Biological resources within oceans can be used in sustainable or
unsustainable ways
Ecosystem services
The processes by which the environment produces resources used by humans such as
oxygen, food, water + minerals.
Supporting services:
Necessary for production of all other ecosystem services; soil formation, water, nutrient
cycling, photosynthesis.
Provisioning services:
Products obtained from ecosystems; food, fuel, natural medicines, fresh water.
Regulating services:
Benefits obtained from ecosystem processes regulation; air quality, erosion, water natural
hazard regulation.
Cultural services:
Non-material benefits; recreation, spiritual enrichment, aesthetics
Natural capital = Natural resources with a value to humans.
Cannot always be replaced by economic capital (value of ozone layer/Amazon rainforest in
climate regulation.
Natural income = Annual yield from natural resources.
Sustainability =
Avoidance of depletion of natural resources to meet the needs of today, without
compromising the ability of future generations to meet their own needs.
Domains of sustainable development:
Environmental = ensuring natural capital does not exceed replenishment
Economic = Conservation balanced with value of resources
Political = Public policy making
Cultural = Complexity of contemporary society
Criticisms:
Argued meaning has changed from “conservation management” → “economic
development”
Stretched to include non-renewable resources which cannot be sustainable.
Krill – renewable biological resource
Importance:
Small shrimp-like crustacea that live for about 5yrs. Inhabit upper parts of water column +
are able to swim up/down but not against currents.
• Sequester carbon = 35million car emissions/year
• 1 billion tonnes biomass estimated more than humans (computer modelling + hydro
acoustic surveys).
• Base of food web.
Resource use, stakeholders + socioeconomic context:
• 1970s commercial krill harvesting; significant industry in Southern Ocean.
• Mainly processed for direct human consumption (paste, frozen tails, oil), animal
feeds or bait in sports fishing.
• Currently only 5 countries harvest krill (Norway = 50+% annual catch).
• Concern large-scale exploitation would collapse stocks as sustainable threshold
exceeded by fishing.
Threat of warming seas:
Average Antarctic Peninsula temps risen 2.5 degrees in 50yrs.
Krill feed on algae under sea-ice at larval stage + boosts adult growth in early spring food
scarcity (nursery for young krill in 1st winter).
Phytoplankton blooms promote growth as sea-ice retreats but sea ice rapidly melting in
Antarctic Peninsula (key breeding location).
Management:
CCAMLR = Commission for the Conservation of Antarctic Marine Living Resources (1982).
25 member states of ACs + EDCs.
• Aims to monitor + regulate commercial interests in krill.
Establishing catch limits difficult due to commercial krill fishing industry.
• Decline in krill due to quantity of krill removed.
Total Allowable Catch (TAC) established – current threshold 620,000 tonnes/yr (1%
unexploited biomass).
• Increasing TAC requires harvesting to be spread over region to avoid overfishing of
Antarctic Peninsula.
Krill trawlers operate in sheltered locations around islands where dense conc. is predictable.
Main foraging area for predators (penguins + whales).
Fishing economically unviable at lower densities.
• CCAMLR stakeholders dominated by ACs
Majority long-term scientific interest in Antarctica (Australia + UK).
China’s significance reflects maritime power + large population to feed.
Conservation balanced with fishing so existing ecological relationships within Antarctic
ecosystem are maintained.
Challenges in illegal-fishing + predicting climate change. Contested maritime international
management.
Cod – renewable biological resource
Global importance:
• Food fish supply increasing at annual average rate of 3.2%, above world population
growth.
• Average consumption 9.9kg 1960 → 19.2kg 2012 per capita.
• 58 million people in fishery primary sector in 2012.
• Provides 2.9+billion people with over 20% of animal protein.
Overfishing:
• North Sea stocks decreased by 84% 1970s→ 2006.
• Catch consistently underestimated (discards not recorded). 35% global fish catches
wasted + illegal fishing estimated 26million tonnes/year
• Atlantic Cod = ‘vulnerable’ by IUCN
• Crisis in Common Fisheries Policy. 88% European stocks overexploited.
Management:
• 2017 = N.Sea cod stocks ‘sustainable’ for first time in 20yrs (maritime Stewardship
Council)
90% UK cod imported; all from regions of MSC sustainability.
Head of UK marine policy at WWF = “recovery remains fragile”
• Exploitation rate used to calculate maximum sustainable yield (MSY)
MSY > annual fish recruitment = biomass depletes
Multispecies Model (MMSY) now used to integrate food web impacts + ecology.
• New monitoring system + ‘Visual watch room’ track vessels globally to decrease
illegal fishing.
• ICEs = International Council for the Exploration of the Sea
Independent + intergovernmental scientific body.
Close cod-fisheries + cod by-catch fisheries.
Increase net mesh size to decrease immature fish catch (unpopular with fisherman as it
reduces flexibility).
• Minimum landing sizes (MLSs) enforced via port examinations to discourage
immature fish capture.