Eduardo Infantes - Global change oceans Flashcards
Eutrophication
Algae on top of the water is a sign of eutrophocation. Too much nutrients added. Fertilizers end up in there. Lots of algae, absorbs sunlight, plants on the bottom die, algae die when they have eated the nutrients, bacteria eat the dead algae. Bacteria might use up all oxygen, everything dies.
What leads to eutrophication
Fertilizers - nitrates
Overfishing - removal of top predators
Sewage - phosphates
Overfishing and eutrophication
Example: cod reduction - increased sprat - reduction in zooplankton - lots of chlorophyll a, microalgae, eutrophication
Nutrient sources eutrophication
Point sources: directly attributable to one influence. Relatively easy to regulate. Wastewater effluent, runoff from disposal, untreated sewage, mm.
Nonpoint sources: come from non-defined and diffuse sources. From agriculture, runoff from pasture, septic tank leakage, mm. Tricky to monitor.
Yearly input of N and P baltic sea
Nutrient reductions since 1990s: improvement in sewage water treatments, nutrient reductions in farming, run-off in agriculture more controlled.
Because of improved governance in the baltic sea.
Status eutrophication baltic sea
97% is eutrophied.
15% in bad status, large areas in poor status. Nutrients are trapped in there.
Prevention of eutrophication
Removal of nutrients before entering the water system:
Waste water plants, run-off (filter, or remove nutrients), cleaning products (reduce phosphorous in detergents), agriculture (proper planning of fertilizers), farming (alternative practices).
Eutrophication recovery measures
Remove water and replace with clean water.
Drain upper layer of sediment.
Artificial oxygenation, speeds up chemical reactions.
Chemical precipitaion by adding iron and aluminium.
Good for small lakes, but very difficult to apply at sea.
Overfishing
The removal of a species of fish from a body of water at a higher rate than the species can replenish its population naturally.
Overfishing impacts
Reduce the size of the fish.
Reduce the predators.
Disturb the trophic cascades.
Increases algae growth.
Ghost fishing gear (lost equipment).
By-catch kills.
Overfishing solutions
Increased regulations.
Enforcement of regulations.
Stop trawling.
More protected areas.
Sustainable farming.
Ocean acidification
More carbon in air - more carbon in water - creates carbonic acid
Acidification affects differents animals
Stimulates plant growth. Molluscs, echinoderms and corals affected badly. Crustaceans and fish not affected much.
Acidification impacts
Reduced growth of calcifying organisms.
Increased growth of plants.
Disturbed trophic cascades and food webs.
Change in ecosystem functions.
Change in ecosystem services.
Acidification solutions
Reduce emissions of CO2.
increase renewable energy.
Conserve/restore coastal vegetation as buffer zones.
Invasive species
Plants, animals or fungi that have been intentionally or unintentionally moved to a new environment, where they spread and repidly cause damage to biodiversity, economy, and potentially human health.
Invasive species competition with local
Fast growth.
Rapid reproduction.
High dispersal ability.
Tolerance of a wide range of environmental conditions.
Ability to live off of a wide range of food types.
Association with humans.
Invasive species pathways
Shipping - ballast waters, ship hulls.
Navigational canals - transporting species via inalnd water.
Aquaculture - escpate/overspill introduced for farming.
Aquarium trade - release of exotic species.
Invasive species impacts
Disturbing native habitats.
Extinction of endemic flora and fauna.
Overwhelming important ecosystems.
increased competition and predation.
Invasive species solutions
increased and enforced regulations.
Reporting of invasive species.
Exploitation of invasive species by humans?
Plastic polution
Marine plastic polution is caused by plastic ranging in size from large, original material such as bottles and bags, down to micorplastics formed from the fragmentation of plastic material.
Plastic polution threat to coastal habitats
Plastic polution accumulates in saltmarshes, mangroves and seagrass, since they are depositional habitats.
Plastic polution sources
Mismanaged plastic waste.
Maritime plastic debris.
Microplastics (primary or in-use product wear)
Fishing gear is the most common type in the sea.
Pathways: rivers, wind, atmoshperic deposition, direct input to oceans, run-off, treated or untreated wastewater.
Plastic polution impatcs
Destroys coastal habitats.
Animals get entangled.
Ingestion.
Chemical exposure.
Plastic polution solutions
Reduce the use of plastic.
Support legislation to reduce plastic production and waste.
Reuse.
Recycling.
Microplastics - avoid products containing microbeads.
Coastal development
Changes that are casued by human activities that alter the conditions and the landscape of the coastline.
Coastal development impacts
Increased erosion and sedimentation.
Change in sediment dynamics.
Human disturbance of wildlife.
Run-off water and plastic litter.
Coastal hardening to reduce erosion.
Coastal development solutions
Distance between shoreline and new constructions.
Restore natural habitats.
Work with nature solutions - restore nature and use it as coastal defense.
Coastal retreat.
Reasons for sea level rise
Ice sheets and glaciers are melting.
The oceans are expanding because of the heat.
Sea level rise impacts
Inreased coastal erosion.
More frequent storm surge floodings.
Coastal inundation.
Socio-economic impacts.
Destruction of coastal habitats.
Land/freshwater contamination with salt.
Sea level rise solutions
Green-house gases reduction.
Distance between shoreline and new constructions.
Habitat resoration.
Coastal retreat.
Salt resistant crops.
Seagrass restoration with seeds
Seed harvesting and collection. Seed germination and storage. Seed planting. Very low success rate.
Seagrass restoration using transplants
Take a plant, put it in another location. Easy, good for small-scale restoration. Bad becasue it impacts the donor bed, and the plants need to adapt to the new habitat.
Ways of planting:
Single-shoot methods.
Shoots with anchors.
Sediment plug methods.
