Ecology: Introduction Flashcards
1
Q
Which 5 major mass extinctions are recognized?
A
- Shortly after the evolution of the first land-based plants, about 450 million years ago.
- About 350 million years ago which led to the formation of the coal forests.
3 and 4. Two major extinctions during the Triassic period (250 - 200 million years ago).
- The great extinction at the end of the Cretaceous Period (65 million years ago).
2
Q
What is the sixth extinction prediction?
A
- Some scientists believe we’re already in the 6th mass extinction
3
Q
Timeline of marine and terrestrial defaunitation
A
4
Q
What is the average decline of marine species during the years?
A
40-90%
5
Q
What is the Anthropocene?
A
- The era we’re in now where humans are the dominant geological force.
- From the Greek Anthropos ‘human being’
and kainos ‘new’. - First used by Crutzen and Stoermer in 2000
6
Q
What is the basic concept of the term Anthropocene?
A
The basic concept is that humans are now a major geological and environmental force, as important as, or more important than, natural forces.
7
Q
A
Changes in the atmosphere are approaching a planetary climate tipping point.
There is suggestion that a global cascade of tipping points might led to a new, less habitable, ‘hothouse’ climate state.
8
Q
What percentage of humans lives in cities now?
A
- over 50%
- In 2030: 60%
9
Q
What are the economic, social and environmental challenges related to cities?
A
10
Q
Where are most of the largest cities of the world located?
A
In coastal areas
11
Q
Paris Agreement aims on climate in relation to cities (December 2015, at the COP21)
A
- Cities action arm to reach sustainable development
- Strong presence of local and regional Governments (#Cities4Climate)
- New Urban Agenda tool to reach Paris Agreement
11
Q
Why is new urban agenda tool important?
A
- Cities are key to tackling global challenges, such as poverty, social inequalities, and climate change.
- Urbanization as a tool and engine for sustainable development
12
Q
What is the history of humans impacting coastal environments?
A
- Harbour installations since the Bronze age
- Marine resources exploited since at least the Palaeolithic
- During the Roman times marine coastal landscapes were far from pristine
13
Q
A
Estuarine and coastal areas degradation is related to human population growth and impact
(Lotze et al 2006. Science)
14
Q
Human impacts on coastal and marine ecosystems have a distinct temporal sequence
A
15
Q
Predicted importance and direction of different impacts
A
16
Q
Fishing (as a human impact on coastal and marine ecosystems)
A
- It is the oldest cause of human extinction of species
- E.g. Steller’s sea cow (Hydrodamalis gigas); a large herbivorous marine mammal (sirenid), described in 1741 by Georg Wilhelm Steller.
Steller and his crew were shipwrecked and discovered and hunted the sea cows.
The Steller Sea became extinct in 1768
17
Q
Direct and indirect effects of fisheries (picture)
A
18
Q
Direct effects on fished species..
A
- Many marine species have been/are
overexploited - Sometimes to functional extinction or even
complete extinction
19
Q
Name an example of overfishing
A
- The overfishing of Ostrea Edulis reefs
- Beds of O. edulis severely depleted or physically destroyed around most European coasts by late 19th century
- Due to overfishing, outbreaks of diseases,
habitat transformation, and nonnative
competitors and parasites
20
Q
What is another direct effect of fisheries?
A
- Habitat destruction
- The world oceans have been altered down to > 800 m in depth by destructive bottom trawling producing comparable effects on the deep sea
floor to those generated by agricultural ploughing on land.
21
Q
What is an indirect effect of fisheries?
A
Overfishing of keystone species alters ecosystem structure and functioning
22
Q
Name 2 examples of the indirect effects of fisheries.
A
- the fishing/hunting of top predators such as sea otters can cause a demographic burst of
herbivores such as sea urchins and the collapse of kelps and other vegetation - the overfishing of phytoplankton feeders such as oysters can cause algal blooms and
dystrophy/hypoxic crises
23
Q
Aqauculture as an impact (picture)
A
24
Types of pollution (as a human impact on coastal and marine ecosystems)
- Pollution from pesticides, herbicides, fertilizers
and other chemicals
- Urban organic pollution or from intensive farming
- Thermal
- Acoustic / Electromagnetic / Artificial lighting
- (Micro)plastics
25
Percentages of pollutants entering the ocean
26
What is biomagnification?
- Many of the pollutants concentrate in biological tissues along the food chain
- It means that higher-level predators-fish, birds, and marine mammals-build up greater and more dangerous amounts of toxic materials than animals lower on the food chain.
- particularly concerning isse in marine systems where food chains are longer than on land (eg Minamata disaster 1956)
27
What was the Minamata disaster?
Minamata disease (M. d.) is methylmercury (MeHg) poisoning that occurred in humans who ingested fish and shellfish contaminated by MeHg discharged in waste water from a chemical plant (Chisso Co. Ltd.).
28
Example of petroleum Hydrocarbon pollution (As type of pollution)
- Ex. 1. Exxon Valdez (1989)- Prince William Sound, Alaska
* 10 million gallons (≈ 38 million
liters) of oil spilled
* 400 miles of shore line affected
* $3 billion and 2 summers cleaning
- Ex. 2. The prestige (November 2002) - Spain
* Sunk with 20 million gallons of viscous fuel oil
* Hundreds of miles of coastline affected
* Destroying wildlife, fisheries and shellfish industries
- Ex. 3. Persian Gulf war (1991)
* 240 million gallons of oil spilled
- Ex. 4. BP offshore drilling rig (April 20 2010)
* Spilling 5,000 barrels/day = 200,000 gal/day
29
Organic enrichment and eutrophication (as type of pollution)
- Eutrophication = excessive increase in chemical nutrients in an ecosystem.
- Leads to increase in ecosystem's primary productivity
- Lack of oxygen
- Severe reduction in water quality and animal populations
30
What percentage of U.S. coastal waters and Europe's Atlantic coastal water present symptoms of eutrophication?
- 78% of US coastal waters
- 65% of Europe's Atlantic coastal water
31
Map showing global distribution of eutrophic zones
32
What are the largest culprits (boosdoeners) for eutrophication?
Rivers and runoff of fertilizers and waste from
agriculture, livestock and humans
33
Exponential growth of syntethic fertilisers since 1910
34
What are the consequences of excess of in nutrients?
- Surface turbidity
- Bottom hypoxia (dissolved O2 concentration < 2 mg/ l)
This leads to the positive feedback as seen in the picture.
35
Effect of nutrient loading on primary producers (picture)
36
Role of nitrogen and phosphorus in coastal Fucus/Zostera food web (picture)
37
Global map of hypoxic zones
38
Marine litter - plastics (as type of pollution)
- Marine litter is human-created waste that has been discharged into the coastal or marine environment.
- The term Plastic generally refers to polymers that soften on heating, and can be moulded (Plasticós = Greek for “to mold”)
39
2 graphs showing the increasing of plastic and microplastic production and use
40
Frequency of occurence of polymer types in 42 microplastic debris sampled at sea or in marine sediments
41
Classification of plastic litter
42
Classification of microplastic
43
What are the main origins of microplastics?
–Fibers: Fishing nets, textiles
–Granular: shipping, sewers, packaging…
–Plastic films: tourism, shipping,…
–Spherules: scrubbers in (hand) cleansers: used in harbours.
44
Pathway of plastic entering the ocean (picture)
45
Surface ocean plastic by mass (graph)
Global: 268 950 tonnes of plastic
46
Surface ocean plastic in particles (graph)
Global: 5.25 trillion plastic particles
47
North pacific gyre
- Reaches from Japan to California, Hawaii is located near the center of the gyre.
- Water flows in a clock-wise direction.
- Plastic collects on the northern edge of the gyre where water transported by the currents builds up.
- Results in movement of organisms to new habitats where they may harm or disturb the local ecosystem.
48
MPs found in a range of organisms, and potential for trophic transfer
49
What kind of effects can microplastics have?
- Physical effects
- Chemical effects
50
Indirect effects of microplastics
- Chemical pollution: Through ingestion of toxic chemicals in and on plastic particles.
- Man-made Persistent Organic Pollutants (POPs)
51
Examples of Man-made Persistent Organic Pollutants (POPs)
1. PCBs (Polychlorinated Biphenyls)
Characteristics:
lipophilic=fat loving
carcinogenic=cancer causing
2. Pesticides like DDT (extremely toxic)
Characteristics:
lipophilic
extremely toxic
endocrine disruptors
52
What are other toxic compounds of plastic?
* Plastic is made with other chemicals, called
additives, which are toxic to living organisms:
– Plasticizers: added to plastic polymers to change plastic properties
– Flame retardants
* Plastic monomers are often harmful to living
cells:
– BPA (Bis-phenol A): endocrine disruptor = disrupts the hormones of animals, including humans
– Styrene (Monomer of Styrofoam): Carcinogenic = cancer causing
53
Noise pollution (As type of pollution)
- Type of energy pollution in which distracting, irritating or damaging sounds are freely audible.
- On land, noise is a pervasive pollutant that directly affects the health and well-being of exposed humans and wildlife; It can damage
bridges and produce cracks in buildings.
54
Zones of Noise Influence
55
Sound production of humans in the ocean
56
What type of sound travels further in the ocean?
Low frequency sounds
57
Effects of Seismic Survey on Abundance
and Catch of Cod and Haddock
58
Artficial light pollution (as type of pollution)
59
Reported biological effects of artifical light at night (ALAN)
At land studies have repoprted a variety of effects, including alterations of:
* Location of prey
* Increased prey detection
* Altered circadian rhythm
* Increased activity levels and shifted typical morning and evening activity peaks into Night
* Increased rates of tumor growth and metabolism
* Reduced nocturnal activity
* Earlier initiation of singing
* Predator avoidance and reduced food consumption
* Suppressed immune response
* Altered timing of nocturnal migration
* Disruption of seasonal acclimatization of thermoregulation
60
In the sea, what habitats are most likely to be impacted by ALAN?
- High shore habitats
- Due to a more intense exposition to outdoor nocturnal lightings (mostly from lamps along coastal streets and promenades, or within harbours, ports and marinas)
