25ab69a8-f41c-4236-a56f-1eec667434ac urn:uuid eng UTF-8 nonGeographicDataset nonGeographicDataset 2025-06-23T06:47:37 creation ISO 19115 2016 2016 SoE Marine Chapter - State and Trends - Seamounts 25ab69a8-f41c-4236-a56f-1eec667434ac The Marine chapter of the 2016 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Expert Assessment "The state and trends of quality of habitats and communities – Seamounts". The full Expert Assessment, including figures and tables (where provided), is attached to this record. Where available, the Data Stream(s) used to generate this Expert Assessment are accessible through the "On-line Resources" section of this record. DESCRIPTION OF HABITAT/COMMUNITY FOR EXPERT ASSESSMENT Seamounts (undersea mountains, often with volcanic origin) provide ‘oasis’ habitats of hard substratum and are widely considered to represent sites of elevated biomass and productivity in the deep ocean. Their habitats can support dense aggregations of corals and associated high biodiversity; these represent vulnerable marine ecosystems (VME) (e.g. UNGA 2006; Clark et al 2011). The geological definition of a seamount (elevation of >1000 m) has no relevance to biodiversity valuation because smaller features are frequently found to support high, if not the highest, biodiversity. An ecological definition (e.g. Pitcher et al. 2007) is recommended. Australia’s marine realm encompasses many seamounts; the best known are the Tasmanian seamounts and the Tasmantid seamount chain. Additional seamounts have been discovered and mapped on the Lord Howe Rise and the Norfolk Ridge, as well as on Australia’s southern margin in the GAB. Seamount communities to ~1500 m depth in the south-east and south-west regions are associated with biogenic habitats formed mostly by the stony coral Solenosmilia variabilis (Koslow et al 2000; Thresher et al. 2014). Its matrix of dead and life coral, built up to a layer of at least 1.6 m thickness in places, forms a habitat for other corals, urchins, brittle- and snakestars and crustaceans (Thresher et al. 2014). Communities and habitats on deeper reaches of seamounts (>1500 m) are less well studied; they are usually less diverse and sparser, although areas of extraordinary high biomass have been observed in the south-east region (Thresher et al. 2014). The seamounts in the Tasmantid chain are mapped and well used by various commercial fisheries, but their epifaunal communities remain poorly documented (Williams et al. 2012). DATA STREAM(S) USED IN EXPERT ASSESSMENT This assessment is based on data derived from Marine National Facility Surveys described in MarLIN (http://www.marine.csiro.au/marlin/search.html) and accessible through the CSIRO Data trawler (http://www.cmar.csiro.au/data/trawler/). Links to specific data sets are provided in the "On-line resources" section of this record. • Voyage of Discovery north-west (SS05/2007) • Voyage of Discovery south-west (SS07/2005 & SS10/2005) • Tasmanian seamounts surveys (SS01/2000, SS04/2006 & SS02/2007, SS01/2008 & TT01/2008) • Habitat Mapping (SS01/2000, SS04/2004) • Habitat and population assessment of giant crabs (2003 - 2005) • NORFANZ survey of Lord Howe Rise and Norfolk Ridge (TAN0308 - NORFANZ) 2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details] • 2016 • Assessment grade: Very good-Poor Assessment trend: Stable- Improving Confidence grade: Adequate high quality evidence and high level of consensus Confidence trend: Adequate high quality evidence and high level of consensus Comparability: Grade and trend are somewhat comparable to the 2011 assessment • 2011 • Assessment grade: Very good Assessment trend: Stable Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus CHANGES SINCE 2011 SOE ASSESSMENT There is substantial information on the impact of trawling on seamounts in the South-East Marine Region available. {"type": "Polygon", "coordinates": [[[102.65625000000001, -47.4609375], [162.421875, -47.4609375], [162.421875, -7.207031249999999], [102.65625000000001, -7.207031249999999], [102.65625000000001, -47.4609375]]]} 102.65625000000001 162.421875 -47.4609375 -7.207031249999999 biogenic habitat epifaunal community expert assessment seamounts State_and_trends_seamounts_final.pdf documentDigital EXPERT ASSESSMENT - Seamounts [direct download] PDF DATA STREAM USED IN EXPERT ASSESSMENT - Voyage of Discovery north-west SS 05/2007 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Voyage of Discovery south-west SS 10/2005 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Tasmanian Seamounts surveys SS 01/1999 [survey details only, no data currently available] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Tasmanian Seamounts surveys SS 11/2006 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Tasmanian Seamounts surveys SS 02/2007 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Tasmanian Seamounts surveys SS 01/2008 [survey details only, no data currently available] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Tasmanian Seamounts surveys TT 01/2008 [metadata only] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Habitat Mapping SS01/2000 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Habitat Mapping SS04/2004 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Habitat and Population Assessment of Giant Crabs 2003-2005 [online access point] documentDigital HTML DATA STREAM USED IN EXPERT ASSESSMENT - Norfolk Ridge / Lord Howe Rise Biodiversity Discovery Survey (NORFANZ) [online access point] documentDigital HTML State of the Environment (SoE) reporting webpage documentDigital HTML