Keep up to date with Shelley the LEARNZ Teacher during this field trip.
Day three–Thursday 5 March
Kia ora koutou,
Technology has made our lives easier. It has also helped scientists to learn more about our marine environment. Today we met Leigh Tait who is a marine ecologist and a huge fan of the latest technology. Leigh works for NIWA and he gets to play with drones and remotely operated underwater vehicles. His work has taken him all over New Zealand and to Antarctica. Leigh was keen to share his work, so we met with him and drone pilot Brendon Smith at Ōhope Wharf. Before Brendon and Leigh could show us how to fly a drone, Leigh had to face some challenging questions from Te Rerenga School during the final field trip web conference. You can listen to a recording of this web conference to find out more.
We were worried that it was going to be too windy to fly a drone later in the day, so Brendon quickly organised the drone and it was in the air within minutes. This drone is smaller than some of the ones that Leigh and Brendon use and it copes with the wind better. Leigh uses the drone to take images of what’s growing on the seashore. Today we were looking at seagrass in the estuary. Seagrass is an important plant because it provides food for many creatures and produces oxygen.
Leigh laid out a transect with two 30-metre-long tape measures a metre apart. This gave him a sample area where he could identify what was living within the area and photograph it. Leigh will use this information to teach a computer programme how to identify species from photos taken by the drone. In this way Leigh can use the drone to record where seagrass is growing over a much larger area and monitor changes in seagrass growth over time.
Leigh has carried out similar work in Kaikoura after the massive 2016 earthquake. Using a drone, he could see how different seaweed species had responded to uplift caused by the quake. This project used a special type of camera that took multispectral images. These images record light in different bands which our eyes can’t see. This gives scientists extra information which means they can identify different species. It was amazing to see the maps that Leigh could create using this technology.
We ended the day at Ōtarawairere Bay. A track with many steps led us up and over a rocky headland to a spectacular beach. Here we were able to scramble around a rocky reef to explore a different type of marine ecosystem. Waves crashed against the rocks and stopped us from taking a closer look into some rock pools. I caught a glimpse of a huge crab before it scuttled into the water. We had to return to the beach as the tide came in and claimed the rocky platform. It was a great reminder of how dynamic this environment is and how incredible the creatures are that live within it. We are so lucky in Aotearoa to be surrounded by ocean. Our seas provide us with so much and we can all play our part in looking after them.
It has been a fantastic week celebrating Seaweek here in the Bay of Plenty. I hope you’ve enjoyed the field trip and can join us on another one soon.
Ka kite āno,
Shelley, the LEARNZ field trip teacher.
Watch the videos and meet the experts.
Day two–Wednesday 4 March
Kia ora koutou,
We headed over to the western side of Ōhiwa Harbour this morning to find out more about the research that Kura has been doing. Ōhiwa Harbour is bigger than I thought, and it took a long time to drive around to Kura’s restoration site. From here we could look across to the sandspit to where we were yesterday. This side of the harbour is much more rugged, with more forest and hardly any people. I couldn’t wait to head out on a kayak and explore.
Before we could go kayaking, we had to organise our gear and complete the live web conference. It can be a bit tricky connecting to the internet from such remote places, but we eventually managed to talk to Brooklyn School and answer their fabulous questions. Kura talked about some of the amazing things she has seen while diving and it made me want to learn how to scuba dive. It also made me realise that we still have a lot to learn about our oceans and what lives within them.
With showers of rain and thunderstorms predicted we were keen to get out on the kayaks as quickly as possible. Helen from KG kayaks gave us a safety briefing and issued us life jackets. We headed down to the water’s edge to launch the boats and followed Kura out to her kūtai (mussel) restoration lines. A line of buoys mark where the mussel lines are. Some of the buoys were only just visible, weighed down by so many mussels clinging to their surface. It was a real struggle to pull up the heavy lines, but fantastic to see so many mussels growing. Kura will take these mussels to the last remaining natural mussel bed in the harbour. Here they will help sustain and grow the mussel bed. It was amazing to be out on the water and I was reluctant to head back to shore.
After drying off and sorting the kayaks Kura showed us how to make mussel lines. Kura has chosen to use natural materials because they don’t harm the environment. The mussel lines at this site are made out of tī kōuka (cabbage tree) fronds. At other sites she has used harakeke (flax). Any natural material that you can weave into a strong line can be used. Lines that have a larger surface area give more space for mussels to attach to. You could try designing and making your own mussel lines. Unlike plastic mussel lines these lines will naturally break down and drop to the harbour bottom, creating a habitat for mussels. Kura hopes that restoration sites like this will help keep the water healthy and eventually help increase the number of mussels in the harbour.
Kura has also been involved in another trial in Ōhiwa Harbour. This trial was to try and stop pātangaroa (sea stars) from eating mussels. Scientists used cages to try and protect the mussels. The problem was the sea stars always managed to get through these cages. Lots of different designs and materials were used but nothing worked for more than about three months. The cages had small holes in them to allow water to flow through them. Somehow the sea stars managed to find their way through the smallest of gaps. The sea stars have outsmarted the scientists, so Kura is focusing her efforts on restoration stations and trying to find out why there are so many sea stars in the harbour.
It’s been amazing finding out about Kura’s work and now I’m looking forward to flying a drone tomorrow – all in the name of science!
Watch the videos and meet the experts.
Day one–Tuesday 3 March
Kia ora koutou,
The Bay of Plenty is the perfect spot to be during Seaweek. Here you can experience stunning beaches, warm water, sheltered harbours and estuaries full of wildlife. We headed over the hill from Whakatāne to explore Ōhiwa Harbour. This harbour is known as a food basket and supports a variety of birds and marine creatures. Kura Paul-Burke from the University of Waikato met us at the Port Ōhope Wharf. Kura is a marine scientist and she was keen to share her knowledge of the area.
Before we could go exploring, we spoke to Owairoa School during the live web conference. Students had some challenging questions and were curious to find out more about this special place. It was interesting to hear about some of the animals that people often see in the harbour, including bronze whaler sharks, orca and eagle rays. You can find out more by listening to a recording of the web conference.
After the web conference it was time to take the shoes off and head into the water. Students from Kutarere School have been learning about the harbour and were excited to see what creatures Kura had found on a recent diving trip. We all waded out to the catch bags which Kura had left soaking in the harbour. It was exciting to see how many pātangaroa or sea stars she had found. Kura also had a collection of kūtai, green lipped mussels. Both these creatures are well adapted to life in the ever-changing harbour.
Kūtai play an important role in this ecosystem. Not only do these shellfish provide food for people but they also filter the water. They feed on plankton and other microscopic sea creatures which are free-floating in seawater. Mussels need to filter a huge volume of water in order to get enough food to eat, so a typical mussel will filter about a bathtub of water each day. This filtering helps keep the water clean so improves the health of the whole harbour ecosystem.
It was incredible to see so many pātangaroa. There were lots of different sizes and each 11-armed sea star had a slightly different colour. It was interesting to discover that despite their name this species can have between 9 and 13 arms. These critters are now very common in the harbour and they love to eat mussels. Mussel beds in the harbour have got smaller and smaller with pressure from sea stars, people and pollution. Kura has talked to local elders who shared their knowledge of how the harbour used to be. This has helped scientists to understand how the harbour has changed over time.
Talking to Kura made me realise how important it is to think about all the impacts on a marine ecosystem. Once we have done this we can work on managing these impacts to keep our ecosystems healthy.
Tomorrow we will look at how we can try to restore mussel beds in Ōhiwa Harbour.
Watch the videos and meet the experts.
Travel day–Monday 2 March
It’s been a long day of travel to get to our destination for this week's Sustainable seas field trip in Ōhiwa Harbour. I travelled by air from Dunedin airport to Christchurch airport. Then I boarded another flight from Christchurch to Rotorua. From Rotorua, the LEARNZ team and I drove to Whakatāne. It was all worth it though because Whakatāne is a beautiful place right on the North Island’s east coast. The Whakātane Harbour has a famous statue of Wairaka. You can find out more about her here.
We are looking forward to visiting Ōhiwa Harbour to find out about it's ecosystem and importance as mahinga kai (a food gathering place). We'll also be exploring how people are working together to protect this special place.
