Description: <DIV STYLE="text-align:Left;font-size:12pt"><P STYLE="margin:0 0 11 0;"><SPAN>Detrital absorption (DET) measures the amount of light absorption in the blue part of the spectrum (wavelength 443 nm) by detrital material. Detrital material includes both coloured dissolved organic matter (CDOM) and suspended sediment covered by an organic surface film. CDOM is a complex mixture of acids formed from the breakdown of organic matter in soil or water. Elevated levels of detrital absorption near coasts can indicate increased freshwater inputs to the coastal zone. Measuring variations in detritus (CDOM and suspended sediment) along with phytoplankton are important to enable better understanding of ecological systems, carbon cycles, and water quality related concerns. Variation in light penetration and wavelength due to detrital material and CDOM can influence the growth of different types of macroalgae in different ways. For example, red algae showed better photosynthetic performance when light attenuation was dominated by phytoplankton and detrital matter compared to green and brown algae, which performed better when particulate matter from sediment caused attenuation (Thoral et al. 2023). This layer shows the total detrital absorption coefficient estimated using a quasi-analytic algorithm (QAA) applied to MODIS-Aqua data based on Pinkerton et al. (2018), blended with adg_443_giop ocean product (Werdell, 2019). Resolution is at 500m coastally and 4km offshore of absorption per meter.</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN STYLE="font-weight:bold;">Reference:</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Pinkerton, M.H. (2018). Ocean colour satellite observations of phytoplankton in the New Zealand EEZ, 1997–2018. NIWA report MFE18301-2018180WN, Prepared for Ministry for the Environment, June 2018. Pp 56.</SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Thoral, F., Pinkerton, M.H., Tait, L.W., Schiel, D.R. (2023). Spectral light quality on the seabed matters for macroalgal community composition at the extremities of light limitation. Limnology and Oceanography, 68(4), p 902-916.</SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN>Werdell, P. J., Behrenfeld, M. J., Bontempi, P. S., Boss, E. S., Cairns, B., Davis, G. T.,et al. (2019). The plankton, aerosol, cloud, ocean ecosystem (PACE) mission:status, science, advances. Bull. Am. Meteorol. Soc. 100, 1775–1794.</SPAN></P></DIV>
Service Item Id: af04b9230428489c8db732327323722c
Copyright Text: National Institute of Water and Atmospheric Research Ltd. (NIWA)