Biodiversity - Exploiters and Exploited

• 4/5
• P. falciparum 

Protozoan parasite (eukaryotic cell)

• Via a mosquito vector 
• - genus Anopheles

• Cyclical fever 
• Due to syncronized rupturing of red blood cells releasing pryogens into the blood

the fouling of underwater pipes and other surfaces by organisms such as barnacles and algae

• 1. Molecular fouling - conditioner biofilm produced. 1 min. 
• 2. Microbial biofilm - bacteria and diatoms. 1-24 hours
• 3. Biofilm - Microalgae and protozoans. 1 week. 
• 4.  Macro-community - various species. 2-3 weeks

• Alevins (Still have yolk sac)
• Fry (5cm long)
• Parr (parr marks - stripey couple of years)
• Smolt (getting ready to go into sea, moves down river)

• 1. Honey hunting
• 2. Provision of nest building spaces and forest keeping
• 3. Simple hives, skeps
• 4. Rational hives with moveable frames

• Domesticated species tend to lose genetic diversity. Honey bees have gained it. 
• E.g. bees in Canada found to have 71% more genetic diversity than wild honey bees

• Parasites: e.g. varroa destructor 
• Disease: a problem in close confined hives but made worse by the import of bees commercially 
• Colony Collapse Disorder: made worse by general stresses and other factors
• Killer Bees: different strains of bees mixing causes problems such as Africanised honey bees

• 1. A new species has been produced as a result
• 2. Caterpillars are more docile
• 3. Adults can't fly
• 4. 33-50% of their genetic diversity has been lost

• Transgenic silkworms 
• - produce stronger silk (e.g. using spider gene) 
• - produce other compounds - use them as "bioreactor" → biomolecules, enzymes and drugs

• Two Phases
• Solitary and Gregarious

• → gregarious congregate and move together in swarms and bands, travelling large distances
• → increased disease resistance helps them in these large numbers
• → can travel long distances and wipe out crops

• Hopper Control:
• - dig trenches
• - beat
• - burn
• - poisoning/baiting

• Swarms:
• - Sodium arsenate bait
• - Scare away from landing on crops

• Insecticides: 
• - ground spraying of bands → spray vegetation with persistent organochloride insecticide such as BHC or Dieldrin
• - Aerial spraying using ultra-low-volume (ULV) techniques 
• Better scouting and prediction
• Green Muscle  

• 1. In mosquito 
• 2. In liver
• 3. In red blood cell

• Acts as a vector
• Facilitates sexual reproduction of the parasite

Only lives 3-4 weeks (depending on conditions) and sexual reproduction in the mosquito may not happen quick enough

• - Host specific → no other animal reservoir 
• - Vector Specific →  only Anopheles spp. 
• - Vector behaviour → mosquito rests after feeding so can use DDT 
• - Duration of sporogony →  takes 10-30 days

• 1. Sporozoite injected when mosquito feeds
• 2. Infects liver cells as hepatic schizont 
• 3. Releases merozoites into blood which infect RBC
• 4. Develop into trophozoites and schizonts, in turn producing more merozoites 
• 5. Also produce sexual forms (gametocytes)
• 6. These taken up by mosquito where they mature into gametes in the gut
• 7. Fertilised form able to cross midgut wall as oocyst 
• 8. Oocyst develops new sporozoites which migrate to salivary glands → infect new vertebrate host

• Insecticides e.g. DDT - kill mosquitoes in resting place
• Target breeding → drainage, covering of water bodies, fish, oil on surface
• Effective Treatment → prevent carriers being produced and spread of disease 
• Bed nets
• Transgenic Mosquitoes → population replacement or supression

• Quinine 
• - production still from the plant bark 
• - easy to OD
• Chloroquine 
• + acts as quinine but hard to OD
• + cheap and wide-acting 

• Artemisinin 
• + only alternative to quinine in severe cases
• + much less toxic w. fewer side effects
• + affects broader range of stages
• - expensive as needs growing 
• - needs combining with another drug as not long lasting → ACT (artemisinin combined treatment with another anti-malarial)

• - Co-evolution of the virus and rabbits →  initial strains strong but evolve to be weaker to ensure they don't wipe out the host.
• - Has resulted in changes in rabbit distribution. Some areas in the UK now have more rabbits

Collectively A$70 million benefits

• Not great as a vector
• - Needs high count of bacteria to become infected (10000 compared to only 10 in humans) 
• - Only 50% of infected fleas get blocked 

(Some species better than others - rat better than human)

• - Causes blockage in vector which forces it into the host when the flea is trying to feed
• - Produces bacterial biofilm allowing it to become the infectious it has
• - Only need 10 bacteria to infect a human
• - Carried to lymph nodes and hides & multiplies inside macrophages (hiding from immune system)

140%

• Total: £2x10⁸ per year 
• (Annual cost to US navy: US$ 1billion)

• (Tributyltin) 
• Oysters: shells become bubbly/thick. 
•      high mortality of larvae 
•      Cost US $147 million loss in oyster production
• Dog whelks: predators of barnacles
•      Imposex → females develop male parts and cannot breed, may die 
•      by 1980's 90-100% females are imposex on south coast (UK)
• Larger species: accumulates 
•      some fish and mammals 
•      squid off Japan found to have 48000x as much TBT as water

2008 - all TBT coatings banned

• Tin-free controlled depletion paints 
• problems: some creatures become resistant + not as effective as other options
• Use restricted by 2006

• Silicones 
• But vessels must not be idle for long
• Last 3 years
• Expensive
• Sensitive to damage
• May still have contamination problems

Enzyme-based systems

• Biomimetics → what stops organisms getting biofouled? 
• - Natural chemicals 
• - surfaces e.g. shark placodes 
• - microfibres -

They reproduce in high numbers so populations can bounce back well

• "marine weeds"
• -annual, opportunistic, grow very fast and have no age class reserves
• - crash suddenly 
• →  Fish-type management not appropriate 
• →  Need dynamic modelling inc. environmental conditions to help work out how many to take, when and where

• Line
• Drift Netting 
• Fish Traps

• Raise salinity 
• Raise temperature
• Alter daylight hours 
• (usually happens in spring in wild)

• Fish escapes 
• Sea Lice 
• Fouling of the sea bed
• Algal blooms could be linked → toxins from the blooms get into shellfish and salmon →  toxic to humans

• Chemicals
• - Hydrogen Peroxide
• - Pyrethroids →  extremely toxic to marine life and not specific to lice
• Drugs in diet
• - Ivermectin
• Treat on site before stocking sea pens
• Decrease Net Fouling 
• Fallowing 
• - wait 2-3 months before restocking pens →  lice disperse 
• Vaccines
• - in development 
• Cleaner fish 
• - E.g. wrasse 
• - raised in pens at 5% of stock

• Ovulation induced by coitus
• Drop a litter and can get pregnant again while lactating
• Gestation only 30 days
• Does ready to breed at 6-10 months →  sometimes breed same year as born 
• Can live 8-9 years so can have many offspring in lifetime

• 37-44% →  more than most domestic mammals 
• Most of this makes them more docile/behaviour changes

Southern Europe (Spain, prtugal, france)

• Hunting
• Predatory species encouraged →  cats, foxes 
• Fences 
• Chicken Cholera but didn't work
• Myxomatosis
• Rabbit Haemorrhagic Disease (RHD)

• Are they different species or not? 
• Hybrids

E.g. Is the red wolf a hybrid with coyotes?

• 1905: bill passed to allow infection of wolves with mange. 
• Use of strychnine
• 1970s: plans to reintroduce wolves
• 1995: first wolves reintroduced and cared for by tribe
• 2008: now many wolves there →  wolf tourism contributes $35 million USD annually

• Less elk
• → trees regenerate along streams
• → good for trout
• → beavers return 
• → dams encourage mink, muskrats and ducks
• → stream banks also more stable → better quality water

• coyote numbers down
• → fox numbers may be increasing

Apis melifera 

$250 billion

• Chemical control BUT now mostly resistant to pyrethroids 
• Monitoring hive
• Comb trapping 
• Forcing artificial swarm to new clean hive

Bombix mori 

• Resistance to high temps
• humidity
• disease
• Adaptation to artificial diets
• Getting second generation in a year

• Outbreak prevention: control aggregating populations before gregarisation 
• Proactive: control small swarms
• Reactive: Control serious swarms