Ecosystem effects of mining Dr Matt Pinkerton Presentation to the - - PowerPoint PPT Presentation

Ecosystem effects of mining Dr Matt Pinkerton

Presentation to the EPA DMC – Chatham Rock Phosphate Wednesday 15 October 2014

Ecosystem effects of mining

2 Direct effects Habitat- mediated effects Ecosystem effects

• Direct mortality from mining
• peration
• Impacts of the sediment plume
• Other direct impacts (noise etc)
• Species / life-stages may be

impacted by change of habitat Effects on individual species Food-web

3

T h e r m

• c

l i n e

Primary production Bacteria, detritus Viruses Micro-zooplankton Meso-zooplankton Macro-zooplankton Mesopelagic fish Cephalopods Meroplankton Vertical detrital flux Hyperbenthos Benthos

• Ocean colour remote sensing
• Phytoplankton incubations (NPP)
• Underway surface bio-optics
• Nutrient analysis
• Flow cytometry
• Bacterial activity
• Water column structure
• Stable isotope analysis
• Lipid biomarkers
• Zooplankton grazing experiments
• Zooplankton nets
• MOCNESS (fine-mesh towed nets)
• Midwater trawling
• Opening-closing cod-end
• Multi-frequency acoustics
• Acoustic target strength analyses
• Thorium isotopes
• Hyperbenthic trawls (Brenke sled)
• Benthic trawls (beam trawls)
• DTIS (Deep-towed Imaging System)
• Multicorer
• Sediment traps (moored, floating)
• Benthic landers
• …

Components

• f food-web

Measurements

Mixed layer Meso- pelagics Hyperbenthics Demersals Benthos

4 Day Dusk Night

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• Midwater catch >134 species
• >23 mesopelagic fish species

Bathylagidae Bathylagus longirostris Bramidae Brama brama Diretmidae Diretmus argenteus Gonostomatidae Margrethia obtusirostra Macrouridae Lepidorhynchus denticulatus Myctophidae Diaphus danae Myctophidae Diaphus osterfeldi Myctophidae Electrona carsbergi Myctophidae Electrona paucirastra Myctophidae Electrona risso Myctophidae Electrona subaspera Myctophidae Gymnoscopelus piabilis Myctophidae Lampanyctodes hectoris Myctophidae Lampanyctus australis Myctophidae Lampanyctus intricarius Myctophidae Lampichthys procerus Myctophidae Protomyctophum andriashevi Myctophidae Protomyctophum luciferum Myctophidae Protomyctophum normani Myctophidae Symbolophorus spp. C Phosichthyidae Photichthys argenteus Platytroctidae Perspasia kapua Serrivomeridae Serrivomer samoensis Sternoptychidae Argyropelecus gigas Sternoptychidae Argyropelecus hemigymnus Sternoptychidae Maurolicus australis Sternoptychidae Sternoptyx obscura Stomiidae Chauliodus sloani Stomiidae Idiacanthus atlanticus Stomiidae Stomias boa boa amphipod Cyphocaris richardi amphipod Gammaridae amphipod Themisto gaudichaudii amphipod Vibilia robusta decapod Acanthephyra pelagica decapod Gennades gilchristi decapod Oplophorus novaezeelandiae decapod Pasiphaea australis decapod Pasiphaea balssi decapod Pasiphaea sp. (barnardi) decapod Sergestes arcticus decapod Sergia potens euphausiid Euphausia similis euphausiid Euphausia spinifera euphausiid Nematoscelis megalops jellyfish Mitrocomella sp. jellyfish Polaria rufescens? jellyfish Periphylla periphylla mysid Neognathophausia ingens pteropod Cymbulia peroni house pyrosoma Pyrosoma sp. salp Iasis zonaria salp Thetys vagina siphonophora Hippopodius hippopus squid Histioteuthis hoylei squid Iridoteuthis maoria squid Teuthowenia pellucida arrow squid Nototodarus sloani warty squid Moroteuthis ingens, M. robsoni red squid Ommastrephes bartrami giant squid Architeuthis

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• Organisms have different ranges / movement capabilities
• Not one “Chatham Rise food-web”
• Trophic model considers large area: 222,800 km2
• Mainly bounded by 1250 m and 250 m depth contours

Chatham Rise: defining the study area for the trophic model

Chatham Rise food-web (trophic) model

7

Trophic importance: overall importance of group in food-web

8

Ecosystem effects of mining

9 Direct effects Habitat- mediated effects Ecosystem effects

• Direct mortality from mining
• peration
• Impacts of the sediment plume
• Other direct impacts (noise etc)
• Species / life-stages may be

impacted by change of habitat Effects on individual species Food-web

Direct and habitat-mediated impacts

10

Rank trophic importance Group Location of spawning/early life stages. Habitat dependence. Likely direct effects of mining/plume on productive capacity 1 Phytoplankton Whole Chatham Rise; planktonic. No significant impact. 2 Detritus benthic Not relevant – no spawning Negligible impact on in/out flows of detritus at scale of Chatham Rise. 3 Detritus water Not relevant – no spawning Negligible impact on in/out flows of detritus at scale of Chatham Rise. 4 Mesozooplankton Can reproduce in water column or

• n/near the seabed. Planktonic.

Probably low overall. 5 Small demersal fish Not known – diverse group. Likely to vary between species. Some may require hard benthic substrate for spawning/early life stages. Not known, but could be high if key species in group spawn in/close to mining area. 6 Hoki Spawn outside Chatham Rise area. Early life stages widespread in area. Low direct impact. 7 Het. flagellates Whole Chatham Rise; planktonic. Negligible impact at scale of Chatham Rise. 8 Arthropods (e.g. prawns & shrimps) Unlikely to move large distances. May depend on habitat (hard or soft) to

• spawn. Early life stages planktonic.

Probably low. 9 Meiobenthos Whole Chatham Rise; very small scale movement. Negligible impact at scale of Chatham Rise. 10 Bacteria_water Whole Chatham Rise; planktonic. Negligible impact on bacteria at scale of Chatham Rise. 11 Mesopelagic fish All likely to be pelagic spawners. Early life stages planktonic. Probably low, but not well known for most species in group.

Direct and habitat-mediated impacts

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Rank trophic importance Group Location of spawning/early life stages. Habitat dependence. Likely direct effects of mining/plume on productive capacity 12 Macrozoo krill May be pelagic or benthic spawners. May require benthic habitat. Semi-nektonic. Not known, but could be high if key species in group spawn in/close to mining area. 13 Macrozoo gelatinous Largely/entirely planktonic and likely to be pelagic spawners. Early life stages planktonic. Probably low. 14 Cephalopods Poorly known. Likely to vary between species and some may require had benthic habitat for spawning/early life-stages. Not known, but could be high if key species in group spawn in/close to mining area. 15 Macrobenthos Whole Chatham Rise. Small scale

• movement. Spawning will depend on

suitable habitat (hard or soft). Likely low at scale of Chatham Rise for group as a whole, but some species in group may occur only close to mining areas 16 Rattails & ghost sharks Ecology not well known. Could make spawning migrations. Spawning could depend on hard benthic habitat. Not known, but could be high if key species in group spawn in/close to mining area. 17 Hake guild Hake spawning not near mining area. Spawning/juvenile areas of other species in guild less well known. Probably low for hake. Not known for other species in guild. 18 Bacteria sediment Whole Chatham Rise Negligible impact on bacteria at scale of Chatham Rise. 19 Ling guild Ling spawning not in mining area. Spawning/juvenile areas for other species in guild less well known. Probably low for ling (though reasons for hotspot not known). Not known for other species in guild.

Conclusions

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• 1. Model / trophic importance limitations
• 2. Higher ecosystem effects associated with impacts on species with:
• 3. Anticipated direct/habitat-mediated impacts of mining on 10 of the 11 groups with

the highest trophic importances are likely to be low or negligible (because they are widely spread over the Chatham Rise or planktonic)

• 4. The four trophic groups with the highest direct/habitat-mediated risk from mining

and high trophic importances are likely to be:

• Trophic model – no habitat
• Not dynamic; not spatially resolved
• Small number of trophic groups
• Focus on major energy flows

Conclusions

13

• 1. Model / trophic importance limitations
• 2. Higher ecosystem effects associated with impacts on species with:
• 3. Anticipated direct/habitat-mediated impacts of mining on 10 of the 11 groups with

the highest trophic importances are likely to be low or negligible (because they are widely spread over the Chatham Rise or planktonic)

• 4. The four trophic groups with the highest direct/habitat-mediated risk from mining

and high trophic importances are likely to be:

• higher trophic importance
• providers of structured benthic habitat
• spawning / early life stages have particular dependence on the region of mining
• known/likely dependence on hard (structured) benthic habitat
• Trophic model – no habitat
• Not dynamic; not spatially resolved
• Small number of trophic groups
• Focus on major energy flows

Conclusions

14

• 1. Model / trophic importance limitations
• 2. Higher ecosystem effects associated with impacts on species with:
• 3. Anticipated direct/habitat-mediated impacts of mining on 10 of the 11 groups with

the highest trophic importances are likely to be low or negligible (because they are widely spread over the Chatham Rise or planktonic)

• 4. The four trophic groups with the highest direct/habitat-mediated risk from mining

and high trophic importances are likely to be:

• higher trophic importance
• providers of structured benthic habitat
• spawning / early life stages have particular dependence on the region of mining
• known/likely dependence on hard (structured) benthic habitat
• Trophic model – no habitat
• Not dynamic; not spatially resolved
• Small number of trophic groups
• Focus on major energy flows

Conclusions

15

• 1. Model / trophic importance limitations
• 2. Higher ecosystem effects associated with impacts on species with:
• 3. Anticipated direct/habitat-mediated impacts of mining on 10 of the 11 groups with

the highest trophic importances are likely to be low or negligible (because they are widely spread over the Chatham Rise or planktonic)

• 4. The four trophic groups with the highest direct/habitat-mediated risk from mining

and high trophic importances are likely to be:

• small demersal fish
• hard-bodied macrozooplankton (krill)
• cephalopods
• rattails & host sharks
• higher trophic importance
• providers of structured benthic habitat
• spawning / early life stages have particular dependence on the region of mining
• known/likely dependence on hard (structured) benthic habitat
• Trophic model – no habitat
• Not dynamic; not spatially resolved
• Small number of trophic groups
• Focus on major energy flows

Conclusions

16

• 1. Model / trophic importance limitations
• 2. Higher ecosystem effects associated with impacts on species with:
• 3. Anticipated direct/habitat-mediated impacts of mining on 10 of the 11 groups with

the highest trophic importances are likely to be low or negligible (because they are widely spread over the Chatham Rise or planktonic)

• 4. The four trophic groups with the highest direct/habitat-mediated risk from mining

and high trophic importances are likely to be:

• higher trophic importance
• providers of structured benthic habitat
• spawning / early life stages have particular dependence on the region of mining
• known/likely dependence on hard (structured) benthic habitat
• Trophic model – no habitat
• Not dynamic; not spatially resolved
• Small number of trophic groups
• Focus on major energy flows
• small demersal fish
• hard-bodied macrozooplankton (krill)
• cephalopods
• rattails & host sharks