remiconnesson/oceanservice-noaa-facts huggingface dataset:
# What threats do seabirds face?

![California western gull chicks](/facts/seabirds960.jpg "California western gull chicks")

_In California, frequent human-caused disturbances to seabirds include low-flying aircraft, close approaches by motorized and non-motorized boats, humans on foot, and general ocean and coastal users._

In California, for example, nesting and migrant seabird populations are significant resources with colonies throughout the state. Over time, these populations have been impacted by a variety of man-made sources, including oil spills, gill-net and other fisheries, various contaminants, habitat destruction, introduced predators, and human disturbance.

These disturbances can cause nesting seabirds to flee from and abandon their nests, leaving eggs or chicks exposed to predators, or causing eggs to fall from the nest. In some cases, disturbances can cause complete breeding failure of a seabird colony, and ultimately may cause colony abandonment. These disturbance events can result in a reduction of the long-term health and survival of affected marine species, and when coupled with changing oceanic conditions and other human-induced stressors, cumulative small impacts can impart large-scale harm.

The Seabird Protection Network at Gulf of the Farallones National Marine Sanctuary addresses human disturbance to breeding seabird colonies along the central California coast. These efforts are accomplished through an organized outreach and education program combined with law enforcement and other seabird management actions. Monitoring of California seabird breeding colonies helps guide outreach, education, and management efforts of the Network.
# What's the difference between seals and sea lions?

## Seals and sea lions are marine mammals called '**pinnipeds**' that differ in physical characteristics and adaptations.

![seals and sea lions](/facts/seal-sealion.jpg "seals and sea lions")

Sea lions (left) are brown, bark loudly, "walk" on land using their large flippers and have visible ear flaps. Seals have small flippers, wriggle on their bellies on land, and lack visible ear flaps.

Have you ever wondered about the main differences between seals and their "second cousins," the sea lions?

Both seals and sea lions, together with the walrus, are pinnipeds, which means "fin footed" in Latin.

But seals' furry, generally stubby front feet — thinly webbed flippers, actually, with a claw on each small toe — seem petite in comparison to the mostly skin-covered, elongated fore flippers that sea lions possess.

Secondly, sea lions have small flaps for outer ears. The "earless" or "true" seals lack external ears altogether. You have to get very close to see the tiny holes on the sides of a seal’s sleek head.

Third, sea lions are noisy. Seals are quieter, vocalizing via soft grunts.

Fourth, while both species spend time both in and out of the water, seals are better adapted to live in the water than on land. Though their bodies can appear chubby, seals are generally smaller and more aquadynamic than sea lions. At the same time, their hind flippers angle backward and don't rotate. This makes them fast in the water but basic belly crawlers on terra firma.

Sea lions, on the other hand, are able to "walk" on land by rotating their hind flippers forward and underneath their big bodies. This is why they are more likely to be employed in aquaria and marine shows.

Finally, seals are less social than their sea-lion cousins. They spend more time in the water than sea lions do and often lead solitary lives in the wild, coming ashore together only once a year to meet and mate.

Sea lions congregate in gregarious groups called herds or rafts that can reach upwards of 1,500 individuals. It's common for scores of them to haul out together and loll about in the sand, comprising an amorphous pile in the noonday sun.
# What's the difference between dolphins and porpoises?

![a dolphin](/facts/dolphin.jpg "Dolphins have longer noses, bigger mouths, more curved dorsal fins")

_Dolphins have longer noses, bigger mouths, more curved dorsal fins, and longer, leaner bodies than porpoises. The Northeastern Offshore Spotted Dolphin, shown here, has a falcate, or sickle-shaped dorsal fin and light spotting on the belly._

![a harbor porpoise drawing](/facts/harborporpoise.jpg "Dolphins have longer noses, bigger mouths, more curved dorsal fins")

_The [harbor porpoise](http://www.westcoast.fisheries.noaa.gov/protected_species/marine_mammals/cetaceans/harbor_porpoise_id.html) has small pointed flippers and no beak. The dorsal fin is small and triangle-shaped._

People use the terms dolphins, porpoises, and whales to describe marine mammals belonging to the order Cetacea (from the Greek work _ketos,_ “large sea creature”), and often use them interchangeably. The orca, or killer whale, for example, is actually the largest member of the dolphin family.

Dolphins are by far more prevalent than porpoises. Most scientists agree that there are 32 dolphin species (plus five closely related species of river dolphin) and only six porpoise species.

So what’s the difference? It essentially comes down to their faces (who can forget Flipper’s famous “grin”?), their fins, and their figures. Dolphins tend to have prominent, elongated “beaks” and cone-shaped teeth, while porpoises have smaller mouths and spade-shaped teeth. The dolphin’s hooked or curved dorsal fin (the one in the middle of the animal’s back) also differs from the porpoise’s triangular dorsal fin. Generally speaking, dolphin bodies are leaner, and porpoises’ are portly.

Dolphins are also more talkative than porpoises. Dolphins make whistling sounds through their blowholes to communicate with one another underwater. Scientists are pretty sure that porpoises do not do this, and some think this may be due to structural differences in the porpoise’s blowhole.

Dolphins and porpoises have many similarities, one of which is their extreme intelligence. Both have large, complex brains and a structure in their foreheads, called the melon, with which they focus sound waves used to navigate their underwater world.

It is likely that more (or fewer) differences between dolphins and porpoises will be revealed as researchers continue to investigate these intriguing sentinels of the sea.
# What is an invasive species?

VIDEO: What is an invasive species? Here's an overview in under two minutes. [Transcript](#transcript)

Invasive species can harm both the natural resources in an ecosystem as well as threaten human use of these resources. An invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and other means.

Invasive species are capable of causing extinctions of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can result in huge economic impacts and fundamental disruptions of coastal and Great Lakes ecosystems.

### Video Transcript

Invasive species are animals or plants from another region of the world that don’t belong in their new environment. They can be introduced to an area by ship ballast water, accidental release, and most often, by people. Invasive species can lead to the extinction of native plants and animals, destroy biodiversity, and permanently alter habitats.
# What is the largest sea turtle?

## The leatherback is the largest living sea turtle.

![Leatherback turtle consuming a jellyfish](/facts/leatherback.jpg "Leatherback turtle consuming a jellyfish")

Leatherback turtle consuming a jellyfish off Cape Cod. (NMFS Permit #1557-03).

Weighing in at between 550 and 2,000 pounds with lengths of up to six feet, the leatherback is a big turtle! Leatherback sea turtles can be distinguished from other species of sea turtle by its lack of a hard shell or scales. Instead, leatherbacks are covered with a firm, rubbery skin.

You can find leatherback sea turtles as far north as Canada and the northern Pacific Ocean. They tend to nest in the tropics, however. Within the United States, the leatherback is known to nest in southeast Florida, Puerto Rico, and the U.S. Virgin Islands.

The leatherback sea turtle feeds primarily on jellyfish.

The U.S. federal government has listed the leatherback as endangered worldwide. Primary threats to the turtles include incidental take in commercial fisheries and marine pollution, as well as the harvest of eggs.
# What makes the right whale right?

##### **Stellwagen Sightings**

Stellwagen Bank National Marine Sanctuary in Massachusetts is a seasonal feeding area for right whales, as well as humpback, fin, sei, and minke whales. The sanctuary is a popular [whale watching destination](https://stellwagen.noaa.gov/visit/whalewatching/whalewatching.html) and important conservation site for these animals.
# What is coral bleaching?

![iStock image showing longitude lines](/facts/coralbleaching-large.jpg)

_Can coral survive a bleaching event? If the stress-caused bleaching is not severe, coral have been known to recover. If the algae loss is prolonged and the stress continues, coral eventually dies. Download this infographic: [In English](/facts/coralbleaching.pdf) | [In Spanish](/facts/Blanqueamiento-de-corales_NOAA traducida-por-DRNA.pdf)_

Warmer water temperatures can result in coral bleaching. When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality.

In 2005, the U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event. The warm waters centered around the northern Antilles near the Virgin Islands and Puerto Rico expanded southward. Comparison of satellite data from the previous 20 years confirmed that thermal stress from the 2005 event was greater than the previous 20 years combined.

Not all bleaching events are due to warm water.

In January 2010, cold water temperatures in the Florida Keys caused a coral bleaching event that resulted in some coral death. Water temperatures dropped **\-6.7 degrees Celsius** [![12.06 degrees Fahrenheit](/bs4/img/question.svg)](about:/about/welcome.html#units) lower than the typical temperatures observed at this time of year. Researchers will evaluate if this cold-stress event will make corals more susceptible to disease in the same way that warmer waters impact corals.

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### Infographic Transcript: What is coral bleaching?

-   Coral Bleaching. Have you ever wondered how a coral becomes bleached?
-   Healthy Coral: Coral and algae depend on each other to survive. Corals have a symbiotic relationship with microscopic algae called zooxanthellae that live in their tissues. These algae are the coral’s primary food source and give them their color Stressed Coral: If stressed, algae leaves the coral. When the symbiotic relationship becomes stressed due to increased ocean temperature or pollution, the algae leave the coral's tissue. Bleached Coral: Coral is left bleached and vulnerable. Without the algae, the coral loses its major source of food, turns white or very pale, and is more susceptible to disease.
-   WHAT CAUSES BLEACHING? Change in ocean temperature Increased ocean temperature caused by climate change is the leading cause of coral bleaching. Runoff and pollution Storm generated precipitation can rapidly dilute ocean water and runoff can carry pollutants — these can bleach near-shore corals. Overexposure to sunlight When temperatures are high, high solar irradiance contributes to bleaching in shallow-water corals. Extreme low tides Exposure to the air during extreme low tides can cause bleaching in shallow corals. NOAA’s Coral Reef Conservation Program.
# Can penguins fly?

## No, technically penguins cannot fly.

![A group of Antarctic Gentoo penguins](/facts/penguins.jpg "A group of Antarctic Gentoo penguins")

A group of Antarctica's Gentoo penguins follow a well-worn path to their nesting area from the sea where they go to feed.

Penguins are birds, so they do have wings. However, the wing structures of penguins are evolved for swimming, rather than flying in the traditional sense. Penguins swim underwater at speeds of up to 15 to 25 miles per hour.

As adept swimmers, penguins spend a lot of time in the water. Some penguins spend up to 75 percent of their lives in the water. Like other birds, penguins do lay eggs and they raise their chicks on land.

All penguins live in the Southern Hemisphere.
# What is NERRS?

## The National Estuarine Research Reserve System, or NERRS, is a partnership between NOAA and coastal states to **study and protect vital coastal and estuarine resources**.

![Great Bay National Estuarine Research Reserve](/facts/nerrs.jpg "Great Bay National Estuarine Research Reserve")

Great Bay National Estuarine Research Reserve is located on the New Hampshire and Maine border.

National Estuarine Research Reserves serve as "living laboratories," with opportunities for both scientists and graduate students to conduct research. Reserves also conduct long-term water quality and habitat monitoring.

The National Estuarine Research Reserve System is a network of 29 areas representing different biogeographic regions of the United States. The reserves are protected for long-term research, water quality and habitat monitoring, education, and coastal stewardship. Each reserve is managed on a daily basis by a lead state agency or university, with input from local partners. NOAA provides funding, national guidance, and technical assistance.

Reserve staff work with local communities and regional groups to address natural resource management issues, such as non-point source pollution, habitat restoration, and invasive species. Through integrated research and education, the reserves help communities develop strategies to deal successfully with their coastal resource issues.

Reserves provide adult audiences with training on estuarine issues of concern in their local communities. They also offer field classes for K-12 students and support teachers through professional development programs in marine education.
# How does pressure change with ocean depth?

## Pressure **increases** with ocean depth.

![An image of Pisces V,a deep-submergence vehicle (DSV) ](pressure.jpg "An image of Pisces V")

Pisces V is a three-person submersible that can operate at depths up to 6,500 feet. This vehicle allows scientists to observe the deep sea under tremendous ocean pressure.

At sea level, the air that surrounds us presses down on our bodies at 14.7 pounds per square inch. You don't feel it because the fluids in your body are pushing outward with the same force.

Dive down into the ocean even a few feet, though, and a noticeable change occurs. You can feel an increase of pressure on your eardrums. This is due to an increase in hydrostatic pressure, the force per unit area exerted by a liquid on an object. The deeper you go under the sea, the greater the pressure of the water pushing down on you. For every 33 feet (10.06 meters) you go down, the pressure increases by one atmosphere.

Many animals that live in the sea have no trouble at all with high pressure. Whales, for instance, can withstand dramatic pressure changes because their bodies are more flexible. Their ribs are bound by loose, bendable cartilage, which allows the rib cage to collapse at pressures that would easily snap our bones.

A whale's lungs can also collapse safely under pressure, which keeps them from rupturing. This allows sperm whales to hunt for giant squid at depths of 7,000 feet or more.
# What is the geoid?

##### **Print Your Own Geoid**

Do you have access to a 3D printer? Print your own scale model of the geoid with a free plan created by a NOAA [geodesist](/facts/geodesist.html)! This model exaggerates the bumpy surface of the geoid so it is easy to see the irregular shape of the planet's global mean sea level and reduces the diameter of the Earth to just a few inches.

[Download](/facts/geiod-model.stl)

_Please note that this model includes a wide, flat base that makes it easier to print on most home 3D printers. The base also serves as a stand to display the geoid model._

Did you know? - *Scientists at the National Geodetic Survey are working on a 15-year-long project to [make accurate height measurement better, faster, and cheaper](https://oceanservice.noaa.gov/geodesy/height-measurement/). This project is called the Gravity for the Redefinition of the American Vertical Datum, or GRAV-D for short. When it’s completed, you will be able to get accurate heights to within about an inch for most locations around the nation.*

- [National Geodetic Survey](http://geodesy.noaa.gov/)

- [National Spatial Reference System](https://oceanservice.noaa.gov/facts/nsrs.html)

- [NGS Geoid information](http://www.ngs.noaa.gov/GEOID/)

-
# Are dolphins fish?

## Dolphins are mammals, not fish.

![Photo of a dolphin](/facts/dolphin-fish.jpg "Dolphins are mammels.")

The Eastern Spinner Dolphin is distinguished by its triangular dorsal fin and uniform gray color.

Even though they live in the ocean all of the time, dolphins are mammals, not fish.

Like every mammal, dolphins are warm blooded. Unlike fish, who breathe through gills, dolphins breathe air using lungs. Dolphins must make frequent trips to the surface of the water to catch a breath. The blowhole on top of a dolphin's head acts as a "nose," making it easy for the dolphin to surface for air.

Other characteristics of dolphins that make them mammals rather than fish are that they give birth to live young rather than laying eggs and they feed their young with milk. Also, like all mammals, dolphins even have a tiny amount of hair, right around the blowhole, which is a little different than the scales of a fish.

Whales and porpoises are also mammals. There are 75 species of dolphins, whales, and porpoises living in the ocean. They are the only mammals, other than manatees, that spend their entire lives in the water.
# Why is the ocean salty, but rivers flowing into it are not?

![Braided river delta at low tide Lower Cook Inlet Kachemak Bay Alaska. Credit: Alaska Shorezone.](/facts/riversnotsalty.jpg "Braided river delta at low tide Lower Cook Inlet Kachemak Bay Alaska. Credit: Alaska Shorezone.")

_Braided river delta at low tide Lower Cook Inlet Kachemak Bay Alaska. Credit: Alaska Shorezone._

In the beginning, the primeval seas were probably only slightly salty. But over time, as rain fell to the Earth and ran over the land, breaking up rocks and transporting their minerals to the ocean, the ocean has become saltier.

Rain replenishes freshwater in rivers and streams, so they don’t taste salty. However, the water in the ocean collects _all_ of the salt and minerals from _all_ of the rivers that flow into it.

It is estimated that the rivers and streams flowing from the United States alone discharge 225 million tons of dissolved solids and 513 million tons of suspended sediment annually to the ocean. Throughout the world, rivers carry an estimated four billion tons of dissolved salts to the ocean annually.

About the same tonnage of salt from ocean water probably is deposited as sediment on the ocean bottom and thus, yearly gains may offset yearly losses. In other words, the ocean today probably has a balanced salt input and output (and so the ocean is no longer getting saltier).
# What is a navigation response team?

![navigation response team boat](/facts/nrt1.jpg "navigation response team boat")

_A NOAA Navigation Response Team vessel. These boats feature both depth-finding and sidescan sonar systems for detecting dangerous obstructions on the ocean floor._

NOAA's navigation response teams, part of the Office of Coast Survey, survey the seafloor in ports and harbors that have undergone infrastructure updates, shoreline alterations, or seafloor changes. They measure depths and look for underwater hazards that could endanger vessels, to update nautical charts for commercial and recreational mariners.

Coast Survey strategically places navigation teams around the country. While 80 percent of their time is spent acquiring data for chart updates, they must also maintain a state of readiness for rapid mobilization for response after emergencies.
# Do alligators live in the ocean?

## Alligators are primarily freshwater animals and they do not live in the ocean.

![A sunbathing alligator](/facts/alligator.jpg "A sunbathing alligator")

An alligator enjoying the sun's rays. Image courtesy of U.S. National Park Service.

There are many things you may encounter when swimming in the ocean. Alligators probably aren’t one of them.

While alligators can tolerate salt water for a few hours or even days, they are primarily freshwater animals, living in swampy areas, rivers, streams, lakes, and ponds.
# What ocean basin has the most corals?

## The Pacific Ocean has the most coral species.

![Coral reef](/facts/most-coral.jpg "Coral reef")

Generally, there are about twice as many coral species in Pacific Ocean reefs as in Atlantic Ocean reefs.

Reef-building corals are restricted in their geographic distribution by factors such as the temperature and the salinity (salt content) of the water. The water must also be clear to permit high light penetration.

Because of these environmental restrictions, reefs generally are confined to tropical and semitropical waters. The diversity of reef corals (the number of species), decreases in higher latitudes up to about 30° north and south, beyond which reef corals are usually not found.

Generally, there are about twice as many coral species in Pacific Ocean reefs as in Atlantic Ocean reefs.
# Why do whales make sounds?

## Whales make noise to communicate, locate food, and find each other.

![A humpback whale in the singing position](/facts/whalenoise.jpg "A humpback whale in the singing position.")

A humpback whale in the singing position.

Whales are very social creatures that travel in groups called “pods.” They use a variety of noises to communicate and socialize with each other. The three main types of sounds made by whales are clicks, whistles, and pulsed calls.

Clicks are believed to be for navigation and identifying physical surroundings. When the sound waves bounce off of an object, they return to the whale, allowing the whale to identify the shape of the object. Clicks can even help to differentiate between friendly creatures and predators. Clicks have also been observed during social interactions, suggesting they may also have a communicative function.

Whistles and pulsed calls are used during social activities. Pulsed calls are more frequent and sound like squeaks, screams, and squawks to the human ear. Differing vocal “dialects” have been found to exist between different pods within the same whale population. This is most likely so that whales can differentiate between whales within their pods and strangers.

Whales also use their tails and fins to make loud slapping noises on the surface of the water to communicate nonverbally. The sound can be heard for hundreds of meters below the surface and may be a warning sign of aggression or a tool to scare schools of fish together, making them an easier meal.

In the Stellwagen Bank National Marine Sanctuary, NOAA scientists attached sensors to whales in order to track their movement patterns. They hope to learn about the whales’ behavior and communication as well as to observe how human interaction affects their behavior.