Although most of us know that whales and dolphins are highly intelligent mammals, with brain sizes comparable to those of humans, scientists and researchers are continually discovering how these animals are perfectly adapted to their marine environment, and rely on certain senses to successfully hunt and navigate in the wild.
Toothed whales, also known as Odontocetes, that use echolocation are primarily dolphins, porpoises, river dolphins, orcas and sperm whales. These animals emit calls or 'clicks' into their environment and analyze the echoes that return from various objects around them. From the differences in the echoes, they are able to distinguish relative distance, size, and type of object, seemingly studying it in detail without ever laying eyes on it.
In a recent study conducted on a captive toothed whale in Hawaii, researchers found that the whale could focus a sound beam and adjust it to accurately identify two objects with only a hairline fracture difference in width. In observing the whale respond to similar objects placed in her environment, scientists found the whale would intensify the level of echolocation beam to formulate a specific image of the objects, thus getting a larger proportion of energy back from the objects when the beam of sound increased, and creating a clearer image her target.
Toothed whales literally map the world around them using sound, and this extraordinary ability enables them to follow and track prey by only using their sense of hearing. These animals have had to adapt to environments with little light (e.g. many whales hunt in deep waters where little or no light permeates) or poor visibility (e.g. river dolphins hunt in muddy waters using sound to locate prey). The accuracy in using echolocation is a must for animals that rely on this technique to capture prey. Some species, such as the Narwhal, also use echolocation to navigate Arctic waters and locate breathing holes in the ice. These mammals must rely on the accuracy of these echoes to find where and when their next breath will be. Researchers have also found that toothed whales are able to heighten the sensitivity of their hearing when required, but also block out loud damaging sounds when present.
When Odontocetes species emit 'clicks', these sounds travel through a fatty structure at the front of their skull called the Melon. The latter, distinguishable from the bulbous shape of the animal's head, acts as an acoustic lens, focusing the clicks into sound beams of adjustable size. This incredible feature is what makes toothed whales perfectly adapted to their watery world, and equipped to picture the world around them before they ever see it.
Citation: Victoria Gill. "How whales and dophins focus sound beams on prey", BBC Science & Environment. 22.03.12. Wikipedia online encyclopedia. "Animal Echolocation" http://en.wikipedia.org/wiki/Animal_echolocation
Even if you have never heard of sustainable development, this term is crucial to our modern world, and even more relevant when considering the existing pressures humans inflict upon our natural resources. For millions of years, the evolution of man has been a mix of adaptation, exploitation, and developing at faster rates as the centuries rolled on. Our history has been shaped by the discovery of the health benefits and economical profits central industries as agriculture, forestry and fisheries provide. Sustainable development is needed more than ever to ensure the management and conservation of our natural and finite resources.
Our planet is now carrying 7 billion inhabitants. This is an incredible amount of people and an even more astounding number when we think that most humans depend on agriculture for food (e.g. cattle, chicken, grains, vegetables, etc.), fisheries for protein (e.g. fish, shellfish, mammals, etc) and forests for wood (e.g. building materials, paper, etc.).
Sustainable development is key to safeguarding the resources we rely on to live, and protecting the economies and trade relations that depend on resource yield and profit. Global fisheries are an industry that extracts over 100 million tons of fish from our oceans annually. Agriculture is the predominant industry causing the deforestation of the planet's most ancient rainforests and wildlife habitats. Humans must understand and respect that our global environment sustains life on earth, but our natural resources are not endless reservoirs and they can be destroyed if not safeguarded. Humans have already contributed to the extinction of multiple marine and terrestrial creatures, through our insatiable desire for meat, valuable body parts, pelts, etc.).
Although individuals, governments and industries are not about to halt the exploitation of the resources our global community relies on, we must limit what we take from the environment, for its sake and our own. Humans have fished nearly all the large species of fish beyond sustainable limits, and this threatens the future needs of our growing world population. If the oceans are fished out, how will we feed the 3.5 billion people who depend on seafood as their primary source of protein?
Understanding sustainable development and incorporating ethical principles in our everyday life plays a role in how we shape the consumption, use and demand of our natural resources. Action and participation are needed on every level, whether from citizens or large corporations, all must be involved in developing our world while considering factors such as the environmental health and food security.
Prominent industries such as agriculture, fisheries and forestry have been growing over time, and are now shaping the basic cycles, patterns and temperatures of our world climate. Global Warming is a phenomena of environmental change thought to be caused by a multitude of factors relating to industrial pollution, waste, and increasing carbon emissions altering our atmosphere and oceans. The chemistry of our planet is changing, and with that we are witness to extreme environmental degradation, reckless exploitation, and poorly designed trade policies. Our oceans are suffering increased acidification while deforestation is reducing the oxygen-purifying gift our forests provide. The insatiable demand for meat and livestock has destroyed vast expanses of native land while the waste of farmed animals is a great contributor of greenhouse gas emissions polluting our atmosphere every single day.
Restoring our global environment, both on land and at sea, is crucial if we are to secure continued life on earth. Although our oceans have provided seemingly endless supplies of seafood for millions of years, humans are aggressively fishing, and like other primary industries, we are exploiting natural resources to dangerous limits. We can each shape our lifestyle to respect the environment the best we can. Our voices can be heard, and if we become engaged in preserving our natural world, we will secure a better future for our planet and its inhabitants.
Agriculture and Agri-Food Canada: http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1175526032952&lang=eng
International Institute for Sustainable Development: http://www.iisd.org/ecp/es/Citation: "Environment and Human Security". International Institute for Sustainable Development. http://www.iisd.org/ecp/es/
With the 2003 release of 'Finding Nemo', many of the ocean's hidden treasures came to life, and the enchanting characters of the film, from Nemo the Clownfish to Bruce the shark, brought marine wildlife into our homes and hearts.
Beneath the waves lies an aquatic world with magical webs of life, with creatures too small to see and others too large to fathom. However, like in 'Finding Nemo', the underwater world must contend with a growing human presence above and beneath the waves. Although Nemo was poached from the sea by a man looking to fill his aquarium, there are other threats to marine life such as over-fishing, pollution and habitat degradation.
According to the International Union for the Conservation of Nature (IUCN), 1 in 6 species from 'Finding Nemo' is vulnerable to extinction. Although hard to imagine the wonderful characters from the film loosing their habitat or being fished out of the sea, this is the reality for many of the real creatures found in our oceans.
Marine turtles like 'Squirt' and 'Crush' and 1/2 of all Hammerhead sharks like 'Anchor' are endangered with extinction. Each year, thousands of marine turtles are still hunted in parts of the world, especially in areas where it is tradition to consume turtle meat. Destructive fishing methods such as long-lining and drift-nets claim the lives of innocent turtles every year when the animals get caught in fishing gear.
'Bruce' and 'Chum' tried hard to curb their fishy diets in 'Finding Nemo', but unfortunately they would be facing far more serious challenges if they swam in our seas. Today, over 73 million sharks are killed each year, and these global hunts are taking place in large part due to a high demand for 'shark fin soup'. For thousands of years, Chinese culture has regarded the shark's fin as a sign of affluence or 'high class', and therefore the tradition of the soup evolved by serving the dish at important functions like banquets and weddings. Today, Asian cultures still identify with the soup, which creates a huge demand for the fins, and is therefore contributing to a huge decline in most shark species on our planet.
Remember 'Mr.Ray'? He was the wise Eagle ray who taught Nemo and his friends at school, and although there are a multitude of different species of rays roaming our oceans, the Eagle ray is today threatened along with the majestic Manta ray.
Sometimes we need to be reminded of the things that we cherish (like beautiful ocean wildlife!), and shown that we can always learn from the world around us. Especially when is comes to our living environment.
"Human beings are the stewards of the earth and we are responsible for protecting the species that share our environment" -Simon Stewart, chair of IUCN Species Survival Commission.
All cartoon images © of Disney & Pixar's 2003 Finding Nemo.
The whales that call our oceans home today are very different from the early mammals that are part of their ancestry.
Ancestry: This term refers to individual species which share a genetic (biological) relationship, a common decent with older primitive animals known to have lived on earth.
According to various studies and archeological findings, early records of whales have been found in fossils discovered in certain areas of Egypt, Pakistan, and the U.S. (United States).
Fossils: These are remains or traces of animals preserved over time. Leaving an indent or bone specimen embedded in rock, findings called "fossils" are usually a minimum of 10,000 years old!
The Basilosaurus and the Ambulocetus are two species thought to have lived millions of years ago, and have specific attributes and characteristics leading researchers to confirm they were part of the great whale ancestry.
Basilosaurus: First believed to have been reptilian sea monsters or ancient lizards, Basilosaurus fossils were originally found in America (U.S.) and later suggests that they were in fact the "Giant whales" of their time. Possessing mammalian sets of teeth, fossils also showed the presence of short legs tracing early whales back to a terrestrial (living on land) past.
Ambulocetus: Possibly an early form of 'whale', skeletal remains of Ambulocetus show a set of legs probably used for propulsion and a similar method of hearing as modern whales. With no external ears, these species are likely to have felt vibrations through their jawbone. Called the "walking whale", Amulocetus looked like a furry Crocodile, but was actually on its way to becoming the biggest ocean mammals on earth!
Here are two videos created by the BBC to re-create what the behaviour and appearance of these ancient species would have been like:
Evolution-Giant Whales-BBC Science
Primitive Whale-BBC Science
Across our world oceans, shark populations are being threatened by destructive human activities such as Shark Finning. For more information on this topic, please link to our blog from February 22nd, 2011: http://www.eco-odyssey.com/blog/3/Saving-our-Sharks.html
Shark Trust is a great organization committed to helping the sharks of our world survive by making sure humans know and understand how important they are to our ocean ecosystems.
They have a fantastic Educational resource page on their website, and its packed with tools, games, and information about sharks. There are ways for all of us to get involved in helping our oceans, big and small, we can all do something!
This link is also very useful to teachers, who can download the Marine Educators Teaching Toolkit as incorporate ocean education in schools.
So Kids, suggest it to your parents and teachers, and have fun learning about the world's fascinating sharks!
"Sea Choice: Healthy choices, healthy oceans" is a Canadian Sustainable Seafood Program working with other organizations to develop, educate and promote healthy oceans by providing solutions and ways we can all play a role in this cause.
Kids are especially lucky because Sea Choice is proud to add an "Educator's Guide" that teachers and parents can use to bring ocean education right into the classroom and into your home. This guide provides tools and tips so that children of all ages can participate in becoming active ambassadors in supporting our living oceans.
Ask you parents to download this guide or suggest it to your teacher at school so that you and your friends can begin to make a difference for our ocean friends!!
Compiled by: George H Burgess and Cathleen Bester
BOOKS!!!-Recommended reading material from the Florida Museum of Natural History.
Click here to link to the list of wonderful books carrying you into the underwater world of sharks...
Reading opens our minds to all types of wonders, and learning about our ocean environment will hopefully motivate you to help protect it now and in the future!
The Grey Nurse Shark, also known as the sand tiger shark and the spotted ragged-tooth shark was the first shark in the world to be protected.
Listed as vulnerable in some countries, the Grey nurse shark is critically endangered in eastern Australia in part because of destructive shark-netting programs.
Grey nurse sharks may look threatening, but they are placid and slow-moving animals capable of beautiful interactions with humans.
Due to their late reproductive maturity and birth rates of only 2 pups every 2 years, Grey Nurse sharks are especially vulnerable to extinction. So let's help to protect these incredible animals!