A New Global Seafloor Geomorphic

Features Map - Applications for

Ocean Conservation and

Management

Miles Macmillan-Lawler, Peter Harris, Elaine Baker, Jonas Rupp

GRID-Arendal, Geoscience Australia, Conservation International

Why Map Seafloor Geomorphology?

• Seafloor geomorphology can be mapped at

global scale using existing data

• Is a useful surrogate for biodiversity at the global

scale. i.e Seamounts have a different suite of

species to Abyssal Plains

• Support improved management of the marine

environment (eg MSP, feature inventories)

• Can be built upon using other physical and

biological data

Heezen and Tharp, 1960’s

Interpretation of seafloor

morphology – drawn by hand!

Global Map 1977

From Agapova et al.

(1979)

Improved digital bathymetry now available!

• SRTM30Plus v7 + other data

• Features defined based on shape, slope, rugosity and TPI etc.

• Combination of automated algorithms and expert interpretation

• Minimum feature size mapped ~10 square kilometres

Geomorphic Feature Interpretation

How do we map seafloor geomorphic features?

bathymetry contours

Slope TPI

IHO Categories

Global Seafloor Geomorphic Features Map

Some interesting statistics

• 131,192 separate polygons

• 10,234 seamounts and guyots

• Passive margin continental shelf width nearly 3x that of active margins

• Polar submarine canyons are twice as large

• Large rift valley segments are associated with slow spreading rates

Application of the GSFM for management

• Pacific – PACIOCEA & EPOG

• Global MPA representativeness

• VME identification

• CCZ assessment

PACIOCEA project area

Features in the PACIOCEA project area

features in the PACIOCEA project area

What summarises the PACIOCEA project

area

• Small amount shelf and slope

• Large amount of abyssal habitats, esp hills and

mountains

• Escarpment, seamount, guyot, ridge trough

trench and plateau all represented above global

average

Classification of seamounts and guyots and

canyons

• Seamounts and guyots important features for

biodiversity.

• PACIOCEA project area contains 2784

seamounts, 93 guyots.

• Classified based on geomorphometric and

physical parameters

Seamount and guyot classificationParameter Classes Relevance

Height Small (< 2000 m)

Large (> 2000 m)

Larger seamounts cover more depth ranges and thus

potentially more species habitats

Peak Depth Shallow – photic (< 50 m)

Shallow – mesophotic (50 – 150 m)

Medium – fishable depths (150 – 2000 m)

Deep (> 2000 m)

Seamounts that extend into the photic or mesophotic

zones will support different species that those that do

not. Shallow seamounts (less than 2000m) may be

exposed to fishing pressures using current fishing

techniques.

Seamount type Seamount

Guyot

Guyots have a truncated peak and may offer different

habitat at the peak depth range than an equivalent

height seamount.

Salinity No significant variation (not used) No variation observed in the deep waters of this region

Dissolved oxygen Low (<1 ml/l)

Adequate (>1 ml/l)

Low dissolved oxygen (< 1ml/l) can inhibit some

organisms

Temperature Cold (<4 degrees)

Cool (4-12 degrees)

Warm (>12 degrees)

The temperature range 4-12 degrees Celsius represents

the temperature range for the cold water coral Lophelia

pertusa

Maximum

Bottom Current

Weak (< 0.125 ms-1)

Strong (> 0.125 ms-1)

Stronger maximum bottom currents are likely to lead to

greater disturbance and promote a different suite of

species.

Physical Data

Seamount and guyot classification

• 28 different categories of seamount

• Only 9 categories have 50 or more seamounts

Seamount and guyot classification

Global MPAs – WDPA

August 2013 version

By 2020, at least 17 per cent of terrestrial and inland water areas and 10 per cent of coastal and marine areas, especially areas of particular importance for biodiversity and ecosystem services, are conserved through effectively and equitably managed, ecologically representative and well-connected systems of protected areas and other effective area-based conservation measures, and integrated into the wider landscape and seascape.

CDB - Aichi Target 11

• 3% of the oceans in

MPAs

• 97% of MPAs in EEZs

• Majority of MPAs

small

• Majority of area from

few large MPAs

Global Status of MPAs

What features are represented in MPAs

Abyssal Plains – Globally 0.7 % in MPAs

Cape Verde

Abyssal Plain

Seamounts – Globally 2.9 % in MPAs

Kelvin seamount in

northwest Atlantic

Trenches – Globally 8.5 % in MPAs

Japan Trench

Less than 3% of MPAs are in ABNJ

TrenchesSeamountsAbyssal Plains

Representation in MPAs

Globally what’s in and what’s not?

• Feature representation ranges from 0.5 and

8.5%

• Deep water features poorly represented

• Representation of features varies in the different

oceans

• Features in ABNJ poorly represented

Questions?

miles.macmillan-lawler@grida.no

www.grida.no

www.bluehabitats.org