Thursday, 16 June 2016

Water Drop Races

The Curious Kiwis helped me explore the surface tension of water with some water drop races.  They had to get their drop from one end of the paper to the other without it breaking.




What is holding the drops together?
How hard would you have to blow to break the drop?
Could you get the drop back together again?

Fish Friendly Flood Gates

Another one of Hamish's projects is to oversee the installation of Fish Friendly Flood Gates (FFGs).


These gates close slowly during flooding or tidal movements to allow fish easy passage upstream.  This gate has been installed just outside of Te Puke.

There is a lot of science involved in these gates...
Water flow
Forces
Weights
Cantilevers
Tidal effects
Fish monitoring



Just the right amount of weight is required to make them work properly.
Hamish is doing a bucket test to work out how much more weight is needed on this gate installation.







Thursday, 12 May 2016

Refraction Time

Some smart scientists from the Future Force helped trial an activity today that will be included in the new House of Science water kit.
They learnt that light bends when it travels from air through water.  Refracto-Cat got our thinking started as we made scientific observations using our prior knowledge and making connections to discuss why his face was so distorted.

Why do you think RefractoCat's face is so round?

The Future Force scientists made predictions about what might happen to their faces if they looked through a glass jar.



They then had a go themselves to test their predictions.

Empty Jar


Jar filled with Water



Some interesting observations were made when Ryan put his fingers behind the jar. 
What can you see?
What are your ideas about what has happened to his fingers? 


Have a look at this video that explains more about light refraction and why things look bent when we put them in water.

Monday, 9 May 2016

Electro Fishing


Last week, I was very lucky to spend 5 days with some Scientists from the Regional Council and NIWA out in the streams and rivers around Te Puke and Pongakawa areas catching fish using a method called electrofishing.

This fishing method pulses an electrical current into the water which stuns any fish in the vicinity.  They are only asleep for just enough time to catch them in a net that is draped across the water.


The fish are then placed gently in a bucket with some water to keep them alive, then identified, counted and measured before being returned safely to the water.




Identifying, counting and measuring fish in our waterways gives scientists a really good understanding of what is living in our streams and rivers, how far they are able to migrate as well as the quality of the water as some fish are VERY fussy about having clean habitats to live in.

Here is a picture of a massive eel we caught, measuring more than 1 metre.  Julian says it would be over 100 years old! As soon as she woke up she slithered out of the net and right back to her home under the stream bank.


Over the week we monitored the Ohineangaanga, Raparapahoe, the Kaikokopu (your stream Logan K), the Pongakawa River and the Wharere canal - plus a lot of small tributaries to these waterways.

A huge thank you to Rochelle and Julian for teaching me so much about our local fish.

Scientists really do have the best jobs!



Thursday, 17 March 2016

A watery day in the Rangitaiki Catchment

We drove a very long way up into the hills in the Rangitaiki catchment on Wednesday to test the water in 5 different stream locations.
My job was to sit in the back of the ute and navigate the way with a topo map (my map skills are very rusty!)
It is a beautiful area of NZ up past Galatea - misty hills and clear waterways.

Rochelle is collecting bottles of water for chemical and bacterial analysis.
She also placed a meter in the water to check the temperature, pH, dissolved oxygen and salinity levels.  The results are sent via bluetooth to an iPad.
All this information is recorded in a BOP Regional Council database.  The scientists use their skills to analyse what it all means over time and check to see if any events (like heavy rainfall or dairy or forestry runoff have effects on the water).

There were some very slippery slopes to walk down.  I slipped and skidded down this one on my bottom!

Craig is gauging the flow of the stream.

Just the Facts:
A Topo map shows the physical features of a landscape - it uses shading and lines to show how steep the terrain is and also waterways, plains and plantings.  Have a look here at a topography map of Te Puke.  Can you find a map key (also called a legend) to work out what all the lines and colours mean?


Oysters tell a story

Another way scientists check the health of our marine water is with oysters.
 These oysters were collected from Ohiwa harbour and were deployed to the Tauranga harbour in various locations late last year.  Sitting in their cage for 3 months, they feed by filtering water over their gills.  If there is pollution in the water, the oyster flesh will tell the story of what type of contaminant it is.  Rob is the scientist whose feet you can see in the picture.  He dived down into the marina to collect the cage.  You can read more about the project in this article from the BOP times.

There were a few hitch-hikers attached to the cage when we pulled it out of the water.  Can you see what they are?
Just the facts:
Birgus Latro is a giant hermit crab which lives on land.  Its common name is the Coconut Crab although it is also known as the Robber crab because it can steal your pots and pans and even eat your cat!
Can you find out where in the world it lives and why it is called the Coconut crab?


Thursday, 3 March 2016

Oil Spill Monitoring

Another very important job for the Scientists at Bay of Plenty Regional Council is to keep our harbour clean.
Last year in April, a terrible accident occurred.  1500 litres of oil was spilled in Tauranga harbour!
How many milk bottles is that?
How many drink bottles?
Coastal Scientist Rob Win is still checking the harbour at low tide for oil from the spill - a whole year later!
You can read the details of the spill in this Stuff article from last year.
Most of the oil floated out into the Maungatapu area of the harbour.
We waded out in the Maungatapu mud this morning and collected shellfish and sediment samples that are bagged up and then sent to the laboratory in Whakatane.  The laboratory staff will test all the samples and let Rob know if there is still any unwanted oil in this area.

You can still see the oil stains on the top edge of this retaining wall.

This is a view towards the road up from Turret Road to Welcome Bay.  The big tunnel works are happening behind the trees in the background.

Here are a couple of Titiko (sand snails) that are sitting on top of the sand at low tide.

We had to pick up quite a few at each site so that the Laboratory Technicians have enough snail meat to test for oil residue.

It got pretty muddy in some places.  

Digging for Macomona (Wedge Shell).  They live about 5cm below the surface in the black mud.  The black mud is pretty smelly.  This is because there is no oxygen in it.  Peew! 

We also collected loads of cockles which live just below the mud surface.

Just the Facts:
Cockles are filter feeders - this means they suck water and nutrients in through the gap in their shells.  They tell us whether there is oil IN the water.

Macomona are surface feeders - they suck water and nutrients from the water's surface.  
They tell us whether there is oil ON the water.


 A beautiful morning to get wet and muddy!