Ecosystem effects of mining Dr Matt Pinkerton Presentation to the EPA DMC – Chatham Rock Phosphate Wednesday 15 October 2014
Ecosystem effects of mining • Direct mortality from mining operation Direct • effects Impacts of the sediment plume Effects on • Other direct impacts (noise etc) individual species Habitat- • Species / life-stages may be mediated impacted by change of habitat effects Ecosystem effects Food-web 2
Components Measurements of food-web • Ocean colour remote sensing Primary production • Phytoplankton incubations (NPP) • Underway surface bio-optics • Nutrient analysis Bacteria, detritus Mixed • Flow cytometry Viruses layer • Bacterial activity Micro-zooplankton • Water column structure • Stable isotope analysis • Lipid biomarkers Meso-zooplankton • Zooplankton grazing experiments Macro-zooplankton • Zooplankton nets Meso- • MOCNESS (fine-mesh towed nets) Mesopelagic fish pelagics T • Midwater trawling h Cephalopods e r • Opening-closing cod-end m Meroplankton o • Multi-frequency acoustics c l i n • Acoustic target strength analyses e • Thorium isotopes • Hyperbenthic trawls (Brenke sled) Vertical detrital flux Hyperbenthics • Benthic trawls (beam trawls) • DTIS (Deep-towed Imaging System) Demersals • Multicorer • Sediment traps (moored, floating) Hyperbenthos • Benthic landers • … Benthos Benthos 3
Day Dusk Night 4
• Midwater catch >134 species • >23 mesopelagic fish species amphipod Cyphocaris richardi Bathylagidae Bathylagus longirostris amphipod Gammaridae Bramidae Brama brama amphipod Themisto gaudichaudii Diretmidae Diretmus argenteus amphipod Vibilia robusta Gonostomatidae Margrethia obtusirostra decapod Acanthephyra pelagica decapod Gennades gilchristi Macrouridae Lepidorhynchus denticulatus decapod Oplophorus novaezeelandiae Myctophidae Diaphus danae decapod Pasiphaea australis Myctophidae Diaphus osterfeldi decapod Pasiphaea balssi Myctophidae Electrona carsbergi decapod Pasiphaea sp. (barnardi) Myctophidae Electrona paucirastra decapod Sergestes arcticus Myctophidae Electrona risso decapod Sergia potens Myctophidae Electrona subaspera euphausiid Euphausia similis Myctophidae Gymnoscopelus piabilis euphausiid Euphausia spinifera Myctophidae Lampanyctodes hectoris euphausiid Nematoscelis megalops Myctophidae Lampanyctus australis jellyfish Mitrocomella sp. Myctophidae Lampanyctus intricarius jellyfish Polaria rufescens? Myctophidae Lampichthys procerus jellyfish Periphylla periphylla Myctophidae Protomyctophum andriashevi mysid Neognathophausia ingens Myctophidae Protomyctophum luciferum pteropod Cymbulia peroni house Myctophidae Protomyctophum normani pyrosoma Pyrosoma sp. Myctophidae Symbolophorus spp. C salp Iasis zonaria Phosichthyidae Photichthys argenteus salp Thetys vagina Platytroctidae Perspasia kapua siphonophora Hippopodius hippopus Serrivomeridae Serrivomer samoensis squid Histioteuthis hoylei Sternoptychidae Argyropelecus gigas squid Iridoteuthis maoria Sternoptychidae Argyropelecus hemigymnus squid Teuthowenia pellucida Sternoptychidae Maurolicus australis arrow squid Nototodarus sloani Sternoptychidae Sternoptyx obscura warty squid Moroteuthis ingens, M. robsoni Stomiidae Chauliodus sloani red squid Ommastrephes bartrami Stomiidae Idiacanthus atlanticus 5 giant squid Architeuthis Stomiidae Stomias boa boa
Chatham Rise: defining the study area for the trophic model • Organisms have different ranges / movement capabilities • Not one “Chatham Rise food - web” • Trophic model considers large area: 222,800 km 2 • Mainly bounded by 1250 m and 250 m depth contours 6
Chatham Rise food-web (trophic) model 7
Trophic importance: overall importance of group in food-web 8
Ecosystem effects of mining • Direct mortality from mining operation Direct • effects Impacts of the sediment plume Effects on • Other direct impacts (noise etc) individual species Habitat- • Species / life-stages may be mediated impacted by change of habitat effects Ecosystem effects Food-web 9
Direct and habitat-mediated impacts Group Location of spawning/early life stages. Likely direct effects of mining/plume on Rank Habitat dependence. productive capacity trophic importance Whole Chatham Rise; planktonic. No significant impact. 1 Phytoplankton Not relevant – no spawning Negligible impact on in/out flows of detritus at scale of Chatham Rise. 2 Detritus benthic Not relevant – no spawning Negligible impact on in/out flows of detritus at scale of Chatham Rise. 3 Detritus water Can reproduce in water column or Probably low overall. on/near the seabed. Planktonic. 4 Mesozooplankton Not known – diverse group. Likely to Not known, but could be high if key species vary between species. Some may in group spawn in/close to mining area. require hard benthic substrate for Small demersal spawning/early life stages. 5 fish Spawn outside Chatham Rise area. Early Low direct impact. life stages widespread in area. 6 Hoki Whole Chatham Rise; planktonic. Negligible impact at scale of Chatham Rise. 7 Het. flagellates Unlikely to move large distances. May Probably low. Arthropods (e.g. depend on habitat (hard or soft) to prawns & spawn. Early life stages planktonic. 8 shrimps) Whole Chatham Rise; very small scale Negligible impact at scale of Chatham Rise. movement. 9 Meiobenthos Whole Chatham Rise; planktonic. Negligible impact on bacteria at scale of Chatham Rise. 10 Bacteria_water All likely to be pelagic spawners. Early Probably low, but not well known for most Mesopelagic 11 fish life stages planktonic. species in group. 10
Direct and habitat-mediated impacts Group Location of spawning/early life stages. Likely direct effects of mining/plume on Rank Habitat dependence. productive capacity trophic importance May be pelagic or benthic spawners. May Not known, but could be high if key species Macrozoo require benthic habitat. Semi-nektonic. in group spawn in/close to mining area. 12 krill Largely/entirely planktonic and likely to be Probably low. pelagic spawners. Early life stages Macrozoo planktonic. 13 gelatinous Poorly known. Likely to vary between Not known, but could be high if key species species and some may require had benthic in group spawn in/close to mining area. habitat for spawning/early life-stages. 14 Cephalopods Whole Chatham Rise. Small scale Likely low at scale of Chatham Rise for movement. Spawning will depend on group as a whole, but some species in suitable habitat (hard or soft). group may occur only close to mining areas 15 Macrobenthos Ecology not well known. Could make Not known, but could be high if key species spawning migrations. Spawning could in group spawn in/close to mining area. Rattails & depend on hard benthic habitat. 16 ghost sharks Hake spawning not near mining area. Probably low for hake. Not known for other Spawning/juvenile areas of other species species in guild. in guild less well known. 17 Hake guild Whole Chatham Rise Negligible impact on bacteria at scale of Chatham Rise. Bacteria 18 sediment Ling spawning not in mining area. Probably low for ling (though reasons for Spawning/juvenile areas for other species hotspot not known). Not known for other in guild less well known. species in guild. 19 Ling guild 11
Conclusions • Trophic model – no habitat 1. Model / trophic importance limitations • Not dynamic; not spatially resolved • Small number of trophic groups • Focus on major energy flows 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: 12
Conclusions • Trophic model – no habitat 1. Model / trophic importance limitations • Not dynamic; not spatially resolved • Small number of trophic groups • Focus on major energy flows 2. Higher ecosystem effects associated with impacts on species with: • 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 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: 13
Recommend
More recommend
