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
Top Related