plankton & MPAs Flashcards
benthic
the substrate (eg. rock, mud, sand)
eg…
- littoral
- sublittoral
- bathyal
- abyssal
- hadal
pelagic
the water column
eg…
- epipelagic
- mesopelagic
- bathypelagic
- abyssalpelagic
- hadalpelagic
what is used to catagorise realms?
- depth
- light
- position relative to continental shelf
nekton
pelagic organisms that can maintain their position against water currents
nektos: swimmer
plankton
pelagic organisms that cannot maintain their position against currents
planktos: wanderer
2 types of planktonic organisms catagorised by mode of nutrition
- phytoplankton (plant-like)
-> capable of 1º production via p/s - zooplankton (animal-like)
-> derive nutrition by consuming other organisms
types of planktonic organisms catagorised by size
- Mega-plankton -> 20 cm +
- Macro-plankton -> 2cm – 20 cm
- Meso-plankton -> 200 μm - 2cm
- Micro-plankton -> 20-200 μm
- Nano-plankton -> 2 - 20 μm
- Pico-plankton -> 0.2 - 2 μm
planktonic organism examples
4
- diatoms
- dinoflagellates
- coccolithophorids
- cyanobacteria (Blue-green algae)
why are cyanobacteria ecologically important?
- dominant 1º producer in the oceans
- many are food for small zooplankton
- some toxic -> if they bloom: can impact whole ecosystems
cyanobacteria
- capable of p/s
- typically up to 5µm in size
- many can use N₂ gas as source of nitrogen (they ‘fix nitrogen’)
- cyanobacteria can occur as single cells, filaments, or colonies
coccolithophorids
- single celled eukaryotes (protists)
- capable of p/s
- small (less than 20 μm)
- characterized by calcium carbonate coccoliths
why are coccolithophorids ecologically important?
- 1º producers in coastal and open ocean waters
- form blooms that look chalky white in open ocean
- major contribution to CaCO₃ sedimentation
diatoms
- single celled eukaryotes (protist)
- capable of p/s
- 5- 200 μm and fast growing (1-3 generations per day)
- characterized by producing a silica ‘box’ around cell -> composed of 2 halves called ‘valves’ or ’frustules’
- can also occur as single cells or chains
why are diatoms ecologically important?
- major 1° producers in coastal (i.e., neritic) waters
- important food source for zooplankton and larval fish
- on geological timescales sedimentation of dead diatoms leads large silica deposits (diatomaceous earth)
how else are diatoms important?
(not ecologically)
- forensics (diagnose location of drowning)
- diatomaceous earth used as…
-> abrasive in toothpaste and polishes
-> absorbent for nitroglycerin
-> filtration of liquids (e.g., beer)
Dinoflagellates
- single celled eukaryotes
- 10- 200 μm
- characterised by 2 whip-like flagella
- some “armored” with cellulose plates, others are “naked”
why are dinoflagellates ecologically important?
- some phytoplankton, some zooplankton, some are both (called mixotrophy)
- can eat smaller cells and are food for larger zooplankton
- can form harmful blooms -> cause disease in wildlife and humans, e.g., Pfiesteria hysteria causes skin lesions and mass mortality in many fish species
mixotrophy
allows a species to be both plant and animal like
viruses and bacteria
- viruses are the most abundant ‘life form’ in the ocean (estimated 1030 viruses)
- every second, approx 1023 viral infections occur in the ocean
- major source of mortality and disease in organisms from phytoplankton to whales
- bacteria are important heterotrophic decomposers (although the cyanobacteria are important autotrophs)
- bacteria play a critical role in major element cycles (e.g., the carbon and nitrogen cycles)
microzooplankton
- small metazoan & protozoa (i.e., heterotrophic unicellular eukaryotes) form critical link in marine food webs
- consume bacteria and nano-phytoplankton
- feed mesozooplankton & larval fish
ciliates
- characterised by ‘hair-like’ cilia on cell surface associated with movement & feeding
- important grazers in the marine plankton
mesozooplankton
exclusively metazoan (i.e., animals)
copepods
- small crustaceans
- account for ~95% of the planktonic biomass (dom taxonomic group in plankton)
- highly diverse (over 13000 species)
- most important grazers of 1º producers (particularly diatoms)
-> feed by sieving water - important ‘egesters’ too (C.R.A.P)
-> major pathway for carbon export to deep oceans
3 major groups of copepods
- harpacticoids (benthic)
- cyclopoids
- calanoids
protected area
- clearly defined geographical space, recognised, dedicated & managed, through legal or other effective means…
- to achieve long-term conservation of nature with associated ecosystem services & cultural values
- created by delineating zones with permitted & non-permitted uses within zone
Global Importance of Biodiversity in the UK’s Overseas Territories
- 24 endemic bird sp
- 100 endemic reptiles (0 in GB & NI)
- 500 endemic invertebrates (> 99.2% of
endemic terrestrial invertebrate sp occurring on UK territory) - 200 endemic plants
- ~50% of world’s breeding albatrosses
- one of world’s major coral reef nations
- 94% of known British sp
Uk overseas territories (UKOTs)
- Isle of Man
- Jersey, Guernsey, Alderney, Sark
- Gibralta
- Cyprus Sovereign base areas
- British Indian Ocean territory
- Ascension Island
- St Helena
- Falkland Islands
- Tristan Da Cunha
- South Georgia
- British Antarctic territory
- Pitcairn Islands
- Cayman Islands
- Bermuda
- Turks & Caicos Islands
- British Virgin Islands
- Anguilla
- Montserrat
Ascension Island
bright spot for marine conservation in tropical Atlantic
- discovered by Portuguese in 1501
- claimed by Britain in 1815 to defend St Helena
- politically part of the UKOT of St Helena, Ascension Island & Tristan da Cunha
- governed by appointed representatives from UK Foreign & Commonwealth Office supported by elected Island Council
- primarily functions as UK & US military base and telecomm. hub
the problems
(concerning MPAs)
- only 7.7 % of ocean in MPAs
- only 2.7 % of ocean is highly protected
- MPA coverage is ↑ but still short of target set for 2020 (in Aichi Biodiversity targets)
-> & v short of 30% by 2030 that is thought to be min. needed to stabilize marine ecosystems
BRUVs
Baited Remote Underwater Video systems
-> fish surveying tool
-> stationary, seafloor camera with bait to attract fish
paper parks
- areas are designated as ‘protected’ on official documents…
- but may not receive necessary resources, enforcement or conservation measures to ensure effective protection of env & biodiversity