Ecology Lesson 7 Flashcards
Lionfish
They prey on fish that aren’t prepared for them. They are an invasive species. They are now in Florida and Caribbean, and they out compete the native ones that are there (they are originally from the Atlantic Ocean). Their range had expanded in Atlantic waters. They eat grazing fish that keep mircoalgae down.
Invasive species
Introduced somewhere it’s not from by humans (deliberately or accidentally). Once you have an invasive species that comes in and does very well it’s hard to stop. We use conservative biology to deal with these problems.
What is conservation biology?
Applying ecological theory to aid in biodiversity conservation. Coined 50 years ago. How do we optimize our approach to tackle the biodiversity crisis.
Approach of conservation biology?
provide a scientific foundation for conservation
decisions
Goal of conservation biology
slow, halt, or reverse the loss of biodiversity. Stop animals from going extinct.
International Union for the Conservation of Nature (IUCN)
Many conservation organizations feed into it, then it has a role of working and coordinating at the international level. A group scientists set down and look at all of the available data. Specific organisms have a specialist group to look at it. Then they categorize species and put then into a set of categories based on the extinction risk. They create the red list.
IUCN Red List
List of species at risk of global extinction. Every 4-5 years there’s an update to see if the animal population has increased or decreased. They have numeric thresholds and values in terms of how much the population shrunk.
IUCN Red List categories
- Extinct (EX)
- Extinct in the wild (EW)
- Critically Endangered (CE)
- Endangered (EN)
- Vulnerable (VU)
- Least Concern (LC)
- Data Deficient (DD)
- Not Evaluated (NE)
What red list categories are considered endangered (risk of extinction)?
- Critically Endangered (CE)
- Endangered (EN)
- Vulnerable (VU)
Extinct
The species is gone
Extinct in the wild
The last of the species is in captivity (zoo).
Critically Endangered
10 years til extinct
Endangered
Risk is lower than CE, take longer to go extinct.
Least Concern
No risk of extinction
Data Deficient
Not enough information to understand.
Not evaluated
Haven’t has time or resources to figure out yet.
How many species are threatened with extinction?
More than 46 300 species
How many species have been assessed in the red list?
166 000
How many species have been scientifically described?
1.2 million
Guess of how many species there are in total?
8.7 million
Shortfin mako
Current status: Endangered.
Population size: unknown.
Threatened by overfishing, both as a target and bycatch (trying to kill something else but accidentally kill it) species.
Found in tropical and temperate waters (NS).
Sumatran rhinoceros
Current status: critically endangered. Without intercession it will go extinct (even with it, it still might have genetic issues and go extinct).
About 30 mature individuals left. Threatened by human disturbance (illegal logging/land conversion) and poaching. Horns have high value.
Sea otter
Current status: Endangered. Global population decreasing. Threats: oil spills, disease,
climate change. They have nearly gone extinct but then recovered (so it can improve).
COSEWIC
Committee on the Status of Endangered Wildlife in
Canada
Panel of scientific experts to identify and assess
species at risk in Canada based on:
* Population size (number of individuals)
* Recent decline
* Threats to populations/habitats
How does the management and conversation of endangered species?
Individual governments.
COSEWIC categories
Extinct
Extripated
Endangered
Threatened
Special concern
Extinct (COSEWIC)
Gone everywhere. It’s the only one that applies globally. ie. great auk
Extirpated
Gone in Canada but found elsewhere. Not many on this list. ie. Eastern tiger salamander.
Endangered (COSEWIC)
Could soon be extirpated (from Canada). ie.
Loggerhead sea turtle
Threatened
Could soon be endangered (in Canada). What you may want to be focusing your resources on, if you want it on Canada ie. Rufa red knot.
Special Concern
Vulnerable (current threats). Keep an eye on it. ie.
Grizzly bear.
COSEWIC at the population level
Can have individual populations going extinct or being at high risk when other populations may be doing a bit better. ie. Atlantic walrus
Can COSEWIC status be different from IUCN?
Yes. it doesn’t mean one is better than the other.
Intersection of science and policy– and politics?
Different politician and political parties will have a different weight that they give to biodiversity and conservation.
Who’s decision to do something about COSEWIC is it?
Made by politicians.
Steps for getting an action done by the COSEWIC
COSEWIC recommends listings on the species at risk act (a plan for recovery) to the Federal Minister of Environment and Climate Change. Within 90 days get an initial response. Then within 9 moths can a final decision.
Final decision options for COSEWIC
-Send report back to COSEWIC.
-Accept then on SARA
-Reject (no listing)
SARA (species at risk act)
Federal legislation since 2003
Goals:
* Prevent extinctions/extirpations of wildlife in Canada.
* Plan for the recovery of endangered or threatened
species.
* Must develop a management plan for listed species.
Conserving biodiversity
Need at many levels
Species level
* Species in need of protection
* (IUCN Red List, COSEWIC, SARA)
Genetic level
* Genetic diversity worthy of conservation to build resilience.
How to conserve genetic diversity?
Maintain large populations
* preserve total genetic diversity and more genetic diversity.
Protect isolated populations
* preserve unique genetic types. May have a pool of genetic diversity that isn’t found elsewhere. One you lose it, it’s very difficult to get back.
Ecosystem level of red list
Less than 10 years old. ie. coral reef is endangered. Aral Sea (Central Asia) is collapsed (instead of extinct). It used to support fairly large fishies and now it can’t. Decrease diversity.
Benefits of biodiversity means also what?
Ecosystem servies. The benefits people obtain from ecosystems. Through this we can communicate the value of ecosystems in a different way that maybe reaches people differently.
Provisioning services
Supply the goods themselves, such as food, water, timber, and fibre from ecosystems.
Provisioning services examples
ie. * Foods (e.g. fisheries)
* New medicines and
pharmaceutical
compounds
* Clean air and water
Regulating services
Govern climate and rainfall, water (e.g. flooding), waste, and the spread of disease. Keep the place habitable.
Regulating services examples
- Erosion control & coastal protection.
- Climate regulation (carbon sequestration by forests is very important).
- Pollination to help with crops and agricultural products.
Cultural services
Cover the beauty, inspiration and recreation that contribute to our spiritual welfare.
Cutural services examples
- Recreation & mental health (like nature walks).
- Spiritual and aesthetic (the beauty).
- Tourism (the reason people visit a country).
Supporting services
Include soil formation, photosynthesis and nutrient cycling, which underpin growth and production. We need to live the basis of the ecosystem.
Supporting services examples
- Biodiversity
- Nutrient cycling
- Primary productivity
Monetary value of ecosystem?
125 trillion/year
Threats to biodiversity
Habitat-loss
Overharvesting
Introduced species
Pollution
Climate change
Overpopulation
What can have a big effect on the population?
By reducing the consumption of individuals.
Impacts of threats
Impact: lower K. e.g. habitat loss. Reduce habitat less animals can live there.
Impact: negative r. e.g. over-harvesting of otters, as population declines.
Why are small populations more likely to go extinct?
- Stochasticity – chance (random) events
- Genetic problems can arise in small populations
Stochasticity events
Population size varies from year to year. Small populations may go extinct if there is a “bad year” because they get to zero with no wiggle room. ie. disease, tough year for food, etc.
Genetic problems
Genetic variability lost in small populations (genetic drift). Less able to adapt to changing environment. Low variability.
Inbreeding (mating with relatives) can occur in small populations. Expression of deleterious alleles. Reproductive problems. Why it’s hard to being a small population pack up to higher numbers.
Minimum viable population (MVP)
Smallest population size that is likely to
persist into the future
* Future: time period (e.g. 100 years)
* Likely: probability (e.g. 95% chance)
Modelling
* For a 95% change of persisting for 100 years, MVP = 100 bears or the small population size will kick in.
* Current N is around 1,000 bears. Not all can reproduce.
Effective population size
The number of individuals that effectively participates in producing the next generation.
Ne : Effective population size
Ne is always less than or equal to N
Conservation of genetic diversity
- Not everybody gets to breed
- Sex ratio (not 50:50)
- Mating system
So the actual genetic contribution is smaller than population size.
