A bait ball is a spherical formation that a school of fish make when they are being threatened by larger predators, such as dolphins, sea lions, and bigger fish. This instinctual behavior is a defense mechanism so that fewer fish are exposed during this feeding frenzy. When a school of fish has no protection from rocks and crevices they must use their vast numbers to their advantage. Bait balls typically do not last longer than ten minutes due to the vast amount of energy it takes to make this tightly packed ball. It is typically a fishes last ditch defensive measure because it can draw the attention of other predators like birds and sharks.
Each fish coordinates with its neighbor through visual site and the use of their lateral line. The lateral line is an organ located along both sides of the fishes body. Noted by faint dots along their scale, this lateral line can sense subtle pressure changes in the water and help direct them instantaneously.
Here at Catalina Island you can see a bait ball almost everyday, in varying sizes and species. Here are the most common species of fish that make up bait balls around Catalina Island.
distinctive flashy quality
release air bubbles as they swim
freckles on back
greatest body width underneath pelvic fin
appear glittery or sparkly
random solitary fish open their mouths wide and flare their gill covers in order to feed
dark on back with no markings
jaw shifted farther back
elongated body that is straighter and thinner than sardines
often hover motionless as if they were frozen,
can mix in with other species of fish
lateral line bends down due to longer pectoral fin
Navigation is the ability for an organism to travel to a relatively precise target, generally at a considerable distance, without the need for familiar landmarks. It is an extraordinary feat requiring a variety of senses, techniques, and adaptions to allow for successful navigation.
Humans and Sight
For humans, sight is the most commonly used sense to navigate. Tracing back a thousand years ago to traditional Polynesian cultures, people have been using the stars, specifically fixed stars, for tracking and to stay en route towards their destination. Nowadays, we have technological advances that aid us in navigation, like Google Maps, satellites, and compasses, but celestial bodies remain a constant and dependable asset. In addition to sight, different animal species have evolved specific senses to assist them in the open ocean.
Some animals, such as dolphins, utilize their sense of hearing through a process called echolocation to navigate through the open ocean during times of low visibility. These animals produce high-frequency sound waves that echo back with information such as the direction they are traveling and the location of objects around them.
Crabs, who often live in dark and murky areas, need to be able to navigate to food sources. Crabs use chemoreceptors found on thin, short hairs of their inner antenna, call aesthetascs, which allow them to smell chemicals in the water released by their prey. They not only have a well-developed sense of smell, but have the ability to taste biomolecules in the water using specialized hairs on their mouthparts, pincers, and feet to detect prey. Their acute senses are so crucial to survival, that the majority of their brains are detected to processing scents and tastes!
Small hair-like appendages of the Green Crab that aid in prey detection by taste.
For some seabirds like the Arctic Tern, the Wandering Albatross, or the Sooty Shearwater, navigation is no joke! Traveling thousands of miles for up to seven years at a time over a featureless blue ocean is quite a feat, requiring some fine-tuned navigational techniques. Studies have shown that many migratory birds use celestial navigation to determine North and Southward orientation, just like humans! But certain hypothesizes suggest that seabirds also use their sense of smell to create scent maps. In a study where birds had their sense of smell blocked, the test group was less likely to find food sources and their nesting grounds, suggesting that olfactory navigation is a technique adopted by many seabirds!
The Wandering Albatross has been observed to spend anywhere between 5-7 years at a given time at sea, making them expert navigators.
The lateral line system is an extensive network of canals and sensory receptors that can detect disturbances in the water. The majority of fish species have this lateral line that assists in navigation by sensing pressure changes and providing spatial awareness to avoid underwater obstacles.Some fish are able to use the lateral line as a type of sonar to feel the movement of water reflect off objects around it, which is especially useful in low visibility areas, such as the deep sea.
The lateral line consists of hundreds of superficial neuromasts, or sensory structures of cilia. Many of these neuromasts are embedded in lateral line canals open to their environment through pores that allows them to detect water movements.
Magnetoreception, the sixth navigational tool illustrated in the video, is an animal’s ability to detect the Earth’s magnetic field in order to determine North and Southward orientation. Many invertebrates like mollusks and insects, as well as vertebrates like birds and sharks,use this as a natural global positioning system when navigating long migration routes. One example, sea turtles, use magnetoreception as hatchlings when swimming out to the open ocean, and as adults when traveling towards specific feeding, mating, and nesting locations.
Magnetite is found in sea turtles as well as some bird and fish species. This iron mineral can tell animals their position on the globe as well as the direction they are heading. This explains why sea turtles can migrate all around the ocean and find themselves nesting on the same beach as their female ancestors.
The open ocean can be a challenging place to navigate, but the animals that live there utilize their senses to the max in order to find food, avoid underwater obstacles, and be completely aware of their direction of travel.
Geology is the study of the Earth’s structure and its substances. Some of our instructors focused on geology and marine geology in their college degrees. This week we want to focus on rocks! Because they rock (lol)!! On our planet there are three major types of rocks; metamorphic, igneous, and sedimentary.
Metamorphic rocks results from pressure, heat, stress, or a combination which changes an existing parent rock. Examples are schists; blue, green, and amphibolite. Consisting of many fine layers, these split easily and may be rich in mica. When a parent rock shale is heated to 300 °C, blue schist forms. When a parent rock shale is heated to 450 °C, green schist forms. When parent rock basalt is heated to 600 °C, amphibolite will form. The state rock of California is actually another type of metamorphic rock: serpentine! Serpentine forms from a parent rock basalt when it is heated to 400 °C.
Igneous rocks are the result of hot magma cooling and hardening. These can be intrusive or extrusive. Intrusive igneous occurs when magma cools underground, hardening slowly. This can produce large crystals. A local example is white microgranite, forming visible veins at Long Point, Catalina. Extrusive igneous rocks occur when magma cools quickly above ground due to air exposure, i.e. lava. These crystals will be small, not necessarily visible. Here on Catalina we have red-brown basalt and red-white rhyolite, from the high peaks of the island, what once were volcanoes.
Sedimentary rocks are the result of rock particles or pieces of once living organism carried by water being deposited on land, river beds, lakes, beaches, and the ocean bottom. Eventually, these layers of particles are compacted into a new solid rock. Seventy-five percent of Earth’s surface rock are sedimentary. The fascinating types of sedimentary rocks composed of dead organic material such as plankton are called biogenous bottoms! Biogenous bottoms are sometimes referred to as oozes depending on the most common type of shell material in the sediments.
Calcareous oozes (calcium carbonate, calcite, limestone) result from a dominance of calcium shells which were originally from organisms such as foraminifera, snails, and sea urchins. These calcareous oozes are never found deeper than about 4,000 to 5,000 meters because the calcium dissolves at deeper depths.
Siliceous oozes (silica, glass, diatoms, diatomaceous earth) results from a dominance of siliceous (glass) shell pieces made from planktonic organisms like diatoms and radiolarians. Where there are major plankton blooms with a sudden die off there are tremendous numbers of diatoms that reproduce and die each year contributing to the siliceous material on the sea floor. This shell material may build up at the rate of 1mm to 1cm every 1,000 years depending on the productivity.
When you picture a sea turtle you probably think of endless tropical blue water, colorful corals and a perfectly brown-green watercolor turtle shell coasting along the reef. Perhaps you think of the tiny, minutes hatched baby sea turtles making a break for their big blue home on the beaches of Caribbean countries… Regardless of whatever picturesque ‘Blue Planet’ turtle scene pops into your mind, it probably isn’t one off Southern California, or Catalina to be specific. Although we may not imagine sea turtles to be majestically roving the SoCal oceans, they are indeed here! What?! YES! I know… it’s awesome. Out here on Catalina we are seeing them more and more, almost as if they have made a home and are here to stay! We love seeing these turtles, especially on snorkels with kids so we all can enjoy their incredibly chill demeanor, but what has brought them to Catalina and why are they sticking around?!
The Green Turtle, Chelonia mydas, is typically found in tropical to subtropical waters. It is common for some turtles to wander up the coast in warm summer months and retreat south once the water temperature starts to drop. The one exception is a resident green turtle population in the South San Diego Bay. In this area the water is warmed by thermal output from the Duke Energy power plant which then keeps the turtles year round in the warmer water. This warm water outflow provides a great habitat for eel-grass and other marine plants to flourish, giving the turtles a constant meal. Because of these specific circumstances it isn’t unlikely to see turtles cruising the South San Diego Bay all year, then why we are starting to see them year round north of San Diego? What could that mean?!
Here at CIMI we are able to find green turtles all year round. This means that, just like us, some of these turtles must have deemed residency on the island, even during the cool winter months. There is a resident sea turtle in Cherry Cove, as well as Guano Rock and a few that seem to wander in between Torqua and Toyon Bay. Our waters seem to be providing a suitable home for these adorable turtles, even though it is a bit out of their normal range. Perhaps these turtles have adapted to withstand colder water for a few months or maybe our waters aren’t dipping to such frigid temperatures. Whatever the reason may be, it appears our turtles are here to stay so keep an eye out on your next snorkel for one! This isn’t the first time we’ve seen warm water species breaching their ranges moving up the coast of California.
Between 2014 and 2016 California experienced an extended marine heatwave. Typically winds blow from the north down the coast, keeping the entire west coast cool along with southern currents that push warm water toward Mexico. During this event, these winds were weakened and surface currents reversed, pushing warm water north causing southern species to be brought in those currents. This marine heatwave of warm water is often referred to as “the blob”. The Blob caused sea surface temperatures to peak 7 degrees above normal temperatures resulting in many ecological implications.
During this lengthy heatwave, the Blob pushed many warm water species from Baja up to northern California. A total of 67 non-native species were recorded out of their range and 37 of those had never been recorded that far north before!! Species like bottlenose dolphins, spiny lobsters, several types of sea slugs, pelagic red crabs (tuna crabs), comb jellies, and pink striped barnacles had all been pushed up the coast in the Blob all the way to Bodega Bay (north of San Francisco). See if you recognize any animals from the collage below of a few species that were found in chilly NorCal waters!
Dramatic weather events like The Blob make us consider the future of our coasts. Will these species continue to move north as sea surface temperatures rise? If that is the case then we may start seeing many more resident sea turtles around Catalina. Warmer ocean temperatures can cause ecological shifts in habitats, food chains and abundances of animals. We will be keeping our eyes peeled during any future heatwave events, potentially even more severe, for any foreign friends, especially more turtles!!!
So this is a pyrosome? Cool, what does that mean?!?
Pyrosomes are colonial organisms made up of hundreds to thousands of individual tunicates called Zooids! Our pyrosome friends may appear like a strange species of jellyfish however they are more closely related to us! This is because they posses a spinal cord and are taxonomically grouped with the Chordata Phylum. Scientist use this method called taxonomy to group and organize all organisms on earth based on similar characteristics. To be part of the Chordata phylum the shared characteristic required is a notochord, like a back bone. This is what separates Pyrosomes from the Jellyfish which classified as an invertebrate meaning an organism without a backbone!
The Taxonomy break down looks like this:
Now that we are starting to wrap our minds around what a pyrosome is, what is it doing out in the ocean?
Pyrosomes are free-floating colonies of zooids in the pelagic open ocean where they filter feed on microscopic plankton. The colonies of zooids are connected by tissue communicate and coordinate behavior such as propelling the colony through the water. Each individual zooid pulls water from the outside to its microscopic plankton filtration station, once that water is filtered the zooid expels the water into the inside of the cylinder body. The volume of water being filtered by each individual zooid gives the colony propulsion mobility. Pyrosome colonies can range in size from a few centimeters and up to 60 feet long! The giant pyrosome can grow large enough a human can swim though the internal cavity! The zooids grow though the process of asexual reproduction to make new identical zooids that enlarges the colony. Sexual reproduction is used to create a new colony.
How can pyrosomes affect our oceans?
Pyrosome populations can explode into what scientist call a “bloom” with hundreds to thousands of colonies. A bloom of pyrosomes may have a big impact on the benthic food webs. When the pyrosome dies, its gelatinous body sinks rapidly to the oceans bottom creating a pyrosome buffet for all the bottom dwelling critters!
Why are pyrosomes so fascinating?!?
Pyrosomes are a somewhat rare occurrence on Catalina Island but when they arrive they have our full attention here at CIMI. What makes them so fascinating is their ability to produce bioluminescent light! Together the colonies of zooids communicate and when one zooid emits light, they all do! They can produce enough light to see from many yards away as they are washing up on the beach or propelling themselves through the water column.
Have you ever wondered how we see the light and the world around us? Depending on where you are in the world half of the day is most likely spent illuminated by the sun. Most life on earth is dependent on light or the ability to see. So what exactly is light?
To put it in the absolute simplest way possible, light is a form of electromagnetic radiation. Electromagnetic radiation exists in the form of waves and is measured by its wavelengths and classified by frequencies. Different wavelengths result in different forms of electromagnetic radiation.
The spectrum of electromagnetic radiation from longest wavelength to shortest is Radio waves, Microwaves, Infrared, Ultraviolet, X-Rays, and Gamma Rays. Between Infrared and Ultraviolet frequencies exists the wavelengths of electromagnetic radiation that are visible to the human eye.
Out of all the different frequencies that exist, why did we adapt to seeing these frequencies? The most likely reason is that these frequencies are the most abundant ones produced by the sun that actually reach planet earth. Plants and animals simply grew to what they had available.
Because colors that we see are just different frequencies of ERM, does that mean that there are colors we can’t see? The answer is yes. Human beings only have three types of color receptors in our eyes. We have color receptors for reds and greens, blues and yellows, and black and white. Some animals have many more like the mantis shrimp. The mantis shrimp has a whopping 16 different color receptors. There’s no way to know what exactly the world would look like through the eyes of a mantis shrimp but it can be fun to imagine.
In the relaxed camp atmosphere it’s almost too easy to find yourself swaying with the palm trees, entranced in the soothing sounds of the ocean while locked in a daze at the clouds rolling overhead but today we are talking all things scat. Surrounded by the beauty in nature, you’re feeling endlessly grateful for the present day at Fox Landing, until one fateful step when you feel an all too familiar squish beneath your sandal. You know it’s not the firm dirt path, you’ve stepped right into a mountain of fox feces! We share a home with a variety of organisms; terrestrial, marine, native or not, every animal inhabiting Catalina Island eats, sleeps, and poops here, just like us! Scat is animal feces or dropping and based on the animal, scat will differ in size, shape, color, consistency, and contents. Scat can be used to identify, learn about, and track animals. Safety first: don’t touch scat…without gloves on!
The Santa Catalina Island Fox, a species of Channel Island fox, can be found roaming our cove. Most often seen at night attempting to break into a trash can or scurrying away from the slightest noise. Their diet consists of mice, birds, eggs, fruit, berries, insects, and for some, anything they are capable of scavenging from humans (Leave no trace!). Fox poop is smelly, small and tubular or log shaped. Droppings are often left in high areas, as a way to mark territory. It is not unusual to find fox feces at the tops of staircases or on rock walls around camp.
A number of animals have been introduced by humans to Catalina. Included in these non-native species are the herbivorous American Bison and Mule Deer who spend their time grazing the island. Bison consume mostly grasses, herbs, and shrubs. They leave the largest brown poop patties I have ever seen while traversing the mountainsides. Mule deer will graze grasses and herbs as well as eat berries or fruits if they can find any. When the urge becomes too great, a standing mule deer will drop dozens of small, round, or bean shaped pellets in a single release of solid waste.
Within our ocean and tanks marine organisms also experience the pleasure of excreting their waste. The sea hare and sea cucumber are among some of our greatest producers of scat. A Sea Hare is a squishy bodied invertebrate in the phylum Mollusca. Feasting daily on different species of algae and expelling small, brown-green seed shaped waste throughout our touch tank, shark tank, and octopus tank. Plankton living in the sand or floating in the water column are no match for a hungry sea cucumber. This invertebrate, of the phylum Echinodermata, leaves in its wake a pile of long log shaped stool. Although this camouflaged waste blends in with the sand, our team of aquarists are filled with joy when they spot it and siphon it out of the touch tank.
Here at CIMI our backyard is full of all kinds of marine animals. The biggest of these animals includes the many species of cetaceans (whales, dolphins, and porpoises), which pass through the channel between Catalina Island and California quite frequently. As large as these animals are, chances are that you will be viewing them from a distance whether it’s on land or on a boat. Most of the time the only thing you will get to see from these magnificent creatures are there whale spouts, flukes (tail fins), or their backs whenever they surface and dive.
When whales spout, you will see a geyser of water shoot up into the air that can be seen from miles away. This water that is shooting out however is not seawater but it is the condensation of the warm insulated air that is being shot out of the whales lungs mixing with the comparatively cold air from outside. Every species of whale has a distinctive kind of shape of their blowholes and also has different sized lungs therefore each type of spout shape and size. Each species of whales also will have different shaped flukes and ridges of their backs. The whales that frequently go through our channel include some larger baleen whales such as the grey whale, blue whale, fin whale, and humpback. Baleen Whales have two blowholes whereas toothed whales like dolphins and porpoises only have one single blowhole.
The grey whale can have two very widely dispersed spouts in a “v” formation and can be between 9 and 16 feet in the air. They lack a dorsal fin but have several knuckle like ridges on its back that show as it surfaces or dives down. Their flukes are convex and usually ragged with a distinctive deep notch in the middle making the shape of a “whale” groomed mustache. They may pass through the Catalina Channel coming from the arctic on their way to forage for food in Southern California and Mexico.
Blue whales have been in the channel migrating to tropical waters in order to give birth to breed and give birth to their young. Their flukes are much less robust than the grey whales fluke with much more straight trailing edge and a shallow notch in the middle. Their spouts can be up to almost 40ft high and look like a slender column of spray that looks like the green stalk of a carrot. Blue whales have a small triangular and variably curved fin dorsal fin sitting towards its caudal region and have a smooth back.
Fin whale are very similar in appearance to the blues where they have a slightly more robust and curved dorsal fin and fluke and can be seen year round near the sea of Cortez.
Humpbacks have a rugged looking fluke with robust curves and many ridges through out the fluke as well as a deep v shaped notch in the middle of the fluke. They have a low stubby dorsal fine with a broad based followed by slight ridges going down its back towards the fluke. Their spouts can be up to 9 feet high and can be heart shaped. They can typically be found in higher latitudes during the summer to feed in colder water and in the winter will head to warm watered breeding grounds.
The most common toothed whales that come through Catalina Island include the Rissos, common, and bottlenose dolphin and on a rare occasion even an Orca or killer whale. Orcas can be found on the Pacific coast especially in Washington but will sometimes follow food all the way down to Southern California. They have a very distinctive black and white pattern on their tails and have a very widely dispersed spout.
So just based on their fins, spouts, and flukes you can be an expert in recognizing these magnificent animals. Next time youʼre out on the ocean be sure to bring a pair of binoculars to see if you recognize any whales from a distance!
Spring is in bloom and wildflowers of all colors are decorating our hillsides on Catalina Island. Just look at them! Bright red Indian Paintbrush, Castilleja affinis (Fig. 1) and white Bush Anemone (Fig. 2) are some you are likely to see while hiking around. Starting with the south facing slopes, the island begins a transition from the more earth toned brown landscape of summer and fall into one of vibrant and cheerful colors from February through May. The Shooting star, Dodecatheon clevelandii, is a favorite for many people, with its purple shape (Fig. 3), while the Blue Dicks, Dichelostemma capitatum, are a form of wild onion that was used by native Tongva for food (Fig.4)
But where do they hide all year long? Well, one of the perks of being a wildflower is that you don’t have to make an appearance all year long! These wildflowers are known as “annuals”, meaning the seeds will germinate in the fall or winter rains, flowers will bloom in the spring, and then they ripen to seed towards the end of the spring season. This completes the annual cycle and allows it to start again.
As the south facing slopes are exposed to more sunlight for longer periods throughout the day, these slopes will tend to bloom earlier in the wildflower season, followed by the shadier north facing slopes.
After a heavy rain season this year, the abundance of wildflowers is noticeably greater than in past years of drought. As it turns out, in order for the wildflower seeds to germinate, they require continued moisture, or at least enough that the soil remains moist. Without this, the plants will dry out before they get to flower! We really enjoy these annual bursts of color, so rain, rain, don’t go away!
Baby blue eyes, Nemophila menziesii, is only known to exist in one population on Catalina Island. Photo by Amy Catalano
Deerweed, Acmispon dendroideus, are endemic to the Channel Islands. Photo by Amy Catalano
On Catalina Island there is a wide variety of animals. Some of the animals that we see include ravens, foxes, bison, sea lions, and whales! Each of these 5 animals make vocalizations, or sounds, for specific reasons.
The common raven typically tends to use one of two calls. The first call is a loud caw or groan. Ravens use this call to communicate with each other. Their call can be heard by ravens that are a mile away! The second call that ravens make is a fast, repetitive caw. Ravens typically use this call when they are hunting prey like rodents, worms, or insects!
The Channel Island fox, Urocyon littoralis, is a relatively quiet animal. However, it can make up to 40 sounds and calls! These calls are used by a foxes to convey different messages to one another. For example, foxes will bark to alert other members of its skulk about danger, such as an approaching predator. The male foxes bark to attract a mate and growl to protect their territory. Female foxes bark to locate their cubs. Sometimes, the small cubs will let out a littlebark just to get mom’s attention!
A bison can often be heard snorting, grunting, and even coughing! Male bison attract a mate by making a deep, low rumbling sound called a bellow. The length, volume, and frequency of the bellow indicates which male is the most dominant and therefore the most likely to find a mate! The female bison uses calls to locate her young. She will produce low grunts and wait for the calf to respond with high-pitched grunts! They repeat this process until they can find each other.
Sea lions communicate both audibly and visually. When they make a sound, they also strike a distinct pose! Male sea lions lift their heads up high in the air and bark when they are claiming their territory. When they are barking to defend their territory from other sea lions, they will bark right in the face of the trespassing seal lion! The female sea lions bark to locate and protect their pups. The female sea lion lets out a loud yell and listens for her pup’s weak crying response!
Whales use clicks, whistles, and calls to communicate with their pod. Toothed whales called odontocetes use echolocation to help them navigate and find food! When echolocating, whales will make a clicking sound and wait for the sound to echo back to them. When the whales hear the echo, they are able to identify the location of the object or animal they are trying to find! Some whales can echolocate prey that is over 1,500 feet away! Whales also whistle and call to socialize with other members of their pod. Scientists discovered that whales have different dialects to help them differentiate between their pod and strangers! Certain low frequency calls can travel more than 10,000 miles across the sea. Pretty wild, right?!
We would like to thank you for visiting our blog. Catalina Island Marine Institute is a hands-on marine science program with an emphasis on ocean exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and ocean happenings. This blog has been created by our staff who have at least a Bachelors Degree usually in marine science or related subjects. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science and ocean information. Feel free to leave comments, questions, or share our blog with others. Please visit www.cimi.org for additional information. Happy Reading!