remiconnesson/oceanservice-noaa-facts huggingface dataset:
# What is ocean noise?

![Humpback whales swimming underwater](/facts/ocean-noise.jpg "Humpback whales swimming underwater")

_Humpback whales swimming underwater. Photo credit: Ed Lyman/NOAA, under NOAA permit #14682_

Many marine organisms rely on their ability to hear for their survival. Sound is a highly efficient means of communication underwater and is the primary way that many marine species gather and understand information about their environment. Many aquatic animals use sound to find prey, locate mates and offspring, avoid predators, guide their navigation and locate habitat, as well as to listen and communicate with each other.

Over the last century, human activities such as shipping, recreational boating, and energy exploration have increased along our coasts, offshore, and deep ocean environments. Noise from these activities can travel long distances underwater, leading to increases and changes in ocean noise levels in many coastal and offshore habitats.

These rising noise levels can negatively impact ocean animals and ecosystems. Higher noise levels can reduce the ability of animals to communicate with potential mates, other group members, their offspring, or feeding partners. Noise can also reduce an ocean animal's ability to hear environmental cues that are vital for survival, including those key to avoiding predators, finding food, and navigating to preferred habitats.
# What is a gyre?

## A gyre is a large system of rotating ocean currents.

![a map of the earth showing gyres in the world ocean](/facts/gyre.jpg)

There are five major gyres, which are large systems of rotating ocean currents. The ocean churns up various types of currents. Together, these larger and more permanent currents make up the systems of currents known as gyres.

Wind, tides, and differences in temperature and salinity drive ocean [currents](/facts/current.html). The ocean churns up [different types of currents](/education/tutorial_currents/welcome.html), such as [eddies](/facts/eddy.html), [whirlpools](/facts/old-sow.html), or [deep ocean currents](/facts/conveyor.html). Larger, sustained currents—the [Gulf Stream](/facts/gulfstreamspeed.html), for example—go by proper names. Taken together, these larger and more permanent currents make up the systems of currents known as gyres.

There are five major gyres: the North and South Pacific Subtropical Gyres, the North and South Atlantic Subtropical Gyres, and the Indian Ocean Subtropical Gyre.

In some instances, the term “gyre” is used to refer to the [collections of plastic waste and other debris](/facts/garbagepatch.html) found in higher concentrations in certain parts of the ocean. While this use of "gyre" is increasingly common, the term traditionally refers simply to large, rotating ocean currents.

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Currents don’t just move water. They move [people and goods](https://oceanservice.noaa.gov/facts/currentdata.html), as well as pollution and debris. To better understand how currents move people and things, NOAA collects and shares data on tides and currents. This data guides safe navigation of coastal waters, search and rescue operations, disaster clean up, and design of coastal development projects.

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**Last updated:** 06/16/24  
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Did you know? - Currents don’t just move water. They move [people and goods](https://oceanservice.noaa.gov/facts/currentdata.html), as well as pollution and debris. To better understand how currents move people and things, NOAA collects and shares data on tides and currents. This data guides safe navigation of coastal waters, search and rescue operations, disaster clean up, and design of coastal development projects.
# What is marine telemetry?

![a seal with animal telemetry device](telemetry.jpg "seals on a beach")

_Telemetry tags help researchers discover where marine animals are, where they go, and what their environments are like._

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](https://www.noaasis.noaa.gov/POLAR/ARGOS/argos.html).

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).

These observations significantly improve our understanding of animals’ [locations](https://www.fisheries.noaa.gov/feature-story/how-do-scientists-know-where-fish-go) and how they respond to climate change and human-made disturbances. Telemetry data also improves [population estimates](https://www.fisheries.noaa.gov/southeast/endangered-species-conservation/shark-and-sawfish-surveys-and-tagging) 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.

Did you know? - *The national [Animal Telemetry Network](https://atn.ioos.us), part of the NOAA-led [U.S. Integrated Ocean Observing System (IOOS®)](https://ioos.noaa.gov/), uses several telemetry technologies to monitor a host of aquatic life. Researchers work hard to ensure tagging devices are minimally intrusive and do not harm animals.*
# Can a coral reef recover from bleaching and other stressful events?

## If local threats are reduced, coral reefs have a greater chance of surviving a larger climate event, such as bleaching.

![​Coral reef​s ​​​​in the clear blue waters of Kure Atoll in ​Hawaii's Papahānaumokuākea Marine National Monument​](/facts/reef-resilience.jpg "​Coral reef​s ​​​​in the clear blue waters of Kure Atoll in ​Hawaii's Papahānaumokuākea Marine National Monument​")

​Coral reef​s ​​​​in the clear blue waters of Kure Atoll in ​Hawaii's Papahānaumokuākea Marine National Monument​.

Climate change and ocean acidification can result in mass [coral bleaching](/facts/coral_bleach.html) events, increased susceptibility to disease, slower growth and reproductive rates, and degraded reef structure.

There are no quick fixes when it comes to a changing climate. In the long term, coral reefs around the world will benefit the most from the reduction of greenhouse gases. In the short term, we can improve coral reef resilience by addressing local stressors, like runoff from land-based sources of pollution and overharvesting of fish.

[NOAA’s Coral Reef Conservation Program](http://coralreef.noaa.gov/) is helping local managers and communities do just that. The idea is simple. We know climate change is the single greatest global threat to coral reefs. Promoting reef resilience is a local solution. A resilient coral reef is one that can either resist a large-scale stressful event or recover from it. For this to happen, local threats must be kept to a minimum to reduce stress and improve overall reef condition. Scientists are also honing ways to evaluate how resilient a coral reef ecosystem is so that managers can take targeted actions that have the greatest impact.

Healthy coral reefs support an amazing diversity of marine life and are often called the rainforests of the sea. Coral reefs provide many benefits to people, including [coastal protection](/facts/coral_protect.html), food, [jobs](/facts/coral_economy.html), [medicine](/facts/coral_medicine.html), and recreational activities.

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Just as people tend to get sick when under stress, so do corals. If local stressors to coral reefs are reduced, the corals have a better chance of recovering from an event such as coral bleaching. In this way, the reefs are more resilient.

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**Last updated:** 06/16/24  
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Did you know? - 

- Just as people tend to get sick when under stress, so do corals. If local stressors to coral reefs are reduced, the corals have a better chance of recovering from an event such as coral bleaching. In this way, the reefs are more resilient.
# How does pollution threaten coral reefs?

Impacts from land-based sources of pollution—including coastal development, deforestation, agricultural runoff, and oil and chemical spills—can impede coral growth and reproduction, disrupt overall ecological function, and cause disease and mortality in sensitive species. It is now well accepted that many serious coral reef ecosystem stressors originate from land-based sources, most notably toxicants, sediments, and nutrients.

Within the U.S., there are numerous locations where coral reef ecosystems are highly impacted by watershed alteration, runoff, and coastal development. On U.S. islands in the Pacific and Caribbean, significant changes in the drainage basins due to agriculture, deforestation, grazing of feral animals, fires, road building, and urbanization have increased the volume of land-based pollution released to adjacent coral reef ecosystems.

Many of these issues are made worse because of the geographic and climatic characteristics found in tropical island areas. Together they create unique management challenges.

## Infographic Text

### Threats to coral reefs: land-based sources of pollution

As human population and development expands in coastal areas, the landscape is altered, increasing land-based source of pollution and threatening coral reef health.

### Pollution (e.g., sedimentation, toxins, pathogens, increased nutrients):

-   **Causes** disease and mortality.
-   **Disrupts** ecological functions.
-   **Changes** dynamics and feeding behaviors.
-   **Prevents** coral growth and reproduction.

### Land-based sources of pollution include:

-   **Failed septic systems**: nutrients and pathogens.
-   **Coastal development & impervious surface**: sedimentation and toxins.
-   **Stormwater runoff**: sedimentation, toxins, nutrients, and pathogens.
-   **Deforestation**: sedimentation.
-   **Oil and chemical spills**: toxins.
-   **Road construction**: sedimentation.
-   **Agriculture**: nutrients and sedimentation.

### How you can help!

-   Apply fertilizers and pesticides sparingly.
-   Pick up after your pets.
-   Wash your car on your lawn.
-   Dispose of lawn clippings in a compost pile.
-   Harvest rooftop rain water through rain barrels or rain gardens.
-   DO NOT dump paint, oil, antifreeze, debris, or other household chemicals into street gutters or storm drains.
-   Clean up spilled brake Fluid, oil,greaseand antifreeze
-   Maintain proper septic system function with inspections and pumpouts every 3-5 years.
-   Seek shade between 10 am & 2 pm, use Ultraviolet Protection Factor (UPF) sunwear, and choose sunscreens with chemicals that don’t harm marine life.
# What is a King Tide?

## A King Tide is a popular, non-scientific term people often use to describe **exceptionally high tides**.

![a king tide](/facts/king-tide.jpg "A king tide in California")

A king tide viewed from south of Pier 96 in San Francisco, California, in February, 2016. Credit: Dave Rauenbuehler

A King Tide is a non-scientific term people often use to describe exceptionally high tides. Tides are long-period waves that roll around the planet as the ocean is "pulled" back and forth by the gravitational pull of the moon and the sun as these bodies interact with the Earth in their monthly and yearly orbits. Higher than normal tides typically occur during a [new or full moon](/facts/springtide.html) and when the Moon is at its [perigee](/facts/perigean-spring-tide.html), or during specific seasons around the country.
# What are the Roaring Forties?

![A research vessel ploughs through the waves, braving the strong westerly winds of the Roaring Forties in the Southern Ocean.  Credit: Nicolas Metzl, LOCEAN/IPSL Laboratory](/facts/roaring40s.jpg "A research vessel ploughs through the waves, braving the strong westerly winds of the Roaring Forties")

_A research vessel braves the strong westerly winds of the Roaring Forties during an expedition to measure levels of dissolved carbon dioxide in the surface of the ocean._

During the Age of Sail (circa 15th  to 19th centuries), these strong prevailing winds propelled ships across the Pacific, often at breakneck speed. Nevertheless, sailing west into heavy seas and strong headwinds could take weeks, especially around [Cape Horn](https://earthobservatory.nasa.gov/images/83713/tierra-del-fuego-and-cape-horn) at the southern tip of South America, making it one of the most treacherous sailing passages in the world.

The Roaring Forties take shape as warm air near the equator rises and moves toward the poles. Warm air moving poleward (on both sides of the equator) is the result of nature trying to reduce the temperature difference between the equator and at the poles created by uneven heating from the sun.

This process sets up [global circulation cells](https://www.weather.gov/jetstream/circ), which are mainly responsible for global-scale wind patterns. The air descends back to Earth’s surface at about 30 degrees’ latitude north and south of the equator. This is known as the high-pressure subtropical ridge, also known as the [horse latitudes](/facts/horse-latitudes.html). Here, as the temperature gradient decreases, air is deflected toward the poles by the Earth’s rotation, causing strong westerly and prevailing winds at approximately 40 degrees. These winds are the Roaring Forties.

The Roaring Forties in the Northern Hemisphere don’t pack the same punch that they do in the Southern Hemisphere. This is because the large land masses of North America, Europe, and Asia obstruct the airstream, whereas, in the southern hemisphere, there is less land to break the wind in South America, Australia, and New Zealand.

While the Roaring Forties may be fierce, 10 degrees south are even stronger gale-force winds called the Furious Fifties. And 10 degrees south of the Furious Fifties lie the Screaming Sixties! We can thank the intrepid sailors of yore for these wildly descriptive terms.

Did you know? - *The circulation of wind in the atmosphere is driven by the rotation of the Earth and incoming energy from the sun. Wind circulates in each hemisphere in three distinct cells, which help transport energy and heat from the equator to the poles. The winds are driven by energy from the sun at the surface as warm air rises and cold air sinks.*

- [What are the doldrums?](https://oceanservice.noaa.gov/facts/doldrums.html)

- [What are the horse latitudes?](https://oceanservice.noaa.gov/facts/horse-latitudes.html)

- [What are the trade winds?](https://oceanservice.noaa.gov/facts/tradewinds.html)

- [What is a current?](https://oceanservice.noaa.gov/facts/current.html)

-
# How does overfishing threaten coral reefs?

Coral reef ecosystems support important commercial, recreational, and subsistence fishery resources in the U.S and its territories. Fishing also plays a central social and cultural role in many island and coastal communities, where it is often a critical source of food and income.

The impacts from unsustainable fishing on coral reef areas can lead to the depletion of key reef species in many locations. Such losses often have a ripple effect, not just on the coral reef ecosystems themselves, but also on the local economies that depend on them. Additionally, certain types of fishing gear can inflict serious physical damage to coral reefs, seagrass beds, and other important marine habitats.

Coral reef fisheries, though often relatively small in scale, may have disproportionately large impacts on the ecosystem if conducted unsustainably. Rapid human population growth, increased demand, use of more efficient fishery technologies, and inadequate management and enforcement have led to the depletion of key reef species and habitat damage in many locations.

## Infographic Text

### Threats to coral reefs: Overfishing

Coral reef fish are a significant food source for over billion people worldwide. Many coastal and island communities depend on coral reef fisheries for their economic, social, and culture benefits. But too much of a good thing can be bad for coral reefs.

-   #### Fishing Nurseries
    
    Nearshore habitats serve as nurseries for many fish. Catching young fish in nets removes them before they can help replenish the population.
-   #### Marine Debris
    
    Traps set too close to reefs and marine debris, such as ghost traps lost nets, monofilament, and lines can damage coral reefs, which take a long time to recover.
-   #### Indiscriminate Fishing
    
    Use of non-selective gears, like nets and traps, often removes more herbivorous fishes. These fish eat algae and help keep the ecosystem in balance.
-   #### Fishing Spawning Aggregations
    
    Some species gather in large numbers at predictable times and locations to mate. Spawning aggregations are particularly vulnerable to overfishing.
-   #### Fishing Too Many Big Fish
    
    Large fish produce more young that are likely to survive to adulthood. Their absence means fish populations dwindle over time.

### How you can help

-   Educate yourself on local fishing rules and regulations. Your state fishery agency or bait and tackle shop can help you learn more.
-   Make sustainable seafood choice. Learn more: [www.fishwatch.gov](https://www.fishwatch.gov/)
-   Only take what you need. Catch and release fish that you don't plan to eat.
-   Be a responsible aguarium owner. Know where your fish come from and DO NOT release unwanted fish into the wild.
# What is aquaculture?

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

As the demand for seafood has increased, technology has made it possible to grow food in coastal marine waters and the open ocean. Aquaculture is a method used to produce food and other commercial products, restore habitat and replenish wild stocks, and rebuild populations of threatened and endangered species.

There are two main types of aquaculture—marine and freshwater. NOAA efforts primarily focus on marine aquaculture, which refers to farming species that live in the ocean and estuaries.

In the United States, marine aquaculture produces numerous species including oysters, clams, mussels, shrimp, seaweeds, and fish such as salmon, black sea bass, sablefish, yellowtail, and pompano. There are many ways to farm marine shellfish, including “seeding” small shellfish on the seafloor or by growing them in bottom or floating cages. Marine fish farming is typically done in net pens in the water or in tanks on land.

U.S. freshwater aquaculture produces species such as catfish and trout. Freshwater aquaculture primarily takes place in ponds or other manmade systems.

NOAA is committed to supporting an aquaculture industry that is economically, environmentally and socially sustainable. NOAA experts and partners work to understand the environmental effects of aquaculture in different settings and provide best management practices to help reduce the risk of negative impacts.

## Video Transcript

Aquaculture is breeding, raising, and harvesting fish, shellfish, and aquatic plants. Basically, it’s farming in water. U.S. aquaculture is an environmentally responsible source of food and commercial products, helps to create healthier habitats, and is used to rebuild stocks of threatened or endangered species.
# What is ocean etiquette?

VIDEO: What is ocean etiquette? Here's an overview in under 30 seconds. [Transcript](#transcript)

## Marine Wildlife Viewing Guidelines

-   Learn before you go. Read about the wildlife, viewing sites, and local regulations to get the most from your wildlife viewing experience.
-   Keep your distance. Use binoculars, spotting scopes, and cameras with zoom lenses to get a closer look.
-   Hands off. Never touch, handle, or ride marine wildlife. Touching wildlife, or attempting to do so, can injure the animal, put you at risk, and may also be illegal for certain species.
-   Do not feed or attract wildlife. Feeding or attempting to attract wildlife with food, decoys, sound, or light disrupts normal feeding cycles, may cause sickness or death from unnatural or contaminated food items, and habituates animals to people.
-   Never chase or harass wildlife. Never completely surround the animal, trap an animal between a vessel and shore, block its escape route, or come between mother and young.
-   Stay away from wildlife that appears abandoned or sick. Some marine animals, such as seals, leave the water or are exposed at low tide as part of their natural life cycle—there may be nothing wrong with them. If you think an animal is in trouble, contact local authorities for advice or report it to the [NOAA Fisheries stranding network](https://www.fisheries.noaa.gov/national/marine-life-distress/marine-mammal-health-and-stranding-response-program).

More marine wildlife viewing guidelines, specifically when viewing wildlife in national marine sanctuaries, are available [online](https://sanctuaries.noaa.gov/protect/oceanetiquette.html).

### Video Transcript

Wildlife vewing is a popular recreational activity. Remember to alawys keep a safe distance, just like theses coral reef divers.