Textbook:
Biological Oceanography: An Introduction, C.M. Lalli, T.R. Parsons, Elsevier, Open University Oxford, 2000. Chapter 4
Basic ecological divisions of the sea
(Lalli & Parsons 1995) Marine communities
Plankton: passively drifting, despite some smale scale movements Virioplankton Bacterioplankton (Bacteria + Archaea) Mycoplankton Phytoplankton Protozooplankton / Metazooplankton
Nekton: actively moving against currents Benthos: living in the benthal. Phytobenthos, Zoobenthos, Bacteriobenthos (Bacteria,Archaea)
Holoplankton: entire life cycle as plankton Meroplankton: only partially planktonic life cycle
Size classes of the plankton
(Sieburth 1978) A marine pelagic food web
(Garrison 1999)
Classic food chain, microbial loop and viral loop
Microbial Loop Phytoplankton Zooplankton Fish „herbivorous“ carnivorous
dissolved organic material
viruses
protozoans
sinking Phytoplankton, marine snow heterotrophic sinking bacteria fecal pellets Abundances of groups of planktonic organisms
Copepods <20 L-1 <102 L-1 Cladocerans <60 L-1 <102 L-1 Rotifers <500 L-1 <103 L-1 Ciliates <100 mL-1 <105 L-1 Flagellates <1000 mL-1 <106 L-1 Algae <1000 mL-1 <106 L-1 Bacteria <1-10 Mio mL-1 <1010 L-1
Zooplankton sampling devices
Niskin bottles mounted on a CTD (conductivity, temperature, depth) Zooplankton sampling devices
Common hand net Big net
Zooplankton sampling devices
Bongo net Multi-net Major taxonomic groups of the zooplankton 1
Realm Protista
Phylum Flagellata
often mixotrophic (Euglenophyta, Dinophyta, Cryptophyta, Chromophyta)
Phylum Rhizopoda
Class Amoebina, naked Amoebae, mainly benthic, few planktonic forms. “ Testacea, mainly benthic, wenige few planktonic forms. “ Foraminifera, strictly marine, calcium carbonate frustule, mainly benthic but several planktonic forms. “ Heliozoa, mainly limnetic “ Radiolaria, strictly marine, silicate frustule, mainly planktonic.
Phylum Ciliata
Besides flagellates most important group of the marine protozooplankton
Protozooplankton (Foraminifera) Protozooplankton (Foraminifera)
Protozooplankton (Foraminifera) Protozooplankton (radiolariens)
Protozooplankton (ciliates)
Strombidium capitatum
Vorticella sp. Major taxonomic groups of the zooplankton 2
Realm Animalia
Phylum Cnidaria
Class Hydrozoa, manly marine, planktonic stage (medusa, gellyfish), benthic stage (polyp), order Siphonophora strictly planktonic.
“ Scyphozoa, strictly marine.
Phylum Ctenophora, strictly marine.
Phylum Nemathelminthes
Class Rotatoria (rotifers), important limnetic group, very few marine forms, reproduction by parthenogenesis.
Phylum Chaetognata (arrow worm), strictly marine. predator
Phylum Mollusca
Class Gastropoda (snails), few holoplanktonic forms (Pteropoda). “ Cephalopoda (octopus), strictly marine, smallest forms are transient to the nekton.
Major taxonomic groups of the zooplankton 3
Realm Animalia ff
Phylum Annelida
Class Polychaeta, few marine planktonic forms.
Stamm Arthropoda
Class Crustacea Subclass Phyllopoda, mainly limnetic, important group of the limnetic zooplankton, reproduction by parthenogenesis. “ Copepoda, important group of the zooplankton. “ Decapoda, important group of the marine zooplankton. Euphausiacea (Krill), important order of the decapods.
Phylum Chordata Sub-phylum Tunicata
Class Appendicularia, important group of the marine zooplankton. “ Thaliacea, important group of the marine zooplankton. Major taxonomic groups of the zooplankton 4
Meroplanktonic Larvae of:
Benthic animals
(Trochophora-larvae of polychaetes, Nemertini, Sipunculidae, bryozoans) Veliger-larvae, of Bivalvia (shells), Gastropods (snails), Pluteus-arvae, of seeurchins, Bipinnaria-larvae, of starfish, Nauplii, Zoea, Megalopa of benthic crustaceans.
Insekts (Chaoborus)
Fish
Meroplankton
Lalli & Parsons 1995 Metazooplankton (hydrozoans)
Polyorchis sp.
Eutonina sp.
Mitrocoma sp.
Cnidaria (syphonophores)
Lalli & Parsons 1995 Metazooplankton (hydrozoans)
Syphonophora
Physophora sp.
Ctenophora
Hormiphora sp.
Bolinopsis vitrea.
Pleurobrachia sp. Chaetognath (arrow worm) (Sagitta elegans)
Lalli & Parsons 1995
Chaetognath
Syphonophora Staatsqualle Pteropoda
Corolla spectabilis
Polychaeta Crustacea
Lalli & Parsons 1995 Hirche 1995
Copepods
Hirche 1995 Crustacea (copepods)
Paraeuchaeta elongata
Paraeuchaeta norvegica
Copepoda
Eurytemora Pseudodiaptomus inopinus affinis
Cyclopoidea Calanoidea Paired egg cluster 1 egg cluster Krill (Decapoda, Euphausiaceae)
Euphausia superba
Food web in the Southern Ocean
Lalli & Parsons 1995 Tunicata, Appendicularia
Oikopleura sp.
Tunicata, Appendicularia
Oikopleura sp. Tunicata, Thaliaceae (salps)
Cyclosalpa affinis
Tunicata, Thaliaceae (salps)
Iasis zonaria Alternation of generations Tunicata, Thaliaceae
Cyclosalpa bakeri Cyclosalpa affinis
Tunicata, Thaliaceae
Cyclosalpa sp. Tunicata, pyrosomes
Pyrosoma tuberculata.
Diel vertical migration of the zooplankton
Lalli & Parsons 1995 Diel vertical migration of the zooplankton
Lalli & Parsons 1995
Diel vertical migration of the zooplankton
Lalli & Parsons 1995 Saisonal vertical migration of the zooplankton
Lalli & Parsons 1995
Trophic levels in food webs– unproductive regions
6 levels Unproductive regions Primary producers: nano- and picophytoplankton. Many transfer steps with low size increments.
Lalli & Parsons 1995 Trophic levels in food webs – continental shelf
4 levels Continental shelf, Primary producers: microphytoplankton. Transfer steps with medium size increments.
Lalli & Parsons 1995
Trophic levels in food webs – upwelling regions
3 levels Upwelling regions, nutrient rich Primary producers: macrophytoplankton. Few transfer steps with large size increments.
Lalli & Parsons 1995