MARLBOROUGH DISTRICT COUNCIL He körero no te Kaunihera o Wairau Sounds News New report released on wattles in Picton Report identifies sources of Te Hoiere/ Pelorus sedimentation Marlborough District Council recently commissioned NIWA to study sediment sources in Te Hoiere/Pelorus Sound using the latest scientific techniques. Costal Scientist Oliver Wade says the new study improves our understanding of the area's human-induced and natural erosion sources that impact the marine environment. A new Council-funded report investigates watle infestations around Waitohi/Picton. Led by Lincoln University researchers. the report was commissioned to determine the dominant species of wattles in the area, identify the likely long-term structure of the vegetation and assess its fire hazard now and in the future. The report concludes with some management recommendations, cautioning that wattles are difficult to control and any meaningful control would require substantial funding and a long commitment. initiotives - either existing or new - to find funding and foster the best outcomes for biodiversity. However, for Council when our resources are limited, we need to balance local community desires with our strategic regional biodiversity and biosecurity priorities," Mr Underwood "The report identifies the sources of sediment deposited in Te Hoiere Pelorus River catchment and Mahau Sound" said. "Seventy percent of material deposited in the Sound over the last century is legacy sediment. Goldmining, native forest clearance, pastoral forming and more recent agricultural and forestry activities have all left their legacy. Thirty percent of the Lincoln University reseerchers suggested the most effective way to reduce wottle infestations is to foster the regeneration of native vegetation, reduce pressure from deposited sediment comes from contemporary land uses browsing feral animals and aim to close the native canopy. "Subsols and streambank erosion are the largest contemporary sources of sediment. with smaler proportions attributed to erosion from land associated with primary industry and native forest. These proportions vary according to location," M Wade said The full report - Scientific investigation into Wottie infestotions in the vicinity of Woitoh Picton by Dr Tim Curran, Dr Jon Sulivan and Dr Azharul Alam can be The effects of increased sol erosion and sedimentation have ranged in scale, from localised impacts on cockle beds in Mohau Sound to extensive catchment-wide soil erosion and sedimentation since European settlement. For further information go to: www.meroushaovt.endomentoastalsedimentation The NIWA report is caled 'Sources of fine sediment and contribution to sedimentotion in the inner Pelorus Sound Te Holere' and is accompanied by a short summary document called "Trocing the sediment in Pelorus Sound. found at: httos mEA Council's Biosecurity Manager Jono Underwood seys the wattle infestation around WaitohiPicton has been raised by the community as a concerm in recent years, especialy a perceived link between wattle flowering and allergy symptoms "However, the r enew report cites several studies from Australia and New Zealand that have found minimal links between wattle polien and allergies." he said "In terms of fire hazard, researchers found wattle dominated stands represent a relatively high fire hazard, with moderate to high flammatility material However, many of the native tree species regenerating under wattie species have low flammability, which suggests fire hazard risks will decline over time as the landscape transitions to native vegetation "The main wattle species found around Waitohi/Picton, Acocia deaibata, is used for firewood and shelter and can be ab council in the Acacia species via programmes within their Regional Pest Management Plans." "The good news is wattle doesn't spread ke wilding pines, which have wind-blown seeds. Wattles are generaly spread through human activity such as land disturbance or sol movement, as their are long ived in the soil, waiting for that disturbance for their gemination said Mr Underwood. e South Island manages any Katuna River in food 1S November 20. Sedmentoden food woters irundonng low-lying formiand, with the Havelock esary and Cuten Poine in the dsonce TRACING THE SEDIMENT IN PELORUS SOUND "While broad-scale wattle management is not a strategic biosecurity there are opportunities for communities to decide how to manage wattles locally. There are some great community programmes already in Wakewa Bay and Havelock torgeting wattles and other invasive species," Mr Underwood said. "The best approach is to look at the wider alignment across ecological restoration Council's Harbours team - working to ensure our waterways are safe for everyone to enjoy. Contact the Harbour Master's Office if you need advice or information about Marlborough's harbours. Harbou 03 520 7400 | HARBOURS MARLBOROUGH.GOVT.NZ www.MARLBOROUGH.GOVT.NZ I 03 520 7400 I 15 SEYMOUR STREET, BLENHEIM, 7201 NEW ZEALAND MARLBOROUGH DISTRICT COUNCIL He körero no te Kaunihera o Wairau Sounds News New report released on wattles in Picton Report identifies sources of Te Hoiere/ Pelorus sedimentation Marlborough District Council recently commissioned NIWA to study sediment sources in Te Hoiere/Pelorus Sound using the latest scientific techniques. Costal Scientist Oliver Wade says the new study improves our understanding of the area's human-induced and natural erosion sources that impact the marine environment. A new Council-funded report investigates watle infestations around Waitohi/Picton. Led by Lincoln University researchers. the report was commissioned to determine the dominant species of wattles in the area, identify the likely long-term structure of the vegetation and assess its fire hazard now and in the future. The report concludes with some management recommendations, cautioning that wattles are difficult to control and any meaningful control would require substantial funding and a long commitment. initiotives - either existing or new - to find funding and foster the best outcomes for biodiversity. However, for Council when our resources are limited, we need to balance local community desires with our strategic regional biodiversity and biosecurity priorities," Mr Underwood "The report identifies the sources of sediment deposited in Te Hoiere Pelorus River catchment and Mahau Sound" said. "Seventy percent of material deposited in the Sound over the last century is legacy sediment. Goldmining, native forest clearance, pastoral forming and more recent agricultural and forestry activities have all left their legacy. Thirty percent of the Lincoln University reseerchers suggested the most effective way to reduce wottle infestations is to foster the regeneration of native vegetation, reduce pressure from deposited sediment comes from contemporary land uses browsing feral animals and aim to close the native canopy. "Subsols and streambank erosion are the largest contemporary sources of sediment. with smaler proportions attributed to erosion from land associated with primary industry and native forest. These proportions vary according to location," M Wade said The full report - Scientific investigation into Wottie infestotions in the vicinity of Woitoh Picton by Dr Tim Curran, Dr Jon Sulivan and Dr Azharul Alam can be The effects of increased sol erosion and sedimentation have ranged in scale, from localised impacts on cockle beds in Mohau Sound to extensive catchment-wide soil erosion and sedimentation since European settlement. For further information go to: www.meroushaovt.endomentoastalsedimentation The NIWA report is caled 'Sources of fine sediment and contribution to sedimentotion in the inner Pelorus Sound Te Holere' and is accompanied by a short summary document called "Trocing the sediment in Pelorus Sound. found at: httos mEA Council's Biosecurity Manager Jono Underwood seys the wattle infestation around WaitohiPicton has been raised by the community as a concerm in recent years, especialy a perceived link between wattle flowering and allergy symptoms "However, the r enew report cites several studies from Australia and New Zealand that have found minimal links between wattle polien and allergies." he said "In terms of fire hazard, researchers found wattle dominated stands represent a relatively high fire hazard, with moderate to high flammatility material However, many of the native tree species regenerating under wattie species have low flammability, which suggests fire hazard risks will decline over time as the landscape transitions to native vegetation "The main wattle species found around Waitohi/Picton, Acocia deaibata, is used for firewood and shelter and can be ab council in the Acacia species via programmes within their Regional Pest Management Plans." "The good news is wattle doesn't spread ke wilding pines, which have wind-blown seeds. Wattles are generaly spread through human activity such as land disturbance or sol movement, as their are long ived in the soil, waiting for that disturbance for their gemination said Mr Underwood. e South Island manages any Katuna River in food 1S November 20. Sedmentoden food woters irundonng low-lying formiand, with the Havelock esary and Cuten Poine in the dsonce TRACING THE SEDIMENT IN PELORUS SOUND "While broad-scale wattle management is not a strategic biosecurity there are opportunities for communities to decide how to manage wattles locally. There are some great community programmes already in Wakewa Bay and Havelock torgeting wattles and other invasive species," Mr Underwood said. "The best approach is to look at the wider alignment across ecological restoration Council's Harbours team - working to ensure our waterways are safe for everyone to enjoy. Contact the Harbour Master's Office if you need advice or information about Marlborough's harbours. Harbou 03 520 7400 | HARBOURS MARLBOROUGH.GOVT.NZ www.MARLBOROUGH.GOVT.NZ I 03 520 7400 I 15 SEYMOUR STREET, BLENHEIM, 7201 NEW ZEALAND