Aerial images show wetlands on private land disappearing at alarming rate

To mark World Wetlands Day (February 2), Forest & Bird is releasing aerial images of wetlands disappearing on private land at an alarming rate.

The images, taken in Southland, show a number of wetlands on private land completely or partly disappearing in the seven years from 2007-2014.

“This is our national shame. The rate and extent of wetland destruction in New Zealand has been recognised as among the highest in the world,” says Annabeth Cohen, Forest & Bird’s Freshwater Advocate.

Ms Cohen says wetlands on private land are most in danger of being drained and destroyed. “New Zealanders may think wetland loss is a thing of the past, but recent reports confirm that we are still losing wetlands every day.”

“Forest & Bird estimates a third of our remaining wetlands are on private land – we are in real danger of losing these special places unless the government does something meaningful this year.”

Ms Cohen says wetlands play a vital ecological role, providing unique habitat for threatened plants, birds, and fish. A fifth of native bird species use wetlands as their primary habitat.

Since 2001, at least 13 percent of New Zealand's freshwater wetlands, have been damaged or destroyed. This includes 214 wetlands that are completely gone and another 746 that were partially destroyed between 2001-2015.[1]

Ms Cohen says national regulations are inadequate to protect wetlands. As a result, regional council plans are highly inconsistent and some allow wetlands to be drained, cleared of vegetation, or opened up to livestock.

“As we mark World Wetlands Day, we’re calling on the government to show leadership. Environment Minister David Parker needs to stop any further destruction by requiring regional councils to map and protect their wetlands.”

“We also call on the Minister to set a goal for councils to double the wetlands in their region, by restoring wetlands that have been degraded and destroyed.”

A recent study on wetland loss in New Zealand is the first to categorise wetlands as ‘at risk’ of being destroyed due to the presence of drainage channels (as seen in the aerial images).[2] This drainage work is often associated with the increase in dairy farming.

The theme of this year’s World Wetlands Day recognises the significant role wetlands play in fighting climate change.

“Healthy wetlands will help protect people and wildlife from the impacts of climate change," says Ms Cohen. “They act as coastal buffers, shielding our lowlands from storm surges. They reduce floods and relieve droughts, as well as absorbing and storing carbon.”

“We need every single wetland we’ve got—and more—if our native bird and fish species are going to stand a chance in the face of climate change.”

The aerial images were prepared for a report for Environment Southland by Richard Ewans, Eco-South, and have been shared with permission from Environment Southland.

Background notes
• Less than 10 percent of New Zealand’s original extent of wetlands remain.
• There are no figures indicating national wetland destruction since 2015.
• The National Policy Statement (NPS) on Freshwater Management is being reviewed by Minister David Parker this year and is the most immediate opportunity to strengthen wetland protection.
• A draft NPS on Indigenous Biodiversity has been developed by key stakeholders (including Forest & Bird) and presented to Minister Nanaia Mahuta and would also provide much greater protections for wetlands.

Table 1: Forest & Bird, QGIS estimation of total freshwater wetlands (ha) and private land wetlands (ha) per region and nationally. This data will contain a degree of inaccuracy due to the imprecise knowledge of wetlands on private land. See data sources below.

Region Total freshwater wetlands (Ha) Private land (Ha) Private land (%)
Auckland Region 2483 1,800 72%
Bay of Plenty Region 3254 2,532 78%
Canterbury Region 19340 9,189 48%
Gisborne Region 903 874 97%
Hawke's Bay Region 2438 2,354 97%
Manawatu-Whanganui Region 6925 4,855 70%
Marlborough Region 1307 691 53%
Nelson - Tasman Region 5137 805 16%
Northland Region 14052 6,529 46%
Otago Region 23784 10,983 46%
Southland Region 46825 11,107 24%
Taranaki Region 2949 1,550 53%
Waikato Region 27857 10,573 38%
Wellington Region 2752 1,573 57%
West Coast Region 83971 12,118 14%
National 243976 77,533 32%

Regional highlights:
• Since 2001, more than 15 percent of wetlands in Auckland, Waikato, Gisborne, Manawatu-Whanganui, Wellington, Marlborough, and Canterbury have been damaged (reduced in size) or destroyed.
• Wellington has damaged (reduced in size) the greatest proportion of its wetlands since 2001 (over 37 percent)
• West Coast is the largest wetland region in New Zealand, and has damaged the largest area of wetlands in hectares. Nearly 11,000 hectares have reduced in size since 2001.
• Canterbury has damaged the second largest area of wetlands since 2001. Nearly 6,000 hectares of wetlands have reduced in size.
• Both Waikato and Southland have damaged around 4,000 hectares of wetlands each since 2001.

Region by region

Northland
• Since 2001, seven percent of wetlands (just under 1,000 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 6,500 hectares (46 percent) of wetlands on private land.
Auckland
• Since 2001, 20 percent of wetlands (just over 5,000 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are approximately 1,800 hectares (72 percent) of wetlands on private land.
Waikato
• Since 2001, 15 percent of wetlands (just over 4,200 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 10,600 hectares (38 percent) of wetlands on private land.
Bay of Plenty
• Since 2001, eight percent of wetlands (just over 250 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 2,500 hectares (78 percent) of wetlands on private land.
Hawke’s Bay
• Since 2001, three percent of wetlands (just over 80 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 2,300 hectares (97 percent) of wetlands on private land.
Gisborne
• Since 2001, 18 percent of wetlands (170 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 870 hectares (97 percent) of wetlands on private land.
Taranaki
• Since 2001, eight percent of wetlands (230 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 1,600 hectares (53 percent) of wetlands on private land.
Manawatu-Whanganui
• Since 2001, 17 percent of wetlands (nearly 1,200 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 4,900 hectares (70 percent) of wetlands on private land.
Wellington
• Since 2001, 37 percent of wetlands (1,000 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 1,600 hectares (57 percent) of wetlands on private land.
Nelson & Tasman
• Since 2001, four percent of Tasman wetlands (over 180 hectares) have been partially destroyed (reduced in size).
• Nelson only has 3 hectares of wetlands currently.
• Forest & Bird estimates that there are about 800 hectares (16 percent) of wetlands on private land in the Nelson and Tasman areas combined.
Marlborough
• Since 2001, 20 percent of wetlands (just over 300 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 690 hectares (53 percent) of wetlands on private land.
Canterbury
• Since 2001, 29 percent of wetlands (just over 5,800 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 9,200 hectares (48 percent) of wetlands on private land.
West Coast
• Since 2001, twelve percent of wetlands (over 10,700 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 12,100 hectares (14 percent) of wetlands on private land.
Otago
• Since 2001, nine percent of wetlands (2,300 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 11,000 hectares (46 percent) of wetlands on private land.
Southland
• Since 2001, eight percent of wetlands (nearly 4,000 hectares) have been partially destroyed (reduced in size).
• Forest & Bird estimates that there are about 11,100 hectares (24 percent) of wetlands on private land.

Sources

Reports
• Belliss, S, Shepherd, J, Newsome, P, & Dymond, J (2017). An analysis of wetland loss between 2001/02 and 2015/16. Landcare Research Contract Report LC2798 for the Ministry for the Environment.
• Ewans, Richard. Environment Southland Wetland Inventory and Monitoring Project: Monitoring Wetland Extent Outside of Public Conservation Land and Assessment of Wetland Status in the Southland Region. Eco-South and Environment Southland, 2018.
• Myers, Shona C. A Biodiversity Planning Snapshot - How Well Are Councils Protecting Biodiversity? NZ Ecological Society Conference, Wellington 2018.
• Myers, S.C., et al. Wetland Management in New Zealand: Are Current Approaches and Policies Sustaining Wetland Ecosystems in Agricultural Landscapes? Ecological Engineering, vol. 56, 2013, pp. 107–120., doi:10.1016/j.ecoleng.2012.12.097.
• Robertson, Hugh, et al. Loss of Wetlands since 1990 in Southland, New Zealand. New Zealand Journal of Ecology, 2018, doi:10.20417/nzjecol.43.3.
• StatsNZ. http://archive.stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/wetland-extent.aspx

Data Sources for Forest & Bird QGIS calculations in Table 1
DOC Public Conservation Areas: https://koordinates.com/layer/754-doc-public-conservation-areas/
LINZ Managed Crown Properties: https://koordinates.com/from/data.linz.govt.nz/layer/53358/
Wetland extent, 2001-2016 (used for calculation): https://koordinates.com/from/data.mfe.govt.nz/layer/95347/
Current wetland extent, 2013 (used for visual comparison):https://koordinates.com/from/data.mfe.govt.nz/layer/52676/

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[1] Belliss, S, Shepherd, J, Newsome, P, & Dymond, J (2017). An analysis of wetland loss between 2001/02 and 2015/16. Landcare Research Contract Report LC2798 for the Ministry for the Environment.
[2] Robertson, Hugh, et al. Loss of Wetlands since 1990 in Southland, New Zealand. New Zealand Journal of Ecology, 2018, doi:10.20417/nzjecol.43.3.

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