remiconnesson/oceanservice-noaa-facts huggingface dataset:
# What are nature-based solutions?

![Mordecai Island, New Jersey, protects the Back Bay areas of Long Beach Island. In 2015, part of the salt marsh island was restored with dredged material and planted with native vegetation. (Photo credit: NOAA)](/facts/mordecai-island-960.jpg)

_Mordecai Island, New Jersey, protects the Back Bay areas of Long Beach Island. In 2015, part of the salt marsh island was restored with dredged material and planted with native vegetation. (Photo credit: NOAA)_

Nature-based solutions intentionally use natural and nature-based habitats, such as marshes or human-made oyster reefs, and natural processes, such as river currents, in infrastructure projects to reduce coastal hazard risks and deliver multiple economic, social, and environmental benefits.

Other examples of nature-based solutions are created coral reefs, human-made dunes, and the building up of [barrier islands](/facts/barrier-islands.html), or the [salt marshes](/facts/saltmarsh.html) on them, with sediment.

Why would we want to build up a salt marsh? [Coastal communities](/facts/coastalthreat.html) are particularly vulnerable to storms because they are at the interface between the land and sea, yet 40% of the U.S. population lives near a coast. Barrier islands and their salt marshes make coasts more [resilient](/facts/resilience.html) to catastrophic weather events, such as hurricanes, and their accompanying storm surge.

Salt marshes provide a lot of other benefits to humans. These environments protect people and infrastructure from day-to-day wave energy; they provide habitat for wildlife; and they [bury carbon](about:/facts/bluecarbon.html#:~:text=Blue%20carbon%20is%20simply%20the,dioxide%2C%20which%20contains%20atmospheric%20carbon). They also provide places for recreation activities and contribute to improving water quality.

However, some barrier islands and their salt marshes are rapidly disappearing as a consequence of many factors, including sea level rise. To offset this problem, some federal agencies are using clean sediment dredged from shipping channels to restore habitats that are being lost.

NOAA looks at nature-based solutions projects such as these and asks questions, such as what kind of management actions can facilitate better outcomes for the marshes? What do we get out of nature-based solutions, and how does that amended system compare to the original, untouched system in the way it functions, provides habitat, and buries carbon? Fifteen years from now, will we still get the benefits that we were intending to get out of them? What is the effect of this amendment on the ability of the marsh to break waves or protect the downwind areas from wave energy? Is the marsh going to pull out the carbon dioxide from the atmosphere as well as it did before we placed the material?

Answering these questions is the first step in optimizing the rebuilding of salt marsh environments that do so much for us.
# What is a barrier island?

![a barrier island](/facts/barrier-island960.jpg "What is a barrier island?")

_[Satellite image](https://earthobservatory.nasa.gov/images/88619/cape-hatteras-national-seashore) of Cape Hatteras National Seashore on the Outer Banks of North Carolina. Credit: NASA’s Earth Observatory._

Barrier islands form as waves repeatedly deposit sediment parallel to the shoreline. As wind and waves shift according to weather patterns and local geographic features, these islands [constantly move, erode, and grow](https://earthobservatory.nasa.gov/world-of-change/CapeCod). They can even [disappear entirely](https://oceanservice.noaa.gov/education/tutorial_currents/media/supp_cur03c.html).

They are generally separated from the mainland by tidal creeks, bays, and [lagoons](https://oceanservice.noaa.gov/facts/lagoon.html). Beaches and sand dune systems form on the side of the island facing the ocean; the side facing the shore often contains [marshes](https://oceanservice.noaa.gov/facts/saltmarsh.html), tidal flats, and [maritime forests](https://oceanservice.noaa.gov/facts/maritime-forest.html). These areas are important [habitat](https://oceanservice.noaa.gov/education/tutorial_estuaries/est06_habitats.html) for seabirds, fish and shellfish, and nesting sea turtles.

Many barrier islands are found off the U.S. Gulf and East coasts, such as the Outer Banks off North Carolina. Barrier island chains tend to form near river deltas and in areas with low tectonic activity and relatively flat coastal terrain. The rocky cliffs and shifting tectonic plates off the West Coast, along with other features of the terrain and tides, prevent barrier islands from forming there.

These islands are critical to protecting coastal communities and ecosystems from extreme weather. Beach dunes and grasses on barrier islands absorb wave energy before the wave hits the mainland. This generally means smaller storm surge and less flooding on the coast.

Unfortunately, barrier islands are disappearing at an alarming rate. Erosion can be caused by human activities such as ship traffic, hard levees, and infrastructure projects, even those far upriver. Damming and dredging projects can significantly affect the amount of sand and sediment available to fortify barrier islands. The effects of climate change, including rapid sea level rise and extreme weather events, can cause or worsen barrier island erosion.

NOAA supports natural and nature-based infrastructure projects that restore and protect barrier islands and the benefits they provide to coastal communities and ecosystems. Thousands of acres of barrier islands and marshland have been restored or enhanced as part of [Gulf Spill Restoration](https://www.gulfspillrestoration.noaa.gov/) projects. These projects address damage to natural resources and wildlife from the Deepwater Horizon oil spill, but the restored barrier islands also provide added [coastal resilience](https://www.fisheries.noaa.gov/feature-story/noaa-and-partners-build-coastal-resiliency-natural-infrastructure-louisiana) and protect important estuary habitats.
# How much oxygen comes from the ocean?

![a close-up view of the roiling ocean](/facts/ocean-surface-960.jpg)

_The surface layer of the ocean is teeming with photosynthetic plankton. Though they're invisible to the naked eye, they produce more oxygen than the largest redwoods._

Scientists estimate that roughly half of the oxygen production on Earth comes from the ocean. The majority of this production is from oceanic [plankton](/facts/plankton.html) — drifting plants, algae, and some bacteria that can photosynthesize. One particular species, Prochlorococcus, is the smallest photosynthetic organism on Earth. But [this little bacteria produces up to 20% of the oxygen in our entire biosphere](https://ocean.si.edu/ocean-life/plankton/every-breath-you-take-thank-ocean). That’s a higher percentage than all of the tropical rainforests on land combined.

Calculating the exact percentage of oxygen produced in the ocean is difficult because the amounts are constantly changing. Scientists can use [satellite imagery](/facts/satellites-ocean.html) to track photosynthesizing plankton and estimate [the amount of photosynthesis occurring in the ocean](https://earthobservatory.nasa.gov/global-maps/MY1DMM_CHLORA/MOD17A2_M_PSN), but satellite imagery cannot tell the whole story. The amount of plankton changes seasonally and in response to changes in the water’s nutrient load, temperature, and other factors. Studies have shown that the amount of oxygen in specific locations [varies with time of day and with the tides](https://www.whoi.edu/multimedia/ocean-earth-oxygen-bank/).

It’s important to remember that although the ocean produces at least 50% of the oxygen on Earth, roughly the same amount is consumed by marine life. Like animals on land, marine animals use oxygen to breathe, and both plants and animals use oxygen for cellular respiration. Oxygen is also consumed when [dead plants and animals decay](/facts/carbon-cycle.html) in the ocean. There is also oxygen in the atmosphere which has accumulated over hundreds of millions of years. As land animals, most of the oxygen humans breathe comes from this source.

This is particularly problematic when algal blooms die and the decomposition process uses oxygen faster than it can be replenished. This can create areas of extremely low oxygen concentrations, or [hypoxia](/hazards/hypoxia/). These areas are often called [dead zones](/facts/deadzone.html), because the oxygen levels are too low to support most marine life. NOAA’s [National Centers for Coastal Ocean Science](https://coastalscience.noaa.gov/) conducts extensive research and forecasting on algal blooms and hypoxia to lessen the harm done to the ocean ecosystem and human environment.
# What is the intertidal zone?

## The **intertidal zone** is the area where the **ocean meets the land** between high and low tides.

![A tide pool within Monterey Bay National Marine Sanctuary](/facts/intertidal-zone.jpg)

A tide pool within [Monterey Bay National Marine Sanctuary](https://montereybay.noaa.gov/).

Intertidal zones exist anywhere the ocean meets the land, from [steep, rocky ledges](/facts/highesttide.html) to long, sloping sandy beaches and [mudflats](https://www.nps.gov/subjects/oceans/mudflats.htm) that can extend for hundreds of meters. Four physical divisions, each with distinct characteristics and ecological differences, divide the intertidal zone. They are the:

-   Spray zone: dampened by ocean spray and high waves and is submerged only during very high [tides](/tidefrequency.html) or severe storms.
-   High intertidal zone: floods during the peaks of daily high tides but remains dry for long stretches between high tides. It is inhabited by hardy sea life that can withstand pounding waves, such as [barnacles](/facts/barnacles.html), marine snails, [mussels](https://oceantoday.noaa.gov/buildinggoodmussels/), [limpets](https://www.nps.gov/cabr/blogs/species-spotlight-owl-limpet-lottia-gigantea.htm), [shore crabs](https://www.nps.gov/media/photo/view.htm?id=ED947026-155D-4519-3E5539BC77BCADD8), and [hermit crabs](https://www.chesapeakebay.net/discover/field-guide/entry/hermit_crabs).
-   Middle intertidal zone: over which the tides ebb and flow twice a day, and which is inhabited by a greater variety of both plants and animals, including [sea stars](/facts/starfish.html) and anemones.
-   Low intertidal zone: virtually always underwater except during the lowest of [spring tides](/facts/springtide.html). Life is more abundant there because of the protection provided by the water.

Sea creatures arrange themselves vertically in the intertidal zone depending on their abilities to compete for space, avoid predators from above and below, and resist drying out. Residents of the higher intertidal zones can either close themselves up in their shells to remain moist and ward off predators, or are mobile enough to retreat to a submerged zone when the tide goes out. In the lower parts of the intertidal zone, many plants and animals attach themselves in place and are very sturdy, very flexible, or otherwise well suited to stand up to wave energy.

Larger marine life, such as seals, sea lions, and fish, find foraging for food ideal at high tide in the intertidal zone, while a large variety of shorebirds, looking for their meals, stroll hungrily over the intertidal zone at low tide.

Did you know? - Take only [photographs and leave only footprints](https://oceanservice.noaa.gov/facts/ocean-etiquette.html)! Empty shells are recycled and reused by
animals such as hermit crabs. Seaweed tossed on the shore decomposes and recycles nutrients
back into the marine ecosystem.
# How do hurricanes affect sea life?

![A sunken vessel in Vieques, Puerto Rico](/facts/hurricanes-affect-sea-life.jpg "A sunken vessel in Vieques, Puerto Rico")

_A sunken vessel among a coral colony in Vieques, Puerto Rico, on Oct. 23, 2017. Following Hurricane Maria in 2017, NOAA and partners removed a total of 479 displaced vessels and 3,668 hazardous chemical containers. Teams also relocated approximately 400 coral colonies._

When a storm churns across the ocean, the warm surface waters provide additional moisture and can fuel the storm into a hurricane. As the hurricane grows larger and more potent, it can generate waves as high as 18.3 meters (60 feet), tossing and mixing warmer surface waters with the colder, saltier water below. The resulting currents can extend as far as 91.5 meters (300 feet) below the surface, wreaking deadly havoc on marine life.

If the wild currents fail to break up coral reefs in their path, the rain-infused water they bring reduces salt levels and otherwise stresses corals. As the hurricane moves toward shore, the underwater tumult can cause shifting sands and muddy shallow waters, blocking the essential sunlight on which corals and other sea creatures rely.

Slow-moving fish and turtles and shellfish beds are often decimated by the rough undercurrents and rapid changes in water temperature and salinity wrought by a hurricane. Sharks, whales, and other large animals swiftly move to calmer waters, however, and, generally speaking, are not overly affected by hurricanes.

Did you know? - *Delicate branching corals, like staghorn and elkhorn species, are among the most vulnerable to
breakage and can be reduced to rubble during hurricanes or even less severe storms. Sometimes,
though, the breaking of coral into pieces may actually help a [coral colony reproduce through a process called fragmentation](https://floridakeys.noaa.gov/corals/reproduce.html). If conditions are favorable and the coral fragments come to rest where they can reattach to the seafloor, fragmentation can result in colonies flourishing in new
locations. In other instances, [corals that reproduce through broadcast spawning](https://floridakeys.noaa.gov/whatsnew/around/2011/coralspawn.html) may get a little extra help from late summer storms, which help the coral larvae disburse to uncolonized areas.*

- [NOS role before, during, and after hurricanes](https://oceanservice.noaa.gov/hazards/hurricanes)

- [Hurricanes: Friend or foe to coral reefs?](https://floridakeys.noaa.gov/whatsnew/around/2012/hurricanes.html)

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

-
# What is a tide pool?

![tide pool in West Quoddy Head, Maine](tide-pool960.jpg)

_Tide pools are found in intertidal zones, which are areas where the ocean meets the land: from steep, rocky ledges to long, sloping sandy beaches and vast mudflats._

![tide poool in Monterey Bay, California](/facts/tide-pool360.jpg)

##### **Tide Pool Tips**

-   The best time to visit tide pools is at low tide.
-   Bring a bag with you to pick up any plastic, paper, glass, or metal trash on the beach.
-   Find footholds on bare rocks, which are less slippery than those colonized with algae and other sensitive sea life.
-   If you peek under a rock, put it back where and as you found it. Leave the animals and plants alone.
-   Do not collect intertidal species. It is illegal to do so in many areas.

Formed in depressions along the shoreline of rocky coasts, tide pools are filled with seawater that gets trapped as the tide recedes. While these small basins at the ocean’s edge typically range from mere inches to a few feet deep and a few feet across, they are packed with sturdy sea life such as snails, barnacles, mussels, anemones, urchins, sea stars, crustaceans, seaweed, and small fish.

As ocean water retreats outside the tide pool during low tide, the [resident marine life](https://montereybay.noaa.gov/visitor/TidePool/species.html) must endure hours exposed to the sun, low oxygen, increasing water temperature, and predators such as wading birds that specialize in dining in these shallow pools. At high tide, the pool’s plants and animals are bathed in fresh seawater, but must endure the pounding of crashing waves and foraging fish with temporary access to the shoreline.

To survive in this rugged environment, tide pool inhabitants often cling very tightly to any rock to which they can adhere. [Barnacles](/facts/barnacles.html), for example, produce a fast-curing cement that lets them stay put. This natural substance is among the most powerful glues known to exist. In fact, researchers are trying to figure out if and how it can be harvested or reproduced for commercial use.

The space in a tide pool may be limited, but the food there is plentiful. Every wave at every high tide delivers fresh nutrients and microscopic organisms, such as [plankton](/facts/phyto.html), to support and replenish the pool’s intricate food chain. Washed in by the waves, these organisms nourish the smallest animals, which, in turn, sustain the larger ones.
# What is a glass sponge?

##### **Did you know?**

_Glass sponge reefs were thought to have gone extinct about 40 million years ago, leaving behind giant fossil cliffs that stretch across parts of Spain, France, Germany, and Romania. In 1987, however, a team of Canadian scientists discovered 9,000-year-old living glass sponge reefs on British Columbia’s northern coast. To date, these are the only such reefs known to exist._

Glass sponges in the class _Hexactinellida_ are animals commonly found in the deep ocean. Their tissues contain glass-like structural particles, called spicules, that are made of silica (hence their name). Some species of glass sponges produce extremely large spicules that fuse together in beautiful patterns to form a “glass house”—a complex skeleton that often remains intact even after the sponge itself dies. The skeleton of the glass sponge, together with various chemicals, provides defense against many predators. Nonetheless, some starfish are known to feed on these rare creatures of the deep.

Most glass sponges live attached to hard surfaces and consume small bacteria and plankton that they filter from the surrounding water. Their intricate skeletons provide many other animals with a home.

The most famous glass sponge is a species of _Euplectella,_ known as the “Venus flower basket,” which builds its skeleton in a way that entraps a certain species of crustacean inside for life. This sponge often houses two small, shrimp-like Stenopodidea, a male and a female, who live out their lives inside the sponge. The crustaceans breed, and when their offspring are tiny, they escape to find a new Venus flower basket of their own. The pair inside the basket clean it and, in return, the basket provides food for the crustaceans through its waste. The animals eventually grow too large to escape the sponge, so they are forced to "stay put" for the rest of their lives.

Did you know? - *Glass sponge reefs were thought to have gone extinct about 40 million years ago, leaving behind giant fossil cliffs that stretch across parts of Spain, France, Germany, and Romania. In 1987, however, a team of Canadian scientists discovered 9,000-year-old living glass sponge reefs on British Columbia’s northern coast. To date, these are the only such reefs known to exist.*
# What is the most commonly found ocean litter?

![Cigarette and cigarette filter found on the beach at Sandy Point State Park, MD. (Photo Credit: NOAA)](cigarettes-960.jpg)

_Cigarette and cigarette filter found on the beach at Sandy Point State Park, Maryland._

Broken bottles, plastic toys, food wrappers ... during a walk along the coast one finds any of these items, and more. In all that litter, there is one item more common than any other: cigarette butts.

Cigarette butts are a pervasive, long-lasting, and a toxic form of marine debris. They primarily reach our waterways through improper disposal on beaches, rivers, and anywhere on land, transported to our coasts by runoff and stormwater. Once butts reach the beach, they may impact marine organisms and habitats.

Most cigarette filters are made out of cellulose acetate, a plastic-like material that’s easy to manufacture, but not easy to degrade. The fibers in cigarette filters behave just like plastics in our oceans, the UV rays from our sun may break the fibers down into smaller pieces, but they don’t disappear. One solid filter ends up being thousands of tiny [microplastics.](/facts/microplastics.html)

Here’s what you can do about keeping those cigarette butts, lighters and cigar tips from spoiling our ocean:

-   If you smoke, don’t flick your butt! Place it in a proper receptacle.
-   Organize cleanups in your local community. Make sure you document your findings with the [Marine Debris Tracker App.](https://marinedebris.noaa.gov/partnerships/marine-debris-tracker)
-   Be an environmental steward in your own community. Spread awareness about cigarette butt litter.
-   Worried about the smell from cigarettes in your pocket? Purchase a pocket ashtray! These trays can come in the form of metal boxes or vinyl pouches, fit in your pocket, purse, or backpack, and extinguish cigarettes until they can be properly disposed of in the trash.
-   Recycle your butts! Although it is not common, there are a few places, like the City of Vancouver, and organizations, like TerraCycle, that will actually recycle your filters for you. Check to see if there any programs in your area.

_The [NOAA Marine Debris Program](https://marinedebris.noaa.gov/) is the U.S. Federal government's lead for addressing marine debris._

Did you know? - *Cigarette butts continue to rank among the most common types of marine debris found. [The Ocean Conservancy’s 2018 International Coastal Cleanup Report](https://oceanconservancy.org/trash-free-seas/international-coastal-cleanup/annual-data-release/) stated that 2,412,151 cigarette butts were collected worldwide in 2017. This is an increase from the 1,863,838 butts collected around the world in 2016.*
# What is an sponge?

##### **Did you know?**

_Whether you’re dealing with humans or [horseshoe crabs](/facts/horseshoe-crab.html), it’s important to mind your manners. Being respectful of ocean life is vital to protecting endangered species, federally-protected species, and thousands of other species. Learn more about [ocean etiquette](/facts/ocean-etiquette.html)._

Given the vast size of the ocean, it is impossible to know the exact number of species that live there. Research suggests, however, that the number of species in the ocean is decreasing. The continued decline in the health of many ecosystems, coupled with [rising extinction rates](https://nca2014.globalchange.gov/report/regions/oceans#statement-16748), are likely outpacing species’ ability to evolve to tolerate the conditions of our rapidly changing planet. It is not all bad news, though. Researchers around the world continue to study marine life and habitats to help develop new strategies to preserve vital ocean ecosystems.

One recent effort—[the Census of Marine Life](https://oceanservice.noaa.gov/facts/marine-census.html)—was an international project spanning 10 years that recorded the diversity, distribution, and abundance of life in the ocean. More than 2,700 scientists from 80 nations contributed to the Census. The results of their research, which included 540 marine expeditions, were reported at The Royal Society of London in October 2010. The [Ocean Biogeographic Information System](http://www.iobis.org/) contains the Census data. NOAA Fisheries is responsible for the protection, conservation, and recovery of [endangered and threatened marine and estuarine species in the United States](https://www.fisheries.noaa.gov/topic/endangered-species-conservation) under the Endangered Species Act.

Did you know? - *Whether you’re dealing with humans or [horseshoe crabs](https://oceanservice.noaa.gov/facts/horseshoe-crab.html), it’s important to mind your manners. Being respectful of ocean life is vital to protecting endangered species, federally-protected species, and thousands of other species. Learn more about [ocean etiquette](https://oceanservice.noaa.gov/facts/ocean-etiquette.html).*