8 ANTHROPOGENIC ACTIVITY & MARINE BENTHOS

Question 1

Various assessments been made about variety of individual stressors and their cumulative impact on the ocean. What do most of these reflect use of?

Answer 1

Most of these reflect use of ocean for:

• food
• materials and resources including energy extraction and generation
• and space (tourism, waste disposal, territorial boundaries, military use, marine protected areas, shipping routes etc)

Question 2

Halpern et al 2008 developed an ecosystem- specific, multiscale spatial model to synthesise … global data sets of anthropogenic drivers of … change for 20 marine ecosystem to determine this global map of … impact. Their analysis concluded that … area is unaffected by human influence and that a … fraction (41%) is … affected by … drivers

Answer 2

17
ecological
anthropogenic
no
large
strongly
multiple

Question 3

Largely areas of relatively little human impact remain, particularly near…

Answer 3

The poles.

Question 4

Despite controversy, there’s general agreement that … demand for … … and resources is …

Answer 4

human
ocean space
expanding

Question 5

What is a stressor? (compensation response)
What sort of influence can they have?
What duration can they have?
What may forcing be expressed as?

Answer 5

Any physical, chemical or biological factor that requires a COMPENSATION RESPONSE by affected organisms, thus placing CONSTRAINTS on the PRODUCTIVITY & DEVELOPMENT of ecosystems.

They can have a local influence (e.g. exposed vs sheltered) or regional or global in scope.

They may be short or long term in duration & forcing may be expressed as a PULSE (snapshot in time) or PRESS (building over time) pressure.

Question 6

Stressors are … dependent and aren’t … expressed, or …, across species, habitats or seasons.

The effect of an individual stressor depends on the …, frequency and … of stress, and can lead to either semi-permanent or permanent … adjustments.

Answer 6

context
universally
received

intensity
duration
ecological

Question 7

When acting in concert, multiple stressors can either … (synergistic) or, conversely, can … (antagonistic) impacts to systems relative to those expected based on observations of single stressors.

Answer 7

exacerbate

alleviate

Question 8

Overall, the interaction effect across all studies was …, suggesting that … interactions are likely to be common in nature.

Answer 8

synergistic

Question 9

There are a multitude of stressors whose effects are modified by a vast array of complexities, but the major categories of human activities that result in major stresses on ocean can be generalised into 5 major categories:

Answer 9

1. Pollution
2. Unsustainable resource use
3. Habitat fragmentation & destruction
4. Species invasions
5. Climate change

Question 10

What did Thomas Huxley’s statement that fisheries are inexhaustible in inaugural speech illustrate?

Answer 10

How changing perspectives & knowledge may influence decisions about the relative importance of emergent stressors.

Question 11

Assuming long term change has taken place, effects of that change are less likely to be seen if a … baseline has been used relative to when a … baseline is used.

Means that as directional … continues, accepted thresholds for environmental conditions continually … - phenomenon referred to as … baselines …
^ due to lack of past info or lack of experiences of past conditions.

Answer 11

recent
historical
forcing
adjust
shifting baselines syndrome

Question 12

What is an example of shifting baselines syndrome in practice? (fish)

Answer 12

competitive angling based around catching a big fish, but what constitutes a big fish has changed over time as fisheries have been over exploited.

Question 13

What are some benthic pressures?

Answer 13

• Resource exploitation
• Waste disposal and pollution
• Nutrient loading and hypoxia
• Offshore construction & manmade object
• Sound and vibration
• Chemicals & pharmaceuticals
• Carbon sequestration

Question 14

What is the generic hierarchical impact chain linking sectors linking sectors and activities to an ecological characteristic via a specific pressure?

Answer 14

simple impact chain (sector activity -> generates pressure -> impacts ecological characteristic)

Question 15

Single sectors/specific human activities tend to have … effects.
e.g. transport of … (shipping) can result in … (petrochemicals), species … (ballast washing), noise and …, direct animal … (mammal collisions) or … (propellor turbulence, sediment resuspension)

Answer 15

multiple
good
introductions
vibration
injury
turbulence

Question 16

Multiple activities can contribute to a particular effect, and these may include … activities.
e.g. …, oil and … extraction, renewable …, … activity, and recreational … all contribute to … and vibration.

Implication - single impact chains can be resolved but multiple stressors and/or multiple activities causing same stressor become hard to resolve.

Answer 16

sectoral
transport
gas
energy
construction
activity
noise

Question 17

An ecological characteristic (e.g. a species or feature of an ecosystem) can by impacted by … sectors and multiple …, forming a complex … of …-pressure impact chains.

A separate … chain is generated for every combo of sector, pressure and ecological characteristic.

Each sector can generate … pressures, but these compounding effects can be hard to …

Most of ocean is likely to be impacted by … simultaneously occurring … that result from multiple sectors, resulting in … or complex synergistic or … interactions.

Answer 17

multiple
pressures
network
sector
impact
multiple
resolve
multiple
pressures
additive
interactions

Question 18

What is the planetary boundaries concept?

What is a safe operating space?

Answer 18

Human activities have the potential to push the earth system outside the stable environmental state of the Holocene, with consequences that are detrimental or even catastrophic for large parts of the world.

Rockstrom et al identified safe operating space using biophysical data from the Holocene as a habitable baseline.

Question 19

Not all human interventions are negative. What are the positive experiences referred to as?

Answer 19

Bright spots (observable community success beyond the norm), seeds (social, technological, economic, or social-ecological ways of thinking or doing), and hope spots (special places that are critical to health of the ocean).

Question 20

Nature based solutions are an … concept that builds on approaches that collectively use the features & complex system processes of ecosystems to achieve multiple … for nature, the … and society.

They offer potential to …, sustainably … and restore natural or … ecosystems, while providing other benefits for health, the economy, … and the …

Includes…

Answer 20

umbrella
benefits
economy

protect
manage
modified
society
environment

protection, restoration or management of natural & semi natural ecosystems, sustainable management of aquatic systems and working lands like croplands or fisheries, or the creation of novel ecosystems in and around e.g. cities.

Question 21

What are examples of resource exploitation?

Answer 21

bottom fishing
mineral extraction
manganese nodules
diamonds

Question 22

What are examples of waste disposal?

Answer 22

radioactive waste disposal
sewage dumping
marine litter