L7-Marine invasion Flashcards
how many waves of marine invasions where their?
two possibly a new third
different vectors
What is a marine invasion?
human mediated transport of species outside their natural range
What was vector of the first wave?
wooden ships, critters attaching to boats.
What were the features of animals of first fave?
filter feeders
lecithotrophic
good competertitos
adults
What was second wave?
ballast waters
What where the features animals of second wave?
wide range of niches
predators and filter feeders
plantonick species
came as larvae
What is the new emerging wave?
Aquaculture
both directly and indirectly
domestication
aquarium trade
Impacts of the first wave?
smaller impact
• Competitive displacement?
• Changes in nutrient cycling?
• Empty Niche-not much lived on made made structures
Impacts of second wave?
• Prey upon native species-prey less well adapted
• Changes in nutrient cycling
• Habitat destruction and modification
more destructive
How easily can marine species be controlled?
• Once established, impossible to control
What are possible control strategies?
- Reduce transport
- Reduce spread
- Reduce establishment
What affects establishment?
• Fundamental niche
Physical conditions
Biochemical confitions
• Realised niche
Receiving communityHow does species diversity effect invasion?
makes habitat harder to invade
What is the invasion paradox?
- Increasing diversity in experiments tends to reduce invasibility
- Natural populations with higher diversity can be more invaded
What causes invasion paradox?
areas with more diversity also have more resources for invaders
How does pollution affect invasive species?
invasive species doe better in areas with more pollution
how are artificial structures different to natural?
provide novel growing surface not found in nature
low flow environment with lots of area for growth
Artificial structures rob coastal systems of energy
How do artificial structures effect energy transport?
animals on structures
increase co2 production
animal on piers eat 78x the productivity than the area they cover
How much biomass doe artificial structures add to port phillip bay?
9,649,000 kg or 3700 elephants
What are solutions to artificial structures?
clear structures that allow autotrophs to grow
How do oxygen levels affect invasive species?
Invasive species can tolerate lower oxygen
levels than native species
How do invasive species avoid competition?
avoid low oxygen
who uses more oxygen invasive or native?
invasive species
