Transcript Spatial and Temporal Nutrient Patterns in Coastal Waters of Kaloko-Honokōhau Tracy Wiegner1, Jason Adolf1, Jim Beets1, Rebecca Most2, Erik Johnson2, and Judy Walker2 1Marine 2Tropical Science.

Spatial and Temporal Nutrient Patterns in Coastal Waters
of Kaloko-Honokōhau
Tracy Wiegner1, Jason Adolf1, Jim Beets1, Rebecca Most2,
Erik Johnson2, and Judy Walker2
1Marine
2Tropical
Science Department, University of Hawaii at Hilo
Conservation Biology and Environmental Sciences Graduate Program,
University of Hawaii at Hilo
Groundwater is the predominant freshwater source to leeward coasts
on the Hawaiian Islands
Coral Reef
Preliminary Questions to Identify ‘Hot Spots’
of Biological Transformations
1. How do surface water dissolved nitrogen (N) concentrations
vary spatially and temporally?
2. How do the relative percent contributions of N forms to the
dissolved N pool vary spatially and temporally?
3. How do dissolved N concentrations change with depth and
vary temporally?
Site: Kaloko-Honokōhau
Approach
1. Map surface water characteristics
using a water quality sensor
2. Collect pelagic and benthic water
quality samples
Aerial infrared imagery from C. Glenn.
Sampling
Stations
Fish
Pond
How do surface water dissolved N
concentrations vary spatially and
temporally?
Salinity
ppt
May 2010
High concentrations of NO3- & DON were found
near the fish pond with low salinity waters
July 2010
Nitrate
µM
May 2010
Concentrations & spatial
patterns varied between
months
July 2010
DON
µM
May 2010
July 2010
How do the relative
% contributions of
dissolved N forms to
the dissolved N pool
vary spatially &
temporally?
MAY 2010
NO3DON
Increasing %DON
%DON increased offshore
%NO3- increased inshore
JULY 2010
Relative percentages
changed monthly, but
spatial patterns were
consistent
Changes occurred within
200 m of fish pond wall
Increasing %NO3-
How do dissolved N concentrations change with depth
& vary temporally?
Depth Profiles at Station 14
NO3- Conc. (µM)
Salinity (ppt)
35
0
40
2
4
0
0
0
1
1
1
2
2
2
3
3
3
4
5
Depth (m)
0
Depth (m)
Depth (m)
30
DON Conc. (µM)
4
5
6
6
7
7
8
8
10
20
4
5
6
6/22/2010
7/27/2010
7
8
Concentrations decreased with depth & profile patterns were consistent between months
Thank you!
Gillian Wysock, Mauritius Bell, Jonatha Giddens, Kerrie
Krosky, Joao Garriques, Brain Yannutz, Caitlin Kryss,
Ambyr Mokiao-Lee, Nakoa Goo, and Jackie Troller
And our partners at the NPS:
Sallie Beavers and Lindsay Cramer