Plankton and Plankton Communities

Question 1

how are zooplankton important in terms of fisheries?

Answer 1

larval survival and dispersal -> e.g. artic krill, jellyfish

Question 2

how are zooplankton a nuisance?

Answer 2

to aquaculture, fisheries and bathing

Question 3

what are holoplankton?

Answer 3

spend whole lifecycle in the plankton

Question 4

what are meroplankton?

Answer 4

spend part of life in plankton (e.g.) fish larvae

Question 5

what are the names of the categories which define zooplankton with depth?

Answer 5

pleuston
neuston
tychopelagic

Question 6

what are pleuston?

Answer 6

zooplankton which float on surface of the water

Question 7

what is an adaptation of pleuston?

Answer 7

UV protection pigments e.g. Man o’ War jellyfish

Question 8

what are neuston?

Answer 8

zooplankton found near the surface of the water

- movement affected by water

Question 9

what are tychopelagic?

Answer 9

normally live on the bottom, sometimes stirred up/swim up

Question 10

what are the size categories for plankton?

Answer 10

nanoplankton 
microplankton 
mesoplankton 
macroplankton 
megaplankton

Question 11

how big are nanoplankton?

Answer 11

2 to 20 um

Question 12

how big are microplankton?

Answer 12

20 to 200 um

Question 13

how big are mesoplankton?

Answer 13

0.2 to 20mm

Question 14

how big are macroplankton?

Answer 14

2 to 20cm

Question 15

how big are mega plankton?

Answer 15

> 20cm

Question 16

what size categories of plankton are most phytoplankton and protists?

Answer 16

nanoplankton and microplankton

Question 17

what are the groups of plankton?

Answer 17

diatoms 
Forminifera and radiolaria
Ciliophora
Copepods
Euphasiids
Molluscs
Polychaeta
Chaetognatha
Echinoderm, gastropod believe and polychaete larvae
Fish eggs and larvae
Medusa of scyphozoa

Question 18

primary factors which affect planktonic communities

Answer 18

solar radiation, nutrient concentrations

Question 19

secondary factors which affect planktonic communities

Answer 19

upwelling 
turbulence 
grazing intensity 
water turbidity
temperature

Question 20

what is a WP-2 net?

Answer 20

a monofilament nylon mesh ~200um (usually)
deployed vertically
sections can be closed off (‘throttled’) with a line to sample particular depth range

Question 21

describe a CalCOFI net

Answer 21

aka ring trawl
1m diameter at mouth, trawled horizontally
mesh 500-1000um
has weight to hold it down in water

Question 22

what is a MOCHNESS?

Answer 22

multiple opening and closing net and environmental sensing system - high tech net

Question 23

what is a continuous plankton recorder?

Answer 23

~270um gauze net
has mechanism inside with series of rolers
cut to 10 nautical mile sections

Question 24

other methods of plankton detection (no nets)

Answer 24

ecosounders - bubble interfere though
video systems - 3D laser illumination
plankton pumps - encounter plankton -> electrical/optical signal

Question 25

Key feature of radiolaria and forminifera

Answer 25

Perforated shell, cell membrane sticks out of holes to catch food

Question 26

Key feature of ciliophora

Answer 26

Can pop in and out of cup (lorica), on a stalk

Question 27

What are chaetognatha?

Answer 27

Arrow worms