YOUNG & green

Forest and Bird, Issue 280, 1 May 1996, Page 44

YOUNG & green

EUGENIE SAGE meets three lively Christchurch students whose initiatives have provided useful information about nature’s processes and who have tried to inspire more careful treatment of their local Avon-Heathcote river system.

OW 15, Bryn Fenwick can’t remember when he first became interested in natural history although he recalls often carrying buckets and collecting sandhoppers as a young child during seaside field trips with his parents. As a third former Bryn was curious about the effects of rubbish such as paper and plastic on crabs, snails and other inhabitants of the Avon-Heathcote estuary. As part of a project for the Canterbury secondary school science fair he surveyed the types and amounts of natural and urban detritus found around the estuary. Drift kelp, weed, feathers and shells were the most common natural debris at his 12 survey sites, with plastic, paper, glass and wire the main types of human rubbish. Plastic products accounted for

over a third of the rubbish at some sites. In two experiments, one in controlled conditions and the other in the field, he investigated whether seashore animals such as crabs and an amphipod (common beach flea) ate and helped break down the rubbish and clean up the estuary. He concluded that paper products such as brown paper bags, paper towels, and magazine pages were eaten by these species. As expected, none of the animals fed on plastic. Bryn calculated that with the help of amphipods, a brown paper bag which would normally take about five years to decompose would be broken down in about 64 days. During his debris survey Bryn often found takeaway food wrappings and packaging and drink cans among the sea’s leavings on the strand line, especially in areas close to picnic sites and carparks. Turning his research findings into conser-

vation advocacy he designed posters for distribution around local fast food outlets with the message, "Hemi the crab says, ‘Keep your rubbish to yourself. We can only process paper, not plastic," and "There are over 60 different types of animals and plants on the beach. Let’s keep it that way by recycling our rubbish." Bryn’s estuary work has convinced him that changing the "big picture" through national policies is more important than individual action in reducing plastic pollution. "Plastic products are a curse — they strangle seals, suffocate whales and they take ages to biodegrade. But even if I avoid using things with plastic, that’s not going to affect the manufacturers one bit. It would be really good if there was a system like in Japan where before any new product came onto the market the manufacturer had to have a complete system

worked out of how that product was going to be recycled and reused. It couldn't just be used and thrown away." A trip into the Lake Sumner Forest Park with DoC staff, as part of a Young Conservator prize for his research, helped expand his horizons from the coast to the forest. It led to Bryn spending a week helping DoC by listening for great spotted kiwi in the beech forests around the Lewis Pass on one of DoC’s Conservation Volunteer projects. "It’s good being out in the bush, doing something different but feeling you're doing something worthwhile while you're tramping." RYN HAS inspired his younger brother, 13-year-old Celyn, to pursue similar environmental projects. Like Bryn’s "Cleaning Up the Estuary" project, Celyn’s "Mud Crabs on the Move" research has picked up awards at the regional science fair, ECNZ’s national science fair and the Canterbury Regional Council’s Resource Management Award. Celyn’s work centred on the Woolston Cut built a decade ago to shortcut one of the loops in the Heathcote River and allow flood flows to move downriver more quickly. At the time of construction little thought was given to the effects of seawater travelling further back up the river on each high tide. With the increased salinity, however, riverbank trees died and mud crabs moved upstream, their burrowing contributing to riverbank collapse. The ensuing "corrective" engineering resulted in a barrage that closes the short-cut and restores the natural flows around the loop, except during heavy rainfall and flood conditions. Celyn wondered "where the crabs went" after the barrage’s construction. His field surveys confirmed that with the reduced salinity upriver, mud crabs are no longer found as far upstream as they were in earlier surveys. Small black snails have taken over their burrows. His experiments in the laboratory showed that mud crabs can detect salinity changes in the surface water and would actively move into artificial burrows containing more saline water, leading Celyn to conclude that they could move down river towards the sea. A follow-up survey earlier this year showed the upper limits of the mud crab population is further downstream than last year. Celyn’s project also involved looking at different types of bankworks and their relative attractiveness as wildlife habitat. "People have treated this part of the Heathcote river really badly — they used to

pump tar into it and dump car bodies. In some places people dump lots of rubbish on the edge of the banks but the council is trying to strengthen the banks by planting and it’s getting nicer." Bryn and Celyn’s workbooks and their exhibits for science fairs are peppered with photographs, sophisticated histograms, pie charts and graphs. Their science projects have made both brothers more aware of the estuary and river environments. They have also increased an already extensive knowledge of these habitats’ plants and animals. Celyn is a supporter of the Kaikoura marine reserve proposal. "If people just keep taking fish, there will be none left — it’s good for kids to see live fish — it’s part of growing up." On field trips with his mother he often explains to university zoology students the best way to retrieve hermit crabs from their shells without hurting them and collects tuatua for later dissection and analysis. "I like doing field work, it’s relaxing and it’s nice being next to the sea." As a result of media publicity, Bryn and Celyn have addressed several community and service groups about their projects, helping their audiences learn more of the effects of human activities on the estuary and rivers. The science projects have occupied large amounts of school holiday time and been fitted into a busy schedule along with music lessons, badminton, photography and theatre sports. Both reckon the research and field work is more interesting than school science. ISMAYED BY the rubbish on the [) banks of the Avon River near his home, nine-year-old Thomas Dobbie organised several clean-ups with friends, filling rubbish bags with an assortment of debris from old cigarette lighters to perfume bottles. "It was an interest in animals first," he says, "but then the environment popped its head in the door." As an enthusiastic member of Forest and Bird’s Kiwi Conservation Club, Thomas set up an Animal Kingdom Club at his primary school to encourage his classmates to become more interested in wildlife. The club published a newsletter with jokes and information about animals around the world. With parental help they organised their own club outings to the estuary and other areas, as well as club fun nights with quizzes about animals. The grounds of his school also benefited from the club’s clean up campaign with the students organising

rubbish collecting forays. "We hoped it would mean other kids would have a different opinion about throwing rubbish on the ground." Now 12, Thomas’ love of nature has led to a focus on school science projects on wasps, crystals and birds. He brims with ideas about how he would improve the Christchurch environment if he and Mayor Vicki Buck traded places. "I would try and interest the city’s citizens in buying land on the Port Hills and covering it in native plants again. I’d encourage recycling, especially of plastics, maybe by paying people a small amount of money like they do with aluminium cans. "Td stop people using wood fires so that we can get rid of some of the smog, try to stop the council putting in any more roads to stop car fumes and encourage people to bike or bus to school and to work." Safeguarding Christchurch’s groundwater would also be high on Thomas’ list of mayoral projects. "Groundwater is what makes Christchurch unique yet people waste it — turning on sprinklers in the middle of the day when it just evaporates. When people wash their cars on the street, all the water runs into the gutter and pollutes our rivers. It’s the little things that are important," he says. Thomas has clear views on the government’s fiscal policies. "Instead of spending money on tax cuts we could spend money on the environment, on possum control and encouraging people to use buses. The environment is more important because in the future we could have no trees, the air would be really hard to breathe and it would be awful to smell, there would be no pure water and just about the whole of New Zealand would be either farming or cities." ; All three students are optimistic, however, about the potential for making New Zealand’s clean green image more of a reality. Bryn says, "You can’t change things by yourself, but by contributing ideas and working with others, you can help change the bigger picture. And these days young people are more aware of the environment and the impact our activities have so we are in a better position than adults." @

EUGENIE SAGE lives in Christchurch and is Forest and Bird’s field officer for the northern South Island.