Tag Archives: marine biology

A Shout out to Sharks

They are the most feared, yet the most misunderstood, of all marine animals – apex predators that pre-date the dinosaurs by an estimated 200 million years.

Of the almost 500 species of sharks swimming in our oceans, only a handful are the complex killers we hear about on the news – the majority have a far more sensitive side.

The reality is sharks don’t have a mean bone in their body… in fact they have no bones at all! Their skeletons are comprised of cartilage which is flexible and lightweight – allowing some to reach speeds of close to 100 kilometres an hour.

But while their sleek, race car bodies have helped them to survive for so long, ironically, it is also contributing to their downfall. Shark cartilage is used in beauty treatments and alternate medicines – a part of the reason 100 million of them are killed every year by humans.

It seems we have a love/hate relationship with these fish – while movies like Jaws are enough to keep some of us high and dry on the sand during a trip to the beach, others go to great lengths to absorb nutrients from sharks, adopting an eat or be eaten approach.

Shark fin soup is a delicacy in Asia and demand for the prestige product has led to the decimation of some species including the scalloped hammerhead. The process of removing the dorsal fin from a live animal is illegal in Australian waters, but the practise is difficult to police.

But what many of us miss in our obsession with sharks, is some of their truly extraordinary abilities. Unlike humans, they breathe through gills, so their nostrils are purely dedicated to smelling. Their sense is so refined, they can detect one drop of blood in 100 litres of water. Even more astounding is they can identify which of their two nostrils picked up the scent to determine the direction to swim to track their prey.

But it’s not just smell they’re tuned into – their ability to pick up on electrical impulse and vibrations is so acute, they can sense a Double A battery from 3 kilometres away. And while these skills are designed to help them locate food, some species can survive for up to 3 months between meals – the ultimate fasting regime!

Apart from their unparalleled skill in sensing their next feast, sharks are also well equipped to chow down their catch. They are known for their multiple rows of razor sharp teeth – and it appears they have an endless supply. While humans have one set of large teeth to last a lifetime, many species of sharks can grow tens of thousands, quickly replacing any that have gone blunt and fallen out.

And while this may seem terrifying to us, the reality is we are not on their menu. Attacks on humans are generally a case of mistaken identity – surfers are the most common target, mimicking the shape of a seal on the surface. While it may be of little comfort, statistically, you are more likely to be killed by a falling coconut or a flying champagne cork than to be taken by a shark.

Ocean Life Education runs a Shark Discovery program that helps to separate fact from fiction when it comes to the most feared fish in the sea. It is one of our most popular presentations as we explore all the fascinating features that make these apex predators such effective hunters yet strangely vulnerable at the same time.

When all the hype and hysteria is removed, it is easy to see how sharks play a vital role in maintaining balance in the marine eco-system. Deep down, (and also on the surface of their snout!), they really are quite sensitive.

Marine Biologist for a Day

Over the past few years, hundreds of primary schoolers have enjoyed our holiday sessions that inspire them to care for the ocean – now it’s time for the high schoolers to get in on the action.

Due to popular demand, our Marine Biologist for a Day program has been adapted to cater for an older audience who want a more in depth look at the world of marine science.

Students will have the chance to examine in detail our impact on the ocean including environmental stress on coral reef systems, water acidification and plastic pollution.  We will discuss a wide range of ideas on how to better care for the health of our seas.

The aim of the program is to making learning fun and relevant, examining animal classification to discover how each creature fits into the aquatic world.

The program will be very interactive, with students observing the dissection of a dead fish to reveal the organ make-up and development of a mullet.

And our most popular feature will still be included – the chance to gently touch our living sea creatures – an opportunity that never gets old at any age!

This program will provide a valuable insight to the workings of the aquatic world for any high schooler who has a passion for the ocean or is considering a career in marine sciences.

But we haven’t forgotten the younger students – our classic Marine Biologist for a Day will still be running in school holidays – we’re just expanding the program to grow with your kids.

For more details check out https://www.oceanlifeeducation.com.au/programs/marine-biologist-for-a-day/

Monitoring marine debris

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Marine Debris event at Sealife Mooloolaba

By Katie-Anne

During my time as a Marine Education Officer I have been invited to many open conversations, workshops and conferences, so when I was invited to attend a night of conversation around marine debris at Sealife Mooloolaba, I thought it was a great networking and information sharing opportunity. What I wasn’t expecting, was that the night would cause a shift in my understanding of the importance of data collection and the sway that citizen science can have.

The night was organised by the Sunshine Coast Council and included guest speakers from Targaroa Blue, Sealife Mooloolaba, Coolum and North Shore Coastare, Reefcheck Australia and the SCRC Turtlecare program. These stakeholders have a volunteer or not-for-profit element to their conservation work and as such the passion exuded by each speaker was all encompassing.

One statement said it all.

Naomi Edwards from Tangaroa Blue foundation opened with a statement:

“If cleaning the beach is all we do, it is all we will ever do.”

A very bold statement which had everyone sitting up and listening with open ears. What Naomi meant was that collecting debris is an amazing opportunity to identify what is washing up, where it comes from and how it entered the marine environment.

Citizen science creating real change

Through this train of thought the Australia Marine Debris Initiative (AMDI) was born. The organisation has a global database in which volunteers, community groups and organisations can input data based on the size, material and type of item collected from the beaches and river clean ups. This means me, you and the little old lady down the road can contribute to the collection of scientific data.

Tangaroa Blue then uses this data to work with Industry and government organisations to create change on a large scale. Once upon a time this type of citizen science was dismissed as ‘not scientific’, however, it appears this broad quantitative science is gaining more traction within the scientific and government communities. The exciting thing that I discovered was that local government authorities are willing to see this as a feasible data collection means for identifying possible trends within the environmental systems.

But how is the raw data used to do this? Well, I thought the same thing until I discovered that the data can be viewed by anyone and can be collated to create reports on the website and can be (including a variety of graphs…..everyone loves a good graph) tailored for specific beaches or communities. This opens the opportunity for the identification of trends and problematic pollutants within this locality and to identify where the most common types of pollutants have originated from. Once specific pollutants or trends have been identified, this data can be used as a basis for change in the form of prevention by a strategic approach within the local community.

It is this type of focused solution planning, or pollutant focused planning, that the Sunshine Coast Council is showing an interest in. An example of the positive use of this data is with the implementation of a ban on the release of balloons at council events and in council-managed reserves by the Eurobodalla Shire Council. This was the direct result of collation of data relating to balloons found on the local beaches and the education on balloon impacts on the marine environment that was given by the local environmental officers.

Community action is important for scientific data

This is the key shift in thinking from simply cleaning the beach (which I do not want to underestimate the importance!) to using this necessary and vital community action as an opportunity for data collection and potentially as a platform for societal change. Essentially this database and others like it are enabling members of the community access to relevant data to drive changes from a community based ground roots level.

More information

For more information about Tangaroa Blue, the Australian Marine Debris Initiative or upcoming clean up events, visit www.tangaroablue.org.

Other organisations mentioned:

Sunshine Coast Council TurtleCare program

Sealife Mooloolaba

Coolum and North Shore Coastare

Reefcheck Australia

Jellyfish: Weird, Wonderful and a Dangerous sting

jellyfish

Image: swellnet.com

All jellyfish sting and that’s the unfortunate truth.

Every jellyfish fires out millions of little stinging cells called nematocysts, similar to a bee sting only much smaller and many more of them. The only difference is in the potency and the length of the sting barb and the reason for this variation is due to how they catch and eat their prey. Some jellies like to catch and eat small fish that are fast and agile. A jelly needs to subdue its prey fast so it doesn’t get damaged in the ordeal or escape. So some have very powerful neurotoxin venom and this is what can be dangerous to humans.

Common types of jellyfish

For years we have been aware of the dangers of the Box Jellyfish. It has the most powerful venom and is the largest of the dangerous Jellyfish. It has a reputation for causing fatalities, especially to those with predisposed heart or respiratory conditions.

The Bluebottle (or Man-o-war or Sea Wasp) is another common Jelly responsible for the greatest number of injuries to swimmers due to their numbers and being found further south than the Box Jellyfish.

In the last few years however, we have heard more about a much smaller but quite insidious fellow – the Irukandji. This guy is indeed a small species of Box Jellyfish, of which there are 16 different species. The two most common and responsible for most deadly stinging occurrences are the Carukia barnesi and Malo kingi.

These Irukandji grow anywhere from 5-25mm, each one with 4 long tentacles up to 1m in length. Their sting initially is moderately irritating with symptoms of their venom delayed anywhere between 5 to 120 minutes after. On average it takes 30 minutes for symptoms to appear and include severe lower back pain, nausea and vomiting, difficulty breathing, profuse sweating, severe cramps and spasms, and a feeling of impending doom. Some species also cause severe hypertension (high blood pressure). Irukandji syndrome can be fatal, but generally is not. Hospitals throughout tropical and subtropical Australia have good evidence-based protocols for managing Irukandji syndrome, and most people stung make a full recovery.

Alarming research into the Irukandji

Scientists from James Cook University Townsville Queensland have made some alarming recent discoveries about the Irukandji.

Unlike all other jellyfish known to science, Irukandji have stinging cell on their medusa (dome/bell), believed to be an adaptation to sting prey from anywhere on their body due to their small size to increase their chance of catching prey. The other worrying feature is that the most well-known immediate remedy for jellyfish stings, vinegar, actually promotes the discharge of venom into Irukandji victims up to 50% more. Scientists believe this increase to be of lethal consequence and now advise avoiding use of vinegar on victims if unsure what type of jellyfish was responsible. Blue Bottles and Box Jellyfish have fairly easy to detect stinging marks, thus vinegar in those cases is still suggested.

What does this mean for us?

It is now well documented the occurrence of these jellyfish in waters as far south as Hervey Bay and Fraser Island. It is evident that with increasing water temperatures (1 to 2 degrees over the past few years) has led to a migration of Jellyfish including Irukandji into more southern waters. How far south will they go, no one can say for certain, but awareness and vigilance is required when visiting beaches and reefs all over Queensland. Being prepared and knowing what to do is important for our safety and wellbeing.

And a final note, this is not a case for hysteria. There have been some false identifications of Irukandji and bigger box jellyfish in recent months. The morbakka or Moreton Bay Jellyfish is related but nowhere near as dangerous.

Learn more

If you’re interested in learning more about the Weird & Wonderful creatures of the Sea, check out our school holiday program or invite us to your school to deliver a curriculum-based program.