
This post was written by Ed Robeck, Director of Education and Outreach at the American Geosciences Institute (AGI) and School of Rock October 2023 instructor.
On the transit from Reykjavik to Amsterdam during IODP expedition 400T, the seas are giving our group of science educators a lot to think about. Waves of 4-6 meters are moving the JOIDES Resolution in all directions (rolling, pitching, and heaving), and we are all feeling the effects of the storm as it does. In fact, those movements have forced us to slow our headway considerably from what would be normal speed, postponing our arrival by a day. So, of course, a bunch of us started science-ing about the situation.

Fortunately, one of the teachers, DaNel Hogan, has an app (Physics Toolbox Suite) on her phone, which provides the data we need to do some impromptu explorations. The app records acceleration in all three dimensions. Since the dramatic up and down motion was most unusual for us, we paid attention to the z-dimension acceleration first, which turned out to be about ±1 m/sec^2 most of the time, (in round figures—with extremes more like ± 2 m/sec^2 ). Knowing that the acceleration of gravity is 9.8 m/sec^2 , that measurement suggests that a person would experience an effective change in weight (but not mass, unfortunately) of ±10%. That is, a +10% acceleration on the ship’s upward movement, and -10% on the downward movement—or a total of 20% across the period of a single cycle. The period of the oscillations on the ship range from about 6 seconds to about 12 seconds—averaging 9 seconds, which happens to be almost exactly the time it takes to carefully ascend or descend a staircase on the ship. This means that a 150 lb. person would feel themselves change from about 135 lb to 165 lb while moving between decks—a 30 lb. difference in the weight the person would feel. That’s effectively the change from feeling like “I can fly” to something like “I just can’t take another step!” That was a change we could all identify with moving around the ship.

We were talking about this while sitting in the conference room where we spend most of our time, and we noticed empty chairs swinging around in unison. Sometimes they’d rotate about 20º before turning back, and sometimes rotating almost 180º. Is this inertia, suggesting that the ship is pivoting that much beneath them? Probably not. On the wall of the conference room there is a monitor that shows various data about our trip, including the heading (where we’re going) and the bearing (which way the ship is pointing). The two are diverging to varying amounts due to the strong wind off the port bow, (probably with a lot of noise in the signal). The variation we see of 10º – 20º would not support inertia as the main cause of the free-swinging chairs. After some discussion, we came to the shared interpretation that the chair movements have more to do with the chair’s center of gravity being offset from its axis of rotation. With each pitch of the ship, the center of gravity is raised, leading to added torque being generated, which leads to the chair swinging around until the center of gravity is on the low side. When the next movement in the opposite direction takes place, the chair swings the other way.
These are not entirely empty machinations. Some of it becomes important in the core labs. For example, we considered the fact that mass of core segments is important in many calculations of their properties. How does one calculate the mass of a sample when the scale is being accelerated up and down randomly? The solution is conceptually elegant. There are two scales—one with a sample and the other with known mass. The acceleration can be easily calculated based on apparently change in the force on the scale produced by the known mass, which provides a correction for a computer connected to both scales. That correction is applied to the sample reading to calculate its mass in real time.

There are other effects we are observing—sliding of smooth objects, rolling of anything laid on a round side (crayons on tables were especially fun)—all of which we’re getting used to and many of which are more straightforward to explain using a combination of friction, inertia, and gravity. Other effects are now feeling normal, too—loud bangs and vibrations from waves hitting the ship, sloshing of water on the deck, and creaking bookshelves. All in all, the waves have made for a voyage that is even more interesting than anticipated—and for those of us less affected by nausea—an opportunity to apply science to yet another experience provided by life on the JOIDES Resolution.
Ocean Acidification
Do Sea Turtles Get Lost?
Did you know some female sea turtles can travel hundreds—or even thousands—of miles through open ocean before returning to nest on or near the very beaches where they hatched? In fact, Leatherback sea turtles take this long-distance travel to an extraordinary level. Pacific leatherbacks nesting in Indonesia have been documented migrating more than 10,000 kilometers to the West Coast of the United States. That’s the longest migration of any air-breathing marine vertebrate. So how do they accomplish this without Google Maps?
Scientists have found that sea turtles can sense magnetic information and use it as a navigational cue. Because the strength and angle of Earth’s magnetic field vary across the planet, these subtle differences can provide turtles with information about where they are and help guide their movements across the ocean. For turtles that return to their birthplace to nest (a behavior known as natal homing), these magnetic cues may be especially important. It’s an extraordinary system, but even the best navigation can take a turtle only so far.
Despite their great sense of direction, sea turtles don’t always make it where they’re going.
A sea turtle may be capable of navigating thousands of miles, but reaching the right destination is that much more of a challenge when human-caused obstacles lie in the way.
Artificial light is one example. Artificial lighting not only discourages nesting females from coming ashore but also has a harmful impact on hatchlings, which historically emerge from their nests at night and orient toward the brightest horizon. On a natural, undeveloped beach, that is generally the open ocean. But artificial light from coastal development can overwhelm the natural cue, drawing hatchlings inland away from the water and causing them to get lost on day one.
Coastal development not only brings more artificial light and human activity to the shoreline, but it also changes turtle habitats themselves. Buildings, roads and other development can alter or reduce areas sea turtles need for nesting. Shoreline armoring, such as seawalls, can eliminate the dry sand turtles need to successfully nest, while beach driving and other activities can further disrupt nesting habitats. And these challenges extend beyond the beach.
The ocean is getting noisier, too. Sea turtles have internal ears and can hear underwater sounds. Vessel traffic, oil and gas surveys, underwater construction and sonar all add noise to the marine environment. Human-generated sound can cause stress, disrupt normal behaviors or even force marine animals to move from preferred habitats or divert from migratory paths.
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Evolution never saw the plastic grocery bag coming.
Then there’s a threat sea turtles encounter almost everywhere they travel: plastic pollution. Sea turtles evolved over millions of years to spot drifting prey, like jellyfish. But plastic rapidly started to be used only around 60+ years ago.
Our plastic trash entered the ocean so quickly that animals haven’t had time to adapt. To a hungry sea turtle, a floating plastic bag still looks enough like dinner to trick even an experienced turtle. Plastic bags, balloons, soft plastic packaging and other plastics, once swallowed, can block a turtle’s digestive tract or puncture internal organs. And it doesn’t necessarily take much.
A recent Ocean Conservancy study of more than 10,000 marine animal autopsies found that nearly half of the sea turtles studied had ingested plastic. Even more alarming, researchers found that for adult loggerhead turtles, swallowing just one and a half times the plastic in a golf ball was enough to kill 50% of these creatures.
It’s a heartbreaking reminder that something we use for minutes can threaten an animal that’s been roaming Earth’s ocean for more than 100 million years.

Ancient animals still face very modern threats.
Sea turtles survived the extinction event that wiped out dinosaurs. They’ve outlasted shifting continents and dramatic changes to our planet. But surviving millions of years doesn’t make them invincible. Today, they’re facing threats that appeared in the blink of an evolutionary eye: plastic pollution, habitat loss, vessel strikes, fishing gear entanglement and climate change. The remarkable thing is that many of these challenges aren’t inevitable. They’re problems we can all help solve.
Together, we can reduce the amount of plastic that reaches the ocean. We can protect and restore nesting beaches. And we can support policies that protect healthy ocean ecosystems. Every action helps make our waters a safer place for animals that depend on it.
So, do sea turtles get lost? When left to their own devices, not often. Sea turtles have an extraordinary ability to navigate across vast stretches of open oceans. But there’s a bigger question worth asking: Can we help make the ocean a safe place while they make these incredible journeys? Navigation is only part of the challenge for sea turtles trying to find their way home. Sea turtles may know where they’re going, but it’s our job to ensure the ocean and coastlines they depend on are safe when they get there. That’s why Ocean Conservancy is committed to protecting our entire ocean—and all the creatures that dwell there.
We’re fortunate to share the planet with these amazing creatures. Their journeys are a remarkable feat of science and survival. To all the turtles out there: Here’s to finding your way—wherever you’re going!
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The post Do Sea Turtles Get Lost? appeared first on Ocean Conservancy.
https://oceanconservancy.org/blog/2026/08/27/do-sea-turtles-get-lost/
Ocean Acidification
First Spotted, or Simply First Recorded? Velella and Our Ecological Blind Spots
A remarkable strandline discovery deserves attention, but not exaggeration. The arrival of Velella velella on Sylt is probably Germany’s first documented record. It is not the first occurrence in the North Sea, nor is one stranding sufficient proof of a climate-driven invasion.

The discovery of Velella velella on Sylt on 23–24 August 2026 has been announced as the first German record of this oceanic hydrozoan (Listen to the News here). It is an exciting observation, but the word “first” needs careful interpretation. A first documented record is not necessarily the species’ first arrival. It may instead be the first time somebody recognized, photographed and reported it through the right channels. Fragile marine organisms such as Velella decompose rapidly, and their transparent floats are easily overlooked among material on the strandline.
A photographed Velella found on the west coast of Jutland in 2018 was considered the country’s first documented record. However, earlier reports exist (see here). Velella velella, known as the by-the-wind sailor or Segelqualle, is often described in the German media as a “Mediterranean jellyfish.” This is misleading. The species is a widely distributed oceanic hydrozoan found in tropical and warm-temperate waters, including the Mediterranean and the Northeast Atlantic. The familiar blue object is not a single conventional jellyfish but a floating colony of specialized polyps. Its diagonal sail allows wind to push the colony across the sea surface. Velella cannot swim effectively against this transport, so large strandings are principally the outcome of population size, surface currents and persistent onshore winds. The Sylt animals should therefore be understood as oceanic visitors transported into German waters, not automatically as an invasive species or an established North Sea population.
The North Sea has seen Velella before
In February 1988, thousands of colourless Velella floats washed ashore along the Belgian coast after strong westerly storms. The event was described as the first published North Sea record (See the article) Denmark also has a documented history. A photographed colony was found at Grønhøj on the west coast of Jutland on 26 July 2018. It was considered Denmark’s first documented record, although unverified reports exist from 1947, 1976 and 1997. Naturbasen
In Scotland, strandings have been recorded since at least the 1950s, with another mass event in the Clyde in 2002. Scottish Marine Atlas
The Sylt discovery is therefore regionally unusual, but it is part of a longer history of intermittent Velella transport into northern European waters.
Is this climate change?
Ocean warming may increase the probability that warm-water organisms survive and occur farther north, while winds and currents determine whether they reach Sylt in a particular year. Calling this one observation definitive proof of climate-driven range expansion would be premature. Equally, dismissing it as an irrelevant accident would ignore the wider pattern of warming seas and increasing biological movement into the North Sea.
This is exactly why systematic observations matter.
Historical absence from a database is not proof of ecological absence. It may reflect limited monitoring, failed identification or observations that were never preserved. The public can help close this gap. Photograph unusual strandline organisms, record the date and exact location, include a size reference, estimate their number and submit the observation to us (GoJelly/JellySpotter APP) or another biodiversity platform like the iNaturalist. Today’s carefully documented beach find may become tomorrow’s essential evidence of how marine distributions are changing.
Recommened for reading:
- Pires RFT, Cordeiro N, Dubert J, Marraccini A, Relvas P, dos Santos A (2018) Untangling Velella velella (Cnidaria: Anthoathecatae) transport: a citizen science and oceanographic approach. Mar Ecol Prog Ser 591:241-251 https://doi.org/10.3354/meps12266
- Betti, F., Bo, M., … Enrichetti, F. (2019). Massive strandings of Velella velella (Hydrozoa: Anthoathecata: Porpitidae) in the Ligurian Sea (North-western Mediterranean Sea). The European Zoological Journal, 86(1), 343–353. https://doi.org/10.1080/24750263.2019.1671506
Picture courtesy to https://commons.wikimedia.org/wiki/File:20160518_170717_Velella_velella_1.jpg
First Spotted, or Simply First Recorded? Velella and Our Ecological Blind Spots
Ocean Acidification
Lessons from Coastal Legends
Storytelling is one of our oldest human behaviors. Across every culture and continent, people have used stories to share values, pass down knowledge and make sense of the world around them. The tales that survive, retold across generations, kept alive through memory and ceremony, aren’t arbitrary. These coastal legends carry essential wisdom.
For countless coastal communities, that wisdom is related to the ocean.
Here are five coastal stories that are important parts of different oral traditions and teach us about our ocean.
Scotland: Selkie Stories
Early written records from the coast of Scotland describe seal-people who shed their aquatic skins to walk among humans on land.
These are the selkie. Their stories follow a familiar arc. One is discovered on shore, their sealskin is stolen and they are bound to a human life. They marry, raise children, but remain melancholy, always watching the water. When the skin is finally found, they return to the sea without hesitation.
It’s not difficult to see where the concept took root. Gray and harbor seals have strikingly humanesque features like expressive eyes, complex vocalizations, mothers who nurse their pups. Early coastal communities observed those qualities, and the selkie story began to spread. It produced a cultural taboo against the excessive hunting of seals.
Today, the selkie is one of Scotland’s most recognized figures. Conservation organizations have adopted the selkie as a bridge symbol of cultural identity and ocean protection. Gray seal populations in Scottish waters continue to face pressure from abandoned fishing gear and historical culling practices, behaviors the selkie taboo was designed to prevent.
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Pasifika: Wayfinding
Pasifika is a collective term for the Indigenous Peoples of the Pacific Islands. For more than 3,000 years, they’ve managed to pass along extremely complex knowledge on how to navigate the vast expanse of the Pacific Ocean.
Their secret weapon? Storytelling.
They shared stories of the demigod Māui and his canoe, Waka-a-Māui, then navigated by their corresponding constellations in the sky. Tāwhirimātea was the god of wind and storms. When his eyes appeared in the sky (as the Pleiades cluster), it meant that it was a good time to start a long voyage. Stories like these gave navigators a framework for planning their journeys and navigating the distances.
Wayfinding is a science. The people of Pasifika developed their knowledge system through thousands of years of empirical observation, experimentation at sea and rigorous knowledge transmission. The names and stories were a medium of storing and sharing this knowledge, and an effective one at that.
Mexico: Chalchiuhtlicue
Chalchiuhtlicue is the Aztec goddess of rivers, lakes, seas and the ocean, as well as the protector of fishermen and navigators. In Aztec cosmology, she was one of the most actively worshiped deities.
In different stories, she is portrayed as both a creator and destroyer, as surges of water can result in abundant harvests or devastating floods. Today, Mexico’s Pacific and Gulf coasts are among the world’s most biologically rich but storm-exposed marine environments.
Chalchiuhtlicue’s tradition reflects an understanding of how water has the potential to be life-giving or destructive depending on amount and location. Mexico’s Indigenous cultures understood water as the foundational substance of existence, from the ocean to the hydrological routes that fed agricultural soil.
Vietnam: Grandfather Whales
The coastal communities of Vietnam have long shared stories of whales as divine protectors, often referring to them as Cá Ông or “Grandfather Whales.”
It is believed that when fishing boats are lost in a storm, whales physically rescue the crew by sending them toward shore. Several fishing villages in Vietnam still celebrate the Whale Prayer Festival twice a year. Because the whales are so revered, fishermen report whale encounters. Whales received sacred funerals whenever they are beached.
These coastal villages demonstrate a relationship with whale species marked by reciprocity. Sperm whales, humpbacks and gray whales, in fact, show behaviors that are consistent with the stories about rescue. They may approach distressed swimmers, encircle capsized vessels or even support injured kin. When a whale dies, gratitude and grief are expressed. The practice of providing a proper Confucian funeral to beached whales reflects the way that a whale carcass can still sustain hundreds of species after death.


Caribbean: Mami Wata
Many cultures in the Caribbean have carried a belief in Mami Wata. She is an ocean deity, often depicted as a mermaid, who goes by several names: La Siréne in Haiti, River Mumma in Jamaica, and Yemonja in Brazil. Her reinterpretation across several cultures maps how her oral tradition was carried across the Atlantic by enslaved Africans and adapted in different Caribbean settings. Mami Wata is depicted as a beautiful woman, skilled at music, who can be both generous and dangerous. This dual nature is parallel to the Caribbean. It is one of the world’s most biodiverse marine environments, supporting coral reef ecosystems of extraordinary productivity, but it is also a region of violent tropical storms, dangerous currents and unpredictable weather.
Sightings of Mami Wata are thought by some scholars to be related to sightings of manatees. The large, slow marine mammals with humanlike eyes and nursing behavior may match the characterizations of the deity. When the belief in Mami Wata began to decline, so did manatee populations. This reflects a phenomenon researchers call the “sacred species” effect. When a creature holds deep spiritual significance in a culture, harming it carries social and moral consequences that can be more powerful than legal ones. This provides an element of protection that is sometimes more effective than law.
Long before satellites tracked ocean temperatures, people who lived alongside the water were paying close attention. They noticed which creatures signaled safe weather and which behaviors led to abundant catches. They encoded those observations into the stories they told—deities, creatures, warnings and rituals that traveled across centuries intact.
These aren’t relics. Many are living traditions, still practiced and still relevant. And when held up alongside what marine science has since confirmed, the parallels are striking.
The stories contain lessons
What connects a fisherman’s reverence for seals in Scotland to a Vietnamese community’s funeral rites for a beached whale? Around the world, people understand that the ocean is not only a resource for extraction but also offers a relationship to be maintained.
Ocean Conservancy operates on the same understanding. This drives our work today, from protecting marine ecosystems and rebuilding fish populations to fighting the pollution and policy decisions that put our ocean at risk. Right now, aging offshore oil and gas infrastructure is corroding on the seafloor, threatening many of the species that cultures around the world hold dear. The companies that build this infrastructure exploit loopholes to avoid cleaning it up. But we can change that. The proposed Offshore Leasing Standards and Accountability Act before Congress now would require oil and gas companies to take responsibility for their operations before, during and after they drill.
The ocean has always been worth protecting. Add your name and help us pass the Offshore Leasing Standards and Accountability Act now.
The post Lessons from Coastal Legends appeared first on Ocean Conservancy.
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