Primary production and nutrients in Darwin Harbour, Northern Territory

On three trips (in February and October 2004 and February 2006) samples were collected in Darwin Harbour.Primary production, respiration, nutrient fluxes and N fixation were measured.Surface-to-near bottom profiles of temperature and salinity were obtained at each site by CTD. Additional samples were analysed for Chlorophyll a, particulate nitrogen, phosphorus and suspended solids.Dissolved inorganic nutrients (ammonium, nitrate, nitrite and phosphate) concentrations were determined. DON and DOP concentrations were calclulated.Experiments were conducted to determine differences in phytoplankton production and pelagic respiration at different stages of the tide. Phytoplankton growth rates were measured on the basis of changes in concentrations of chlorophyll a using the dilution method.Dissolved oxygen concetration and 15N-nitrogen uptake were determined.Net community production (NCP) and community respiration (CR)were estimated. Gross primary production was calculated as the sum of NCP and CR.
To determine the main sources of primary production and the sources of nutrients supporting growth in a macrotidal estuary, Darwin Harbour.

在2004年2月、2004年10月及2006年2月的三次科考航次中，研究团队于达尔文港(Darwin Harbour)采集了样品。本次研究测定了初级生产力、呼吸作用、营养盐通量以及固氮作用相关指标。通过温盐深仪(CTD, Conductivity-Temperature-Depth)在每个采样站点获取了从表层至近底层的温度与盐度剖面数据。额外采集的样品被用于分析叶绿素a(Chlorophyll a)、颗粒氮、颗粒磷以及悬浮颗粒物含量。测定了溶解无机营养盐——包括铵态氮、硝态氮、亚硝态氮以及磷酸盐——的浓度，并计算了溶解有机氮(DON, Dissolved Organic Nitrogen)与溶解有机磷(DOP, Dissolved Organic Phosphorus)的浓度。开展相关实验以探究不同潮汐阶段下浮游植物生产力与浮游水体呼吸作用的差异。采用稀释法，基于叶绿素a浓度的变化测定了浮游植物的生长速率。测定了溶解氧浓度与15N-氮摄取速率。估算了净群落生产力(Net community production, NCP)与群落呼吸作用(Community respiration, CR)，总初级生产力通过NCP与CR的加和计算得到。
本数据集旨在阐明强潮河口达尔文港内初级生产力的主要来源，以及支撑浮游生物生长的营养盐来源。