adaption: a characteristic that allows an organism to live successfully in a particular environment

algae: simple aquatic organisms that carry out photosynthesis; seaweeds are marine algae

aluminum smelter: a factory where aluminum is extracted from aluminum ore

Amazon Basin: the part of South America that is drained by the Amazon River and its countless tributaries, reaching from the Andes in Peru to the east coast of Brazil

Amazon River: an eastward flowing river in South America that is the largest river in the world by volume

amphipod: an omnivorous member of a group of small crustaceans that includes shrimp, sea lice and sand fleas; a source of food for gray whales

anaconda: an aquatic snake that lives in South America, including in the Amazon River region

apex predator: a species that kills and eats other animals, but has virtually no predators of its own

archipelago: a group of islands

atoll: an island formed from a coral reef, sometimes circular or horseshoe-shaped, with a lagoon in the center

Baja California (Mexico): a peninsula that extends 775 miles southward from northwestern Mexico; the Sea of Cortez lies between Baja California and the Mexican mainland

baleen: plates of keratin (the same material that makes up fingernails) found on the upper jaws of gray whales; used for filter-feeding and trapping amphipods and other tiny foods

baseline: information to be used for comparison; a standard for comparison

beluga whale: a species of cetacean that lives in Arctic and sub-Arctic waters; also called the white whale, it is known for its vocalizations

bioaccumulation: the accumulation of a substance, such as a pesticide or toxic chemical, in an organism

biodiversity: the variation of living organisms within an environment

black earth: dark, fertile soil in the Amazon Basin that contains wood, fish, animal bones and pottery shards and is the result of centuries of slash-and-char soil management

bonnethead shark: a small hammerhead shark, found in the Western Hemisphere

boto: a freshwater dolphin native to the Amazon River; also known as a pink river dolphin and an Amazon River dolphin... Watch video

BR163: 1,100-mile-long Brazilian highway that runs through the heart of the Amazon region

caiman:a small species of crocodilian, similar to the alligator, that lives in Central and South America; known locally as a jacaré

Cape fur seal: a carnivorous marine mammal that lives along the coasts of South Africa and southeastern Australia and eats fish; can weigh up to 730 pounds; fur seals have external ears (like sea lions, but unlike "true" seals)

Cape of Good Hope: a headland extending out from the Atlantic coast of South Africa that influences ocean currents

census: a count of a population of living things

cetacean: a whale, dolphin or porpoise

coral: an invertebrate animal with a calcium carbonate skeleton; related to the jellyfish and the sea anemone; as corals die, their skeletons create reefs

coral bleaching: the release of the symbiotic colored algae normally living within coral animals, which occurs when coral animals are stressed (by high temperatures, for example) and makes the coral appear whites

coral reef: a large underwater formation created from the calcium carbonate skeletons of coral animals; can also refer to the animals living on and near the coral reef

dead lakes: lakes devoid of fish due to pollution or an overabundance of plant life

decompression chamber: a large portable container that divers can enter after they've surfaced to help their bodies return to normal atmospheric pressure

deforestation: the transformation of a forested area to cropland or pasture, typically through logging or burning

dorsal fin: the fin located on the center part of the backs of fish and some marine mammals, such as killer whales and dolphins

dorsal saddle: the gray pigmented area found directly behind the dorsal fin of an orca

echolocation: the use of echoes from sound waves to create a sensory map of an area and to detect prey

ecosystem: a community of living things and its environment; for example, a coral reef is an ecosystem

ecotourism: tourism rooted in the notion of honoring the environment and impacting it as little as possible

electric field: the region around an electrically charged material that affects other electrically charged objects

electrolytes: salts in bodily fluids; needed for the body to function

endangered: in danger of dying out

Endangered Species Act: U.S. law passed in 1973 to protect critically imperiled species from extinction due to "the consequences of economic growth and development untempered by adequate concern and conservation"

endemic: native to a particular area

evolution: changes in the genes and traits of living things over time

fish farming:the raising of fish for commercial purposes in tanks or enclosures, typically for food; also called "aquaculture"... Learn more

fishing net: a net that is dragged through the water by a boat to catch fish; often discarded as trash, entangling and killing wildlife; a discarded net is sometimes referred to as a "ghost net"

food chain: a sequence of living things that describes feeding relationships

French Frigate Shoals: an atoll of the Northwestern Hawaiian Islands, 67 acres in area... Learn more

French Polynesia: a group of South Pacific islands governed by France

Galapagos shark: an aggressive shark that grows to be about 10 feet long; it swims in schools, lives in deep, tropical waters and feeds on smaller fish

genetics: the science of heredity, or how the characteristics of living things are passed from one generation to the next

global warming: the gradual increase in the world's average temperature due to the release of greenhouse gases, such as carbon dioxide, that are released in part by burning gas, oil, coal, and wood

gray reef shark: a shark found near coral reefs in tropical waters; can reach 8 feet in length and can be aggressive

gray whale: a marine mammal that can grow to 45 feet long and 40 tons; feeds on krill and amphipods, lives in the eastern North Pacific, and migrates about 12,000 miles from Alaska to Mexico yearly; formerly also inhabited the Atlantic Ocean, but was probably hunted to extinction there

great white shark: a shark that lives in temperate waters; can grow to more than 20 feet long and eats fish, seals and sea lions

greenhouse gases: any of the atmospheric gases that contribute to the greenhouse effect. Includes carbon dioxide, methane and nitrous oxide

guano: dried bird and bat droppings; rich in phosphate and nitrogen

habitat: the environment in which a living thing resides

hammerhead shark: a member of a group of sharks that have unusually shaped heads, resembling the letter "T"

high-intensity military sonar: sound waves that are used to detect underwater objects; can damage marine mammals' hearing and ability to navigate

hypothesize: to make an educated guess (a hypothesis) based on observations; in science, hypothesizing is often followed by experimenting in order to try to prove the hypothesis

ice floe: a large, flat piece of floating ice

incidental catch/by-catch: fish and other animals killed in fishing gear that was intended to catch other seafood; by-catch is usually thrown away at sea

indigenous: native to a particular area or region

industrial pollution: pollution that can be directly linked to industry such as manufacturing and farming, often occurring as water, air or soil pollution

Intergovernmental Panel on Climate Change: organization established by World Meteorological Organization and the United Nations Environment Programme to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts, and options for adaptation and mitigation

Inter-Oceanic Highway: a highway in Brazil and Peru, currently under construction, that is designed to link Peru’s west coast ports with Rio de Janeiro

invasive species: an organism introduced into a region that then damages the region's ecosystem

Kure Atoll: the northernmost coral island in the world and the most remote island of the Northwestern Hawaiian Islands... Learn more

latitude: imaginary horizontal lines, including the equator, that circle the earth from east to west and indicate distance from the equator, measured in degrees

Laysan Island: the largest of the Northwestern Hawaiian Islands, at 1,000 acres; the site of the only lake (a saltwater lake) in the Northwestern Hawaiian Islands... Learn more

longitude: imaginary vertical lines that circle the earth from north to south and indicate the distance from the prime meridian

longliner: a commercial fishing boat that uses miles and miles of fishing lines and hooks to catch fish; can entangle wildlife not intended to be caught

mahogany: a tree native to the Amazon that is exported to the United States and other countries for use in furniture and other wood products

Mamirauá Reserve: the largest protected area of flooded forest and the first sustainable development reserve in Brazil

mammal: a member of a group of animals that have backbones and hair, breathe oxygen, and care for their young; females of this group produce milk to feed their young

Manaus: a city in northern Brazil located at the junction of the Amazon River and its tributary, the Rio Negro; has a population of about 2 million

margay: a spotted cat native to Central and South America; one of only two cat species that can climb head first down trees due to extreme ankle flexibility

Maro Reef: the largest coral reef in the Northwestern Hawaiian Islands, at about 746 square miles... Learn more

Matamata: a freshwater turtle found in the Amazon, known for its distinctive triangular head, unusual shell and snorkel-like snout... Learn more

matrilineal: descended from a female ancestor

Midway Atoll: an atoll of the Northwestern Hawaiian Islands, former site of a U.S. Naval base... Learn more

migration: the regular movement of animals from one location to another

Mokumanamana Island: a small rock island, the second-smallest island of the Northwestern Hawaiian Islands; surrounded by a large marine habitat... Learn more

Molokai: he fifth-largest Hawaiian Island, between Maui and Oahu

monk seal: an endangered marine mammal that is endemic to Hawaii and particularly to the Northwestern Hawaiian Islands; weighs up to 500 pounds and eats lobsters, eels, small octopuses and reef fishes... Learn more

Monterey Canyon: an underwater canyon off the coast of central California

mysid shrimp: a small marine animal that is a distant relative of the true shrimp

NOAA: National Oceanic and Atmospheric Administration, the governmental agency that oversees the National Marine Sanctuaries as well as other programs and agencies, including the National Weather Service

nanovolt: one-billionth of a volt, which is a measure of electrical potential

National Wildlife Action: sister organization of the National Wildlife Federation, advocates for the conservation interests of hunters, anglers and outdoor enthusiasts from all walks of life and political stripes

native plant: a plant that is naturally found in an area (as opposed to plants that people introduce into an area)

El Niño: an irregularly recurring flow of unusually warm surface waters from the Pacific Ocean toward and along the western coast of South America; prevents upwelling of nutrient-rich, cold, deep water and disrupts typical regional and global weather patterns

Northwestern Hawaiian Islands (NWHI): a chain of islands and atolls extending 1,200 miles northwest of the state of Hawaii... Learn more

ocean currents: regular movement of ocean water from one region of the ocean to another; for example, the North Pacific Gyre

olfactory: related to the sense of smell

open-circuit scuba: a breathing system in which a diver inhales from a tank and exhales into the water; used commonly by recreational divers and for short and shallow dives

orca: a black-and-white toothed whale that is a skilled predator; also called a killer whale

ornamental fish: small fish, less than 8 inches long (20 cm), that are kept in aquariums and prized for their beauty and rarity

overfishing: fishing a population faster than it can replace itself; the population decreases in size as a result

Pearl and Hermes Atoll: a coral island of the Northwestern Hawaiian Islands, surrounded by vast coral reefs; named after two whaling ships wrecked there... Learn more

La Perouse Pinnacle: a steep, tall peak that is part of the French Frigate Shoals and juts out of the center of the atoll; it is a remnant of the volcano upon which the atoll is formed

pH: a measure of the acidity and alkalinity of a solution, expressed by a number on a scale on which neutrality has a value of 7; lower numbers indicate increasing acidity, and higher numbers indicate increasing alkalinity

photosynthesis: process by which plants convert carbon dioxide, water and sunlight into carbohydrates

pirarucu: a large South American freshwater fish that has the ability to breathe air and whose populations have declined due to hunting

plankton: microscopic plant-like (phytoplankton) or animal (zooplankton) organisms that drift in the water

pores: very small openings, such as in the skin

pororoca: a phenomenon that occurs at the mouth of the Amazon River in which the incoming tide forms waves of up to 13 feet high that travel upriver; also known as a tidal bore

predator: an animal that hunts and eats other animals

prey: an animal hunted for food by another animal

producer: a living thing that produces its own food within itself, usually by using sunlight energy in photosynthesis

Quelccaya Ice Cap: the largest glacier in a tropical area, located in the Andes of Peru at an altitude of over 18,000 feet

Raita Bank: a raised area of the ocean floor just 60 feet below the surface in the Northwestern Hawaiian Islands; formed from magma escaping from the earth's crust

Rangiroa: a huge 49-mile-long atoll located about 220 miles northeast of Tahiti; home to a large variety of sharks

rebreather: an underwater breathing system that recycles air; divers inhale air from a tank and exhale air into a machine that recycles the air and makes it available for the diver again; used for longer and deeper research and military dives

resident whales: whales that remain in one location year-round instead of migrating

retina: the part of the eye that is sensitive to light

rookery: a breeding place; often used to describe breeding places for seals and seabirds

satellite: a machine that orbits the earth and is used to transmit and receive communication signals

school (of fish): fish that swim together as a group

scuba: self-contained underwater breathing apparatus; a device that allows divers to breathe underwater for long periods of time

sea slug: an omnivorous soft-bodied marine animal; related to the snail, clam, octopus and squid

sea star: a soft-bodied marine animal with five arms; related to the sea urchin, sand dollar, sea cucumber and brittle star; sometimes called a starfish (but it is not a fish)

seed dispersal: methods by which plants spread their seeds, including animal ingestion, wind and water

shakedown dive: a practice dive to make sure that the equipment works and the divers understand procedures

shark: a type of fish that has a skeleton made of cartilage, breathes through gill slits on the sides of its head and is covered with special scales called "placoid" scales; closely related to the ray and the skate

shoal: a shallow area, often an underwater sandbar; sometimes also refers to an island or group of islands

silvertip shark: a shark species named for the white tips of its fins; found near coral reefs and shorelines near Mexico, eastern Africa, southeast Asia and islands of the Pacific; eats rays, wrasses, tunas, small sharks, octopuses and squid; grows to about 7 feet long and 358 pounds

slaughter: the killing of a large number of animals (including people)

sonar: also called echolocation, a method for locating objects underwater

South Africa: the southern-most country on the African continent

spinner dolphin: a swimming mammal named for its spinning leaps from the ocean; found throughout the tropical and subtropical waters of the Atlantic, Indian and Pacific oceans

spotted eagle ray: a type of fish with a flattened shape and wing-like fins that can reach 8 feet long or longer; named for the white spots covering its back; found in warm oceans; related to the shark and the skate; feeds on clams, oysters, shrimp, octopus, squid, sea urchins and bony fish

stingray: a flat cartilaginous fish that swims with a flying motion and is equipped with a barbed spine in its tail

subsistence hunting: hunting for the sake of survival rather than entertainment

surgeonfish: a group of brightly colored, oval-shaped coral reef fish that includes tangs; named after the small, sharp scalpel-like projection just ahead of its tail

surveillance: close observation and monitoring

taro: vegetable grown in Hawaii (as well as in Africa and Asia)

Tern Island: an island that is part of the French Frigate Shoals and the Northwestern Hawaiian Islands; now a nesting ground for more than a million seabirds; was a refueling station during World War II

threatened (Endangered Species Act listing): a species that is likely to become endangered in the near future

Trans-Amazonian Highway: a highway in Brazil, begun in the 1970s, that was intended to connect remote parts of Brazil with cities and with Peru and Ecuador

tropical rainforest: a rainforest found near the equator, typically characterized by high rainfall, poor soil, and a high diversity of plant and animal species

turbulence: irregular, disturbed or apparently chaotic movement of water or air

upwelling: the upward movement to the ocean surface of deeper, cold and usually nutrient-rich waters, especially along some shores, due to the offshore movement of surface waters

Vale do Javari Indigenous Reserve: the largest reserve for indigenous people in South America

watershed: the area of land where water from rain or melting snow drains downhill into a river, lake or other body of water

Xixuaú-Xiparinã Reserve: a large private nature reserve in Brazil that is home to many species of animals that are at risk of extinction elsewhere in the Amazon

yellow-spotted river turtle: one of the largest South American river turtles; characterized by yellow spots on its head