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Kai Whenua Kai Moana 1, • Endemic – organism is unique to defined…

- - - - High proportion of indigenous species are endemic to NZ
        
        90% terrestrial fauna
        
        80% plants
        
        26% fungi
        
        38% marine animals
        
        Most of this diversity is found in non-forest environments, wetland, alpines and herb fields
        
        Over the last 2 million years the flora and fauna of NZ have also evolved mostly under glacial climates
  - - - Post WW2
        
        Aerial dressing enables fertiliser application in difficult to reach places
        
        Availability of heavy machinery made draining wetlands easier
    - - Conversions
        
        Conversion of exotic forest to dairying
        
        Last 20 years – massive irrigation programs
        
        Central Volcanic Plateau
        
        Canterbury Plains
        
        Often marginal land
- - - - • Biological community and its physical environment
        • Biotic (living) components
        • Plants, animals, microorganisms and their products (wastes, secretions &
        remains)
        • Abiotic (non-living components)
        • Water, nutrients, rocks, heat and solar energy
        
        New Zealand terrestrial ecosystems
        • Department of Conservation have recognised 152 terrestrial ecosystems
        • 78 zonal – climate, temperature and moisture availability
        • e.g. sub-antarctic, alpine, sub-tropical
        • 74 azonal - extreme rock and soil chemistry, extreme heat, and frequent
        disturbance
        • e.g. sand dune, braided rivers, geothermal
    - - • Trophic level = feeding level of an organism in an ecosystem
        • Two groups – producers and consumers
        • Producers - Usually plants produce biomass using photosynthesis
        • Consumers - Organisms that cannot produce nutrients or energy. Obtain nutrients by feeding on other organisms or their remains
      - Types of consumers
        • Primary consumers/herbivores feed on plants
        • Secondary consumers/carnivores feed on herbivores
        • Tertiary consumers feed on carnivores
        • Omnivores eat plants and other animals
        • Decomposers – organisms that feed on remains of other organisms
        Decomposers
        • Detritivores
        • Bacteria and fungi
        • Release nutrients from remains of plants and animals for reuse by primary
        producers
    - - • Sequence of organisms that provides a source of nutrients or energy for the next organism
        NZ examples: Haast egeles eating moas they went extinct after moas went extinct becuase moas where their main food source.
        Rotting logs in our native forest have a lot of benefits for spaces and ecosystems.
      - Food web
        • Most organisms feed on more than one type of organism
        • Most organisms are eaten or decomposed by more than one
        organism
        • Food web – interconnected food chains
      - Examples of food webs
        1) https://www.nature.com/scitable/knowledge/library/food-web-concept-and-applications-84077181
        2) Freshwater food web https://teara.govt.nz/en/diagram/11628/freshwater-food-web
        3) Altered freshwater food web
        https://sciblogs.co.nz/waiology/2014/12/02/food-webs-who-eats-who-and-what-does-that-tell-us/
    - - Definition - the position occupied by an organism in an ecosystem. The niche includes both the organisms physical environment and the role that it plays within the wider ecosystem
      - Examples NZ:
        • In the absence of mammals NZ birds and insects filled ecological niches
        • giant weta filled ecological niche of rodents
        • flightless kiwi – ground dweller and consumed worms
        • moas were grazers
    - - • Ecosystem services = benefits that people obtain from ecosystems
        Four categories
        1) Provisioning - e.g., the production of food, water, medicines, wood and fibres
        2) Regulating - e.g., the control of climate stabilisation, disease control, air purification, plant pollination,
        3) Supporting - e.g., nutrient cycles and crop pollination
        4) Cultural - e.g., spiritual, recreational benefits, connect with environment and each other
        good diagram on lecture slides
      - Ecosystem types and their services
        Lakes and Rivers: Hydrological cycles, flow regulation and flood control, water supply, recreation and food.
        Forests: Climate and erosion control, nutrient cycling, waste treatment, raw material production and carbon storage.
        Agricultural/Horticultural: Commercial food production, erosion control, soil formation, waste treatment, nutrient cycling and pollination.
        Freshwater Wetlands: Storm protection, flood control, habitat, nutrient recycling and waste treatment.
        Estuarine: Spawning and nursery grounds for many species, habitat, waste treatment and nutrient cycling.
      - Example of the value of ecosystems
        •The GDP (Gross domestic product ) for the Waikato region in 2009 was $16.89 billion
        •The estimated value of ecosystem services in the region was estimated at $9.4 billion in 1997
      - Example of the value of ecosystems
        • New York City water quality had declined to unacceptable levels
        • Authorities chose to restore the polluted Catskill Watershed and reduce sewage and pesticide inputs into catchment
        • Restored Catskill Watershed used natural processes to improve water quality
        • Cost of restoring the watershed was $1-1.5 billion compared with $6-8 billion to build a water treatment plant plus $300 million annual running costs
- - - - Eutrophication
        • Lakes, streams, rivers can become enriched in nutrients
        • Excess nutrients result in growth of plants and algae
        • Excess algal growth reduces the amount of light entering the water body
        • When the plants and algae die and are decomposed, oxygen levels in the water are reduced and fish kills can result
        • Algal blooms can be toxic – risks to stock and humans
    - - NItrogen movement through the land
        • Nitrate is very water soluble
        • Is easily leached from soil
        • Transported by surface runoff
        • Wet and boggy areas stop as much N from entering waterways
      - Contamination of groundwater
        • Nitrate is very water soluble and is easily leached to groundwater
        • Nitrate concentrations in groundwater can reach toxic concentrations
        • Blue Baby Syndrome can occur in infants (Nitrate alters the haemoglobin in blood reducing transport of oxygen)
      - Nitrogen containingatin drinking water in NZ
    - - Managing nutrients
        • Farmer education
        • Reducing inputs
        • Preventing nutrients from being released into waterways
        • Regulatory controls
        
        Regulatory controls
        • Regional councils are increasingly developing rules in regional plans to control nutrients
        • Regional plans are developed under the Resource Management Act
        • Rules
        • Control landuse in sensitive areas
        • Limit the application of fertilisers and wastes containing nitrogen and phosphorous
        • Set limits for the amount of nutrients that can be released
        
        Regional plan changes
        • Manawatu One Plan
        • Aims to protect groundwater and surface water from excess nutrients
        • Intensive farming land uses: dairy farming, commercial vege growing & cropping
        • Farms are allocated a maximum value for nitrogen leaching based on the land use capability class
        • Fiercely contested in Environment Court, now operative
        • Cumulative nitrogen leaching maximum means the total kilograms of nitrogen leached per hectare per year for the total area of a farm (including any land not used for grazing) and is calculated using the values for each land use capability class
        • Land use capability class (LUC) means a classification of a parcel of land in terms of five characteristics or attributes (rock, soil, slope*, erosion, vegetation).
        
        Changes in regional plan: Waikato Regional Plan Livestock exclusion Areas April 2006
        • Stock must be kept out of specified waterways in the region, including:
        • any stream flowing into Lake Taupo
        • streams flowing into a harbour or estuary and within two
        kilometres of the coastal marine area
        • margins of significant wetlands in the region and most Waikato lakes
        • some specified streams on the Coromandel Peninsula and other specified streams throughout the region.
        
        Reducing inputs
        • Only using enough nutrients to meet plant requirements
        • Ensuring nutrients are applied at the right time
        • Developing plants/pasture systems that need less nutrients
        • Breeding cows with smaller bladders?
        • Adjusting fertiliser inputs to consider N concentrations in irrigation water?
        
        Mimicking natural processes
        • Restoring or installing wetlands
        • Creating conditions for bacteria to convert nitrate back to nitrogen gas
        • Floating wetlands in lakes
        • Plants use the excess nutrients and can be harvested
        
        Denitrification walls
        • A barrier wall containing organic material e.g. sawdust is installed to prevent nitrate from leaching to surface water
        • Bacteria in the organic material convert nitrate back to nitrogen gas
        
        Riparian planting and fencing
        • Riparian planting
        • Planting along stream and river banks
        • Recent research indicates may not stop nitrates leaching into surface waters
        • Do prevent phosphorous reaching surface water
        • Fencing and stream crossings
        • Keep animals out of the water
        • Prevents animals from defecating and urinating in water
    - - Issues associated with too much N and P
        • Excess N and P
        • Fertiliser application rates in excess of plant requirements
        • High application rates of effluents
        • Urine patches (N)
        • Accumulation of phosphorous in soil as phosphate binds to soil
        • Contamination of surface and groundwater
        • Eutrophication
        • Contamination of drinking water supplies
        • Toxicity to aquatic organisms
      - Limited supply of phosphorous?
        • Supplies of phosphate rock are limited
        • Concerns that deposits will run out
        • Phosphorous is essential for
        agriculture
        • Alternative sources are being considered
    - - Curing bush sickness
        • 1880’s bush around Tokoroa-Taupo-Rotorua cleared for farming
        • Animals did poorly and often died
        • 1930’s cobalt deficiency discovered
        • Cobalt is needed for vitamin B12
        • Cobalt added to the fertiliser as soils are deficient
        • 250,000 ha of farming and affected
  - - - Palm kernel extract PKE
        • Palm kernel extract is leftover from processing palm oil
        • Imported into NZ as stock feed from South East Asia
        • Biosecurity risk?
        • May alter the nutritional profile of milk
- - - - Biodiversity and Maori
        
        kaitiakitanga (guardianship) is central to the expression of Māori culture and identity, and confers obligations on whānau (family), hapū (sub-tribe) and iwi (tribe) to care for environmental taonga (treasures), including species of indigenous flora and fauna.
        
        Treaty of Waitangi Settlements include innovative co-management and co-governance arrangements for natural resources. Māori are increasingly involved in all aspects of biodiversity management, including conservation and customary and commercial use.
        
        Intrinsic value
        
        Intrinsic value = value an entity has in itself for what it is or as an end
        
        Subjective intrinsic value = something is valued for what it is, rather than what it can bring about
        
        Objective intrinsic value = something has properties or features in virtue of which it is valuable, independent of anyone's attitudes or judgments
    - - Goal A – Address the underlying causes of biodiversity loss by mainstreaming biodiversity across government and society
        Goal B – Reduce the direct pressures on biodiversity and promote sustainable use
        Goal C – Improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity
        Goal D – Enhance the benefits to all from biodiversity and ecosystem services
        Goal E – Enhance implementation through participatory planning, knowledge management and capacity building
      - Predator free New Zealand
        
        Aims to rid NZ by 2050 of introduced predators using a coordinated approach
        
        Eradicate predators by supporting new and existing conservation projects, primary sector pest control and community groups
        
        Supported by government funding
        
        Predator free New Zealand The interim 2025 goals are:
        
        Increase by 1 million hectares the areas where predators are suppressed.
        
        Demonstrate predator removal from more than 20,000-hectare areas of the mainland.
        
        Remove all mammalian predators from offshore island Nature Reserves.
        
        Develop science solutions that lead to the removal of at least one small mammal predator species from the mainland
- - - - DDT: physico-chemical properties and environmental persistence
        
        Persistent organic pollutant (t1/2 ~2 to 50 years)
        
        Hydrophobic (not water soluble), accumulates in soil
        
        Sorbs/partitions to soil organic matter
        
        Degraded by abiotic and biotic processes in soil to form DDE and DDD
        
        Microbial degradation is co-metabolic
        
        Fat soluble  able to bioaccumulate in the food chain
      - Managing DDT residues in soils
        
        Legacy of DDT contamination in soils that is being managed today
        
        Soil testing
        
        Required by milk companies – limit is 0.7 mg/kg
        
        May be required by mortgage lenders
        
        Milk testing
        
        Major milk companies e.g. Fonterra routinely test milk for DDE (metabolite of DDT)
        
        Penalties for milk that exceeds acceptance limit
        
        Meat testing
        
        Grazing management
        
        Managing DDT residues on sheep and beef farms on slide (19)
  - - - Sheep dip contaminants
        
        Organochlorine pesticides
        
        1945 to 1961
        
        Lindane
        
        DDT
        
        Dieldrin
        
        Trace elements
        
        Arsenic (1840-1980)
        
        (copper)
- - - - Pugging causes
        
        poor drainage
        
        the soil will stay softer and wetter making it more susceptible to further pugging
        
        poor plant growth – a reduction in pasture yield
        
        greater fertiliser requirements
        
        more topsoil and contaminant runoff to waterways.
    - - Acceleration of erosion
        
        Loss of forest cover - Pasture absorbs less water than trees
        
        Cultivation
        
        Over-grazing
      - New Zealand is erosion prone
        
        High rainfall
        
        Steep terrain
        
        Unstable rock
        
        North and east of NZ particularly affected
      - Eroded soils
        
        Deposited on flood plains
        
        Deposited onto farmland reducing production
        
        Enters streams and rivers ~ 210 million tonnes annually
        
        Washed out to sea or deposited in estuaries
      - Effects of sedimentation in waterways
        
        Stream turbidity
        
        Reduced light reducing photosynthesis
        
        Habitat loss – changes from gravel to mud
        
        Smothering of benthic organisms and clogging of fish gills
        
        Filling of lakes, estuaries and lower river reaches
    - - High class land
        
        Most high-class land was:
        
        in Canterbury (320,000ha) and Southland (184,000ha) in the South Island
        
        in Waikato (287,000ha) and Manawatu-Wanganui (148,000ha) in the North Island.
        
        Lifestyle blocks occupied 10.1 percent (147,000ha) of New Zealand’s national high-class land.
        
        Auckland (35 percent) and Northland (28 percent) had the highest proportion of high-class land converted to lifestyle blocks by 2011.
        
        Between 1990 and 2008, urban areas occupied an additional 0.5 percent of high-class land.
        
        The Canterbury (4,800ha) and Auckland (2,600ha) regions had the most high-class land converted to urban areas from 1990 to 2008
      - Goverment ignores horticulture industy's call to protect soils from urban sprawl
        
        Pukekohe soils are the city's food basket, and the threat of urban development has Horticulture New Zealand pushing for a food security policy to protect them.
        
        Bharat Jivan is a third-generation grower in Pukekohe who's witnessed the creep of housing into the land he crops. A paddock he hoped to buy has been zoned as 'country-style living', which means its value has tripled.
        
        "That makes it uneconomical to crop on, which is a real shame.“
        
        He says not enough is being done to preserve the high-value soil that provides produce to New Zealanders all year round.
        
        "Early potatoes and spring carrots come solely out of this region. The land needs to be identified as a valuable resource for future generations and preserved for rural production.
        
        "To put houses on it would be a complete waste of a precious resource."
      - Goodbye urban sprawl hello apartments
        
        87% of NZers live in urban areas (DIA data)
        
        72% live in 16 urban centres
        
        33% live in Auckland
        
        House size
        
        NZ average is 195 m2 vs UK average of 85 m2
        
        NZ houses tend to be single storied
        
        Low population density
        
        NZ 2,200 people per square km (ppk^2)
        
        London 5,000 ppk^2
        
        Hong Kong 35,000 ppk^2
    - - Potential sources of soil contamination
        
        Insecticides
        
        Herbicides
        
        Fertilisers
        
        irrigation waters
        
        Veterinary medicines
        
        Beneficial re-use of waste products
        
        Biosolids
        
        compost
        
        Effluents
        Wastewaters
      - Impacts of soil contamination
        
        Animal health
        
        Crop health
        
        Effects on soil function e.g. nutrient cycling
        
        Changes to soil structure
        
        Contamination of agricultural products
        
        LIMITED REMEDIATION OPTIONS ONCE CONTAMINANT CONCENTRATIONS REACH UNACCEPTABLE LEVELS
      - Exposure pathways: plants
        
        Root contact with the solid phase
        
        Root uptake from soil pore water/soil solution.
        
        mass flow of water to root through transpiration
        
        Concentration gradient induced by selective uptake of metal ion
        
        Uptake by symbiotic microorganisms and transfer to root
        
        Plants can excrete compounds that release contaminants from soil
        
        Sorption of volatilised compounds.
        
        Dust deposition and/or incorporation of particulates
      - Accumulation in food chains
        
        Soil →earthworm → bird
        
        Soil →plant →animal
        
        Soil →animal
        
        Extent of accumulation depends on the chemical – Cd and DDT bioaccumulate
        
        Bioaccumulation factor (BAF)
        
        BAF = concentration in biota/concentration in soil
        
        Grazing animals also eat soil
        
        Sheep eat 125g of soil per day
        
        Cattle eat 1 kg of soil per day
        
        Higher soil ingestion rates can occur
        
        muddy conditions
        
        drought
        
        short pasture
        
        feed crops e.g brassicas
        
        DCD
        
        Dicyanmide (DCD) is a nitrification inhibitor
        
        DCD was applied to some farms to prevent leaching of nitrate to water bodies and to reduce greenhouse gas emissions
        
        DCD was found in milk products
        
        Use of DCD on farmland has been suspended
        
        Was the potential for contamination of the food chain considered?
    - - Management strategies for Cd in NZ agricultural soils
        
        Voluntary limits on Cd in phosphate fertilisers 280 mg Cd/kg P
        
        Ministry of Agriculture and Forestry Cadmium Management Strategy 2011
        
        To ensure that cadmium in rural production poses minimal risks to health, trade, land use flexibility and the environment over the next 100 years”.
        
        The strategy’s approach is to focus on the key risk areas of:
        
        Protecting human health.
        
        Maintaining trade access and a vibrant productive agricultural sector.
        
        Maintaining flexibility in land use options.
        
        Protecting the environment, particularly soil health and function, groundwater and natural ecosystems.
      - Options to reduce Cd in NZ agricultural products
        
        Potential mitigation options
        
        Use phosphate fertilisers with low levels of cadmium.
        
        Maintain soil pH at the upper recommended limits for crop type.
        
        Maintain high organic matter in soil.
        
        Alleviate any zinc deficiency in the soil.
        
        Avoid fertiliser blends and irrigation water containing high levels of chloride.
        
        Use crop varieties which have a lower level of cadmium uptake.
  - - - Compaction
        
        Compaction occurs when soil is compressed reducing the air pockets between soil particles
        
        Compaction reduces plant growth
        
        Caused by heavy machinery and livestock
        
        50% of dry stock farms
        
        80% of land used for dairying
        
        Viticultural soil needs to be improved (is easing to more compact soils, increased nutrient loss and a decrease in organic matter)
- - - - Benefits of agro-farming
        
        Erosion control
        
        Habitat for birds and insects
        
        Enhances biodiversity
        
        Carbon sequestration
        
        Profitable
- - - - Types of NZ marine ecosystems
        
        60 distinct ecosystems
        
        Hectares to thousands of km2
        
        Physical factors
        
        Depth, temperature, salinity, substrate, water movement (currents & wave action)
        
        Biological factors
        
        Degree of primary production
        
        Key organisms e.g. kelps and sponges provide structure for other organisms
      - NZ Marine ecosystems
        
        Benthic ecosystems
        
        Saltmarsh, mangroves, beaches, rocky reefs, steep-sided canyons, seamounts, deep-sea abyssal plains and trenches
        
        Pelagic ecosystems
        
        Sunlit photic zone
        
        Dark ocean interior
        
        Cold vents– hydrogen sulphide, methane and hydrocarbon seeps
        
        Hot hydrothermal vents- fissure in the earth’s crust that release hot geothermally heated water, found in volcanically active areas like tectonic plate boundaries
    - - Marine birds
        
        Sea and shore birds
        
        Protection for seabirds was introduced in the 1950's
        
        Threatened with extinction
        
        35% of seabird species - petrels, penguins, shags and terns
        
        57% of shorebird species – e.g. herons and dotterels
        
        Threats
        
        Loss or modification of breeding habitat
        
        Introduced predators eating eggs and young
        
        By catch from fishing
        
        Pollution
      - Fish
        
        Pressure from both recreation and commercial fishing
        
        In 2015 17% of fish stocks were overfished
        
        Either depleted or
        
        Collapsed and needs to be closed
        
        Overfished stocks included - Southern blue fin tuna - Pacific blue fin tuna - Orange roughy - Snapper - John Dory - Scallops
      - Marine mammals
        
        29 species of indigenous marine mammals live and breed in NZ waters
        
        Marine Mammal Protection Act 1978
        
        Lack of data for marine mammals
        
        28% of species are threatened with extinction
        
        31% are not threatened
        
        Threats include:
        
        Entanglement in fishing equipment
        
        Ship strike
        
        Habitat degradation due to blasting and dredging
        
        Marine pollution
    - - Whalers and sealers
        
        1792 Arrival of whalers and sealers
        
        Remaining fur seals hunted to almost extinction by 1830s
        
        1830 whaling for Southern right whale began, 80% caught by 1849
        
        Late 19th and 20th century – sperm whales, humpback whales in NZ waters
        
        Last whale harpooned off the coast of Kaikoura in 1964
      - Comercial fisheries
        
        1841 Maori supplying fresh fish to settlers in Auckland
        
        Commercial fisheries were established in the 1850s
        
        1870 Export of fresh rock oysters to Sydney and canning of grey mullet
        
        1877 Fish Protection Act
        
        Regulations for NZ fisheries including closed areas, seasons and gear restrictions
        
        1899 First fishing trawlers
        
        1930’s export of rock lobsters and crayfish, by late 1930s both fisheries had collapsed
        
        1965 Dredge mussel fishery in Hauraki Gulf collapses due to overfishing
        
        1986 Quota management system introduced
        
        NZ's commercial seafood catch
        
        $1.4 billion per year
        
        400,000 tonnes annually of finfish
        
        77,000 tonnes of invertebrates (80% squid)
        
        Figures exclude aquaculture and bycatch
      - Aquaculture
        
        Expanding industry in New Zealand began in 1960s
        
        Green lipped mussels and oysters ~ 56,000 tonnes per year
        
        Salmon ~ 14,000 tonnes per year
        
        Two native species
        
        Kingfish
        
        Hāpuku
    - - New Zealand’s top marine issues
        
        Identified by the Ministry for the Environment in 2016
        
        Global greenhouse gas emissions are causing ocean acidification and warming
        
        Native marine birds and mammals are threatened with extinction
        
        Coastal marine habitats and ecosystems are degraded
  - - - Global demand for fish protein
        
        Land resources are increasingly scarce to support growing global population
        
        Seafood currently supplies 17% of global animal protein
        
        Seafood is a highly regarded source of protein containing essential nutrients including omega-3 fatty acids
        
        FAO data for the last 30 years
        
        Capture fisheries have increased from 69 to 93 million tonnes
        
        Global aquaculture production has increased from 5 million to 63 million tonnes
      - Globally fish are not just fed to humans
        
        Fishmeal
        
        Animal feed
        
        Fertilisers
        
        Aquaculture
        
        Fish oil
        
        Animal feed
        
        Aquaculture
        
        Human supplements
      - Fishing and the NZ economy
        
        Fishing and aquaculture worth $896 million to NZ economy
        
        47,000 jobs
        
        Kaimoana top export commodity for Māori authorities ($304 million)
        
        Informal economy
        
        1/3 NZers recreationally, fish, dive or harvest shellfish
        
        Major fisheries in New Zealand
        
        Squid
        
        Hoki
        
        Ling
        
        These three 66% of commercial wold harvest
        
        Orange roughy
        
        Rock lobster
        
        Paua
        
        Commercial fisheries are managed by
        
        Quota Management System
        
        100 species
        
        638 fish stocks
        
        Ministry of Primary Industries sets annual catch limits for quota management species
        
        Aim is sustainable fisheries
        
        Recreational fisheries
        
        Fisheries (Amateur Fishing Regulations) 2013
        
        7 fishing areas
        
        Area specific regulations may apply
        
        Common regulations
        
        Illegal to sell or trade recreational catch
        
        Daily catch limits apply
        
        Legal size limits apply
        
        Areas may be closed or restricted
        
        Rules for set netting, set lining and spear fishing
        
        Customary management of fisheries
        
        Taiapure is a local management tool established in an area that has customarily been of special significance to an iwi or hapu as a source of food or for spiritual or cultural reasons (s 174 of the Fisheries Act).
        
        Taiapure can be established over any area of estuarine or coastal waters to make better provisions for rangatiratanga
        
        All fishing (including commercial fishing) can continue in a taiapure
        
        Mātaitai reserves provide for customary fishing use and management practices.
        
        developed and managed by local iwi/hapū with MPI, applying customary management and food gathering practices.
        
        Commercial methods of catching fish
        
        Set nets
        
        Longlines
        
        Very long lines with many baited hooks
        
        Pulled through the water
        
        Fin fish
        
        Trawling
        
        Large nets are towed along the seafloor
        
        Shallow and deep waters
        
        e.g Hoki and squid
        
        Dredging
        
        Heavy metal baskets towed along the seafloor
        
        Scallops and oysters
    - - Fishing pressures on marine ecosystems
        
        Damage to habitats by dredging and trawling
        
        By-catch - Accidental death of non-target species
        
        Changes to diversity - Removal of too many target and non-target species
      - Habitat damage
        
        Trawling and dredging are “the two most destructive fishing methods used in New Zealand” (MfE, 2016)
        
        Commercial trawling and dredging tows have decreased since the 1990s
        
        Disturb sediment
        
        Damage corals
        
        By-catch seabed species including crustaceans and brittle stars
        
        Damage is dependent on
        
        Type, weight and size of equipment
        
        Towing speed
        
        Type of seabed habitat
      - By-catch
        
        Marine organisms un-intentionally caught during fishing
        
        MPI has rules in place to minimise by-catch and observers are placed on commercial fishing boats
        
        Birds, whales, dolphins, seals, fish, crustaceans, shellfish….
        
        Longlines – seabirds attracted to hooked bait and become entangled in the lines
        
        Trawling – seabirds collide with trawling equipment
        
        Set nets – seabirds and marine mammals become entangled and drown in the nets
      - Marine protected areas - Marine reserves - Highest level of protection
        
        Marine mammal sanctuaries - Restricted commercial fishing and restrictions on methods of recreational fishing
        
        Recreational fishing parks (proposed) - Restricted commercial fishing - Proposed for Hauraki Gulf and Marlborough Sounds
        
        Marine Protected Areas Act (proposed)
        
        Under consultation
        
        Marine reserves
        
        Species-specific sanctuaries - Rule focus on protecting species
        
        Seabed reserves - Prohibitions on seabed mining, trawl and dredge fishing
        
        Recreational fishing parks
      - Aquaculture
        
        Fastest growing primary industry globally
        
        Efficient way to produce protein
        
        Require 14 kg of grain to produce 1kg of fish protein vs 62 kg of grain for 1 kg of beef
        
        NZ: ~20,000 ha of allocated water space
        
        open ocean
        
        near shore
        
        Aquaculture species cultured globally
        
        Seaweeds and algae
        
        fin fish
        
        molluscs
        
        Crustaceans
        
        Invertebrates
        
        frogs
        
        Marine and freshwater
        
        New Zealand aquaculture
        
        Salmon
        
        Oysters
        
        Green lipped mussels
        
        Paua
        
        Algae
        
        Crayfish
      - Fed vs non-fed species
        
        Non-fed species
        
        Feed on naturally occurring materials from their culture environment
        
        Bivalves – oysters, mussels
        
        Fed species
        
        Fish
        
        Grain/plant protein
        
        Waste products
        
        Wild harvested fish
        
        Cultured plankton & seafood
      - Adverse effects of aquaculture
        
        Depends on the production system and species
        
        Benthic accumulation of debris
        
        alter the seafloor/habitats
        
        Smother benthic species
        
        Increased nutrients which can lead to algal blooms
        
        Alter the water chemistry stressing or killing other organisms
        
        Filter feeders can reduce the availability of food for other organisms
        
        Biosecurity risks
        
        Effects on marine mammals and seabirds - Noise, light and entanglement
        
        Effects from chemicals used in aquaculture
        
        Effects of escaped farmed species upon the environment
        
        Wild fish interactions ‐ aquaculture effects on nonfarmed fish populations
        
        Hydrodynamic alteration of flows ‐ aquaculture effects on the water movement at scales greater
        
        Chemicals used in aquaculture
        
        Depends on the species and the country’s regulations
        
        Alter the water chemistry
        
        Control diseases - Antibiotics - Anti-fungals
        
        Enhance growth - Hormones
        
        Pesticides - Control unwanted fish species - Sea lice - Parasites
      - Multi-species aquaculture
        
        Integrated multi-trophic aquaculture
        
        Growing finfish, plants, invertebrates and shellfish together
        
        Mimicking food chains - One species feeds on the waste products of another
        
        Canadian example - Salmon, kelp and blue mussels - Blue mussels fed on particulate wastes including feed pellets from salmon - Kelp absorbed dissolved nutrients from the water - Reduced waste products and decreased risk of algal blooms
  - - - Macroplastics
        
        Visible plastic debris
        
        Mistaken for food
        
        Wildlife can become entangled
        
        40% increase in entanglement in last 10 years
        
        Large plastic debris is a problem for NZ wildlife
        
        Adverse effects: Ingestion
        
        Microplastics can be ingested by aquatic organisms
        
        Similar size to food items like plankton and fish eggs
        
        Filter and benthic feeders particularly susceptible
        
        Adverse Effects
        
        Feeding
        
        Movement, growth & reproduction
        
        Transfer from prey to predator has been documented
      - Microplastics
        
        Plastic particles < 1-10 mm - NOAA Definition < 5 mm
        
        Primary microplastics - Plastic pellets
        
        Secondary microplastics - Formed from breakdown of larger plastic items
      - Secondary microplastics
        
        Larger pieces of plastic are broken down by
        
        Sunlight
        
        Wind and wave action
        
        Friction on beaches
        
        Includes fibres released from clothing during washing
        
        Nylon
        
        Polar fleece
    - - Chatham Rise phosphorite nodules
        
        Proposed as an alternate source of phosphate for NZ farming
        
        Would have been a global first for mining at these depths
        
        Proposal would involve
        
        Mining 1050 km2 of seabed off the coast of Christchurch
        
        Depths of 250 to 450 m
        
        Method involved a suction hopper dredge and discharging the tailings back onto the seabed
        
        Environmental Protection Agency declined the application
        
        "cause significant and permanent adverse effects”
        
        Destruction of habitat and rare and vulnerable ecosystems
        
        Adverse effects could not be mitigated
        
        Mining proposed to take place in the Mid Chatham Rise Benthic Protection Area
      - Adverse effects of oil spills
        
        Shipping or extraction accidents
        
        Little bit of oil can go a very long way
        
        Depends on type of oil – heavy fuel oils versus light fuel oils
        
        Toxicity to fish and invertebrates
        
        Smothering of habitats
        
        Coating of birds and marine mammals
        
        Reduces insulating and water repelling properties of feathers and fur
        
        Oil dispersants and methods to remove oil can also be very damaging
      - MV Rena disaster
        
        October 2011 MV Rena struck the Astrolabe Reef off the coast of Tauranga
        
        Ship was carrying 1368 containers and 1733 tonnes of heavy fuel oil
        
        ~ 400 tonnes of fuel oil leaked, the rest was recovered from the ship
        
        Oiled wildlife and oil on the beaches
        
        Rare dotterels were relocated as a precautionary measure
        
        2000 seabird deaths
        
        Estimated 20,000 seabirds affected by oil spill
        
        Captain and navigation officer were sentenced to 7 months in prison
    - - Invasive marine species
        
        Drift on ocean currents and ocean debris
        
        Ships and yachts
        
        Ballast water
        
        Hulls of boats
        
        Deliberately introduced?