Plankton and Plankton Communities Flashcards
how are zooplankton important in terms of fisheries?
larval survival and dispersal -> e.g. artic krill, jellyfish
how are zooplankton a nuisance?
to aquaculture, fisheries and bathing
what are holoplankton?
spend whole lifecycle in the plankton
what are meroplankton?
spend part of life in plankton (e.g.) fish larvae
what are the names of the categories which define zooplankton with depth?
pleuston
neuston
tychopelagic
what are pleuston?
zooplankton which float on surface of the water
what is an adaptation of pleuston?
UV protection pigments e.g. Man o’ War jellyfish
what are neuston?
zooplankton found near the surface of the water
- movement affected by water
what are tychopelagic?
normally live on the bottom, sometimes stirred up/swim up
what are the size categories for plankton?
nanoplankton microplankton mesoplankton macroplankton megaplankton
how big are nanoplankton?
2 to 20 um
how big are microplankton?
20 to 200 um
how big are mesoplankton?
0.2 to 20mm
how big are macroplankton?
2 to 20cm
how big are mega plankton?
> 20cm
what size categories of plankton are most phytoplankton and protists?
nanoplankton and microplankton
what are the groups of plankton?
diatoms Forminifera and radiolaria Ciliophora Copepods Euphasiids Molluscs Polychaeta Chaetognatha Echinoderm, gastropod believe and polychaete larvae Fish eggs and larvae Medusa of scyphozoa
primary factors which affect planktonic communities
solar radiation, nutrient concentrations
secondary factors which affect planktonic communities
upwelling turbulence grazing intensity water turbidity temperature
what is a WP-2 net?
a monofilament nylon mesh ~200um (usually)
deployed vertically
sections can be closed off (‘throttled’) with a line to sample particular depth range
describe a CalCOFI net
aka ring trawl
1m diameter at mouth, trawled horizontally
mesh 500-1000um
has weight to hold it down in water
what is a MOCHNESS?
multiple opening and closing net and environmental sensing system - high tech net
what is a continuous plankton recorder?
~270um gauze net
has mechanism inside with series of rolers
cut to 10 nautical mile sections
other methods of plankton detection (no nets)
ecosounders - bubble interfere though
video systems - 3D laser illumination
plankton pumps - encounter plankton -> electrical/optical signal
Key feature of radiolaria and forminifera
Perforated shell, cell membrane sticks out of holes to catch food
Key feature of ciliophora
Can pop in and out of cup (lorica), on a stalk
What are chaetognatha?
Arrow worms
