While most animals found on the sandy bottom areas around CIMI spend most of their time trying to blend in with the sand, the Navanax (Navanax inermis) sticks out like a clown at a camouflage convention. Some head shield slugs like the Navanax and their colorful relatives Nudibranchs have opted out from hiding and instead use colorful displays to send out the message of “yea, I know you can see me, come at me bro…” They spend their time searching the sand for slime trails left by other snails and slugs. Navanax use chemoreceptors on the front of their body to follow these trails of slimy mucous and use their impressive (for a slug) speeds to catch up with, and then devour, their prey.
Navanax will also use this “follow the slime” method to find potential mates. When two of them meet they will first try to eat each other and if that is unsuccessful (usually because they are the exact same size) they will then mate. Scientists have learned a lot about defense mechanisms of other slugs and snails by tracking and recording the eating preferences of the Navanax. Basically, if an eating machine like the Navanax doesn’t want to eat an animal, then that animal is doing something right!
According to the Exxon Valdez Oil Spill Trustee Council, on March 29th, 1989 approximately 11 million gallons, or 17 Olympic-sized swimming pools, of crude oil were spilled into Prince William Sound, Alaska. Due to the amount of oil, timing of the spill, and pristine location in which it occurred, the Exxon Valdez oil spill is still widely considered one of the worst oil spills in history in terms of environmental damage. The spill covered 460 miles, and approximately 1,300 miles of shoreline were impacted. Even after 26 years, the habitat and wildlife are still suffering from effects of the spill.
Though almost all animals were affected by this environmental disaster, birds were among the most immediately and widely affected. The Exxon Valdez Oil Spill Trustee Council estimates that 250,000 seabirds were killed by the spill. Birds are particularly susceptible to oil damage because of their feathers. Birds use their feathers as insulation to protect them from cold water. When oil penetrates feathers, they can no longer hold air to keep the birds warm. Many birds died of hypothermia because of this lack of insulation.
Birds often perform preening, an act of straightening their feathers with their beak. The beak also has a specialized gland that produces an oily substance to keep the feathers waterproof. Along with destroying the effects of this waterproofing substance, crude oil is likely to be ingested by birds while preening. When ingested, the crude oil acts as a poison, killing the bird. Clean up efforts required washing individual animals with dish soap to rid their feathers of crude oil. Unfortunately, it also stripped the feathers of natural oils, so a recovery period was necessary.
Crude oil is considered a persistent oil; meaning natural processes are not usually enough to remove it from the environment. Because a large amount of oil was pouring out of a number of holes into calm seas, the oil slick spread consistently on top of the water. Compounding this issue, the lack wave action or turbulence in Prince William Sound during the spring did not break up the oil into fragments or droplets. Without this breakup of the oil slick, natural processes such as dissolution or biodegradation, along with clean up substances being dropped onto the slick, did not have opportunity to take effect.
There is a simple experiment that can be performed to examine the effects of crude oil on bird feathers. Buy soft feathers from a craft store. Create a “crude oil” mixture by mixing 3 parts vegetable oil and 1 part cocoa powder. Make one bowl each of salt water, fresh water and fresh water with dish soap. Dip feathers in the crude oil mixture and compare the washing effect of each type of water. Feel how oily each feather is after washing. Pouring the crude oil mixture at different speeds can also simulate the effect of turbulence. First, pour the oil into the salt water bowl quickly, taking note of the natural separation of the oil into droplets. Quickly pouring the oil creates turbulence in the bowl, simulating wave action and rough water separating an oil slick. Then, pour the mixture slowly. This represents calm seas, in which the oil will spread evenly, coating the entire surface of the water.
Many animals naturally float at the surface and have to force their way down below the surface. Fish however, have a very convenient adaptation. Two ways to animals in the ocean control their buoyancy, or the upward force exerted by a fluid, are with a swim bladder and an oily liver. Osteichthyes (bony fish) use swim bladders that are filled with oxygen taken in by their gills. The more air in the swim bladder the more buoyant the fish and the less air in the swim bladder the less buoyant the fish. The swim bladder is similar to human lungs in the way that it expands and deflates. Chondrichthyes (cartilaginous fish) use an oil filled liver to control their buoyancy. The oil lightens the shark’s heavy body to keep it from sinking and saves the sharks energy when using its fins to keep itself moving. The oily liver is also used for other daily functions such as digestion. The name for this oil is squalene. Without these organs they would not be able to control their location in the water column. These organs can help them stay neutrally buoyant.
A fun way to test how oxygen and oil react in water is to fill a tank with water and submerge each at different times. Push an upside down cup into the water, air will be trapped inside the cup. Next take a second cup upside down and push it into the water but allow water to fill it. Then you should be able to move the cups close together and pour the air filled cup into the water filled cup. The air will try to escape to the surface but will get caught in the second cup. Do this a second time with a cup full of oil instead of air. A lid will be needed to cover the cup of oil in order to turn it upside down to submerge it. Once submerged in water remove the lid and pour the oil into the cup filled with water. This demo also gives you a chance to observe how the oxygen and oil are positively buoyant and why they need these organs to assist in the vertical movement in the water column.
Here at CIMI, we are a proud proponent of keeping wild places wild. That’s why we’re celebrating the anniversary of the first National Wildlife Refuge. Using an executive order, the conservation-minded President Theodore Roosevelt established the Pelican Island Refuge on March 14, 1903. Since that day, over 560 national wildlife refuges have been created across the United States. The Wildlife Refuge System is an extensive network of protected areas created with the intention of conserving, managing, and even restoring animal and plants populations. Over 150,000,000 acres of our country are dedicated to nation wildlife refuges, protecting over 220 species of mammals, 250 reptiles and amphibians, 700 species of birds, and 1,000 species of fish! These refuges are incredibly important to plants and animals, seeing as over 380 threatened and endangered species call them home.
The California Condor Recovery Program (Recovery Program) is a multi-entity effort, lead by the U.S. Fish and Wildlife Service, to recover the endangered California condor.
There are 39 National Wildlife Refuges in California starting as far south as Tijuana and reaching as far north as Castle Rock on the border between California and Oregon. The Hopper Mountain National Refuge Complex is a system of 4 national wildlife refuges that were established in California to protect the endangered California condor. Due to lead poisoning, poaching, and habitat destruction, California condors were nearly driven extinct in the 29th century. With only 22 individuals left in the wild, drastic measures needed to be taken! Combined efforts to both protect the condors’ habitats with National Wildlife Refuges as well as capture the condors breeding programs has led to a recent boom in their population. Today, California condors are released into the Hopper Mountain National Refuge to roost and live out their lives with minimal human interference; this has led to an increase in numbers to more than 425 in captivity or in the wild, protected by wildlife refuges.
Sea cucumbers are a species of invertebrates under the phylum Echinodermata similar to sea stars and sea urchins. Sea cucumbers live in the benthic zone or ocean floor. They are nocturnal creatures but can be seen in the day as well. Sea cucumber uses their tube feet for locomotion and eating. The mouth is surrounded by twenty retractable tentacles that help them bring food in. They may seem slow, but have a very effective defense mechanism called evisceration in which they can jettison their internal organs to distract or in hopes their prey will eat their organs instead of attacking them. Sea cucumbers can regenerate these organs within days.
Sea cucumbers diets consist of algae, aquatic invertebrates, and waste particles in the ocean. Sea cucumbers are in high demands in Asian markets for their use in medicine and food. Sea cucumbers reproduce by the female launching her eggs in the waters, the male does a similar process with his sperm. Sea cucumbers can also self-reproduce as well.
Sea cucumber’s shape is elongated and is found on the sea floor worldwide. The most common species found on Catalina Island include the warty sea cucumber and the giant California sea cucumber.
Catalina Island is known for its biodiversity and natural beauty both underwater and on land. One creature of particular interest is the American Bison (Bison bison). Have you ever wondered how such a big animal ended up on an island twenty two miles away from the mainland, and hundreds of miles further from the Great Plains?
Though now an iconic feature of the island, the bison were not always here. In 1924, a small herd of 14 bison were brought over to Catalina Island during the filming of the movie The Vanishing American. After filming, the bison were released into the Catalina wild and eventually more were brought over for a breeding program. Having no island predators near large enough to prey on the bison, the herd sized boomed to near 600 by the 1970’s! The bison were grossly overpopulated, causing ecological damage such as over-grazing and erosion. This presented a unique dilemma for the Catalina Island Conservancy: how do you maintain a healthy population of bison on such a small island? Studies showed that about 150 bison could live here sustainably. In 2009, after a few different ideas of how to preserve a healthy herd (including sending off excess bison to market in California or a reserve in South Dakota), a seemingly perfect solution was found. Currently, female bison (called “cows”) are darted with a contraceptive that has a 95% success rate. The contraceptive allows the conservancy to limit the bison numbers to just around 150. This is a great success story of wildlife management for the betterment of both the animals and people.
More than just a tourist attraction on Catalina Island, American Bison are a national treasure. Weighing over a ton, bison are the heaviest land animals in North America. Don’t let their size fool you though, they can also jump up to 6 feet off the ground and run at rapid speeds up to 40 miles per hour. Though they used to be scattered all across the Great Plains, over 20 million bison were killed off as Americans were moving west during the 19th century. By the year 1889, only 1,091 bison were left in the United States. Today, after intense protective measures, bison populations have bounced back to about 500,000 with near 30,000 in conservation herds, like on Catalina. It goes to show that with some environmental awareness and responsible actions, humans are able to coexist peacefully with animals in the natural world.
We would like to thank you for visiting our blog. Catalina Sea Camp 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 minimum a Bachelors Degree in Marine Science or related subject. 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.catalinaseacamp.org for additional information. Happy Reading!