Day Five: 4th May
We are greeted by another calm sea day- great weather for field work!
Our Society is addicted to plastic. I’m typing this blog on a plastic keyboard. You’re viewing it on a plastic screen you’re probably wearing plastic clothes which cam in a plastic bag paid for by a plastic credit card or plastic money. Have you ever wondered about the lifecycle of those products that are so ubiquitous in our everyday life? Have a look around you and write down all the items that surround you that are, or contain plastic. Out of all the different materials available, I would be surprised if less than half of them were plastic. Think about each item that you have touched since you woke up this morning- make a tally sheet and record whether its plastic or not- Why not do it on your plastic smart phone? I think the results will be quite alarming. Did you know that some regions of the Ocean contain more plastic than plankton- in fact plastic can outweigh plankton by a ratio of 6 to 1 in areas such as the Giant Pacific Garbage Dump. Today I was reminded about a 2007 documentary called “Addicted To Plastic” made by Ian Connacher which is still extremely poignant.
Our fourth day involved beach surveys, data entry and more bird necrospies. I tell you what,
I’m getting intimately familiar with the digestive system of the Short Tailed Shearwater! Measuring bird attributes and bird condition is
becoming second nature. Identifying the sex of the birds however is extremely hard.
This is probably because the birds that are washing up are juvenilles, yet to become sexually mature, so the gonads are not very obvious. What a shame that birds who are too young to breed are washing up dead with plastics found in the guts- Some of these birds may have even been fed plastic by their parents as hatchlings as they regurgitate food into their mouths.
We found a wide range of litter, most of which was plastic and categorised it into colour, size and type:
Shearwater necropsy: A mystery solved?
Most of the birds we have collected on the trip have been under weight- less than 300g. Today we dieescted a bird that was over 300g and from the amount of fat and muscle condition, seemed to be in a very health condition- So why had it washed up on a stradbroke beach?
There were no signs of damage on the outside; no puncture wounds or obsvious broken bones. The heart was in good condition and all the organs seemed intact, even the stomach looked full- perhaps full of plastic…
Day Three: 2nd May
Today we were up before 6am to discover more of the Island before breakfast. It gave me a chance to work out the location of Manta Lodge, where I am looking forward to heading towards this Saturday for a couple of dives. It’s the worng season for Manta Rays, but we may be lucky enough to catch some other “charismatic MEGA fauna like dugongs, dolphins or eagle rays. This morning we braved the water for a quick surf amongst the diving Gannets and Shearwaters before we headed back to the lab for a morning of bird necrospies…
Mutton bird stranding?
Mutton birds, otherwise known as Short tailed Shearwaters (or Puffinus tenuirostris), are migratory birds weighing approximately 500 grams that make an annual migration from the northern Pacific to the south Pacific totalling about 15,000km each way. Other species of Mutton birds helped to keep Captain Cook’s sailors alive on their journey throughout the South Pacific, but also form a staple diet of various aboriginal tribes throughout Australia.
By this time of year they have left their breeding grounds in Tasmania and Victoria and are cruising past Queensland to
find warmer parts in the northern hemisphere. Along the way, for various reasons known and unknown they become blown off course and can end up stranded on a beach. The CSIRO scientists of Moreton Bay are collecting the dead birds as they wash up on the local beaches and performing necropsies to find clues as to why these individuals died. Qamar Schuyler tells us that last year over 1800 birds washed up on the east cost of this island alone. If you extrapolate that number out over their entire 15,000km journey from southern Australia to the Aleutian Islands (just south of Alaska). Thats a lot of birds who lose their way- It must be a strong breeding population! In fact, the Tasmanian Park
s and Wildlife Department estimate that 18,000,000 birds migrate to Tassie each year alone.
Phillip Island Ranger Sue Graham tells me that each year the parents leave their burrows on Phillip Island at around Easter time. Aparrently they respond to environmental cues with the changing Victorian weather at that time of the year and they take to the air to begin their annual migration. It’s a fairly brutal way to wean your offspring- while humans try to encourage their children to move out of the family home in their twenties, Short tailed Shearwater parents dont drop any such hints- they just move out of the family home themselves!
Typically the young begin to wonder if their parents will ever come home, and after about two weeks they start to venture out of the burrow. One can excuse them for taking so long, as they are often left alone for weeks at a time while Mum and Dad pop off to Antarctica to pick up some take away Krill (about 6 times during the baby chick’s life apparently). So baby Shearwaters are fairly used to spending solo time in the burrow. This is true survival of the fittest however: those young (called fledglings) who have never come out of their burrows before, let alone attempted to fly, need to fend for themselves, which means hunting for prey (I now personally know they eat plenty of squid!), learning to fly and swim and somehow work out the way to Alaska!
Many birds don’t even make it far from Phillip Island, but those who do make it on the Southerly winds manage to learn how to hunt, fly and navigate all the way to the Northern Hemisphere. Unless something sinister happens- Why large number of birds who have clearly learnt how to fly, hunt and swim end up washed up on Queensland beaches is a mystery that we want to solve. By performing necropsies, we can identify what issues may have lead to the death of these birds.
Scientists take fat and tissue samples from glands you really dont want to talk about at the dinner table. We cut open digestive systems and trawl through oesophagus, stomoachs and intestines looking for toxins, parasites and other clues. We take note of the muscle and fat condition and relate this to beak measurments, which give an indication of how much fat and muscle a health bird with a beak that size is expected to hold.
Here’s why I know that juvenille Shearwaters are highly capable hunters of squid.
That digestive track contained almost 20 squid beaks, most of which had been moved to a special storage compartment to the side of the stomach called a gizzard.
We finished off this afternoon’s activities with a boat trawl along the north western tip of the Island. Qamar is investigating what kind of plastics may be present in these waters and available for animals such as shearwaters and Sea Turtles to consume. A fantastic end to another great day on Stradbroke Island!
Day two: 1st May
What a beautiful morning here at the MBRS! Breakfast on the research station balcony before we headed out to the field where the weather gods* became angry with us and we had to adjourn from our beach litter survey to the relative saftey of the hire bus. It did give us a great opportunity to meet with Heidi Taylor, founder of the Tangaroablue Ocean Care Society and talk about their great work around Marine debris!
*I pressume the polynesian Ocean God Tangaroa was not involved in the downpour on our beach survey given Heidi’s presence!
After our short minibus hudle we braved the artic winds (well they were southerly!) to learn how to conduct an official TEACHWILD marine debris beach transect. Great conversations about sampling methodology and tricks to avoid bias that were applicable to all kinds of surveys. Denise discussed the importance of following procedures to ensure data was consistent, so we measured out a line from the tide mark to the beach vegetation and proceeded to scan the sand for marine debris on both sides of the line up to the dunes…
We also found another two dead seabirds for necroscopy tomorrow. My, we do like doing -oscopies! Today we learnt how a new technique of spectrophotometry is used to establish exact colour of plastics ingested by Sea Turtles.
Another aspect of Qamar Schuyler’s research is to determine if there are any particular colours that seem to be in higher abundance than others. In otherwords, are the Turtles eating one colour plastic in favour of other colours?
How many colours does the Sea Turtle See?
This is difficult to answer for two reasons- We cant ask the turtle as A) it doesnt speak and B) he or she is no longer with us. It is also apparent that a Turtle’s eye may see colours differently to a humans and if we are to be totally realistic, we dont even know if what we humans see is the same- the red that I see on a tomato may be interpreted differently to the colour that you see. So Spectrophotometry to the rescue! This technique measures the exact wavelegth of light that is reflected off an object, so we can objectively determine its colour (a red tomato reflects light in the wavelngth range of 650nm-700nm, a green one would actually absorb this low energy light and reflect light back in the green range of approximately 510nm).
By inserting plastics retieved from the stomachs of Sea Turtles, Qamar can establish the colour of the objects turtles are eating and ultimately, if there is one particular colour that is more commonly consumed. So is it ROYGBIV????
A turtle eye is similar to a human eye, which possess cells that are sensitive to low, medium and high wavelength light from about 350-700nm. It is believed that Turtles may posses another type of photoreceptor that is capable of detecting wavelengths in ultraviolet ranges. They may even be able to detect polarized light without the need for 1980s style sungless- which is kind of a shame, because it would be quite cool to see some turtles swiming around with polaroid sunnies on!
Day One: 30th April
Hello from sunny Queensland!
After an epic journey from Northcote Victoria, via Planes trains, automobiles boats, I arrived at the Moreton Bay Research Station (with a severe addition to my carbon footprint) along with 7 other teachers from Tasmania, South Australia and Victoria .
Our intrepid team of TEACH WILD teachers were briskly swept off in a 4WD Troop carrier to make the most of an ecological event of hundreds of Mutton birds washing up on the eastern side of North Stradbroke Island. My first beach transect travelling at 70km was over about half an hour later with only one bogging event on the beach (photos to come).
While my year 11 Biology class sat in room 218 with Trev watching a Dr Gurokenther von Hagens complete a human dissection to learn about the human digestive system, I worked with CSIRO scientists in an outdoor lab on Green Sea Turtle Necropsies.
THis one died of a killer case of herpes:
Check out the digestive system- oesophagus through to rectum of a Green sea turtle… Not too disimilar to a mammalian digestive system with large and small intestines, pancreas, gall bladder and liver.
Although check out those teeth like things in the oesophagus that stop prey escaping as the turtle spurts out it’s belly full of seawater. Something that unfortunately creates an impenetrable barrier to any plastic that these poor guys might ingest!