marine biodiversity Flashcards
what is biodiversity
- the complete range of species and biological communities
- Genetic variation within species – all of species of a given area
- The range of ecosystem processes – all different biological communities + all processes involving the chemical and physical env
what is a species
- Morphological species – group of individuals that are physiologically distinct from other groups in some key characteristic
- Biological species – group of individuals that can breed with each other in the wild but not with other groups of individuals
what is a population
Group of interbreeding inds of a given species at a sight
what is a Community / assmblage
Groups of pops, of multiple species at a given site
2 main reasons biodiversity is important
- Intrinsic value – has its own worth regardless of worth
- Anthropocentric values
5 Anthropocentric values biodiversity gives
- Vulnerability – removal of biodiversity weakens the system – yields further loss
- Renewable resources – food, fibre, medicines, natural products
- Ecosystem goods + services – a way to put monetary value on the natural world (Direct + indirect use values)
- Insurance – destroyed biodiversity might mean we lose something critical to our survival
- Ethical value – should not endanger our own environment – moral responsibility to protect the environment and other species
8 taxonomy levels
3 Domains – eukarya, archaea, bacteria
6 Kingdoms
Phyla
Class
Order
Family
Genus
Species
what makes up a scientific name
Genus (capital) + species (lower case)
who came up with the taxonomic levels
Linnaeus 1758
how many phyla are in the Marine environment
31
phyla Porifera characteristics
e.g. sponges
- no symmetry
- filter feeders
- sessile
- few tissues
- marine + freshwater
phyla Cnidaria characteristics
e.g. corals, sea fans, jellies, sea pansies, anemones
- radial symmetry
- nematocytes (sting)
- simple nervous systems
- primitive body systems
- mouth no anus
phyla Bryozoans characteristics
e.g. sea moss, sea mats
- sessile
- colonial
- marine + freshwater
- U shaped gut
- filter feeders
phyla Platyhelminthes characteristics
- parasitic / free living
- bilateral symmetry
- some organs
- mouth no anus
phyla Nematoda characteristics
e.g. round worms + threadworms
- unsegmented
- meiofaunal
- complete gut
- parasitic/free living
- 1,000,000 species
phyla Mollusca characteristics
e.g. gastropods, bivalves, cephlapods
- bilateral symmetry
- mantle (organs are kept)
- complete guts
- shell/shell plates/epidermal spicules
phyla Arthropoda characteristics
e.g. decapods
- segmented bodies
- jointed limbs
- hard exoskeleton
- complete gut
phyla Annelids characteristics
e.g. segmented worms
- bilateral symmetry
- can regenerate
- eye-like sensory organs
- complete gut
- hairs
phyla Echinoderms characteristics
e.g. sea stars, urchins
- 5-ray radial symmetry
- no head
- subepidermal plates
- water vasular system
- exclusively marine
phyla Chordata’s 2 groups
Tunicata + Vertebrata
group Tunicata characteristics
e.g. sea squirts, ascidians, larvaceans, salps
- sack-like bodies
- filter feeders
- notochord (spine-like structure)
group Vertebrata characteristics
e.g. fishes, birds, mammals
- backbone
abundance meaning
number of individuals
density meaning
number of individuals / unit area
biomass meaning
mass of living organisms in an area
what is the distribution of species on earth
25% of species marine
75% terrestrial
- But more phyla in marine env than land – all but 3 phyla are marine + 1/3 of phyla are exclusively marine
how are the majority of organisms distributed in the ocean
98% = benthic (associated with seafloor)
2% pelagic (water collumn)
how do we describe benthic organisms and its 4 groups
by size not taxonomy
- Megafauna – cm e.g. fish
- Macrofauna – 250-500um e.g. polychaetes
- Meiofauna – 32-62um e.g. nematodes
- Microbiota - microns e.g. protists
how does benthic organism abundance vary vertically (by depth)
- Slight decrease in abundance as depth increases
- Bacteria (Microbiota) most abundant in all depths
how does benthic organism biomass vary vertically (by depth)
- Benthic biomass has stronger decrease with depth
- 0-2000m = macrofauna most biomass
- > 2000m = bacteria most biomass
how does macrofaunal diversity vary vertically (by depth)
- increases until reaches Mid depth maximum in diversity - then decreases
- Depth varies - 2000-3000m
how do Benthic organisms vary horizontally (geographically)
- Equator = max richness – decreases at the poles
- Hotspots in Indo-west pacific + Indian ocean
what are the Challenges to assessing biodiversity
- underestimated the number of species living in the deep sea
- modern estimates = 2.2 million species in the ocean
3 biggest needs in marine biodiversity research
- Taxonomic training and expertise + jobs
- New technologies + exploration research (funding)
- Foster collaborations + communications internationally
recent developments in marine biodiversity research
Dna sequencing pools:
- dna barcoding (mito COI gene)
- metabarcoding (species ID) / metagenomics (functional genes)
