BIO3021 Lecture Notes - Lecture 3: Fisheries Management, Population Genetics, Otolith
25 May 2018
School
Department
Course
Professor
Lecture 3 – Introduction to Marine Ecology and Marine Life-Histories
Marine Ecology
• Coastal marine organisms – interact most with
• Planktonic and benthic stage
Why its Different (today)
• Physical medium
o Density of sea water
o Developmental medium
o Dispersive larval stages (long distance)
o Freshwater – lower osmotic so have to regulate balance
Marine Life-Histories
• Marine life cycle
o Development → colonisation → survival and growth → fertilisation
Marine Ecological Processes
• Ecological consequences
o Dispersal distances can be much greater and more variable in marine
systems than in terrestrial systems *EXAM
▪ Mean and spread greater: km (log scale)
o Seaweed: short dispersal distances
o Invertebrates shows biggest range: hardly anything to very large
▪ Every kind - Most developmental variation
o Fish: higher end (km) big dispersal distances
• Demographically ‘Open’ Populations
o Populations demographically connected
o All larvae leave and ones that come back are from elsewhere
o Populations resilient to disturbance
• Source-sink dynamics
o Act as sources: produce a lot and can supply population
o Sink: no one comes out demographically
▪ Receives individuals but doesn’t produce any new ones itself
Population Genetics
• Populations separated by large distances tend to be different
o Genetics are the same – all populations are connected
• Very little differentiation among nearby populations in neutral markers
• Exam questions eg.: How has our view evolved from the 60s to today? And
what has changed it?
• Dispersal has consequences
Management consequences
• Fisheries management
o Prevent people from taking wrong type of fish
• Marine protected areas (MPA)
o Not allowed to do any bad stuff
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 3 introduction to marine ecology and marine life-histories. Marine ecology: coastal marine organisms interact most with, planktonic and benthic stage. Why its different (today: physical medium, density of sea water, developmental medium, dispersive larval stages (long distance, freshwater lower osmotic so have to regulate balance. Marine life-histories: marine life cycle, development colonisation survival and growth fertilisation. And what has changed it: dispersal has consequences. Management consequences: fisheries management, prevent people from taking wrong type of fish, marine protected areas (mpa, not allowed to do any bad stuff, need to be large enough to cover great area of dispersal. Are populations demographically connected: hard to track individual larvae small, ocean is very large hard to track, some examples but restricted to specific group. Most marine organisms have dispersive larval stage. Marine populations more open than terrestrial populations but not as open as we once thought.
