Habitat Quality

Question 1

What are two primary ways to assess habitat quality?

Answer 1

Measuring physical attributes (e.g., water quality) and tracking species performance across conditions.

Question 2

Why is ecological context important in habitat assessment?

Answer 2

Because attributes respond differently to environmental changes, and not all indicators correlate.

Question 3

Why is it important to assess marine habitat quality?

Answer 3

Because human activities like pollution and climate change heavily impact marine ecosystems.

Question 4

What percentage of the world’s population lives near the coast?

Answer 4

Around 40%.

Question 5

What are key uses of coastal zones?

Answer 5

Fishing, recreation, shipping, waste disposal, and resource extraction.

Question 6

How long is the UK coastline compared to Europe’s?

Answer 6

UK: ~20,000 km; Europe: ~170,000 km.

Question 7

What proportion of Europe’s continental shelf is coastal?

Answer 7

About 20%.

Question 8

How does habitat degradation affect biodiversity?

Answer 8

It reduces biodiversity, impairing ecosystem function and services.

Question 9

Why are sediment-based habitats important for biodiversity?

Answer 9

They provide structure and are closely linked to ecosystem processes.

Question 10

Is habitat quality a binary concept?

Answer 10

No, it exists on a continuum.

Question 11

What concept explains changing perceptions of ecosystem health over time?

Answer 11

“Shifting baselines.”

Question 12

What happened at Boston Harbor?

Answer 12

It was heavily polluted by sewage but later showed signs of recovery.

Question 13

What issue persisted at a Singapore beach despite appearances?

Answer 13

Hidden fish kills, despite clean-up efforts.

Question 14

What affected coral reefs in a long-term degradation example?

Answer 14

Starfish predation followed by a cyclone.

Question 15

What did Darnell & Soniat (1981) focus on in their definition?

Answer 15

System integrity and service delivery.

Question 16

How did Karr et al. (1986) define habitat quality?

Answer 16

A stable, self-repairing biological system.

Question 17

What did Costanza (1992) include in habitat quality?

Answer 17

Stability, growth, complexity, and disease absence.

Question 18

What changes first under stress?

Answer 18

DNA (mutation), followed by cells, organisms, and ecosystems.

Question 19

What is an example of both a stressor and response?

Answer 19

Low oxygen levels.

Question 20

How does a managed system differ from an unmanaged one?

Answer 20

Managed systems can recover; unmanaged ones often degrade.

Question 21

How long can recovery take in coral reefs vs estuaries?

Answer 21

Weeks for estuaries; centuries for coral reefs.

Question 22

What are reference conditions?

Answer 22

Baseline conditions used to compare habitat quality.

Question 23

What challenges exist in defining reference sites?

Answer 23

Variability in definitions—may be adjacent sites, historical data, or regional averages.

Question 24

How is environmental assessment like medical diagnosis?

Answer 24

It uses symptoms + tests (indicators) to diagnose and manage ecosystem health.

Question 25

Why are macrobenthic species useful in habitat assessment?

Answer 25

They are sedentary, reflect local conditions, and show clear stress responses.

Question 26

What are EcoQOs and how are they used?

Answer 26

Ecological Quality Objectives—used to test hypotheses and monitor ecosystems.

Question 27

What are the 3 components of ecological integrity?

Answer 27

Physical, chemical, and biological integrity.

Question 28

What did Karr (1991) criticize in ecological models?

Answer 28

Oversimplified models that ignore interactions between components.

Question 29

Why is substrate alone not enough to define habitat?

Answer 29

Biological components (organisms) modify and define habitat complexity.

Question 30

What is an example of abiotic vs biotic habitat dominance?

Answer 30

Sediment flats = abiotic; oyster reefs = biotic.

Question 31

Name 3 key challenges to integrated habitat assessment.

Answer 31

Reductionist science, vague definitions of integrity, lack of standardization/quality control.

Question 32

Name 3 of the 8 common assessment approaches.

Answer 32

Indices, multimetrics, physico-ecological models. ## Footnote (Also includes: Catchment-scale, Assemblage, Process-based, Non-taxonomic)

Question 33

Why are indices popular in habitat assessment?

Answer 33

They are easy to communicate and cost-effective but may oversimplify.

Question 34

What organism was originally used in IBI?

Answer 34

Fish.

Question 35

How many metrics does the IBI include?

Answer 35

12 metrics, scored 1 to 5, total score out of 60.

Question 36

What are two IBI adaptations?

Answer 36

Invertebrate Community Index (ICI) and Benthic IBI (B-IBI).

Question 37

What did Diaz et al. (2004) find problematic about existing indices?

Answer 37

Lack of standardization, scientific justification, and holistic coverage.

Question 38

What approach did Diaz et al. recommend?

Answer 38

Functional rather than reductionist.

Question 39

What does the OSI measure?

Answer 39

Oligochaete Score Index Sediment conditions (e.g., redox, methane, oxygen, successional stage) using oligochaete worms by assigning scores. Based on: Presence & abundance of oligochaete species Species-specific tolerance to pollution

Question 40

What is BHQ based on?

Answer 40

Benthic habitat Quality Faunal analysis using sediment profile imagery. Based on: * Species composition (especially macrofauna) * Sensitivity to disturbance/pollution * Sediment features (e.g., structure, stability)

Question 41

What is the BQI and what is it used for?

Answer 41

Benthic Quality Index—combines species tolerance, abundance, and diversity; used in EU WFD.

Question 42

What are key dilemmas in habitat conservation?

Answer 42

Habitat vs species vs function? Proactive vs reactive? Defining priorities.

Question 43

What must be defined before selecting assessment tools?

Answer 43

Management and conservation goals.

Question 44

What is an IBI

Answer 44

Index of Biotic Integrity. A scientific tool used to assess the ecological health of an ecosystem, especially aquatic systems like rivers, lakes, or wetlands Combines multiple biological indicators (usually based on species present) into one score. These indicators often include: * Fish or macroinvertebrate diversity and abundance * Presence of pollution-sensitive or tolerant species * Trophic structure (who eats whom) * Reproductive or life cycle traits

Question 45

What is the Müller Pyramid and what are its levels?

Answer 45

Müller’s Objective Pyramid is a framework linking broad societal goals to practical environmental actions. Levels (top → bottom): Societal Goal – The big-picture aim (e.g., sustainability) Developmental Model – Strategy to achieve the goal EQOs (Environmental Quality Objectives) – Specific environmental aims Quality Standards – Concrete, enforceable thresholds

Question 46

What are the Assessment Approaches: Methods & Uses

Answer 46

📌 Indices – Summarizes environmental data into a single score (e.g., biodiversity index). Helps with quick comparisons. 📌 Multimetrics – Combines multiple indicators to assess ecological health holistically. 📌 Physico-ecological Models – Simulates environmental processes to predict ecosystem changes. Useful for forecasting. 📌 Catchment-scale – Evaluates watershed-level influences, understanding upstream/downstream effects. 📌 Assemblage – Focuses on species groups for biodiversity and conservation planning. 📌 Process-based – Examines ecological functions like nutrient cycling for a deeper understanding. 📌 Non-taxonomic – Uses structural or functional traits instead of species identification, useful when taxonomy is challenging.