Nature Tours on Hilton Head in October: A Marine Wonderland

As summer’s scorching heat gives way to the refreshing coolness of fall, October emerges as a captivating time to experience the aquatic beauty through a nature tour on Hilton Head Island. The island’s enchanting waters are teeming with vibrant marine life, making it an ideal destination for those seeking a unique and unforgettable coastal adventure.

Dolphin Delight

massive pods of dolphins congregating on a private dolphin tour

One of the most awe-inspiring sights you can witness in October is the playful antics of bottlenose dolphins. Hilton Head’s resident dolphin population, consisting of around 200 individuals, remains strong throughout the year. However, this month marks the peak of migratory dolphins season, bringing the total dolphin population to an impressive 500 or more. This is one of the best times of year to take in the nature of the island and explore the waters with a private dolphin tour.

October is a particularly exciting time for dolphin enthusiasts. While these marine mammals can breed and calve year-round, the fall season witnesses a surge in their activities. The waters come alive with larger and more active pods of dolphins. Males and females congregate, playfully wrestling, and even leaping out of the water in a display of acrobatics that you can witness almost daily.

energetic dolphin leaping in the air on a private dolphin tour

Turtle Tales

While turtle nesting season might be winding down, you can still catch glimpses of loggerhead turtles in October. These magnificent creatures occasionally surface for a breath of air, instinctively submerging when they spot boats. Witnessing their bulbous heads emerging from the water is a heartwarming sight and a reminder of the Hilton Head’s commitment to protecting its precious marine life and nature.

Jellies in the Sound

Early October also marks the beginning of the cannonball jellyfish season. These early adults come in thousands, ranging from the size of ping pong balls to baseballs. These jellies make up about 16% of the biomass in the shallow inshore waters along Hilton Head’s coast during the fall. Observing these elegant creatures drifting through the water is a mesmerizing experience.

harmless cannonball jellyfish delight guests on a nature tour

Bait Fish Bonanza

Massive schools of bait fish dominate the waters in October. Mullet and bunker menhaden swim in abundance, often pursued by predators such as sharks and, of course, the ever-energetic dolphins. In the small marsh creeks, mud minnows flourish, creating the perfect setting for witnessing dolphins strand feeding during low tide. This thrilling spectacle is a testament to the intricate web of life in the island’s waters.

huge schools of baitfish springing out of the water to avoid dolphins while on a private dolphin tour

Pelican Parade

While Hilton Head boasts a resident population of brown pelicans year-round, October introduces the fascinating arrival of migrating white pelicans. These colossal birds have with wingspans of up to nine feet! They grace the coastal waters for a few months each winter before they journey northwest for the breeding season. Their elegant presence adds an extra layer of wonder to the island’s fall marine symphony.

Magical October on Hilton Head Island

October is indeed a magical time to experience nature tours on Hilton Head Island. With lighter crowds on the beaches and in restaurants, this month is all about embracing the island’s true essence – being on the water and immersing yourself in the wonders of marine life. Whether you’re a nature enthusiast, an animal lover, or simply seeking a unique and tranquil getaway, Hilton Head Island in October promises an unforgettable experience that will leave you in awe of the ocean’s beauty and the island’s commitment to preserving its natural treasures. To witness this wonderland yourself, book a private dolphin tour and truly enjoy our island!

The Vanishing Mile Isle: What’s Happening in 2023?

The Vanishing Mile Isle is a mile long sandbar exposed at low tide. Officially named Grenadier Shoal on nautical charts, it has been a popular excursion near Daufuskie Island. Tour companies on Hilton Head have taken guests to explore the bar for years. Treasures found include sand dollars, sea shells and shark teeth among the tidal pools

The key to a successful visit lies in catching the right low tide, a phenomenon that varies daily due to the gravitational pull of the sun and moon. Tides around a quarter moon phase result in weak tidal exchanges, while full or new moons bring larger tidal variances.

Understanding a Tide Chart

Tide charts use “Chart Datum,” which includes terms like “mean high water” and “mean lower low water,” representing average high and low tide depths over a 19-year period. Concerning low tide, the focus is on the “mean lower low water” average. Zero on tide charts signifies the average for these low tides.

Normally, any low tide exceeding +0.50 ft above the average allowed for exploration of the Vanishing Mile Isle. During new or full moons, negative tides exceeding 1.5 feet below average would reveal a vast surface area to explore.

2023: A Year of Changes

Spring 2023 brought unseasonably cool weather to Hilton Head, with strong northeastern winds prevailing throughout April and May. These winds not only kept Hilton Head cool but also had a dramatic impact on the Vanishing Mile Isle. The persistent northeastern winds created strong surf, pounding the shoals for weeks, displacing sand, and smoothing out the sandbar. By the time these winds subsided, the island had lost over a foot of its height. What was once visible with a low +0.50 feet, now required a negative tide of -0.50 feet to be seen.

As summer progressed, traditional southern winds helped rebuild the Vanishing Mile Isle. Tybee Island sits directly south of the sandbar, and helps prevent heavy surf buildup, allowing the sand to gradually stack up and the sandbar to return. While not a complete rebuild, by August, almost 6 inches of lost height had been regained.

However, September brought more northeastern winds, including the effects of Hurricane Idalia, Hurricane Lee, and Tropical Storm Ophelia. These winds further flattened the island, making the situation worse than before.

The Vanishing Island has Vanished!

Even a negative tide of -0.50 feet is insufficient to reveal the sandbar. As October approaches, forecasts continue to predict northeast winds, exacerbating the issue. Consequently, Cross Island Cruises has temporarily suspended its beachcombing excursions to the Vanishing Mile Isle until the end of the year, or when conditions improve. While we aim to provide exceptional experiences, the sandbar currently falls short of expectations. Any interest in this tour should contact us directly for alternative ideas of exploring our waters.

Other companies may continue to operate the tour as usual, but it’s advisable to check with them to ensure they are aware of the loss of exposure or if they have alternative plans in mind. Nobody wants to embark on a 2 to 3-hour boat ride with specific expectations, only to find nothing at the destination.

sandbar exposure level 10/28/23, -.21 MLLW

*****OCTOBER 28 UPDATE******

We have seen an improvement in the height of Vanishing Mile Isle. Tours this weekend with a negative low tide level of -.21 feet did present acceptable areas of exploration. We will continue to operate this tour on a limited basis. If interested in taking a tour, feel free contact us to inquire about certain days of availability.

Hilton Head Island Salt Marsh

Hilton Head Island is defined by the salt marsh, one of the most remarkable natural systems on Earth.  The salt marsh has been described as a biological factory without equal. more fertile than an Iowa corn field, and responsible for producing an incredible amount of biomass.  Over 75% of all the commercially caught seafood will spend some point of its life in a salt marsh.

The salt marsh around Hilton Head is inundated with a fresh supply of nutrients, through a massive exchange of water twice daily. Plants and microorganisms break down these nutrients and use them with amazing quickness. This tidal cycle nourishes the vast swaths of salt tolerant Spartina grass, by far the most important plant of the marsh. The cane-like stalks of spartina are the backbone of the marsh’s production, creating nourishment and protecting the young of blue crabs, shrimp, flounder, menhaden, mullet, oysters and dozens of ecological and culinary importance.

The salt marsh is a harsh, stressful place for its residents.  The plants and animals that live here must be super-hardy, able to tolerate drastic changes every few hours as tides advance and retreat.  If one thing defines this taxing world and dictates who survives here, it is salt, mostly common sodium chloride.  Salt marsh organism, both plant and animals, must adapt to varying degrees of salinity.  In fact, many marine marsh creatures need particular salinity levels at various stages of their lives, and salinity may dictate when and where they reproduce.

black needlerush figures predominately in the high marsh zone.
black needlerush figures predominately in the high marsh zone.

The High Marsh Zone

The salt marsh is broken up in zones; the high, mid and low marsh.  The high marsh zone contains a mixture of plants.  Sea lavender, saltgrass, saltwort, and small stalks of spartina appear, but the dominant plant here in this zone is black needlerush.  Named for their extremely sharp tips, which can easily puncture skin, needlerush grows in soils ranging from almost pure sand to fine silt loam and clay mixtures. It also has a high tolerance for anaerobic conditions and helps dilute organic waste that runs into the marsh from the land’s edge, breaking it down before entering the tidal creeks.

In the high marsh, the spartina grass only grows to around a foot high due to the salt content. This area is the saltiest part of the marsh and floods with seawater for a short period of time each day. As the water evaporates, the salt concentration of the soil increases. Evaporation causes the surface water to draw up more water from below the surface which continues to evaporate and leaves the soil with a high salt content. It’s not uncommon to find areas of the high marsh zone that the concentrations are so great- over 3 times saltier than seawater- that nothing is able to grow.  While void of vegetation, these salt pans are wonderful areas for spotting bird and animal tracks.

Periwinkle snail farming on a stem of spartina grass
Periwinkle snail “farming” on a stem of spartina grass

The Mid Marsh Zone

Entering the mid salt marsh, the vegetation is solely spartina grass. Ribbed mussels protrude from the soft mud. Periwinkle snails, the “farmers” of the salt marsh, cling to the spartina stems. As the tide rises, the snails will ascend the stems on their single foot to evade the claws of ravenous blue crabs brought in by the tide.

The spartina’s robust root system here, wide-reaching roots and root-like rhizomes create a relatively firm but squishy walking surface along the pluff mud. In this area, small organisms are actively working. Bacteria, algae, fungi, protozoa, nematodes, copepods, and other microscopic life live in the billions per square inch in and on the mud.

Ribbed mussels in the low marsh zone
Ribbed mussels in the low marsh zone

The Low Marsh Zone

In the low marsh zone, along the creek, is an ideal environment for spartina, a well-known plant for Hilton Head.  The marsh grass is at its most luxuriant, growing to nine feet.  The tides efficiently bring in loads of nutrients and sediments to the upper creek bank and washes away salt, dead matter and other wastes.  Changes in temperature and water salinity are minimal here.  Fiddler crabs are pervasive in this zone, aerating the mud as they burrow for refuge and food.  A healthy salt marsh will boast a million fiddler crabs or more per acre.

This zone is teeming with life; a variety of microscopic organisms such as fungi, bacteria, and algae cover the mud. These provide sustenance to the meiofauna, a collective term for the ultra-tiny creatures such as nematodes, protozoans, copepods, amphipods, and annelids that live on or just below the mud’s surface. The macrofauna, which are more visible, forage for the meiofauna, as well as for algae and bits of dead spartina grass. Examples of macrofauna found here are mud fiddlers, marsh crabs, snails and polychaeta worms. Oyster beds also line the creek banks, while ribbed mussels are particularly abundant in the lower marsh.

Dolphins strand feeding on the right sides of their bodies
Dolphins strand feeding along the bank of the salt marsh

The Need to Protect

The significance of the Hilton Head’s salt marsh cannot be overstated. Not only does it serve as a crucial habitat for several species, but its loss would have far-reaching consequences. Without its role as a nursey for shrimp and crab larvae, commercial industries would suffer. Losing oyster habitats would mean the loss of a natural filter for regulating the health of adjoining waters. No oyster reefs also mean loss of a valuable barrier against storm erosion. The loss of spartina grass would have a ripple effect, leading to habitat loss for nesting birds, foraging mammals, and juvenile marine life. The detritus from the grass plays a critical role in the ecosystem of creeks, sounds, and oceans. Loss of the salt marsh severely disrupts marine life beyond just our shores.

To learn more about the salt marsh, check out the Coastal Discovery Museum! They have an extensive array of information regarding this amazing habitat as well as in depth lectures. Or come out on a tour with us! We’d love to show you how important this is to the future success of Hilton Head and our surrounding area.

Strand Feeding Dolphins of Hilton Head Island

While taking a dolphin tour on Hilton Head Island, there are many opportunities to view wildlife in all its beauty and wonder. Nothing, however, compares with getting an opportunity to witness these beautiful creatures strand feeding along the shores of our waters.

What is Strand Feeding?

Dolphins are well known for their complex social behavior and intelligence. While taking a dolphin tour on Hilton Head, both these traits can be seen exhibited through an amazing hunting technique known as “strand feeding.” It involves herding fish up onto a mudflat in the shallow waters around low tide. Working together to corral the fish into tight groups, the dolphins then turn into the school of fish, creating a massive force of water, pushing themselves and the fish onto the mudflat. They then use their rostrum (beak) to pluck individuals out of the group and swallow them whole. Once they have eaten the fish stranded on the shoreline, they then wiggle themselves back into the water, regroup and do it again.

The few. The proud. The strand feeders.

While its estimated we have a couple hundred resident dolphins that live here full time around Hilton Head, not every dolphin will learn strand feeding as a hunting technique. While both males and females can strand feed, it’s thought the majority of the strand feeders will be female. Visual observations have shown females strand feeding in small groups while their calves stay near observing the action, learning. Even within the female population, its estimated less than 20% will learn strand feeding as a hunting technique.

female dolphin practicing strand feeding

Where to find the strand feeders?

Those dolphins that do strand feed are quite selective on where to do it. Conditions have to be just right. The tide must be low enough to limit fish from escaping back into deeper water. The mud flats have to be the proper angle; too steep and the fish will be able to roll back into the water. Too flat and the dolphins risk getting themselves stuck on the shoreline. Our private dolphin tours on Hilton Head have had the best luck finding them in the smaller creeks that lead to the Calibogue Sound.

strand feeding dolphins in Hilton Head

Right side only!

Dolphins that strand feed will only do so on the right side of their bodies. This brings up some interesting points and some questions that scientists are still working on. Dolphins don’t have the jaw strength to chew their food, so when they feed, the eat things they can consume whole. They do, however, need their teeth to capture their prey. While strand feeding, dolphins are taking in mud, shells, and bits of cordgrass and detritus. These things can damage their teeth over time and wear down the enamel, rendering them useless to grab things over time. Dolphins appear to be aware of this. By strand feeding strictly on one side, they only risk damage to that side of their mouths, leaving a perfectly intact side of teeth to catch prey in the open water.

Why they choose the right side over left is still a mystery to science. It could be a choice due to physiological makeup of the location to the air passage within the blowhole in relation to the pharyngeal aperture within the pharynx that allows them to swallow, or some other anatomical limitation that makes the right side a more preferable feeding side. There are still many things we don’t know about dolphins.

How can you see dolphins strand feeding?

Here around Hilton Head Island, the best way to see dolphins strand feeding is by boat. While we offer Private Dolphin Tours throughout the day, the best opportunity to find strand feedings are at departure times just before dead low tide. Feel free to call us at 843-247-8117 to coordinate an outing to coincide with the tides.

Strand feeding is truly one of the most remarkable feats in nature to witness. To see the coordinated effort put on by these beautiful creatures is something you must see to believe. If you have an interest in reserving a dolphin tour on Hilton Head Island, or just want to get out on the water and see the amazing wildlife our island has to offer, get in touch with us to reserve your private boat charter today!

Family tour getting a view of a lifetime

Things to do on Hilton Head when it rains

Hilton Head is full of things to do outdoors. Beautiful beaches, bike trails, golf courses and boat rides are all major reasons why it’s such a popular tourist destination.  But there are some days the weather doesn’t quite work out the way we’d like. What do to on Hilton Head when it rains?

Don’t let it spoil your trip!  There are plenty of things to do even when the weather runs foul. Here are a few ideas.

Educational Outings

The Beaufort County Library has a Hilton Head location on the north side of the island.  Nothing beats curling up with a good book on a rainy day! The spacious building houses a children’s storytelling area, cozy South Carolina Reading Room, and the popular Friends of the Library Bookstore.  Residents and vacationers alike are welcome to come see what they have to offer.  Open year round, closed on Sundays.

If you have little ones that need to keep their hands and minds busy on Hilton Head when it rains, you should head over to The Sandbox, an Interactive Children’s Museum. Let the imaginations fly in the children’s flight simulator, find their inner Picassso in the Rhythm and Hues art room, or become one with nature in the Loggerhead Sandcastle room.  Hours of entertainment are here, right near Coligny Beach.

Spend some time exploring the history of the island at the Coastal Discovery Museum.  While a good portion of the museum’s exhibits are outdoors, there are some amazing indoor exhibits that include the geological and historical development of the island.  Check out some of the live animals in the Discovery Lab or immerse yourself in the local culture with one of the many rotating exhibits that focus on art, history and environment.  Kids can get an opportunity to meet Myrtle the Turtle, a diamondback terrapin that resides in the Kid Zone!  Located in Honey Horn on the north side of the island, the CDM is a must visit rain or shine.

Indoor Adventures

Ever done battle with robots? Gone hang gliding over an island? Maybe you want to create a magical beast for a pet? If you’re looking for a little excitement in your afternoon on Hilton Head when it rains, check out Atomic VR HHI, the only virtual reality arcade on the island.  With over 30 games to choose from, there’s something for everyone to enjoy. Located near the airport, sessions range from 40 to 130 minutes and are suitable for ages 6 and up.

If you enjoy solving puzzles, head on over to the Hilton Head Escape Room.  You’ll have an hour to work on this interactive adventure as your team is locked in a themed room. You’ll work together following evidence and discover clues in order for you to find the way out! Located near Coligny, you could easily find yourself spending the whole afternoon trying the various themed rooms.

Have a Beverage and Relax

Another great way to spend a wet couple of hours is to spend it at Park Plaza Cinema. A family owned, dog friendly (under 20lbs) movie theater, Park Plaza offers several films, comfortable seats, and an extensive food and drink selection. Showtimes and listings vary at this south located cinema, off Greenwood Drive near the Harris Teeter shopping center.

If it’s just adults in the group you can visit 3 spots of locally made beer, wine and spirits. Hilton Head Brewing Company, Hilton Head Distillery and the Island Winery are all located on the same street on Cardinal Road. Offering group tours and tasting, the Distillery gives you an in depth look at what it takes to make premium hand-crafted spirits, walking you through the entire process. Get a taste and a bite at the island’s first brew pub or get a flight of small batch wines at the Winery. 21 and over.

If the rain carries on into the evening, head on over to the Comedy Magic Cabaret. Known as fun, family oriented entertainment, the Cabaret has been keeping smiles on faces for almost 10 years.  Friday nights is their wildly popular comedy game show “BONK” that’s as much fun to watch as it is to play.  Centrally located on William Hilton Parkway, reservations are required.

Dolphins are already wet!

One of the great things about Hilton Head is the weather. While it may rain, it doesn’t usually rain all day. It often comes in small cells and doesn’t last too long. If it’s a little rain, we’ll still go out on the water to look for dolphins. Believe it or not, dolphins don’t mind getting wet! Give us a call to see what the day looks like!

These are just a few ideas of what to do while you’re waiting for the sun to come back out. There are countless more options on Hilton Head when it rains and its surrounding area you can find. Hopefully the weather cooperates with your vacation, but don’t let a little rain put a damper on your plans to explore.

Spartina Grass

I don’t think anyone’s ever written a riveting story about grass, but if you were, you’d have to make sure the type of grass is worth talking about.  The spartina grass we have that’s found in our salt marsh definitely fits this bill.

Formally called sporobolus alterniflora, and known as smooth cordgrass, it’s the basis of our marine food web. While few organisms actually eat the grass while its alive, plenty of creatures need it for their continued growth and survival.

SURVIVAL OF THE FITTEST

How tough does spartina grass have it? Well, consider the obstacles it goes through for survival.

First, spartina is a freshwater plant that lives in saltwater.  When faced with an submergence of saltwater, most freshwater plants would perish, but spartina has a trick up its sleeve.  Through a process of desalination, the grass draws in saltwater through its roots, “sweats” out the salt, and retains the fresh water. If you were to look closely at a spartina stalk, you’d see salt crystals along its stem and leaves.

Because the marsh is inundated with saltwater from tidal flooding, the soil itself has very little oxygen in it. In the soil exists bacteria that actually creates its own oxygen to survive, and in the process emits a byproduct, hydrogen sulfide, that permeates the soil.  At low tide you can actually smell this rotten egg scent. 

But this hydrogen sulfide presents another challenge to spartina’s survival. High concentrations of hydrogen sulfide are highly toxic to all plants. Spartina is no different here, so why does it flourish here? Well, the plant has an ingenious solution.

Spartina has hollow air tubes that run from the top of the stalk down into its roots. The tubes draw oxygen from the air, down its stem and to the roots, which release the oxygen directly into the soil. This oxidizes the hydrogen sulfide in the soil immediately surrounding the root system, converting it to iron sulfate, which is a non-toxic sulfur. As the roots grow, this little bubble of iron sulfate enriched soil expands, protecting the plant!

SPARTINA: PROTECTOR OF THE LOW COUNTRY

So why is spartina so important? As mentioned before in a previous post, we have really, really high tides. When we have an incoming tide, the grass is almost fully submerged. This allows juvenile fin fish, shrimp larvae and small crabs to use the salt marsh as a nursery. Hiding in the spartina gives these young organisms a chance for survival from predation.  It is estimated that over 70% of all commercial seafood caught off of the coast of the United States will have spent some portion of their lives in these nurseries.

Another reason for their importance is as an erosion barrier.  The spartina lines the tidal creeks of the salt marsh and runs all the way to the tree line.  The seasonal storms we have can bring significant waves and tidal surges.  This grass is a first line of defense to absorb wave action and diffuse it before it reaches the land.

A FOOD SOURCE FOR MANY

Like all things living, spartina eventually dies, but even in death, the grass brings an abundance of life.

The dead spartina grass, called wrack, eventually makes its way out of the marsh on a high outgoing tide.  It gets washed out of the creek, out into the sound, and eventually out into the Atlantic Ocean.  While this is going on, the grass is decaying into detritus. Small microorganisms called phytoplankton will feast on the detritus. The abundance of feeding phytoplankton bring in zooplankton and small fish to feast on them, and in turn, larger organisms like fin fish, crabs, rays and dolphins eat the smaller creatures.

GRASS AS A BEACH BUILDER

And just when you think the grass couldn’t do any more, it has one last role to play. As it floats around the Atlantic, much of the wrack eventually finds itself along our beaches. Here it performs its second duty of an erosion barrier as the wrack breaks down into smaller fragments. It blends in with our fine sand, reinforcing the beaches, creating sand dunes and berms.  The dunes then become annual nesting sites of sea turtles! Loggerheads, greens and leatherbacks all make appearances every year laying thousands of eggs right here on Hilton Head.

From the salt marsh, to the waterways, to our beaches. Spartina plays an irreplaceable role in the ecology of our island.  Without it, we wouldn’t have the diversity or the beauty we often take for granted. Such a simple stalk of grass that does so much to bring life and protect it.  As far as grasses go, spartina is indeed pretty cool. While on your next dolphin tour, you can appreciate all that the spartina does for us.

Muddy Waters

Healthy waters are a staple of healthy island life. While visiting the Island, a lot of visitors will ask about the quality of our water.  They see its brown or green coloration and think it must not be very clean.  There’s a natural inclination to see something murky as unhealthy.   Not only is our water healthy, but its some of the cleanest sea water you’ll find on a coastline! The murkiness you see comes from two things; how much life is in the water and what attracts that life into the water; our pluff mud.

From dirty pluff mud comes clean water

While not clear, manatees don’t mind the opaqueness of Broad Creek during the summers

Pluff mud is a goopy mixture of soil, dead animal and plant matter. The majority of that dead plant matter is the spartina grass that lines our salt marsh. Pluff mud packs down densely and doesn’t allow oxygen to permeate below a few inches of the surface.  Any type of bacteria that survives in the mud has to create its own oxygen and you can actually smell this chemical reaction at work. As the bacteria create oxygen, they emit a by-product into the air, hydrogen sulfide, giving it a distinct aroma. Many people are convinced its smells like rotten eggs. 

The pluff mud lines the bottom of our tidal creeks and its top layer is constantly moving with the strong currents we have here around the island. This primordial soup of nutrients is continually being kicked up and swirled about, never quite getting a chance to settle. As the current moves at its maximum speed churning up the mud, our waters turn a very ruddy brown coloration. This is the predominate color over winter as cool temperatures control the growth of microorganisms.

The Phytoplankton Cometh


Inside the pluff mud is a large amount of decayed animal and plant matter.  This organic material is called detritus. Detritus breaks down in the salt water and allows microscopic algae known as phytoplankton to feed.  These guys are tiny.  We’re talking a fraction of a millimeter in length.  As the phytoplankton eat the detritus, they release oxygen into the water. Warm temperatures and increased sunlight contribute to their growth. During the hot summer months the amount of phytoplankton increases and, while you can’t see them individually, you can see the effects of the colony. A large phytoplankton bloom will turn the water a greenish color.

Clean Water via the Food Web

plenty of food to go around during the warm summer months

Is all this algae bad?  While some areas of the country face environmental catastrophes due to algae blooms, we don’t have that problem here.  There’s a delicate balance to maintain and the salt marsh does an amazing job of regulating this by creating a food web. The algae that feeds off the detritus in turn becomes food for our oyster beds.  Oysters are constantly filtering the waters here, collecting phytoplankton, other algae and bacteria and pushing out clean sea water.

Other organisms that eat phytoplankton, include zooplankton.  Grass shrimp larva, cannonball jellyfish and sea roaches are common examples. They are voracious eaters, taking in as much phytoplankton as they can. In turn, bait fish, shrimp, crabs, and mobula rays make their way here and feed off zooplankton.  These animals will continue the food web, as larger fish, sharks and dolphins will eat the smaller creatures.  The fecal waste of all the animals go back into the water, becoming detritus, feeds the phytoplankton, and the cycle repeats itself over and over.

Keeping a balance for clean water


It’s important to have a balance within our water column.  Any loss of one organism can have profound and devastating effects on the entire ecology. Loss of oyster habitat, overfishing or taking undersized fish out of the food chain all contribute to the decline to our water quality. Fishing restrictions include time, size and quantity give a species a chance to grow and repopulate without human interference.  On land, building restrictions are in place to limit the amount of harmful pollutants entering our creeks and rivers.  Without these regulations, we run the risk of becoming another environmental catastrophe.


While the waters here may not be crystal clear, you can be assured that they are healthy and clean .  The next time you’re out on a dolphin tour exploring the waterways, you can be thankful that our murky waters bring so much life to our island.

Mobula Rays of Hilton Head Island

Hilton Head Island is a well known place to see dolphins in the wild. But did you know we also get an influx of manta and mobula rays coming into the waterways every spring and summer?

Mobula Ray or Manta Ray?

There was a time that manta and mobula rays where considered separate families. It was only within the last 10 years that scientists had realized they shared the same genus. All mantas have now been reclassified into the mobula genus, making them the largest of the mobulas rays. The largest mobula, the giant oceanic manta, can grow up to 3600lbs and have a wingspan of 29 feet. Here on the island we can regularly see the Atlantic devil rays, with a wing span of 4 feet, and occasionally the reef manta, that can exceed 15 feet. Over the past few years several large reef manta have been spotted along the coastline. This video was taken just off of Hilton Head!

Aside from size, another way to tell the difference is mouth placement. A reef manta’s mouth opening will be at the top of its head, directly between its feelers. An Atlantic devil ray’s mouth will be slightly lower.

Intelligence of Mobula Rays

But how smart are these creatures? Mobulas have the largest brains out of all fish, with developed areas for problem solving, communication, and learning. They’ve also passed what’s known as the mirror test, meaning they have the ability to identify their own reflection and have a greater likelihood of being self aware. Studies have shown mobula can also identify individuals within a group (specific humans for example) and react accordingly.

Another example of their intelligence is shown through their hunting techniques. Different from most other rays, mobulas are filter feeders, collecting zooplankton with their cephalic feelers into their mouths as they swim along. One such hunting pattern is with a large group of rays, they will begin to furiously swim in circles, actually changing the flow of the water and trapping the plankton inside the vortex they create.  They’ll then line up, three at a time, one above the other, and enter the water vortex, mowing down the captured plankton.  Very few animals have the knowledge and ability to change their own living environment for their benefit.

Mating habits


While the water here is a bit murky, you can still see these beautiful creatures in action. As the spring waters warm up into the early summer, we get an acrobatic treat from these rays. On any given day on the sound, the mobulas will launch up and out of the water, some somersaulting, some belly flopping, others doing a semi graceful swan dive.  Why they do it is still a mystery to scientists. One theory is that the acrobatics are part of a lengthy mating ritual. 

The females release a pheromone into the water that drives the males crazy and a chase begins.  More males will join in the chase, forming a train of rays, one following the other, following the female.  This can go on for several days. Over time the competing males will lose interest until only one is left. Whether this popcorning action of jumping out of the water is the female garnering their attention or the male showing off their prowess is unknown, but it does provide for a spectacle show. 

Future of the ray


Information on mobula rays is still limited, but numbers suggest their population is going down. While their only natural predators are large sharks and killer whales, human interference plays a pivotal role in their livelihood.  Overfishing, pollution and the effect of by-catch all play a pivotal role in their decline. Locally, there had been recorded documentation of large reef mantas roaming the Port Royal Sound 200 years ago. Unfortunately, these recordings also documented the hunting of these gentle giants with harpoon simply for sport.  The rays we see today pale in size and number compared to the written testaments of the fishermen from the 18th century. Mantas are now a protected species in the United States with the hopes that the protection will give them a greater chance of survival.

Click here for our tour schedule, if you want to get an opportunity to see the mobula rays. Make sure to keep your eyes out on the water for these amazing creatures.  You can be rewarded with a magical display at any given moment. 

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If you have any personal requests or questions about any of our tours, please feel free to reach out by phone, text or email.

(843) 247-8117

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