Chapter 15: Disturbance, Pollution, and Climate Change

Question 1

how do human activities modify the marine environment?

Answer 1

• removal of biomass

- addition of contaminants and physical structures

Question 2

what oceanic region experiences the highest interference from human activities?

Answer 2

coastal shelf areas

• due to being too populated
• mouths of estuaries & bays being safe anchorages and convenient land access

Question 3

coastal shelf environments subjected to the most intensive human activities include what?

Answer 3

• fishing
• aquaculture
• mineral and hydrocarbon extraction
• shipping activities
• tourism
• discharges of effluent and pollutants

Question 4

in order to evaluate the relative ecological imporatance of human interference, its necessary to understand what 2 overlying concepts?

Answer 4

• how marine communities respond to ecological disturbance and environmental change
• to assess the significance of human activities against the scale and frequency of natural sources of disturbance

Question 5

Natural fluctuations

Answer 5

Natural sources of disturbance, due to dynamic processes that affect ecological processes and the structure of communities and habitats such that they are in a continuous process of change

Question 6

Ecological disturbance

Answer 6

any discrete event in time that disrupts ecosystem, community or population structure, and changes resources, substratum availability or the physical environment

Question 7

what is the typical pattern of recolonization? (>1m)

Answer 7

• reduction in resident species’ number and abundance
• short term immigration (2-3 days) of scavenging spp
• longer-term (months to years) recolonization thru larval recruitment

Question 8

Intermediate disturbance hypothesis

Answer 8

moderate disturbance are large enough to create openings for colonizing species in disturbed areas, but mild and infrequent enough to allow the survival of some mature spp in undisturbed areas.

Question 9

what are the three categories of measuring the effects of human activities?

Answer 9

-Univariate responses: measure responses of single factors (ie: sp diversity index)
-Multivariate responses: measure the resonses of ore than one spp
-Distributional techniques:
measures the distribution of indi. or biomass among an assemblage of organisms

Question 10

when measuring species diversity, to ensure efficiency it is important to account for what?

Answer 10

measure at a scale in which an agent of change may operate

Question 11

Biodiversity indices

Answer 11

measure the degree to which species or organisms in a sample are taxonomically or phyogenetically related to each other

Question 12

Multivariate techniques

Answer 12

compare two or more samples based on the extent to which these samples contain the same or different species at varying levels of abundance, and incorporate both species’ identity and abundance or biomass

Question 13

the experimental approach

• why
• how

Answer 13

the right way to look for ‘cause and effect’

• ask correct question at the outset
• compare to a control
• able to replicate
• strong biological gradients need to be taken into consideration
• no pseudo-replication

Question 14

what type of areas are particularily susceptible to eutrophication?

Answer 14

-restricted tidal inundation
-poor water exchange
-susceptible to stratification
(fjords, enclosed bays, areas w/ relatively deep waters

Question 15

what are some effects of climate change?

Answer 15

• sea level rising
• water column warming
• precipitation
• wind speed and patterns
• water-column circulation
• frequency and intensity of storms