L10- Anthropocene ocean Flashcards
why do we use the sea?
- marine resources and sea travel have been essential to the development of civilisation
- technological advances mean we can now extend our influence further from shore and into deeper waters
- exploitation of remote marine resources is becoming cost-effective as we exhaust land-based alternatives
- as result ocean is new economic frontier, with investment driving growth in existing industries and the emergence of new ones
- scientists and civil society organisations see the ocean as key for achieving climate and broad society goals
- these are considerable hopes and expectations for the ocean to sustain future human needs
how is food a claim on ocean
fishing is extedning further offshore, and into deeper waters, accessing more of ocean
-new products including neutraceutical “ superfoods” are in development
- feasibility of exploiting previousl unfished resources ( such as mesopelagic fish)
what is claim on ocean for materials
food
the OECD projects project increase in global materials use from 89gt to 167gt by 2060
increases as seen across a wide range of materials including many that we source from the ocean
material
major materials sourced from the sea include aggregates (sand and gracel) for building- projected to see largest growth
fuel
additionaly oil and gas remain the largest ocean-based industry, accounting for 1/3 of the entire ocean economy
- major recent discoveries of hydrocarbon deposits have been made offshore
- exploration is shifting into deeper wayer
- gas hydrates ( mainly methane) on the sea floor, huge source of carbon, double that of fossil fuels, are also generating interst
metals
mining the deep sea for high-value metals and minerals is a pressing topic in conservation
- deep sea ecossytem are fragile and home to many endemic species
- but in some areas there are high density of polymetalic sulfides, there contain large quantities of materials such as cobalt, nickel, manganese, lithium and copper vital to “ green” tech
- mining them on land has many negative enivronmental and social consequences
what are corresponding claim for ocean space
all of the claims for food and material have a corresponding claim for ocean space
- other space claims include
- energy infastructure
- communication infrastructure
-shipping
- conservation
result in crowded areas
what is the great acceleration
recent expansion of human activities
- concept of the great acceleration first published 2004 (updated 2015)
- documented rapid upturn in a wide range of indicators of human pressure on the earth system from the second half of the 20th century
- spread of human impacts and economic activities into the oceans mirror these trends
- termed the blue acceleration now
what is economic expansion into seas
blue acceleration includes expansion of claims for food, materials and space further into the worlds ocean
- sharpest acceleration has occurred since the start of the 21st century
- claims include renewable and non-renewable resource extraction, with mobile and stationary activities
- this acceleration increases pressure on marine ecosystems, and pushed the earth system as a whole nearer to its limit
what are blue planetary boundaries
thresholds most pushed by
- novel entities - unsure of effect of marine plastics
- biosphere integrity (genetic diversity)
- biogeochemical flows ( nitrogen and phosphorus
what is carbon sequestration, emissions and albedo of ocean
coastal marine habitats can have extremely high carbon sequestration (salt marshes >50 higher then tropical forests)
degredation of mangroves, seagrasses and coastal mashed driving emissions of similar order to deforestation, despite covering 7x less area
- difference in albedo between boreal forest and grassland is similar to the difference between sea ice ( high) and open ocean (low)
effect of degredation of mangroves, seagrass and sea ice
mangrove degredation - deforestation - reduced evapotranspiration - impact on atmospheric energy and moisture balance
seagrass degredation - turbid shallows, increased emissions impact on atmospheric energy and moisture balance
sea ice melting- open water, reduced albedo - impact on atmospheric energy and moisture balance
effect of biosphere integrity
- biosphere integrity is a core planetary boundary, central to the earth system state
has been broken down into two components -
persistence - evolutionary history
functioning- functional diversity
the biosphere integrity index has been developed as a potential way to measure this at a global sclae
what is operationalising a marine boundary
- BII could feasbily be developed for marine ecosystems but we lack data of control sites
measure of functional diversity are well established in marine ecosystems, using information on biolgical traits
there are also numerous size-based indicators developed for fisheries monitioring
- trait-based approaches could enhance current biosphere integrity measure
what is HANPP
human appropriation of net primary productivity
qualifies how much NPP is appropriated by humans (directly or via our crops and livestock)
it has been proposed as an additional planetary boundary because it quantifies effects on human-induced changes in productivity and harvest on ecological biomass flows
- marine ecosystems are responsible for 50% of global primary productivity, similar proportions of NPP flow into fisheries in shelf seas as is appropriated by humans on land
- ocean are comparable to land as carbon sink
what is future prospects of blue planetary boundaries
if planetary boundaries are to be truly representative of the world, they need to fully represent the “blue” ecosystems that cover most of the planet
- planetary boundaries have been widely adopted, but there are valid criticisms of both the detail and the overall concept
- but the need to inlude oceans is equally pressing for any other system that aims to monitor progress towards sustainability
is there equality and access of opportunity to oceans
- costs and benefits of the blue acceleration are not equitably distributed, countries differ in their degrees of access to the sea, countries differ in their capacities to benefit from marine resources
- this is true for both territorial water and more for case for waters outside of national jurisdiction (ABNJ)
- benefits of the blue acceleration disproportionately flow to economically powerful states and corporations, harms are largely affecting developing nations and local communties, small-island developing states and least-developed countries are particularly vulnerable, social and equity issues must be considered on par with environmental concerns in discussion about the ocean
what is seabed grabbing
small island developing states are becoming large ocean states- the cook island has claimed an area of extended continental shelf equivalent to 1,700 times its land surface - countries with limited or no coastline lose out
- most winners are countries that include islands and oversea territories
australia secured >2.5m KM2 of additional seabed thanks to the Heard island and the Mcdonal island, both uninhabited
the UKS total EEZ is the fifth largest in the world
