2016 SoE Marine Chapter - State and Trends - Water column, slope (250 m - 700 m)

Brief description

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 habitats and communities - water column, slope (250 m -700 m)". 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 The major determinants of pelagic habitat can be considered to be temperature (T), salinity (S), light, nutrients, dissolved oxygen (DO), pH, and food availability. The slope waters around Australia are generally warm, saline, well illuminated, low in nutrients, phytoplankton, zooplankton and fish. The primary pressures affecting the pelagic biota in slope waters are related to climatic cycles (e.g. ENSO) and long term climate change impacting on T, S, DO, pH and fishing. The slope waters are particularly sensitive to changes in our boundary currents, the EAC and the Leeuwin which generally flow south, seaward of the shelf break. The pelagic productivity of the slope waters provides most of the food to animals in these waters and on the bottom. The shelf edge canyons can enhance upwelling or ‘capture’ eddies that act to focus phytoplankton into these features. Data collection is sparse but IMOS continuous plankton recorder (CPR) routes around Australia sample largely from this region. DATA STREAM(S) USED IN EXPERT ASSESSMENT Data are computed from the level 3 (L3) daily global products using one merging method following Maritorena and Siegel, (2005). Details can be found at http://www.globcolour.info/products_description.html ---------------------------------------- 2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details] • 2016 • Assessment grade: Good Assessment trend: Unclear Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus Comparability: Grade and trend are comparable to the 2011 assessment • 2011 • Assessment grade: Good Assessment trend: Stable Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus ---------------------------------------- CHANGES SINCE 2011 SOE ASSESSMENT This assessment uses observations from a greater range of spatial and temporal scales allowing a much better assessment of current state and trends to be made. There is also a statistical analysis of temporal change in zooplankton biomass.

Lineage

Statement: QUALITY OF DATA USED IN THE ASSESSMENT Spatial and temporal coverage are excellent. Conversion of ocean colour to chlorophyll a introduces a source of potential error. Data could be extracted for each region to allow improved regional assessments of state and trend.

Notes

Purpose
To describe the state and trends in the quality of the water column community, slope (250 m - 700 m) for use in the Marine chapter of the 2016 State of the Environment report.