david ruck

oceansv  asked:

Hi 😊 I wanted to ask you something. Sea lions often approach divers and people they find swimming where they are. As people must keep a certain distance and not go and approach some animals (whales and dolphins, for example) unless the animal decides to get close, I was wondering if it's okay to be so near them in the water, in case sea lions are the ones that approach people. Thank you!

It’s a great question! Watching marine mammals in their natural habitat can be a great way to learn about the environment and promote conservation (plus, it’s fun!). But it’s always important to give animals lots of space to live their lives and carry out their daily activities. Getting too close can make it harder for animals to feed or rest, which in turn makes it harder for them to survive. With that in mind, as you point out, the Marine Mammal Protection Act prohibits harassing marine mammals in the wild. 

In general, guidelines include:

  • observing wild dolphins, porpoises, and seals from a safe distance of at least 50 yards by land or sea
  • observing large whales from a safe distance of at least 100 yards by land or sea
  • using binoculars or telephoto lenses to see better without getting too close
  • avoiding abrupt movements or circling and entrapping marine mammals between watercraft, or between watercraft and shore.

Still, like you say, sea lions and other animals are quite curious and often do approach divers! Case in point:

Photo in Olympic Coast National Marine Sanctuary; credit David J. Ruck/NOAA

So what do you do when this happens?

Typically, if you see an animal or it approaches you, the best way to go is to remain calm, watch it, and don’t attempt to interact with it. Don’t get any closer than it wants to get, and when it decides to swim away, let it; don’t follow it!

Basically, you shouldn’t closely approach or attempt to interact with marine mammals in the wild – but if they come to you, you can watch calmly. But never attempt to pet, touch, or feed them!

You can find more information about viewing guidelines here and about good ocean etiquette here.

Thanks for taking care of our ocean’s amazing mammals!

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Whoosh! Can you hear the bubbles as these sea lions whiz past in Olympic Coast National Marine Sanctuary? 

Found throughout West Coast national marine sanctuaries, sea lions are graceful and acrobatic swimmers. They use this speed and maneuverability to catch an assortment of small fish and squid! 

(Photo: David J. Ruck/NOAA)

Listening for History: Exploring Thunder Bay National Marine Sanctuary with Sound

How do you find a shipwreck in a 23,000-square-mile lake? For researchers, it can be like finding a needle in a haystack. 

This spring, researchers in Thunder Bay National Marine Sanctuary undertook the second phase of a research expedition to find lost shipwrecks within sanctuary waters in Lake Huron. From May 15 through 26, they used acoustics to explore deep water areas off Presque Isle.

University of Delaware researchers monitor incoming survey data from R/V Laurentian’s science lab. Photo: NOAA

Unlike on land, where features can be documented with aerial imagery or satellites equipped with cameras, visual survey isn’t practical underwater. In some cases the water is too murky, or turbid, to take photographs. At deeper depths there simply isn’t any ambient light. A camera, therefore, would only see darkness unless an array of lights was lowered down with it to illuminate the area.

Sound, however, is astonishingly efficient underwater. The density of water, both freshwater and saltwater, allows sound waves to travel great distances. When these waves encounter an object, they bounce off and in some cases reflect back in the direction of their original travel. In fact, by knowing the speed of sound through water, researchers can calculate how far away an object is. If the object being mapped is the lake floor, in this case the bottom of Lake Huron, the distance to the bottom, or water depth, can be determined by the time delay between a sound wave emitted at the surface and its travel to the lake floor and return back to the source at the surface.

The behavior of sound in water is so reliable that hydrographers can make detailed maps of the seafloor, accurate to within inches. Archaeologists can also use this technology to locate undiscovered shipwrecks. Where the lake bottom is flat and even, a historical shipwreck will appear as a large “anomaly” in the sonar data, a feature that sits upright off the bottom in stark contrast to the surrounding natural features. Once located, researchers can return with additional tools, such as underwater robots or divers, to further document a potential discovery.

University of Delaware sonar technicians Kenny Haulsee and Peter Barron route cables from the echosounder (yellow device in foreground) along a pole mount used to lower and secure the echosounder along the side of the vessel. The team installed and tested the entire sonar system while dockside to ensure proper operation before getting underway within the survey area. Photo: NOAA

Using sound to reveal lost shipwrecks

When researchers are first characterizing the lakebed or seafloor, we use a sonar system that can see a wide strip of the bottom at once. By running a pre-planned grid of overlapping passes – a technique referred to as “mowing the lawn” for the pattern it creates – researchers end up with a complete map of a given area. However, this wide-scanning sonar results in a less detailed image, or lower-resolution one, than a more focused sonar would reveal.

As a result, a dual-phase approach is often needed. That’s where the multiple phases of the Thunder Bay shipwreck expedition come in. In Phase II, completed in May, researchers used a wide-reaching sonar to scan large portions of the lake floor. By surveying large areas as quickly as possible, previously unexplored areas can be covered and new discoveries made.

Once surveyed, archaeologists will examine the data and tag anomalies against the surrounding lake floor. These may turn out to be lost shipwrecks. Then, in June’s Phase III, researchers will return to those targets with more detailed documentation methods.

University of Delaware sonar technician Peter Barron prepares to lower a device that will measure the speed of sound throughout the entire water column. These sound velocity profiles were collected once every four hours during the entire survey. Photo: NOAA

Presque Isle: The intersection of a maritime highway

The waters off Presque Isle in central Lake Huron form a sort of crossroads for the area’s shipping lanes. The lanes for vessels traveling up and down the lakes, whether to and from the Straits of Mackinaw or the Soo Locks, all converge within about 10 miles of the Presque Isle lighthouse. Within this area, many ships have collided and sunk during periods of bad weather or limited visibility. Dozens of known shipwrecks are spread across the lake floor off Presque Isle, and many more have yet to be found.

Many ships have met their end off the shores of Presque Isle in Lake Huron. Photo: David J. Ruck/NOAA

For this reason, researchers from Thunder Bay National Marine Sanctuary selected a large, 100 square mile area off Presque Isle for a wide-area exploratory survey. Partnering with the University of Delaware and using a research vessel from the NOAA’s Great Lakes Environmental Research Lab (GLERL), they conducted a two-week survey mission in May to search for undiscovered shipwrecks.

With a six-person survey crew, the mission involved 24-hour continuous operations for six days. Breaking into two-person watches, members of the team would spend four hours running the survey gear, followed by eight hours off, then another four hours on within a given 24-hour time period. That way, a team of researchers was constantly operating the sonar. The teams logged and organized data files, selected and managed survey scan lines, and communicated with the research vessel’s crew regarding navigation, survey speed, and general movement throughout the survey area.

A preliminary side scan sonar mosaic composed of 24 individual survey lines. Across the lake’s bottom, numerous features can be seen, including geological formations and variable bottom types. Image: University of Delaware.

As sonar data was logged, researchers also took additional measurements of the speed of sound through water. Approximately every four hours, a device was sent to the bottom of the lake. As it traveled, it measured the speed of sound and produced a sound velocity profile. By accurately measuring how fast sound was moving through the water, the researchers could accurately determine the distance to the bottom.

As six days passed, over 400GB of sonar data was logged and 100 square miles of area were covered. Now, researchers have to process all of the data and review it for anomalous objects that may turn out to be new shipwreck discoveries. During Phase III operations, these targets will be investigated with high-resolution sonar onboard an autonomous underwater vehicle operated by Michigan Technological University. Stay tuned for a recap of that leg of the expedition in a few weeks!

Dive into an undersea rainbow in Fagatele Bay! 

This beautiful coral reef is located within National Marine Sanctuary of American Samoa. Here in Fagatele Bay, you’ll find at least 271 species of fishes, 168 species of coral, and at least 1,400 species of algae and invertebrates – all in 0.25 square mile! 

(Photo: David J. Ruck/NOAA)

Take a deep breath this Shipwreck Sunday and explore the wrecks of Thunder Bay National Marine Sanctuary! 

Thanks to the cold, fresh water of Lake Huron, the sanctuary protects one of our nation’s best-preserved collections of shipwrecks. American Union, pictured here, was a three-masted schooner that sank in 1894 after running up on the rocks at Thompson’s Harbor. This is one wreck you don’t have to be a diver to explore: resting only 10 feet beneath the surface, American Union’s remains are easily viewable by kayakers and snorkelers. 

(Photo: David J. Ruck/NOAA)

anonymous asked:

Penguins

Penguins!

While we love penguins, there are actually no penguins in your national marine sanctuaries. With the exception of the Galápagos penguin (which lives in the Galápagos Islands), penguins only live in the Southern Hemisphere. And all U.S. national marine sanctuaries except National Marine Sanctuary of American Samoa (which is not a penguin habitat) are located in the Northern Hemisphere. So sadly, no penguins here.

But!

We do have lots of seabirds! Like…

Tufted puffin, Cordell Bank National Marine Sanctuary, California (Photo: Sophie Webb/NOAA)

Shearwater, Stellwagen Bank National Marine Sanctuary, Massachusetts (Photo: Peter Flood)

Laysan albatross, Cordell Bank National Marine Sanctuary, California (Photo: Laura Morse/NOAA)

Brown pelican, Florida Keys National Marine Sanctuary, Florida (Photo: David J. Ruck/NOAA)

Seabirds like these are key for tracking ecosystem health. It can be hard for scientists to track species like small baitfish, but birds follow those fish, and since birds are above the waves, it’s a lot easier to spot them. 

Learn more about birds in your National Marine Sanctuary System:

Because we don’t want to deprive you, here’s a photo of some emperor penguins in Antarctica. Not a U.S. national marine sanctuary, but it’s still a pretty cool place. (Photo: Michael Van Woert/NOAA)

Though they might look barren from afar, rocky cliffs and seastacks in Olympic Coast National Marine Sanctuary provide key habitat for many marine species.

Crevices and caves offer shelter to small invertebrates, while channels and passageways allow fish to roam with relative protection. Beneath the waves on these rocky reef habitats, you’ll find animal life clinging to every surface, and seaweeds thriving in the upper layers of the water. 

(Photo: David J. Ruck/NOAA)

Feeling like it’s a long week already? 

Take a deep breath and enjoy this shoreline view of National Marine Sanctuary of American Samoa! This beautiful sanctuary protects more than 13,500 square miles of coral reefs and open ocean waters – an area bigger than the state of Maryland. 

(Photo: David J. Ruck/NOAA)

Vroom! 

A NOAA diver in Thunder Bay National Marine Sanctuary explores the wreck of Duncan City using a diver propulsion vehicle, or scooter. Scooters like these help archaeologists and divers cover more ground when investigating shipwreck sites and other areas. 

(Photo: David J. Ruck/NOAA)

This month, we celebrate Asian/Pacific American Heritage Month!

In National Marine Sanctuary of American Samoa, fa'a Samoa – or the Samoan way of life – is the cultural context for all sanctuary activities and functions. Fa'a-Samoa places great importance on the dignity and achievements of the group rather than individuals. Here, a group from the island of Ta'u practices for the annual Flag Day fautasi (longboat) regatta. 

(Photo: David J. Ruck/NOAA) 

Welcome to the Dry Tortugas! 

Located near Dry Tortugas National Park, Tortugas Ecological Reserve in Florida Keys National Marine Sanctuary protects diverse habitats including seagrass beds and coral reefs. Some parts of the reserve, including Riley’s Hump in the southern portion of the reserve, are protected in part because they are a known spawning site for many species of fish – many of which, like groupers, use sound during this important life stage. 

(Photo: David J. Ruck/NOAA)