Environmental Pest Plants

12.3 Land use

Spatial Pattern

Catchment size: 36,930 ha.

Catchment location: North and east across the Whakamarama and Mamaku plateaus from Hiwiroa to Tauranga Harbour.

Predominant land uses (account for 97% of catchment):

- Indigenous forest covers 20,909 ha (56.6%) of catchment, primarily on plateau country in the upper and middle catchments and along the steeps sides of gullies in the middle reaches of all catchments. - Pasture grassland covers 9,905 ha (26.6% of catchment), primarily in the lower and middle catchments on land of low to moderate relief. - Exotic plantation forest covers 4,605 ha (12.4%) on plateau country in middle catchments.

Urban landforms: 82 ha (0.2% of catchment)

Wetlands: 28.7 ha (0.07% of catchment), primarily herbaceous saline wetlands along the Wairoa estuary margins.

Most modified: The lower parts of the Wairoa catchment have been heavily modified by conversion of forests to pasture grassland, orcharding and urban land uses.

Least modified: The upper catchment retains indigenous vegetation on flats and in gullies of the dissected Whakamarama plateau, though this has been modified by logging during the late 19th and early 20th centuries, and clearfelling of broadleaf forest on the plateau and replacement with pine plantations during the late 20th century.

Table 12.2: Land use within the Wairoa catchment.

% of LCDB2 Classification Area (ha) Catchment Broadleaved indigenous hardwoods 127.0 Indigenous forest 20,908.7 Manuka and/or kanuka 219.4 Indigenous Forest 21,255.1 57.6% Coastal sand and gravel Estuarine open water 0.5 Herbaceous freshwater vegetation Herbaceous saline vegetation 28.2 Lake and pond 44.3 Mangrove River 85.9 Wetland Systems 158.9 0.4% Afforestation (imaged, post LCDB 1) 42.1

% of LCDB2 Classification Area (ha) Catchment Afforestation (not imaged) Forest harvested 160.1 Other exotic forest 311.9 Pine forest - closed canopy 3,845.2 Pine forest - open canopy 159.8 Exotic Plantation Forest 4,518.9 12.2% Orchard and other perennial crops 699.8 Short-rotation cropland Orchards and Crops 699.8 1.9% High producing exotic grassland 9,838.0 Low producing grassland 67.1 Pastoral Lands 9,905.2 26.8% Deciduous hardwoods 22.4 Major shelterbelts 55.2 Mixed exotic shrubland Gorse and broom 231.4 Other Exotic Vegetation 309.0 0.8% Built-up area 68.9 Transport infrastructure 1.9 Urban parkland/Open space 11.0 Urban Landforms 81.8 0.2% Not Classified 0.3 ,0.1% Grand Total 36,930.3 100.0%

Legal Protection

This section provides an overview of the areas protected by legal statute and covenants, for the purpose of biodiversity protection.

Department of Conservation

The Department of Conservation administers ha within the Wairoa catchment for conservation purposes.

Reserves to protect indigenous ecosystems, vegetation, habitats, or species comprises 13,559.4 ha (99.1%).

Reserves that have other primary aims, which could conflict with protection of natural values, comprises 121.9ha (0.9%).

Table 12.3: Department of Conservation administered lands within the Wairoa catchment.

Reserve Type (DOC Legal Description) Area (ha) Conservation Park - S.19 Conservation Act 1987 10,248.9 Fixed Marginal Strip - S.24(3) Conservation Act 1987 23.7 Local Purpose Reserve - S.23 Reserves Act 1977 96.8 Recreation Reserve - S.17 Reserves Act 1977 1.4 Scenic Reserve - S.19(1)(a) Reserves Act 1977 49.6 Stewardship Area - S.25 Conservation Act 1987 3,260.9 Grand Total 13,681.3

The upper Wairoa catchment includes 1,902 ha of the Opuiaki Ecological Area, 168 ha of the Mangapapa Ecological Area, and 1,741 ha of the Waiteariki Ecological Area.

Nga Whenua Rahui

There are no Nga Whenua Rahui kawenata within the Wairoa catchment.

QEII

There are seventeen QEII covenants totalling 110.6 ha within the Wairoa catchment.

Table 12.4: QEII covenants within the Wairoa catchment.

Covenant Area (ha) 5/03/020 7.0 5/03/021 28.0 5/03/021B 0.5 5/03/125 4.8 5/03/151 8.4 5/03/160 6.0 5/03/250B 0.0 5/03/288.1 8.2 5/03/288.2 1.3 5/03/288.3 0.9 5/03/322 0.0 5/03/332.1 2.0 5/03/332.2 1.2 5/03/332.3 0.6 5/03/332.4 0.9 5/03/375 33.5 5/03/379 7.4 110.6 Grand Total (0.3%)

Western Bay of Plenty District Council Covenants

Within the Wairoa catchment there are 21 Western Bay of Plenty Covenants, with a total area of 155.7 ha (1.2%).

Table 12.5: Western Bay of Plenty District Council Covenants within the Wairoa catchment.

WBOP Covenants Area (ha) Cov6309 3.89 Cov6395 12.09 Cov6910 1.73 Cov6985 23.49 Cov7068 13.15 Cov7351 25.87 Cov7433 4.16 Cov7532 2.55 Cov7675 22.79 Cov8584 17.19

WBOP Covenants Area (ha) Cov9276 80.44 Cov9622 5.56 Cov9729 6.69 CovFE313 746.51 966.1 Grand Total (2.6%)

12.4 Indigenous vegetation and flora

Vegetation Pattern

Approximately two-thirds (65%) of the 20,909 ha of indigenous forest is dominated by tawa, either in combination with rimu and/or beeches. Just under one-quarter (23%) of forest is highland and steepland softwoods-hardwoods. Unlogged rimu- tawa forest occurs within the Opuiaki Ecological Area, along with dense podocarp stands on alluvial terraces.

Table 12.6: Indigenous forest types within Wairoa catchment.

Forest Type Area (ha) Beeches 96.2 General hardwoods 704.2 Highland and steepland softwoods-hardwoods 4,897.7 Kauri-softwoods-hardwoods 59.7 Rimu-tawa 4,049.1 Rimu-tawa-beeches 258.4 Softwoods 171.6 Tawa 8,876.3 Tawa-beeches 349.3 Unclassified 1,446.2 Total 20,908.7

Species Lists

There are at least 10 lists of vascular plants within the catchment.

Rare or Threatened Species

The Department of Conservation Bioweb database includes the following records:

Brachyglottis kirkii var. kirkii (At Risk-Declining) Hymenophyllum atrovirens (At Risk-Naturally Uncommon) Olearia cheesemanii (At Risk-Naturally Uncommon) Peraxilla tetrapetala (At Risk-Declining) Pimelea tomentosa (Threatened, Nationally Vulnerable) Pittosporum kirkii (At Risk-Declining) Syzygium maire

12.5 Pest plants

Plant Pest RPMS Status Wairoa Wild kiwifruit Total control present Banana passionfruit Progressive control present Boneseed Progressive control present Bushy asparagus Progressive control present Cathedral bells Progressive control present Heather Progressive control present Lantana Progressive control present Old man's beard Progressive control present Wild ginger Progressive control present Woolly nightshade Progressive control present Yellow flag iris Progressive control present

The EBOP RPMS provides lists of species in the following categories: ‗Eradication‘, ‗Total and Progressive Control‘, ‗Boundary Control‘, and ‗Regional Surveillance‘. Explanations for each category are given below:

Eradication pest plants (10 species) - pests of low incidence but with a high threat of spread or seriousness of adverse effects. The objective of this category is to eradicate all known populations by 2020 and immediate eradication of any new occurrences. Total control pest plants (1 species) - pests of low incidence but with high threat of spread or seriousness of adverse effects. The objective is the protection of indigenous biodiversity and production values by controlling currently known populations and immediate destruction of new occurrences. Progressive control pest plants (15 species) - Pest of high incidence in parts of the region, and with high threat of spread or seriousness of adverse effect. The objective is to reduce density and/or distribution with priority given to controlling isolated or satellite populations. Boundary control pest plants (3 species) - Pests of high incidence over the region, and with serious effects. The objective is protection of production values by controlling effects. Surveillance pest plants (23 species) - Plants of known threat of adverse effects, which may be established in parts of the region, but about which there is uncertainty of distribution, and/or threat of spread and/or feasibility of control. There are two objectives for these pests. The first is to increase understanding of the distributions, impacts and control options, the second is to have them voluntarily controlled by land occupiers with assistance from EBOP programmes (EBOP 2003).

EBOP also maintains a database of 123 pest plant species that are of interest or under active management in the Tauranga Harbour catchment. For more information refer to Environment Bay of Plenty‘s Regional Pest Management Strategy, or to their excellent pest plant resources on the internet at http://www.envbop.govt.nz/ Environment/Pest-Plants-and-Weeds. aspx

The Department of Conservation also maintains a pest plant database and this includes the following records for the Wairoa catchment:

Agapanthus praecox Jasminum polyanthum Berberis glaucocarpa Leycesteria formosa Buddleja davidii Pinus spp. Celastrus orbiculatus Pueraria montana Cortaderia selloana Rosa spp. Crocosmia x crocosmiiflora Rubus fruticosus agg. Cupressus lusitanica Selaginella kraussiana Cytisus scoparius Senecio mikanioides Eucalyptus spp. Spartina alterniflora Gladiolus carneus Tradescantia fluminensis Hedychium gardnerianum Ulex europaeus Hydrangea macrophylla Vitis vinifera

12.6 Pest animals

Affecting Species Affecting Vegetation Control Underway Indigenous Fauna Possum    Goat   Red deer Fallow deer Feral pig Ship rat    Norway rat Mustelids   Cats  Mice  Hedgehog  Wasps  Pest fish 

State of the Vegetation

There is a network of foliar browse index lines in the catchment.

Foliar Browse Index vegetation monitoring (Willems 2001; Woods 2008) suggests that the overall condition of vegetation not subject to pest control is moderate. Kamahi was found to be in generally poor condition in both surveys, and browse values on the less-preferred mahoe had increased between 2001 and 2008. There is evidence of sustained impacts on possum-preferred species, and vegetation condition is probably in slow decline.

Understorey condition on the northern Mamaku plateau, including Opuiaki, is among the best in the North Island. The cobalt deficient soils appear to be incapable of supporting large populations of ungulates.

12.7 Indigenous fauna

Avifauna

A suite a common indigenous forest species is present, including kereru, robin, and tomtit. Opuiaki Ecological Area includes a notable suite of threatened species, including kokako, kākā, falcon, kākāriki, long-tailed cuckoo, rifleman, and kiwi.

Karearea breed within Opuiaki Ecological Area.

Bats

Long-tailed bat and short-tailed bat are present at Opuiaki.

Lizards

Copper skink have been recorded in the catchment. Whitaker (2000) has described the results of a survey at Opuiaki.

Other Notable Species

Kākā are likely to be breeding in Opuiaki. Individual blue duck are occasionally sighted in the Opuiaki River, but an effective breeding population is unlikely to remain.

Bittern in wetlands in lower Wairoa River.

State of Terrestrial Indigenous Fauna

Pest animal control within the Opuiaki Ecological Area has facilitated an increase in the kokako population.

Beyond management areas, the states of bird and invertebrate populations are probably comparable with those of other mainland forests not subject to pest control.

Fish Species

Thirteen (13) indigenous freshwater fish species are known to occur within the Wairoa catchment (compared to 20 different species for the wider Kaimai catchment)

Three (3) indigenous species are considered to be in Gradual Decline.

Four (4) introduced fish species have been recorded within Wairoa catchment (compared with nine introduced species for the wider Kaimai catchment). Rudd is a Noxious species (under Freshwater Fisheries Regulations, 1983).

There are various barriers to fish passage into the upper catchment, including a hydro dam in the lower catchment, and large waterfalls on major tributaries (Ngatuhoa Falls on the Ngatuhoa Stream; Te Rereioturu Falls on the Opuiaki River).

Table 12.7: Fish species recorded within the Wairoa catchment.

Scientific Name Common Name Threat Status Indigenous Aldrichetta forsteri Yelloweye mullet Not threatened Anguilla australis Shortfin eel Not threatened Anguilla dieffenbachii Longfin eel Gradual decline Galaxias argenteus Giant kokopu Gradual decline Galaxias fasciatus Banded kokopu Not threatened Galaxias maculatus Inanga Not threatened Galaxias postvectis Shortjaw kokopu Sparse Gobiomorphus cotidianus Common bully Not threatened Gobiomorphus gobioides Giant bully Not threatened Gobiomorphus huttoni Redfin bully Not threatened Grahamina Estuarine triplefin Not threatened Mugil cephalus Grey mullet Not threatened Paranephrops planifrons Koura (Invertebrate) Gradual decline Retropinna retropinna Common smelt Not threatened Exotic Oncorhynchus mykiss Rainbow trout Introduced Salmo trutta Brown trout Introduced Scardinius erythrophthalmus Rudd Introduced Tinca tinca Tench Introduced

Notable Aquatic Habitats

Estuarine marshland and other good quality habitat are present in the lower reaches of the Wairoa River.

12.8 Recreational use

The Wairoa River is heavily utilised for flat-water rowing and kayaking in the lower reaches.

Lake McLaren is used for walking, kayaking, and picnicking. Rudd and tench are present in the lake.

Ngatuhoa Youth Lodge is heavily used by school and youth groups, and other interest groups.

There is a network of walking tracks centred on Ngatuhoa Lodge.

12.9 Current management

Department of Conservation

Monitoring - Seven foliar browse index lines in the catchment, and three more on the catchment boundary (with Upper Waihou). - Kokako monitoring. - Rare plants. - Weeds. - Pest animals: possums, rats, goats, stoats.

Pest plant control - Various control operations.

Pest animal control - Goat control as required. - Possum control in Opuiaki core area, 1,130 ha, 2003, 2004, 2005, 2006, 2007, 2008. - Possum control in Opuiaki canopy area, 4,470 ha, 2006.

Recreation - Extensive network of tracks in the vicinity of Ngatuhoa Lodge.

Regional Council

- Natural heritage Environment Bay of Plenty provides technical advice, expertise, logistic and financial support to conservation on private land through its Environmental Programmes. Fencing is one component of EBOP‘s Environmental Programmes, 43.650 m of fencing has been erected, and is monitored by EBOP, within the Wairoa catchment under Environmental Programmes. Riparian planting, conservation planting, biodiversity protection and support for land use change are other components of tools available to assist landowners to protect and enhance environmental areas and values in the catchment.

District Council

Tauranga City Council (TCC) is undertaking a considerable amount of restoration planting in the lower Kopurererua catchment. TCC also has a comprehensive network of monitoring sites in the natural areas.

The Western Bay of Plenty District Plan contains a schedule of Significant Natural Areas and provisions relating to protection of indigenous vegetation, including the use of Protection Lots and Transferrable Development Rights (TDR) to protect indigenous vegetation when subdivisions are undertaken.

Community Projects

Ngamuwahine Kaimai Landcare Ngatuhoa Lodge

Positive Aspects of Management

Opuiaki Ecological Area Management Area. Intensive possum, rodent, stoat control over 1,130 hectares within the Opuiaki Core Area (2003-2008) to recover kokako population and provide general forest protection

Survey and ‗hotspot‘ hunting is undertaken in parts of the catchment to keep the Opuiaki Ecological Area goat-free.

Large areas of indigenous forest in upper catchment in Kaimai Forest Park. Large contiguous block of unlogged forest in upper catchment largely unmodified by ungulates. Very low deer, goat, and pig numbers.

Lowland forest remnants in headwaters of Ohourere Stream, and middle reaches of Ngamuwahine river and Opuiaki River.

Aspects that Need to be Addressed

Erosion and sedimentation associated with waterways.

Impacts of pest plants in vegetation remnants in lower catchment.

Threats posed by pest animals in areas not subject to active management over most indigenous vegetation within the catchment.

Large scale recent exotic plantation forestry-to-dairy conversions in the upper catchment around Omanawa. Impacts on water quality and loss of wildlife corridors.

13. OMANAWA

13.1 Waterways

Description

Waterways in the Omanawa catchment occur roughly equally in low gradient, medium gradient, and high gradient systems. Low gradient streams occur in the lower catchment and stream gradient increases towards catchment headwaters.

The predominant soil type in the Omanawa catchment is volcanic soils. Some alluvial soils are present in lower catchments.

Just under half the land cover adjoining streams is pastoral grassland (45%), and slightly more than one third is indigenous vegetation (41%).

Almost half the length of low gradient streams (47%) and high gradient streams (45%) flows through pasture.

Table 13.1: Summary of stream length, soil types, and land cover within the Omanawa catchment.

Valley Landform Low Medium High Geology Landcover Gradient Gradient Gradient Length in km (km) (km) (km) Alluvium Urban 2.9 (3%) 2.9 (1%) Miscellaneous Urban 1.7 (2%) 1.7 (0.6%) Volcanic Exotic forest 6.7 (8%) 16.0 (21%) 11.8 (13%) 34.5 (14%) acidic Indigenous 23.0 (27%) 28.5 (38%) 38.8 (41%) 90.2 (35%) forest Pastoral 40.0 (47%) 30.2 (40%) 43.6 (46%) 113.7 (45%) Urban 10.6 (12%) 10.6 (4%) Total 84.9 (34%) 74.7 (29%) 94.1 (37%) 253.7

Rivers and Streams Within the Catchment

The main streams are the Omanawa (which flows into the Wairoa River) and the Kopurererua (which flows directly into Tauranga Harbour, via Tauriko).

Omanawa - Upokokotio - Hukunui

Kopurererua - Tautau

Water Quality

Kopurererua and the Omanawa rivers at SH29 have consistently lower clarity than other rivers within the Tauranga Harbour catchment, being consistently lower than 2 m, possibly due to local geology and erosion products (Taylor and Park 2001).

Cold water springs may explain the (relatively) high total nitrogen levels in the Kopurererua Stream and Omanawa Rivers.

Nitrate Nitrogen in the Kopurererua (at SH29) and the Omanawa (at SH29) are consistently higher than in other Tauranga Harbour catchments, and the latter in particular is trending upward (Taylor and Parks 2001).

Overall water quality in the Omanawa River has trended downward during the 1990s (Taylor and Parks 2001).

13.2 Land use capability

Steep gullies associated with watercourses have little versatility, being Land Classes 7 and 8. Alluvial flats and terraces in lower catchments are arable, highly versatile being Land Classes 3 through 4. Terraces in upper catchments are non-arable but still versatile, predominantly Land Class 6. All land classes have erosion as the primary limitation on use.

LUC Class Area (ha) % of Catchment 1 0.0 0.0 2 419.0 2.4 3 4,045.6 23.3 4 2,415.0 13.9 5 0.0 0.0 6 4,506.7 26.0 7 942.5 5.4 8 3,756.2 21.7 Town 1,202.4 6.9 TOTAL 17,330.0 100.0

LUC Classes Omanawa Sub-Catchment

Class 2 Other 2.4% 6.9%

Class 3 23.3%

Class 8 21.7%

Class 7 5.4% Class 4 13.9%

Class 5

Class 6 26.0%

Omanawa LUC and Land Cover 5000 Other 4500 Pasture & Crop Exotic Forest & Scrub 4000 Indigenous Forest & Scrub

3500

3000

2500

Area (ha) Area ` 2000

1500

1000

500

0 1 2 3 4 5 6 7 8 LUC Class

Figure 13.1: Omanawa catchment - land cover and land use.

13.3 Land use

Spatial Pattern

Catchment size: 17,330 ha.

Catchment location: north from a line between Ngawaro Road and Otanewainuku, to the Tauranga harbour.

Predominant land uses: accounts for 92% of catchment: - pasture grassland 5,263 ha (30.4% of catchment), lower, middle and upper catchments, mostly on land of low to moderate relief. - indigenous forest 6,531 ha (37.7% of catchment), upper catchments on land of low to moderate relief, and along the steeps sides of gullies along main inflowing streams. - Exotic plantation forest 2,776 ha (16%), primarily on elevated plateau. - orchards and crops 855 ha (7% of catchment), warmer lower flat terrain near sea level.

Urban landforms: 1,587 ha (4.9% of catchment), in Tauranga City.

Wetlands: 50.2 ha (0.3% of catchment), primarily saline wetlands along the Omanawa and Kopurererua estuary margins.

Most modified: The lower parts of the Omanawa catchment have been heavily modified by conversion to pastoral orcharding and urban land uses.

Least modified: The upper catchment retains indigenous vegetation on flats and in gullies of the dissected northern Mamaku plateau, though this has been modified by logging during the late 19th and early 20th centuries.

Table 13.2. Land Use within the Omanawa catchment.

% of LCDB2 Classification Area (ha) Catchment Broadleaved indigenous hardwoods 117.2 Indigenous forest 6,531.8 Manuka and/or kanuka 140.7 Indigenous Forest 6,789.7 39.2% Coastal sand and gravel Estuarine open water 3.5 Herbaceous freshwater vegetation 2.0 Herbaceous saline vegetation 44.8 Mangrove 0.1 Wetland Systems 50.5 0.3% Afforestation (imaged, post LCDB 1) 31.0 Afforestation (not imaged) 10.4 Forest harvested 166.1 Other exotic forest 88.1 Pine forest - closed canopy 2,312.1 Pine forest - open canopy 82.4 Exotic Plantation Forest 2,690.2 15.5%

% of LCDB2 Classification Area (ha) Catchment Orchard and other perennial crops 836.5 Short-rotation cropland 18.2 Orchards and Crops 854.7 4.9% High producing exotic grassland 5,196.8 Low producing grassland 66.6 Pastoral Lands 5,263.3 30.4% Deciduous hardwoods 14.9 Major shelterbelts 17.0 Mixed exotic shrubland Gorse and broom 45.6 Other Exotic Vegetation 77.5 0.4% Surface mine 9.5 Surface Mine 9.5 0.1% Built-up area 1,276.6 Transport infrastructure 52.3 Urban parkland/Open space 258.7 Urban Landforms 1,587.6 9.2% Not classified 6.9 <0.1% Grand Total 17,330.0 100.0%

Legal Protection

This section provides an overview of the areas protected by legal statute and covenants, for the purpose of biodiversity protection.

Department of Conservation

The Department of Conservation administers 3,415 ha within the Omanawa catchment for conservation purposes.

Reserves to protect indigenous ecosystems, vegetation, habitats, or species comprises 5,029 ha (99.7%).

Other reserves comprise 15 ha (0.3%).

Table 13.3: Department of Conservation-administered lands within the Omanawa catchment.

Reserve Type (DOC Legal Description) Area (ha) Fixed Marginal Strip - S.24(3) Conservation Act 1987 23.9 Local Purpose Reserve - S.23 Reserves Act 1977 29.6 Recreation Reserve - S.17 Reserves Act 1977 164.3 Scenic Reserve - S.19(1)(a) Reserves Act 1977 570.9 Stewardship Area - S.25 Conservation Act 1987 2,626.2 Grand Total 3,414.9

Nga Whenua Rahui

There are no Nga Whenua Rahui kawenata within the Omanawa catchment.

QEII

There are 16 QEII covenants comprising 92 ha.

Table 13.4: QEII covenants within the Omanawa catchment.

Covenant Area (ha) 5/03/182 4.9 5/03/234 35.2 5/03/250A 8.3 5/03/250B 3.1 5/03/260 15.3 5/03/322 3.1 5/03/350.1 1.3 5/03/350.2 2.7 5/03/350.3 1.1 5/03/350.4 1.6 5/03/362 5.5 5/03/433 1.6 5/03/504 0.5 5/03/596 2.6 5/03/630 2.0 5/03/631 3.5 92.2 Grand Total (0.5%)

Western Bay of Plenty District Council Covenants

There are 21 Western Bay of Plenty Covenants, with a total area of 155.7 ha (1.2%) within the Omanawa catchment

Table 13.5: Western Bay of Plenty District Council Covenants within the Omanawa catchment.

WBOP covenants Area (ha) Cov6357 1.2 Cov6660 2.4 Cov6848 6.6 Cov7049 1.8 Cov7187 2.0 Cov7536 15.7 Cov7737 10.0 Cov7786 13.3 Cov7870 14.6 Cov7941 11.3 Cov7961 23.5 Cov8343 28.2 Cov8359 41.7 Cov8375 21.2 Cov8894 15.0 Cov8909 3.9 Cov9008 41.8 Cov9542 2.7 Cov9926 2.1 N.T. 1.6 260.5 Total (1.5%)

13.4 Indigenous vegetation and flora

Vegetation Pattern

More than a third of the 6,531.8 ha of indigenous forest is tawa forest (2,437 ha), another 20% (1,363 ha) is rimu-tawa forest, both of which occur in the large gullies associated with middle and lower reaches of Omanawa and Kopurererua rivers.

Table 13.6: Indigenous forest types within the Omanawa catchment.

Forest Type Area (ha) Beeches 147.3 General hardwoods 567.7 Highland and steepland softwoods-hardwoods 719.0 Rimu-tawa 1,363.3 Rimu-tawa-beeches 215.3 Tawa 2,437.5 Tawa-beeches 58.8 Unclassified 1,022.9 Total 6,531.8

Species Lists

There are at least nine lists of vascular plants within the catchment.

Rare or Threatened Species

The Department of Conservation Bioweb database contains the following records:

Dactylanthus taylorii (Threatened-Nationally Vulnerable) Tupeia antarctica (At Risk-Declining)

13.5 Pest plants

Plant Pest RPMS Status Omanawa Wild kiwifruit Total control present Banana passionfruit Progressive control present Bushy asparagus Progressive control present Cathedral bells Progressive control present Heather Progressive control present Lantana Progressive control present Old man's beard Progressive control present Wild ginger Progressive control present Woolly nightshade Progressive control present Yellow flag iris Progressive control present

The Department of Conservation also maintains a pest plant database and this includes the following records for the Omanawa catchment:

Actinidia deliciosa Leycesteria formosa Asparagus aethiopicus Ligustrum sinense Berberis glaucocarpa Lonicera japonica Bougainvillea glabra Paraserianthes lophantha Calluna vulgaris Passiflora tripartita Clematis vitalba Paulownia tomentosa Cobaea scandens Pinus radiata Crocosmia x crocosmiiflora Prunus serrulata Dahlia excelsa Robinia pseudacacia Erythrina ×sykesii Rubus fruticosus agg. Hedera helix Salix cinerea Hedychium gardnerianum Ulex europaeus Humulus lupulus Vinca major Jasminum polyanthum Watsonia bulbillifera

13.6 Pest animals

Affecting Species Affecting Vegetation Control Underway Indigenous Fauna Possum   Goat   Red deer  Fallow deer  * Feral pig Ship rat   Norway rat Mustelids  Cats  Mice  Hedgehog  Wasps  Pest fish * Long-standing recreational hunting.

State of the Vegetation

There is no vegetation monitoring undertaken within the catchment, but there is an extensive network of FBI lines in the adjacent Otanewainuku and Otawa Blocks, in similar vegetation types.

Foliar Browse Index vegetation monitoring (Willems 2001, Woods 2008) indicates that the overall condition of vegetation is moderate. However, there is evidence of sustained impacts on possum-preferred species, and vegetation condition is probably in slow decline.

13.7 Indigenous fauna

A suite of typical forest birds is present, including kereru, whitehead, and tomtit. Falcon and kākā are likely to be itinerant visitors, and long-tailed cuckoo, robin, and kākāriki are known from the area.

Lizards

There is a record of striped skink (Oligosoma striatum).

Other Notable Species

Long-tailed bat is likely to be present.

State of Terrestrial Indigenous Fauna

No information on the state of terrestrial indigenous fauna is available for most of the Omanawa catchment. Bird, lizard, bat, and invertebrate populations are probably comparable with those of other mainland forests not subject to intensive predator pest control.

Fish Species

Thirteen (13) indigenous species are known to occur within the Omanawa catchment (compared to 20 different species for the wider Kaimai catchment)

Three (3) indigenous species are considered to be in Gradual Decline.

No introduced fish species have been recorded within Omanawa catchment (compared with nine introduced species for the wider Kaimai catchment).

Gambusia (Mosquito fish) is present, and is classed as an Unwanted Organism.

Table 13.7: Fish species recorded within the Omanawa catchment.

Scientific Name Common Name Threat Status Indigenous Anguilla dieffenbachii Longfin eel Gradual decline Paranephrops planifrons Koura (Invertebrate) Gradual decline Galaxias argenteus Giant kokopu Gradual decline Gobiomorphus huttoni Redfin bully Not threatened Retropinna retropinna Common smelt Not threatened Mugil cephalus Grey mullet Not threatened Galaxias fasciatus Banded kokopu Not threatened Anguilla australis Shortfin eel Not threatened Galaxias maculatus Inanga Not threatened Gobiomorphus cotidianus Common bully Not threatened Gobiomorphus gobioides Giant bully Not threatened Aldrichetta forsteri Yelloweye mullet Not threatened Rhombosolea retiaria Black flounder Not threatened Exotic Oncorhynchus mykiss Rainbow trout Introduced Salmo trutta Brown trout Introduced Gambusia affinis Gambusia Introduced

Notable Aquatic Habitats

Wetlands in the lower Kopurererua catchment (which are subject to restoration effort). Saltmarsh communities on the margins of Tauranga Harbour.

13.8 Recreational use

Recreational hunting.

13.9 Current management

Department of Conservation

Monitoring - None. FBI lines in adjacent forest blocks.

Pest plant control - None.

Pest animal control - None.

Recreation - Management of recreational hunting on Department of Conservation- administered land.

Regional Council

- Natural heritage

Environment Bay of Plenty provides technical advice, expertise, logistic and financial support to conservation on private land through its Environmental Programmes. Fencing is one component of EBOP‘s Environmental Programmes, 40,185 m of fencing has been erected, and is monitored by EBOP, within the Omanawa catchment under Environmental Programmes. Riparian planting, conservation planting, biodiversity protection and support for land use change are also available to assist landowners to protect and enhance environmental features and values in the catchment.

District Council(s)

Community Projects

One care group operates in Matahora Gully in the suburb of Brookfield in Tauranga City. One care group operates on the edge of the Kopurererua catchment, at Castlewold Drive in Cambridge Heights.

Positive Aspects of Management

Lowland forest remnants in large gullies associated with Kopurererua and Omanawa Rivers.

High level of enthusiasm for conservation management within community living in lower catchments, as shown by active Care groups.

Close proximity to large urban area.

Large areas of indigenous forest in upper catchment are contiguous with the Kaimai Mamaku Forest Park, and Otanewainuku Forest.

Aspects that Need to be Addressed

Erosion and sedimentation associated with waterways.

Impacts of pest plants in vegetation remnants in lower catchments.

Threats posed by pest animals in areas not subject to active management.

Water quality in Kopurererua and Omanawa Rivers.

Recent forestry-to-dairy conversions in upper catchment around Ngawaro, leading to impacts on water quality and fragmentation of wildlife corridors.

14. WAIMAPU

14.1 Waterways

Description

Waterways in the Waimapu catchment are slightly biased toward high gradient landforms. Low gradient streams occur in the lower catchment, stream gradient increases progressively toward catchment headwaters.

The predominant soil type surrounding steams in Waimapu catchment is volcanic acidic soils. Some alluvial soils occur in lower catchments.

Just under half the land cover adjoining streams is pastoral grassland (45%), slightly more than one third is indigenous vegetation (41%).

Almost half the length of low gradient streams (47%) and high gradient streams (45%) flows through pasture.

Table 14.1: Summary of stream length and adjacent soil types and land cover within Waimapu catchment.

Valley Landform

Low High Medium Length in Geology Landcover Gradient Gradient Gradient (km) Kilometres (km) (km) Volcanic Exotic forest 3.0 (4.2%) 0.2 (0.3%) 3.2 (1.5%) acidic Indigenous 13.5 (19.3%) 16.2 (30.9%) 16.8 (19.0%) 46.5 (22.1%) forest Pastoral 44.2 (63.2%) 35.6 (67.6%) 71.2 (80.7%) 150.8 (71.6%) Urban 9.3 (13.3%) 0.7 (1.4%) 10.0 (4.8%) Grand Total 70.0 (4.9%) 52.2 (6.4%) 88.3 (5.6%) 210.6

Rivers and Streams Within the Catchment

Waimapu and Kaitemako are the main streams, and the Waimapu has the following tributaries:

Waiorohi Pukekonui Toropeke Mangarewarewa Kirikiri

Water Quality

Total nitrogen, measured for the Waimapu until 1995, showed levels equivalent to the relatively high values found in the Kopurererua and Omanawa Rivers. Total nitrogen levels in both Kopurererua and Omanawa rivers have trended upward since 1995 (Taylor and Park 2001).

Between 1990 and 1995 the Waimapu had consistently high levels of E. coli and Enterococci, among the highest within the Tauranga Harbour catchment (Taylor and Park 2001).

Overall water quality in the Waimapu River has trended slightly downward during the 1990s and was rated moderate-good in 1997 (Taylor and Parks 2001).

14.2 Land use capability

Alluvial flats and terraces in lower and middle Waiorohi are all arable lands, in Classes 3 or 4. Steep gullies associated with the Waiorohi watercourse have little versatility, being Land Classes 7 and 8. Terraces and rolling hill country within the Waimapu catchment are less arable than those of the Waiorohi with middle and upper catchments dominated by LUC 6, with areas of arable land associated with broad flat ridges distributed throughout the catchment. All land classes have erosion as the primary limitation on use, with the exception of a small area above the estuary of the Waimapu that has a wetness limitation.

LUC Class Area (ha) % of Catchment 1 0.0 0.0 2 321.6 2.5 3 1,420.2 10.9 4 2,264.7 17.4 5 0.0 0.0 6 6,532.6 50.1 7 1,288.9 9.9 8 173.5 1.3 Town 889.1 6.8 N/C 138.7 1.1 TOTAL 13,029.4 100.0

LUC Classes Waimapu Sub-Catchment

Other Class 2 Class 8 7.9% 2.5% Class 3 1.3% 10.9% Class 7 9.9%

Class 4 17.4%

Class 6 50.1%

Waimapu LUC and Land Cover 7000

6000 Other 5000 Pasture & Crop Exotic Forest & Scrub Indigenous Forest & Scrub 4000

3000 Area (ha) Area `

2000

1000

0 1 2 3 4 5 6 7 8 LUC Class

Figure 14.1: Waimapu catchment - land cover and land use.

14.3 Land use

Spatial Pattern

Catchment size: 13,029 ha.

Catchment location: North from a line between Ngawaro Road and Otanewainuku, to the Tauranga harbour.

Predominant land uses (account for 88% of catchment):

- pasture grassland 6,021 ha (46.2% of catchment), lower, middle and upper catchments, mostly on land of low to moderate relief - indigenous forest 3,574 ha (27.4% of catchment). - exotic plantation Forest 980 ha (7.5%), primarily on elevated plateau. - orchards and crops 655 ha (5% of catchment), warmer lower flat terrain near sea level.

Urban land use: 1,292 ha (9.9% of catchment, Tauranga City).

Wetlands: 60.0 ha (0.5% of catchment), primarily herbaceous saline wetlands along the Waimapu and Waitao estuary margins.

Most modified: The lower parts of the Waimapu catchment have been heavily modified by conversion to pastoral orcharding and urban land uses.

Table 14.2: Land use within the Waimapu catchment.

% of LCDB2 Classification Area (ha) Catchment Broadleaved indigenous hardwoods 201.0 Indigenous forest 3,574.2 Manuka and/or kanuka 221.8 Indigenous Forest 3,996.9 30.7% Coastal sand and gravel Estuarine open water 13.2 Herbaceous freshwater vegetation Herbaceous saline vegetation 45.1 Lake and pond 1.1 Mangrove 1.7 Wetland Systems 61.1 0.5% Afforestation (imaged, post LCDB 1) 19.3 Afforestation (not imaged) Forest harvested 10.6 Other exotic forest 89.7 Pine forest - closed canopy 499.1 Pine forest - open canopy 180.0 Exotic Plantation Forest 798.7 6.1%

% of LCDB2 Classification Area (ha) Catchment Orchard and other perennial crops 653.2 Short-rotation cropland 2.1 Vineyard 17.7 Orchards and Crops 673.0 5.1% High producing exotic grassland 6,000.0 Low producing grassland 20.5 Pastoral Lands 6,020.5 46.2% Deciduous hardwoods 23.2 Major shelterbelts 13.4 Mixed exotic shrubland Gorse and broom 123.4 Other Exotic Vegetation 160.0 1.2% Surface mine 15.8 Surface Mine 15.8 0.1% Built-up area 1,165.3 Transport infrastructure 5.8 Urban parkland/Open space 121.3 Urban Landforms 1,292.5 9.9% Not Classified 11.0 0.1% Grand Total 13,029.4 100.0%

Legal Protection

This section provides an overview of the areas protected by legal statute and covenants, for the purpose of biodiversity protection.

Department of Conservation

The Department of Conservation administers 403 ha within the Waimapu catchment for conservation purposes.

Reserves to protect indigenous ecosystems, vegetation, habitats, or species comprises 194.9 ha (48.4%).

Reserves with other primary aims comprise 208 ha (41.6.3%).

Table 14.3: Department of Conservation-administered lands within the Waimapu catchment.

Reserve Type (DOC Legal Description) Area (ha) Fixed Marginal Strip - S.24(3) Conservation Act 1987 6.3 Government Purpose Reserve - S.22 Reserves Act 1977 0.2 Historic Reserve - S.18 Reserves Act 1977 2.6 Local Purpose Reserve - S.23 Reserves Act 1977 149.3 Recreation Reserve - S.17 Reserves Act 1977 56.1 Stewardship Area - S.25 Conservation Act 1987 188.6 Grand Total 403.0

Nga Whenua Rahui

There is part of one Nga Whenua Rahui kawenata within the Waimapu catchment, 49.4 ha of the Otanewainuku block crosses into the upper Kaitemako stream.

QEII

There are ten QEII covenants totalling 70 ha (0.5%) of the Waimapu catchment.

Table 14.4: QEII covenants within the Waimapu catchment.

Covenant Area (ha) 5/03/068 4.3 5/03/156 2.5 5/03/261 2.0 5/03/285 1.0 5/03/300 6.2 5/03/325 1.7 5/03/431 3.0 5/03/459 2.5 5/03/736 45.9 5/03/749 1.1 70.1 Grand Total (0.5%)

Western Bay of Plenty District Council Covenants

Within the Waimapu catchment there are 21 Western Bay of Plenty Covenants, with a total area of 155.7 ha (1.2%).

Table 14.5: Western Bay of Plenty District Council Covenants within the Waimapu catchment.

WBOP Covenants Area (ha) Cov6024 2.07 Cov6131 3.31 Cov6413 2.25 Cov6442 2.56 Cov6549 3.96 Cov6570 2.75 Cov6649 1.64 Cov6683 2.77 Cov6817 4.56 Cov7249 11.35 Cov7285 2.68 Cov7349 3.52 Cov7483 11.87 Cov7751 1.65 Cov7782 3.8 Cov7785 4.76 Cov7857 17.64 Cov8268 5.75 Cov8444 8.39 Cov8483 2.05 Cov8899 6.4 Cov8942 10.93 Cov9140 2.4 Cov9218 1.43 Cov9941 9.05 155.7 Grand Total (1.2%)

14.4 Indigenous vegetation and flora

Vegetation Pattern

Most (77%) of the indigenous forest is tawa-dominant (2,576 ha). Unlogged rimu- tawa forest occurs in the vicinity of Otanewainuku, in the headwaters of the Waiorohi Stream.

Table 14.6: Indigenous forest types within the Waimapu catchment.

Forest Type Area (ha) General hardwoods 48.0 Highland and steepland softwoods-hardwoods 0.7 Rimu-tawa 140.9 Rimu-tawa-beeches 5.7 Tawa 2,609.5 Unclassified 769.4 Total 3,574.2

Species Lists

There are at least seven lists of vascular plants within the catchment.

Rare or Threatened Species

The Department of Conservation Bioweb database includes the following records:

Ileostylus micranthus Myriophyllum robustum (At Risk-Declining) Tetragonia tetragonioides (At Risk-Naturally Uncommon)

14.5 Pest plants

Plant Pest RPMS Status Waimapu Wild kiwifruit Total control present Banana passionfruit Progressive control present Boneseed Progressive control present Bushy asparagus Progressive control present Cathedral bells Progressive control present Climbing spindleberry Progressive control 1 site Heather Progressive control present Lantana Progressive control present Old man's beard Progressive control present Wild ginger Progressive control present Woolly nightshade Progressive control present

The Department of Conservation also maintains a pest plant database and this includes the following records for the Waimapu catchment:

Actinidia deliciosa Jasminum polyanthum Akebia quinata Lilium tigrinum Alocasia brisbanensis Lonicera japonica Berberis glaucocarpa Pinus spp. Cortaderia selloana Rhamnus alaternus Crocosmia x crocosmiiflora Salix fragilis Galeobdolon luteum Setaria palmifolia Hedychium gardnerianum Solanum mauritianum Hypericum androsaemum Spartina alterniflora Impatiens sodenii Tradescantia fluminensis

14.6 Pest animals

Affecting Species Affecting Vegetation Control Underway Indigenous Fauna Possum    Goat   Red deer  Fallow deer  Feral pig Ship rat  Norway rat Mustelids  Cats  Mice  Hedgehog  Wasps  Pest fish

State of the Vegetation

TCC has monitoring in place for natural areas within Tauranga City.

There is no vegetation monitoring within the upper Waimapu catchment, but monitoring in adjacent catchments is directly relevant to this area.

Vegetation monitoring within the Otanewainuku Conservation Area (Willem 2000) found that kohekohe and pate foliar cover was recovering to 1994 levels or better as a result of possum control during the mid to late 1990s. Qualitative observation of vegetation within the Otanewainuku Kiwi Project‘s management area suggests possum-preferred canopy species such as kohekohe and northern rata are recovering, and the vegetation condition is improving through time. Northern rata within the management area flowered heavily in summer of 2008/2009.

Foliar Browse Index vegetation monitoring in Otawa/Oropi Forests (Willems 2000) observed browse on every possum-preferred species monitored. All (100%) of raukawa, 70% of kohekohe, 57% of mangeao, and 39% of mahoe exhibited evidence of browse. The survey noted that overall the forest exhibited moderate to high damage from possums, and the appearance of localised areas of possum-induced canopy death. These monitoring results suggest that, beyond management areas, the overall condition of vegetation is moderate but there is evidence of severe impacts on possum-preferred species, and vegetation condition is in decline.

14.7 Indigenous fauna

Other Notable Species

There were ten kiwi within the Otanewainuku Kiwi Project management area (Otanewainuku Conservation Area) around Otanewainuku mountain in 2007.

Robin numbers have recovered since the commencement of pest management in 2002. At least one kokako remains on the flanks of Otanewainuku mountain. A kokako release into the management area is planned for 2010.

State of Terrestrial Indigenous Fauna

No information is available on the state of terrestrial indigenous fauna for the Waimapu catchment, although there is evidence indicating the recent local extinction of at least one threatened bird species, and another had been reduced to the point of local extinction. Outside the boundaries of the Otanewainuku Kiwi Project, bird, bat, lizard, and invertebrate populations are probably comparable with those of other mainland forests not subject to intensive predator control.

Fish Species

Seven (7) indigenous species are known to occur within Waimapu catchment (compared to 20 different species for the wider Kaimai catchment)

Two (2) indigenous species are considered to be in Gradual Decline.

No introduced fish species have been recorded within Waimapu catchment (compared with nine introduced species for the wider Kaimai catchment).

Table 14.7: Fish species recorded within the Waimapu catchment.

Scientific Name Common Name Threat Status Indigenous Anguilla australis Shortfin eel Not threatened Anguilla dieffenbachii Longfin eel Gradual decline Galaxias maculatus Inanga Not threatened Gobiomorphus basalis Giant bully Not threatened Gobiomorphus cotidianus Common bully Not threatened Gobiomorphus huttoni Redfin bully Not threatened Paranephrops planifrons Koura (Invertebrate) Gradual decline Retropinna retropinna Common smelt Not threatened

Notable Aquatic Habitats

Wetlands on the margins of Tauranga Harbour.

14.8 Recreational use

Otawa forest contains fallow deer population popular with recreational hunters.

Track to Otanewainuku mountain summit, which can be accessed from Mountain road.

14.9 Current management

Department of Conservation

Monitoring - None.

Pest plant control - None.

Pest animal control - Goat control. - Recreational hunting management.

Recreation - Otanewainuku Mountain track.

Regional Council

- Natural heritage Environment Bay of Plenty provides technical advice, expertise, logistic and financial support to conservation on private land through its Environmental Programmes. Fencing is one component of EBOP‘s Environmental Programmes, 44,810 m of fencing has been erected, and is monitored by EBOP, within the Waimapu catchment under Environmental Programmes. Riparian planting, conservation planting, biodiversity protection and support for land use change are other components of tools available to assist landowners to protect and enhance environmental areas and values in the catchment.

District Council(s)

TCC manages Mauao (in conjunction with iwi) and other coastal reserves.

Community

Team Kaitemako undertakes general habitat protection works, including weed removal, revegetation planting, and pest control

Waimapu Estuary Managers aims to maintain clean open water enhance indigenous estuarine biodiversity through habitat improvement. in Waimapu Estuary by controlling mangroves, monitoring birds, sediment and benthic fauna, pest plant and pest animal control, pest plant and indigenous vegetation planting to enhance riparian margins and public reserves to increase presence of indigenous fauna.

Mills-Maungatapu aim to protect indigenous birds by controlling rodents on the Maungatapu Peninsula.

Fraser Street Reserve care group is working towards eradication of invasive pest species; especially pampas, wattle, gorse and blackberry within the reserve.

Scantlebury Street Reserve care group

Lagoon Place care group.

Argyll Reserve care group works to weed and maintain a series of indigenous plantings throughout the reserve.

Rotary Park Reserve care group.

Taipari Street Gully Reserve care group.

Moiri Place Reserve care group.

Positive Aspects of Management

Part of Otanewainuku Kiwi Trust‘s management area extends into the upper Waimapu catchment.

Tauranga city council/Environment BOP funded goat and possum control within city council water supply forested area

Close proximity to large urban area.

High level of enthusiasm for conservation management within community living in lower catchments, as shown by active care groups (10) in and around Tauranga City.

Large areas of indigenous forest in upper catchment in Otawa-Otanewainuku Forest.

Aspects that Need to be Addressed

Erosion and sedimentation associated with waterways.

Impacts of pest plants in vegetation remnants in all catchments.

On going dumping of organic and inorganic rubbish throughout the catchments from road access. Some of this leading to ongoing plant pest spread.

Threats posed by pest animals in areas not subject to active management over most indigenous vegetation within the catchment.

15. OTAWA

15.1 Waterways

Description

Half of the waterways in the Otawa catchment are low gradient systems, and just over one-third are high gradient streams (in the upper catchment).

The predominant soil type is volcanic soils. Some alluvial and soft sediment soils occur in lower catchments, with sandy soils adjacent to the coast.

Sixty-one percent (61.4%) of the land cover adjoining streams is pastoral grassland,

Nearly one-fifth (18.9%) of streams occur in urban landcover.

Eighteen percent (18.3%) of streams flow through indigenous forest.

Table 15.1: Summary of stream length and soil types and land cover within Otawa catchment.

Valley Landform Low High Length in Medium Geology Landcover Gradient Gradient Kilometres Gradient (km) (km) (km) Alluvium Pastoral 5.2 (4.2%) 5.2 (4.2%) Urban 18.7 (15.0%) 18.7 (15.0%) Miscellaneous Urban 0.3 (0.2%) 0.1 (0.08%) Soft Exotic forest 1.8 (4.0%) 1.8 (1.4%) Sedimentary Indigenous 0.2 (0.2%) 1.1 (2.4%) 1.2 (1.0%) forest Pastoral 2.0 (1.6%) 2.3 (5.1%) 4.3 (3.5%) Volcanic Exotic forest 0.1 (0.1%) 0.1 (0.08%) acidic Indigenous 2.2 (1.8%) 6.3 (37.7%) 12.9 (28.5%) 21.5 (17.3%) forest Pastoral 29.6 (23.8%) 9.8 (58.6%) 27.0 (59.7%) 66.5 (53.4%) Urban 4.2 (3.4%) 0.7 (4.2%) 4.9 (3.9%) 62.6 (50.2%) 16.9 (13.4%) 45.2 (36.3%) 124.6

Rivers and Streams Within the Catchment

The main streams are the Waitao and Kaitemako.

Waitao - Kaiate - Owairoa - Otawera - Arateka - Rerekawau

Kaitemako

Water Quality

Total nitrogen and nitrate nitrogen for the Waitao were high, but may have been declining since 1997 (Taylor and Park 2001).

Ammonium levels within the Waitao are the higher than other streams within the Tauranga catchment.

Between 1990 and 1995 the Otawa had consistently high levels of E. coli and Enterococci, among the highest within the Tauranga Harbour catchment (Taylor and Park 2001).

Between 1991 and 2000 the Waitao consistently recorded the highest levels of faecal coliforms among streams flowing into the Tauranga Harbour.

The Waitao stream shows an increasing trend and increasing variation in colour.

Overall water quality in the Waitao River was moderate to good but declining in 2000 (Taylor and Parks 2001).

15.2 Land use capability

Most soils within the Otawa catchment have limited versatility, being Land Classes 6, 7, and 8. Soils on flats around Tauranga Harbour have higher versatility, being Land Classes 2, 3, and 4. All land classes have erosion as the primary limitation on use.

LUC Class Area (ha) % of Catchment 1 0.0 0.0 2 407.4 4.1 3 1,184.9 12.0 4 1,928.5 19.6 5 0.0 0.0 6 2,639.6 26.8 7 2,198.7 22.3 8 447.6 4.5 Town 966.9 9.8 N/C 88.9 0.9 TOTAL 9,862.5 100.0

LUC Classes Otawa Sub-Catchment Class 2 Other 4.1% 10.7% Class 3 Class 8 12.0% 4.5%

Class 7 Class 4 22.3% 19.6%

Class 5 0%

Class 6 26.8%

Otawa LUC and Land Cover 3000

2500 Other Pasture & Crop Exotic Forest & Scrub 2000 Indigenous Forest & Scrub

1500

Area (ha) ` 1000

500

0 1 2 3 4 5 6 7 8 LUC Class

Figure 15.1: Otawa catchment - Land cover and land use.

15.3 Land use

Spatial Pattern

Catchment size: 9,862 ha.

Catchment location: north from a line between Ngawaro Road and Otanewainuku, to the Tauranga harbour and the coast at Mt Maunganui and Papamoa.

Predominant land uses (account for 88% of catchment):

- pasture grassland 6,021 ha (46.2% of catchment), lower, middle and upper catchments, mostly on land of low to moderate relief - indigenous forest 1,432 ha (14.5% of catchment), upper catchments on land of moderate relief, and along the steeps sides of the middle Waitao river gully. - Exotic plantation forest 1,350 ha (13.4%) on moderate and steep slopes in the middle catchment. - Urban areas 2,088 ha (20.7%), on highly versatile soils in low relief landforms in lower catchment. - orchards and crops 599 ha (5.5% of catchment), warmer lower flat terrain near sea level.

Urban landforms: 2,088 ha (20.7% of catchment), in Tauranga City.

Wetlands: 60.0 ha (0.5% of catchment), primarily herbaceous saline wetlands associated with estuary margins.

Most modified: The lower parts of the Otawa catchment have been heavily modified by conversion to pasture grassland, orcharding, and urban land uses.

Least modified: The upper catchment retains indigenous vegetation on the Otawa- Otanewainuku ridge stream, although much has been modified by logging.

Table 15.2: Land use within the Otawa catchment.

% of LCDB2 Classification Area (ha) Catchment Broadleaved Indigenous Hardwoods 120.4 Indigenous Forest 1,431.9 Manuka and or Kanuka 197.1 Indigenous Forest 1,749.3 17.7% Coastal Sand and Gravel 16.9 Estuarine Open Water Herbaceous Freshwater Vegetation 8.6 Herbaceous Saline Vegetation 68.5 Lake and pond 24.3 Mangrove 3.5 Wetland Systems 121.8 1.2% Afforestation (imaged, post LCDB 1) 5.8 Afforestation (not imaged) Forest Harvested 42.5 Other Exotic Forest 31.8

% of LCDB2 Classification Area (ha) Catchment Pine Forest - Closed Canopy 793.5 Pine Forest - Open Canopy 361.8 Exotic Plantation Forest 1,235.4 12.5% Orchard and Other Perennial Crops 464.0 Short-rotation Cropland 95.6 Orchards and Crops 559.6 5.7% High Producing Exotic Grassland 3,729.0 Low Producing Grassland 166.3 Pastoral Lands 3,895.3 39.5% Deciduous Hardwoods 17.4 Major Shelterbelts 17.2 Mixed Exotic Shrubland 23.1 Gorse and Broom 88.9 Other Exotic Vegetation 146.6 1.5% Surface mine 43.8 Surface Mine 43.8 0.4% Built-up Area 1,616.6 Transport Infrastructure 1.5 Urban Parkland/ Open Space 470.3 Urban Landforms 2,088.4 21.2% Not Classified 22.1 0.2% Grand Total 9,862.5 100.0%

Legal Protection

This section provides an overview of the areas protected by legal statute and covenants, for the purpose of biodiversity protection.

Department of Conservation

The Department of Conservation administers 399 ha within the Otawa catchment for conservation purposes. Reserves to protect indigenous ecosystems, vegetation, habitats, or species comprises 196.1 ha (49.2%). Other reserves (e.g. Recreation) comprise 202.7 ha (50.8%).

Table 15.3: Department of Conservation administered lands within the Otawa catchment.

Reserve Type (DOC Legal Description) Area (ha) Fixed Marginal Strip - S.24(3) Conservation Act 1987 4.4 Historic Reserve - S.18 Reserves Act 1977 74.8 Local Purpose Reserve - S.23 Reserves Act 1977 1.4 Recreation Reserve - S.17 Reserves Act 1977 126.5 Scenic Reserve - S.19(1)(a) Reserves Act 1977 12.5 Stewardship Area - S.25 Conservation Act 1987 179.2 Grand Total 398.8

Nga Whenua Rahui

889 ha of the Otawa-Kaiate Nga Whenua Rahui kawenata occurs within the Otawa catchment.

QEII

There are no QEII covenants within the Otawa catchment.

Western Bay of Plenty District Council Covenants

Within the Otawa catchment, there are four Western Bay of Plenty covenants, with a total area of 35.6 ha (1.2%).

Table 15.4: Western Bay of Plenty District Council Covenants within the Otawa catchment.

WBOP Covenants Area (ha) Cov6105 2.01 Cov8163 15.35 Cov8289 0.55 Cov9173 17.7 35.6 Grand Total (0.4%)

15.4 Indigenous vegetation and flora

Vegetation Pattern

Forty-four percent (44%) of the 1431.9 ha of indigenous forest is rimu-tawa forest (628 ha), 15% is tawa forest, and another 12% (171 ha) is general hardwoods forest. All three forest types occur on the slopes of Otawa and Otanewainuku in the upper Otawa and Kaitemako streams. Unlogged rimu-tawa forest occurs on and around Otanewainuku, in the headwaters of the Waiorohi Stream.

Table 15.5: Indigenous forest types within Otawa catchment.

Forest Type Area (ha) General hardwoods 171.3 Highland and steepland softwoods-hardwoods 45.6 Rimu-tawa 627.8 Tawa 218.7 Unclassified 368.4 Total 1,431.9

Species Lists

There are at least nine lists of vascular plants within the catchment.

Rare or Threatened Species

Pimelea tomentosa occurs on Mauao. Atriplex hollowayi was recorded at Mount Maunganui in 1890, and Lepidium oleraceum (Cook‘s Scurvy Grass, nau) was recorded in 1942 from Mauao.

The Department of Conservation Bioweb database includes the following records:

Desmoschoenus spiralis (At Risk-Relict) Pimelea arenaria (At Risk-Declining) Pimelea tomentosa (At Risk-Nationally Vulnerable)

15.5 Pest plants

Plant Pest RPMS Status Ōtawa Alligator weed Eradication 1 site White-edged nightshade Eradication ? Wild kiwifruit Total control present Apple of Sodom Progressive control 1 site Banana passionfruit Progressive control present Boneseed Progressive control present Bushy asparagus Progressive control present Cathedral bells Progressive control present Heather Progressive control present Lantana Progressive control present Old man's beard Progressive control present Wild ginger Progressive control present Woolly nightshade Progressive control present

Surveillance pest plants (23 species) - Plants of known threat of adverse effects, which may be established in parts of the region, but about which there is uncertainty of distribution, and/or threat of spread and/or feasibility of control. There are two objectives for these pests. The first is to increase understanding of the distributions, impacts and control options, the second is to have them voluntarily controlled by land occupiers with assistance from EBOP programmes (EBOP 2003).

The Department of Conservation also maintains a pest plant database and this includes the following records for the Otawa catchment:

Chrysanthemoides monilifera subsp. monilifera Erigeron karvinskianus Houttuynia cordata Lonicera japonica Paspalum vaginatum Spartina alterniflora

15.6 Pest animals

Affecting Affecting Species Control Underway Vegetation Indigenous Fauna Possum   2001 Goat  Red deer  Fallow deer  * Feral pig  Ship rat   Norway rat   Mustelids  Cats  Mice  Hedgehog  Wasps  Pest fish 

* Recreational hunting.

State of the Vegetation

Foliar Browse Index vegetation monitoring in Otawa/Oropi Forests (Willems 2000) recorded browse damage on every possum-preferred species monitored. All (100%) of raukawa, 70% of kohekohe, 57% of mangeao, and 39% of mahoe exhibited evidence of browse damage. The survey noted, overall, that the forest exhibited moderate to high damage from possums, and the appearance of localised areas of possum-induced canopy collapse. These monitoring results suggest that the overall

condition of vegetation in the Otawa catchment is moderate, with some evidence of severe impacts on possum-preferred species, and vegetation condition is in decline.

15.7 Indigenous fauna

A suite of typical forest birds is present, including kereru. Falcon and kākā are likely to be itinerant visitors. Kiwi are present (in low numbers) to the south at Otanewainuku, and there are old records from Otawa. Kokako were present in the 1980s (Beadel 1985) and single birds could still be present (Smuts-Kennedy 2002).

Lizards

There is a record of the common copper skink (Cyclodina aenea).

Bats

Long-tailed bats could be present.

Other Notable Species

Hochstetter‘s frogs are present in streams on the southern slopes of Otawa forest, and though a search of the upper Waitao on northern slopes in 2002 failed to locate any individuals, it is not impossible that frogs occur there (Smuts-Kennedy 2002).

More than 100 pairs of grey-faced petrels nest on the northern flanks of Mauao. Thirty chicks were transferred from Motutau in November 1999, thirteen fledged, of which three have returned to breed (Miskelly et al. 2009). The grey-faced petrel colony on Mauao is one of the few remaining colonies on the New Zealand mainland (Taylor 2000).

Little Blue Penguin nest around Mauao and along the coast in general.

State of Terrestrial Indigenous Fauna

No information on the state of terrestrial indigenous fauna is available for most of the Otawa catchment, although there is evidence indicating the recent probable local extinction of kokako which were recorded around Otawa trig in the early 1980s (Forest and Bird 1983).

Bird, lizard, and invertebrate populations are probably comparable with those of other mainland forests not subject to pest control.

Fish Species

Ten (10) indigenous freshwater fish species are known to occur within Otawa catchment (compared to 20 different species for the wider Kaimai catchment)

Two (2) indigenous species are considered to be in Gradual Decline.

One introduced fish species (Gambusia) has been recorded within Otawa catchment (compared with nine introduced species for the wider Kaimai catchment).

Gambusia (Mosquito fish) is an Unwanted Organism.

Table 15.6: Fish species recorded within Otawa catchment.

Scientific Name Common Name Threat Status Indigenous Anguilla dieffenbachii Longfin eel Gradual decline Paranephrops planifrons Koura (Invertebrate) Gradual decline Gobiomorphus huttoni Redfin bully Not threatened Anguilla australis Shortfin eel Not threatened Galaxias maculatus Inanga Not threatened Retropinna retropinna Common smelt Not threatened Galaxias fasciatus Banded kokopu Not threatened Gobiomorphus gobioides Giant bully Not threatened Gobiomorphus cotidianus Common bully Not threatened Gobiomorphus basalis Crans bully Not threatened Mugil cephalus Grey mullet Not threatened Exotic Gambusia affinis Gambusia Introduced

Notable Aquatic Habitats

None present.

15.8 Recreational use

Otawa forest contains a fallow deer herd that is popular with recreational hunters.

15.9 Current management

Department of Conservation

Monitoring - At least two FBI lines on the main ridge, north and south of Otawa trig. - No other monitoring infrastructure.

Pest plant control - None.

Pest animal control - Goat control (ongoing, as required). - Possum control, 2001, 830 ha treatment area. - Recreational hunting management.

Recreation - Otanewainuku Mountain track. - Track to Otawa trig.

Regional Council

- Natural heritage Environment Bay of Plenty provides technical advice, expertise, logistic and financial support to conservation on private land through its Environmental Programmes. Fencing is one component of EBOP‘s Environmental Programmes, 9,747 m of fencing has been erected, and is monitored by EBOP, within the Otawa catchment under Environmental Programmes. Riparian planting, conservation planting, biodiversity protection and support for land use change are other components of tools available to assist landowners to protect and enhance environmental areas and values in the catchment.

District Council(s)

TCC manages Mauao (in conjunction with iwi) and other coastal reserves.

Community Projects

Te Awa O Waitao Stream restoration project aims to restore the locally significant Waitao Stream and wider catchment with a combination of western science and traditional Māori knowledge. It is a joint NIWA, Tangata Whenua and NZ Landcare Trust project. The stream, its mouth and surroundings are very significant culturally and historically to tangata whenua: Nga Potiki, Ngati He, Ngai Tukairangi, Ngati Kuku, Ngati Tapu (‗Ngaiterangi‘), Ngai Te Ahi and Ngati Pukenga. The project is being supported by Tauranga City Council, Western Bay of Plenty District Council, Environment Bay of Plenty, Department of Conservation, Nga Whenua Rahui, local community, and hapu.

Positive Aspects of Management

High level of enthusiasm for conservation management within community living in lower catchments, evidenced by active care groups in and around Tauranga City. Close proximity to large urban area. There are large areas of indigenous forest in upper catchment contiguous with the Otawa-Otanewainuku Forest.

Aspects that Need to be Addressed

Erosion and sedimentation associated with waterways. Fragmented habitats in lower catchments; need for ecological restoration and creation of linkages along streams. Water quality in Waitao stream.

Impacts of pest plants in vegetation remnants in lower catchments. Threats posed by pest animals in areas not subject to active management over most indigenous vegetation within the catchment.