Unit 4 Topic 1 Oceans of the future Flashcards
Reasons for preserving species and habitats (5)
Ecological
Greater biodiversity results in greater ecosystem health
Ethical
Species have the right to exist and animals are entitled to their own lives
Economic
Well managed ecosystems can result in tourism and certain industries which provide money to the economy
Aethsteic
Environmental ecosystems can be a source of beauty and can inspire various arts
Social
A place for people to socialise and can be used to create environmental groups
MPA design criteria
Location
-locate marine reserves considering the location of existing measures, and have fewer larger separate reserves
Selection
-select areas considering the capacity to mitigate threats, unique habitats or species; ecologically important features; small-scale ecosystems and sediment types; heritage sites; minimising socio-economic cost
Design
-the size and shape of the reserve should include continuous depth transects; include entire geomorphic features, with replication; account for connectivity and dispersal; have simple, easily identifiable boundaries; minimising socio-economic costs
Zoning
-include highly protected areas, consider the threats posed by specific activities; apply a precautionary approach to threats and costs and benefits.
‘CAR’ Principles of MPA
Comprehensiveness
Adequacy
Representivness
Management strategies to support marine ecosystem
-Managing threats
Rules to reduce damage (no anchoring boats, no-take zone)
-Zoning
Dividing the area and employing different sets of regulations in certain areas (No entry, no fishing)
-Permits
Special permission required for activities
-Plans
Allow for the further protection of aspects of the reef
NGO’s
A non-government organisation includes private voluntary organisations, nonprofit organisations, and Civil society organisations.
Speed is slow to complete objectives
RCP’s
Representative concentration pathways
RCP’s are computer modelled predictions that account for the influence of greenhouse gasses and other pollutants on climate in the year 2100
The model types of RCP (4)
RCP 8.5
RCP 6.0
RCP 4.5
RCP 2.6
Anual severe bleaching events (ASB)
Defined as an annual exceedance of >8DHW accumulating in a 3 month period
Degree heating week
DHW
DHW
is an indicator of thermal stress on coral and a predictor for coral bleaching.
Example. If the temperature is 2 degrees above the summer maximum for 4 weeks then the DHW indicator is 2x4 = 8 DHW
Coral skeletons
Are a deposit of the mineral aragonite which is a form of calcium carbonate
Extension
-Upwards skeletal growth
Densification
-Lateral skeletal growth
Coral growth in skeletons
Is represented by density bands that represent the growth of coral and is impacted by factors such as temperature, weather events, and changes in nutrients
Coral coring
Method of extracting a sample of coral skeleton density
Coral cores can provide
- Provide credibility to theories surrounding past events and climate patterns
- Environmental data including rainfall, acidity, sedimentation, water pollution, and storm activity
- Scientists can analyse the chemical compounds in corals which represent certain conditions of the oceans
- Calcium carbonate stores can represent environmental data from hundreds and thousands of years ago
Ocean acidification saturation on coral
Ω>3 corals are more likely to survive and reproduce
Ω<3 corals become stressed
Ω<1 shells and other aragonite structures dissolve
Implications of ocean acidification on various organisms
Hard Coral
-carbonate ions become less abundant causing slower skeletal growth. Coral growth will be limited by corroding pre-existing coral structures. Coral larvae will have trouble finding a suitable spot to settle
Coraline Algae
-Most coralline algae species build shells of high-magnesium calcite form of calcium carbonate which is more soluble than aragonite
Shelled organisms
-Shells will become more delicate and smaller resulting in an increased risk of predation
Plankton
-Impacts the food chain as plankton are a food source to various animals. Shell is made of calcium carbonate
The transportation of heat, water and nutrients in the ocean is impacted by the factors (3)
-Ekman spiral
Currents decrease with depth in a spiral based on surface currents moving at a 45-degree angle to the wind direction caused by Coriolis forces and friction
-Upwelling and downwelling
Upwelling where Ekman transport moves surface waters away from the coast and surface waters are replaced with deep, cold, nutrient rich water that wells up from below
Downwelling where Ekman transport moves surface waters towards the coast the water piles and sinks
-La Nina and El Nino
La Nina results in trade winds stronger then normal which cause upwelling off south America which causes lower sea surface temperature overall.
El Nino results in a decreased air pressure patterns weakening wind trades and can reverse direction resulting in warm water being pushed back towards the central pacific and upwelling is decreased due to high water concentration off South America
Normal conditions
Sea surface temperature is higher in the Western pacific waters then waters off South America this is caused by trade winds blowing east to west on the equator this allows for the upwelling off northwest South America
Alterations of thermal regimes
Temperature in aquatic systems is important as it influences factors such as
- Dissolved oxygen
- Water density
- Salinity
Climate change on fish migration patterns
Fish are unable to alter their body temperature so they are influenced by the temperature around them
Many fish stay in the optimal temperature range and their ability to stay in this range influences their feeding time, where they stay and when they migrate and spawn.
Changes in non migratory fish
The shifts will be either higher in latitude or deeper in depth and a decrease in distribution range
Changes in migratory fish
Temperature is the trigger of migration in fish
Increases temperature results in increased migration distances for fish which increases fish mortality
Cause of sea level rise
Melting ice + thermal expansion = rising sea levels
