Mr Bach in the Newspaper

 Keep an eye out in the Daily Post over the next couple of weeks as there should be an article about Mr Bach's participation in the Science Teaching Leadership Programme and a bit about the exciting things he has been doing. I was also lucky to be part of a an educational video filmed for the Bay of Plenty Regional Council about the pest catfish invasion of Lake Rotoiti (see photos below).

Recent Science and Fishing Experiences

 A few photos from some things I have been doing recently. Bottom photo - teaching science to a group of year 5 pupils at the Royal Society building Wellington. Middle photo - being part of filming catfish netting at Lake Rotoiti for Bay of Plenty Regional Council. Top two photos - in case anyone was worried I don't have time to do any fishing, I have been out a lot in my kayak and caught a few nice fish and yes the 4.8kg trout you may have read about in the paper as being the biggest caught in the district on opening day, 1st October, was of course caught by me!!!!!!

Monitoring of Koura Lake Rotoiti

Last week I went out koura monitoring with Fisheries Scientist Ian Kusabs and Laura, a graduate student from Waikato University. Laura set a series of whakaweku (bundles of bracken) at various sites around bays in Lake Rotoiti. Every few months she records the size and numbers of koura living in the whakaweku. The retrieval and replacement of the whakaweku is very labour intensive as you can see from the photos. Unfortunately not many koura were found living in the whakaweku on this occasion and Laura has to now try and work out why. One of the theories put forward by Ian is that the catfish netting programme is drawing the koura out of the whakaweku and into the nets as they pursue the bait put in to attract fish. Laura also took some phytoplankton samples from the bays and measured factors such as water temperature etc.

Pest Catfish Netting

I went out pest catfish netting on Thursday with Jeff and his son, the Bay of Plenty Regional Council contractors. They have nets that they set throughout the main infected bays in Western Lake Rotoiti and the Ohau Channel. They set them one day and check them the next so that the bycatch fish survive. They rotate the nets throughout the various sites over a week. It takes about 4 hours to check and sort all of the nets and record the data for the Waikato University scientists. They record numbers and length if there are less than 10 in a net or a length range if there are more than 10. At the moment the numbers are relatively low, in the 100s for the day, and all of the catfish are small, indicating that the netting programme is keeping the numbers down. The catfish spawning season starts in October though and this was when numbers exploded into the 10,000s last year. Catfish have been found up to the Ohau Channel weir at the channel's exit from Lake Rotorua so it is generally accepted now that catfish are inevitably already in Lake Rotorua and a potential disaster awaits. As you can see from the photos there are a range of fish caught in the nets. Most of the small dark fish are native bullies and the bigger ones are wild goldfish, or morihana, which were an important source of food and a local taonga for Te Arawa after the introduction of trout decimated native fish populations in the 19th century. The fish in Jeff's hand is a koaro, which survive in low numbers in many lakes, of which we caught about 7 altogether. These were the main native fish food source for Maori that existed in huge numbers prior to the introduction of trout. We also caught a number of koura at certain spots. The catch is tipped into a tray and the catfish are removed with pliers. Pliers are used as the catfish have a nasty sharp spine on their back and can turn their front side fins into rigid knives, which I found out to my detriment when I ignored advice and poked around in the tray, my finger coming out stuck deeply into a catfish fin. Ouch!! All by-catch fish were returned to the water unharmed and they swum away. The photo of the catfish is of a large one caught last year. Jeff has his pliers in the back of one of the smaller catfish in one of the photos of a full tray. The task of sorting the small catfish out from the other similar sized fish seemed daunting in the fuller trays but Jeff and his son did it easily. After awhile I found I could easily distinguish the catfish from the rest, more from their slightly different shape and brownish hue compared to the similar coloured and numerous bullies and the catfish's whiskers confirm the identification.

Wellington Science Workshop

 I was in Wellington last week for a workshop with all of the other Science Teaching Leadership Programme participants. We spent 2 days on a marae learning about Matauranga Maori and the science capabilities. I was the only one who knew a karakia kai, so ended up doing it several times. Afterwards we visited  a couple of school with teachers who have already been on the programme. I was happy to see that we are already doing a lot of things these schools showcased. Two interesting projects I saw were a Litter trap in the school drains which was sorted and data collected by the children each week and a working human sundial (see below).

Field Trip with Andy Bruere

I went out on a field trip with Andy Bruere, an engineer with the Bay of Plenty Regional Council. Andy's children went to St Mary's and I had his son in my class for 2 years. Andy explained to me about a lot of the infrastructure around the Rotorua Lakes that he responsible for as an engineer, particularly to do with improving water quality. We went to the alum dosing plant which puts aluminium into the water at the Utuhina Stream and Puarenga Stream to remove excess phosphorus from the water of Lake Rotorua, phosphorus being partly responsible for poor water quality, including algal blooms in the lake. This intervention has been very successful. We also saw the Lake Rotoiti wall, which diverts Lake Rotorua water down the Kaituna River and has vastly improved the water quality in Lake Rotoiti. The photo is of Lake Tarawera, which is currently being monitored carefully and needs to be watched because so many other lakes flow into it either by way of streams or ground water and some of these lakes have poorer water quality themselves.

Water Quality Monitoring

 I went out on the Bay of Plenty Regional Council regular water monitoring run around many streams and rivers that flow into or out of the Rotorua Lakes. The people you see are Dr Troy Baisden for Waikato University with his graduate student Clare and Kasjan from BOPRC. This work is important in order to see how well our waterways are doing and whether they are improving in quality or deteriorating. The tests look for water flow speed, water clarity, suspended solids and nitrogen and phosphorus levels in the water