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

operation

• 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

Thermocline

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

of food-web Measurements

Mixed

layer

Meso-

pelagics

Hyperbenthics

Demersals

Benthos

4

Day

Dusk

Night

5

• 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

6

• 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

operation

• 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 on/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

11

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

12

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