census has allowed sanctuary researchers to document the historical ecology of marine ecosystems subject to resource exploitation. NOAA's Coral Reef Conservation Program, National Marine Fisheries Service, Office of Ocean Exploration and Research, and others also contributed to the Census.
Results of the Census of Marine Life
The results of the Census of Marine Life, were reported at The Royal Society of London in October 2010. The Ocean Biogeographic Information System contains the Census data, with maps and three books. The census increased the number of counted and validated species to 201,206. Scientists found and formally described more than 1,200 new marine species, with thousands more awaiting formal descriptions; discovered and mapped areas in the ocean where marine species congregate; and documented long-term and widespread declines in marine life as well as species resilience and recovery.
The Census of Marine Life found an average of 10,750 known species in specified regions, and researchers believe that for every known species, there are at least four yet to be discovered. The census found another more basic connection in the genetic blueprint of life. Just as chimps and humans share more than 95 percent of their DNA, the species of the oceans have most of their DNA in common, too. Among fish in general, the snippets of genetic code that scientists have analyzed suggest only about a 2 to 15 percent difference, said Dirk Steinke, lead scientist for marine barcoding at the University of Guelph in Canada. “Although these are really old species of fish, there’s not much that separates them,” he said.
Among the things learned from the Census of Marine Life, completed in October 2011 are that: crabs, lobsters and other crustaceans are now believed to be the most common species in the seas of Australia and Japan, whose waters are thought of as the most varied. "When people think of the ocean, we think of fish and whales," Ausubel said. "But the big mammals represent only 2 percent of the total diversity and fish a surprsingly low 12 per cent. We should first think of crustaceans and mollusks," he added. [Source: Virginie Montet, AFP, August 17, 2010]
Almost a fifth of all the marine life are crustaceans, closely followed by shellfish, squid, octopus and snails, which represent 17 percent of the total. Then, with 12 per cent, there is the family of fish, including sharks. The unicellular organisms of the protozoa and algae families as well as other types of organisms which shape plants, are located in fourth place with 10 per cent. Among others are echinoderms such as the starfish, sand dollars and sea cucumbers. Porifera, including sponges and cnidarians, such as sea anemones, corals and jellyfish.
The algae, protozoa, birds and marine mammals that continually cross the world's oceans are considered the most cosmopolitan species, as found in more than one region. Sloane's viperfish (Chauliodus sloani) are found in more than a quarter of the world's oceans.
Tagging of Pacific Ocean Predators (TOPP)
Juliet Eilperin wrote in the Washington Post, “The Census of Marine Life’s Tagging of Pacific Predators (TOPP) project, published in the online version of the journal Nature, deployed 4,036 tags on 23 species of ocean predators, a group that includes several seabirds.It reveals that the eastern Pacific Ocean is akin to Africa’s Serengeti, teeming with wildlife and crisscrossed by migration corridors used by sharks and seabirds. But the census’s greater value might be in advancing knowledge of a largely uncharted underwater world on which we increasingly depend.
“It’s precedent-setting. It’s a tremendous tool for conservation and management,” said Jesse Ausubel, vice president of the Alfred P. Sloan Foundation and co-founder of the Census of Marine Life. “We were literally blind. We can now see. We know what’s underneath now.” Now, for the creatures, “you suddenly see these incredible patterns by these commuters, long distance and short distance,” he said. Seventy-five researchers from five countries collaborated on the project, which cost $20 million to $25 million, analyzing the ocean’s chlorophyll content and tracking the nature of the water through which the predators moved.
Cheryl Lyn Dybas wrote in Natural History magazine: TOPP “focuses on certain areas of the Pacific, among them the California Current, an undersea river of water that flows south along the western coast of North America, beginning off British Columbia and ending near Baja California. The current supports large populations of whales and seabirds, and fuels important fisheries. Its productivity comes from an upwelling of cold subsurface waters, caused by prevailing northeasterly winds. The chilly waters ferry a steady supply of nutrients to the surface. The scientists are also studying an area called the North Pacific Transition Zone, the boundary between cold subarctic water and warm subtropical water, about halfway between Hawaii and Alaska. It’s a major trans-Pacific corridor for the movements of predators and prey. [Source: Cheryl Lyn Dybas, Natural History magazine, September-October 2012]
Among those most heavily involved in in TOPP are marine scientist Barbara A. Block of Stanford University’s Hopkins Marine Station in Pacific Grove, California and biologist Daniel P. Costa of the University of California, Santa Cruz. “TOPP was launched in 2000 by Block and Costa along with Steven J. Bograd of the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center in La Jolla, Randall E. Kochevar of Stanford, and others. The project was part of the Census of Marine Life, a ten-year-long investigation of the diversity, distribution, and abundance of ocean species. TOPP became the world’s largest “biologging” (electronic tagging) study, involving more than seventy-five biologists, oceanographers, engineers, and computer scientists in eight countries. A decade of findings were reported in the journal Nature in June 2011. They reveal that the migrations of twenty-two marine species overlap.
“Block, Costa, and their colleagues use an array of technologies to track species and to record such environmental variables as water temperature, salinity, and depth. The TOPP project alone deployed 4,306 satellite-monitored tags, yielding a massive amount of data. Scientists spent two years synthesizing data sets. They discovered intersecting ocean hotspots and highways of life — and learned much about how marine conditions influence where animals hang out.
The movement patterns of twenty-two species were documented by scientists collaborating in TOPP and their results were described and mapped. Cheryl Lyn Dybas wrote in Natural History magazine: The results show that many migratory marine species, like animals on the Serengeti grasslands, return to the same regions each year, homing in with astonishing fidelity to the places where they were first tagged. “It’s akin to a student from London studying in far-off Rome and coming home each summer at the same moment — but doing it all in the dark without a map or compass, using only his or her internal sense of position and direction,” says Costa. [Source: Cheryl Lyn Dybas, Natural History magazine, September-October 2012]
Tuna, sharks, and blue whales may be cued to seasonal changes in chlorophyll concentrations,” says Bograd. Chlorophyll indicates the presence of phytoplankton, the grasslands of the sea. “These are the oceanic areas where food is most abundant,” said Block. “They’re the savanna grasslands of the sea.” Knowing where and when species migrate is critical information for managing and protecting ecosystems, says biologist Daniel P. Costa of the University of California, Santa Cruz.
The scientists have also looked at the partitioning of habitats by closely related species. Certain species, for example, are attracted to particular water temperatures; these preferences correlate with physiological adaptations. “We can now predict when and where individual species are likely to be in a given ocean region, and begin to understand the factors that control where they go next,” says Costa. “It’s the basis of ecosystem-based management.”
Jacques Cousteau’s famous book about the sea, “The Silent World”, published in 1953, should have had a different title. By that time scientists had recorded more than 180 species, from eels (which emitted a “bubbling ‘put-put’”) to sea bream (“guttural thumps”). The vast acoustic library was assembled mostly by the scientist Marie Fish on Presto recording discs. Sculpin, she wrote, hummed like generators. Sea horses clicked like a person snapping their fingers. Herring knocked, hardtails rasped, bass grunted. Some species were multitalented: Toadfish honked like “a medley of fog horns” to attract mates during the breeding season, then, upon settling down to guard their eggs, uttered a “loud growling sound” to ward off trespassers. Chattiest of all was the sea robin, a bottom-dweller whose yakking, to Fish’s ears, evoked “the cackling and clucking of barnyard fowl.” [Source: Ben Goldfarb, Smithsonian magazine, April 2021]
Ben Goldfarb wrote in Smithsonian magazine: “Fish was not content merely to classify sound. She and her students dissected numerous specimens in search of noisemaking anatomy. Some finfish, she discovered, vocalized by grinding together their jaws or the “pharyngeal teeth” that studded their throats. Porcupinefish, for example, produced a “raspy whine which sounds like a saw or the creaking of a rusty hinge.” Others, like toadfish, vibrated specialized muscles against their air bladders, like drumsticks against a snare. A spawning aggregation of croakers, Fish learned, was capable of raising the ocean’s background volume to 114 decibels — the equivalent of a rock concert. And while the close confines of the lab were ill-suited to studying marine mammals, she correctly hypothesized that whales echolocate, before the phenomenon was first formally described.
Were Marie Fish to drop a hydrophone into the ocean today, she might not like what she heard. Sonar, industrial shipping and explosive seismic surveys for oil and gas increasingly drown out the grunts of croakers and the chuckling of sea robins. The din, known to some researchers as “acoustical bleaching,” has fatally disoriented whales and killed young fish, and the roar of deep-sea mining could soon penetrate even the remotest depths.
In 2018, Tzu-Hao Lin, an assistant research fellow at Academia Sinica, the national academy of Taiwan. founded the Ocean Biodiversity Listening Project, a global open-access database of marine recordings, captured in environments ranging from sunlit coral reefs to seafloor vents. The project, he says, is a “library that establishes the relationship between sound and fish species,” a compendium that may help other scientists understand how human activities are distorting marine soundscapes. The military, too, has been compelled to carry on Fish’s work: In 2018, after conservation groups sued the Navy over the impacts of its sonar on whales, the government settled the case by creating a program called SanctSound, deploying hydrophones and drones to monitor noise in the Florida Keys, the Channel Islands and other marine sanctuaries.
“It was obvious that animal noises were being encountered,” Fish concluded, though precisely which animals was less clear. As she dug deep into maritime history, she found intriguing records: One 19th-century sailor had wondered at sounds reminiscent of “jingling bells” and “enormous harp[s].” Even the siren songs of Homeric legend, she speculated, may have been produced by breeding schools of croakers. To Fish, it was clear that ocean creatures were far noisier than anyone had guessed. Sound waves travel through water efficiently — five times faster than through air — but, as Fish hastened to point out, they don’t readily pass between mediums. If observers had merely “pondered a fact which they might have remembered from their physics lessons,” Fish wrote in Scientific American, they might have known to listen more closely. Yet most of Fish’s peers still considered the briny deep a muted realm. When the explorer Jacques Cousteau published his memoir in 1953, he titled it The Silent World. Fish believed that researchers had simply been listening under the wrong conditions. “Even the most loquacious species are usually silenced by the approach of a vessel,” she observed.
Development of Marine Bioacoustics
Ben Goldfarb wrote in Smithsonian magazine: Among the many puzzles that confronted American sailors during World War II, few were as vexing as the sound of phantom enemies. Especially in the war’s early days, submarine crews and sonar operators listening for Axis vessels were often baffled by what they heard. In the Pacific, the submarine USS Tarpon was mystified by a repetitive clanging and the USS Permit by what crew members described as the sound of “hammering on steel.” In the Chesapeake Bay, the clangor — likened by one sailor to “pneumatic drills tearing up a concrete sidewalk” — was so loud it threatened to detonate defensive mines and sink friendly ships. [Source: Ben Goldfarb, Smithsonian magazine, April 2021]
Once the war ended, the Navy, which had begun to suspect that sea creatures were, in fact, behind the cacophony, turned to investigating the problem. To lead the effort it chose a scientist who, though famous in her day, has been largely overlooked by posterity: Marie Poland Fish, who would found the field of marine bioacoustics. At the Navy’s behest, Fish began to review the voluminous reports that submarines like the Salmon had filed. American sailors, Fish reported, had registered an astonishing array of sounds, including “beeping, clicking, creaking, harsh croaking, crackling, whistling, grunting, hammering, moaning and mewing,” and even “the dragging of heavy chains.”
She returned to the University of Rhode Island and, using funding from the Office of Naval Research, began to experiment. Fish fenced off a series of enclosures in Rhode Island’s Narragansett Bay and lowered hydrophones into the shallows, which allowed her to spy unobtrusively on marine animals. She also developed more invasive techniques, such as running jolts of electricity through laboratory aquariums in hopes of stimulating a reaction from the fish within.
The Navy consulted what Fish called her “underwater detective agency” to identify novel sounds and used her research to train sonar operators to distinguish between enemy vessels and “false targets,” such as whales. She was also dispatched to France, England and Germany to teach allies. A reporter asked whether she’d ever happened to identify a “true target” — a Russian sub. “Yes, but I can’t tell about those,” she said, and changed the subject. In 1966, the year she retired, the Navy gave her a Distinguished Public Service Award, its highest civilian honor. Fish died in 1989, at 88.
What the Ocean Can Teach Us about Life on Other Planets
Life on Earth is found in conditions ranging from the coldest arctic ice to extremely hot hydrothermal systems on the ocean floor. Microbes are also found in very acidic conditions, very salty conditions, and very alkaline conditions. These microbes are called "extremophiles" (which means 'lovers of extremes'). While conditions on the surface of the Earth where humans are happy are likely to be extremely rare outside of our home planet, the range of conditions in which microbes are found on Earth are more likely to be found on other planets and moons. [Source: NOAA]
Some areas of our oceans, for example, may be similar to conditions found elsewhere in the solar system. Jupiter's moon Europa is completely covered by ice, but the tidal energy generated by giant Jupiter is so strong that a global ocean likely exists under the ice that could be 10 times as deep as what we find on Earth. Many scientists think that hydrothermal vents may exist at the bottom of this vast ocean.
This is exciting news, because microbes are found in abundance in hydrothermal vent systems in our oceans. Tubeworms grow near the boundary where hot vent fluid mixes with cold seawater on the ocean floor. They are an example of extremophiles.. Chemosynthetic bacteria living inside the tubeworms derive energy from chemicals emitted in the hot water of hydrothermal vents. Understanding extreme life on Earth might help us identify environments on other moons and planets where life could exist.
Image Sources: Wikimedia Commons; YouTube, Animal Diversity Web, NOAA
Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; “Introduction to Physical Oceanography” by Robert Stewart , Texas A&M University, 2008 uv.es/hegigui/Kasper ; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.
Last Updated March 2023