Rivers and lakes Outstanding water bodies Ecosystems and habitats - - PowerPoint PPT Presentation

Alton Perrie Environmental Scientist, Freshwater PNRP Hearing Stream 5 – 9/4/2018

Rivers and lakes

• Outstanding water bodies
• Ecosystems and habitats with significant biodiversity values

What is aquatic biodiversity in lakes & rivers?

Aquatic biodiversity - impacts

• A wide range of factors can affect aquatic

biodiversity including:

– Water quality degradation – Water quantity/flow modification – Instream habitat degradation – Riparian/catchment habitat degradation – Habitat loss, fragmentation, disconnection, etc. – Introduced flora and fauna

• Policy 31 sets out approach to minimise effects
• n aquatic biodiversity

Freshwater fish

• Twenty indigenous fish

– Mainly endemic – Many considered taonga

• Small, cryptic and nocturnal
• 16 are diadromous (migratory)

– Seasonal spawning/migrations

• 11 have threat ranking

– 2 “Nationally Vulnerable” – 9 “At Risk”

Evidence paragraphs 5.1 to 5.6

Fish distribution

• Different species have different habitat

preferences at both:

– Large scales – Fine scales

• Whole catchments are important
• Mostly migratory species

– Fish passage very important – Upstream and downstream

Evidence paragraphs 5.1 to 5.6

Fish distribution – large spatial scales

Upland species Lowland species

Fish distribution – Fish distribution – fine spatial scales

Shallow, fast flow species Deep, slow flow species

Good fish habitat is not always

• bvious

Aquatic macroinvertebrates

• Species range in sensitivity to water and habitat quality
• Good relationship between macroinvertebrate

community health and forest cover – High forest cover = good “health” – Low forest cover = bad “health”

Outstanding water bodies

• Outstanding lakes

– Lake Wairarapa (WCO: Wildlife habitat) – Lake Kohangapiripiri – Lake Kohangatera

• Expert panel approach
• Lakes criteria:

– Aquatic vegetation values – Water Conservation Order

Outstanding water bodies

• Expert panel approach
• Rivers assessed against four criteria:

– High macroinvertebrate health (MCI) with high indigenous forest cover (>80%) – Indigenous fish diversity (habitat for six or migratory indigenous fish species); and – Threatened fish species (habitat for nationally threated fish species); and – Large (5th order) rivers

Evidence paragraphs 7.1 to 7.6

Outstanding water bodies

• Outstanding rivers

– Te Awa Kairangi (Hutt River) u/s of Kaitoke Dam – Otaki River u/s of and including Pukeatua River – Wainuiomata River u/s of Water Supply intake

• Method M7 in PNRP recognises further

development of outstanding criteria might be required

Evidence paragraphs 7.1 to 7.6

Rivers and lakes with significant indigenous ecosystems

Evidence paragraphs 8.1 to 8.13

• Four criteria originally developed and applied in 2009 to

generate Table 16 of RPS

• These criteria were established to meet overarching

criteria of Policy 23 of RPS:

– representativeness, rarity, diversity and ecological context

• These four criteria were reapplied in 2014 for PNRP

– Table 16 of RPS basically = Schedule F – Schedule F includes a few updates but no major changes

• RPS has been subject to Schedule 1 process

Rivers and lakes with significant indigenous ecosystems

Four Criteria:

• Rivers and streams with high macroinvertebrate health;
• Rivers, streams and lakes that provide habitat for

indigenous threatened/at risk fish species;

• Rivers, streams and lakes that provide habitat for six or

more migratory indigenous fish species; and

• Rivers and streams that provide inanga spawning habitat.

Evidence paragraphs 8.1 to 8.13

Rivers and streams with high macroinvertebrate health

• Used a regional data set to develop thresholds between

macroinvertebrate metrics and indigenous forest/scrub cover

• Indigenous forest and scrub cover threshold applied to

Region to identify sites

• Different (lower) threshold used in Eastern Wairarapa

Evidence paragraphs 8.1 to 8.13

Rivers, streams and lakes that provide habitat for indigenous threatened/at risk fish species

• Used presence of selected threatened/at risk

species from national rankings

• Since 2009, the conservation status for many

species have changed

– Increasing from 30 to 55% of species – New conservation rankings were not included in the re-application of this criterion in 2014

Evidence paragraphs 5.5, 5.6 & 8.1 to 8.13

Rivers, streams and lakes that provide habitat for six or more migratory indigenous fish species

• Used presence of six or more migratory

species

• Both criteria used NIWA’s National

Freshwater Fish Database (NZFFD) to indicate presence

– Best/only dataset available

• Applied at catchment scale

– Multiple species – different habitats – Diadromous (migratory) use whole catchment

Evidence paragraphs 8.1 to 8.13

Rivers and streams that provide inanga spawning habitat

• Identified based on spawning habitat assessments
• Occurs in tidally influenced reaches – limited extent
• Critical spawning period in autumn requires

protection from disturbance

Significant rivers – regional extent

• High macroinvertebrate health criterion

identifies ~26% of Region

• Two main fish criteria identify ~45% of

Region

• If you remove DOC and GWRC Parks

from extent

– Macroinvertebrate health ~11% of Region – Fish criteria ~29% of Region