what a concentration represents, , and mechanisms for nutri rient - - PowerPoint PPT Presentation

Puget Sound basin dynamics, , what a concentration represents, , and mechanisms for nutri rient fl fluxes

Jan Newton University of Washington APL and WOAC Al Devol, John Mickett, Wendi Ruef, Mark Warner, and many technicians over the years

Puget Sound Chesapeake Bay

e

Newton, Stormer, UW-COFS; Data source: NGDC

Bathymetry

0 meters 200 meters

Puget Sound is fjord-like; a glacial-cut estuarine system

• It is deep
• Its nearshore

is narrow

Newton, Stormer, UW-COFS; Data source: NGDC

Implications of a steep nearshore for the ecosystem:

• It is only a narrow “fringe” of nearshore

habitat that supports many species at some point in their life cycle

• Because narrow, we have less ‘leeway’

regarding destruction of nearshore habitat

• Removing or degrading a portion of the

nearshore habitat in Puget Sound does not have the same proportional effect on the living system as in a shallow, flat estuary

Photo: PSAT 2004 State of Sound

0 meters 200 meters

Puget Sound is deep, with strong tides, but sills too

Newton, Stormer, UW-COFS; Data source: NGDC

Puget Sound circulation is retentive

Tacoma Strait of Juan de Fuca

Sill

Stormer, UW; Data source: The Sound CD-ROM” UW-APL, WA Sea Grant, 1997

“reflux”

Implications of reflux for ecosystem:

• Inputs to Puget Sound stay around for a long

time… – Long-lasting effects that can be de-coupled from source elimination

• Biota in Puget Sound have a high degree of

residency

• Both good and bad: this is why Puget Sound is

highly productive, but also highly retentive of contaminants

Photos: PSAT 2004 State of Sound

Ebbesmeyer et al., 1984

BASINS AND SILLS

PSAMP, 2002

Puget Sound Basins

Source: Puget Sound Partnership

Puget Sound Tidal Range

Finlayson, 2006

river

• cean

Estuarine circulation

Buoyant river water flows out of an estuary on surface, dense ocean water flows in at depth, but there is mixing, and sills cause “reflux” of water back in to an estuary.

Thomson, 1994

fast medium slow medium slow very slow

Residence Times

(relative)

Basins

• Hood Canal: slow

circulation, strong stratification

• Main Basin: fastest

circulation, strong mixing

• Whidbey Basin: most

freshwater input

• South Sound: strong

mixing in some locations, slower circulation

“The many faces of Puget Sound”

By Eric Sorensen

Seattle Times science reporter; Monday, June 25, 2001

“Here's how some of the Sound's personalities work:

• The South Sound is so dynamic, with channels and inlets of varying

depth, that different samplings show wildly different profiles.

• The Whidbey Basin off Everett is wonderfully productive in its top layer

to the point where the phytoplankton below 30 feet is shaded out by the phytoplankton above and the incoming sediment of the many rivers. In the lower levels, ocean water can linger and last as long as a year.

• The north part of the Sound's main basin is well-mixed, with strong

tides and sills turning the water regularly.

• The southern part of the basin is more stable, letting phytoplankton

develop more easily.

• Hood Canal has so much phytoplankton that it goes off the researchers'
• graphs. It's also less turbulent, with upper layers letting the waters warm

so much that by midsummer temperatures can top 70º F. By comparison, what's 48º F in Friday Harbor in November will be 48º F in June.”

http://community.seattletimes.nwsource.com/archive/?date=20010625&slug=pugetsound25m0

Thomson, 1994 Oceanic control is strong

Emmett, et al., 2000

Emmett, et al., 2000

WARM COLD

temperature salinity determine density

FRESH SALTY

+ less dense more dense “thermocline”

• r “pycnocline”

Water Structure Water Structure

WARM FRESH COLD SALTY

“stratified” “mixed”

Density structure can be two different ways:

Lo nutrient Hi oxygen Phytoplankton present Hi nutrient Lo oxygen No phytoplankton

And more things vary than just temp. and salinity:

Phytoplankton present No phytoplankton

{ CO2 + H2O C(H2O) + O2 }

sunlight nutrients

Photosynthesis Respiration

Basins

• Hood Canal: slow

circulation, strong stratification

• Main Basin: fastest

circulation, strong mixing

• Whidbey Basin: most

freshwater input

• South Sound: strong

mixing in some locations, slower circulation

4625 3225 3412 2900 2360 1983 2340 2186 1500

~3000 ~2000

n=19 n=19 n=5 x 80 n=30 n=8

Primary Production (mg C m-2 d-1)

>1000-2000 >2000-3000 >3000-4000 >4000-5000

Newton et al., 2000

127 67 48 27 30 41

Chlorophyll a (mg chl m-2)

<30 >30-50 >50-70 >70

32

Newton et al., 2000

• 31/372

29/50 85/77 0/0 64/11 59/54

(P / B) percent increase compared to SJF

<10 >10-50 >50-100 >100

5/19

Newton et al., 2000

What makes Puget Sound unique?

• 2nd largest estuary in the US, one of most productive in the

world

• Deep, glacial fjord average depth 62.5m, max ~280m:
• Chesapeake Bay average depth 6.4m
• San Francisco Bay average 7.6 m, max 30.5m
• Large tidal exchange: 3-4m
• Ocean-dominated salinity: Puget Sound 83% seawater vs

50% seawater for Chesapeake Bay

• Distinct basins

Source: Puget Sound 2015 Fact book, Puget Sound Institute

Problems

• Not all basins work the same, so our

monitoring needs to be distributed.

• Within a basin, there can be strong spatial

variation

• Can be strong temporal variation

High variability

370 profiles in July 2008

Representativeness critical to understanding change in highly dynamic environment. Sensor drift was found to vary 10% for the ORCA buoy oxygen sensors over one month. Using samples from monthly versus every 6 hours intervals was found to account for 50-300% variation

• r error, based on Monte Carlo sub-sampling simulations of 6-h frequency data (Devol et al.2007).

Devol & Ruef

Strong spatial variation

Latitude N Longitude W

Oct 08

Surface maps of dissolved oxygen and chlorophyll concentrations around the ORCA mooring in April 2007. Note correlations of concentration fields.

Distance (m) Distance (m) Distance (m) Distance (m) Distance (m) Distance (m)

DO chl

Devol & Ruef

Problems

• Not all basins work the same, so our

monitoring needs to be distributed.

• Within a basin, there can be strong spatial

variation

• Can be strong temporal variation
• What does a nutrient concentration really

mean?

• Do we understand the system?
• How will things be changing?

Nutrients & Chlorophyll

• Low nutrients could indicate lack of

phytoplankton (persistence of lack of nutrients, thus low biomass)

• Low nutrients could indicate a bloom

(sudden uptake of nutrients with high biomass)

• High nutrients could indicate eutrophication
• High nutrients could indicate upwelling
• High nutrients could indicate lack of

sunlight and slow growth

“In general, the symptoms contributing most to high eutrophic conditions were elevated levels of chlorophyll a, coupled with various combinations of macroalgal abundance, nuisance/toxic algal blooms, and low dissolved oxygen. High chlorophyll a concentrations is also a fairly common natural condition in some North Pacific estuaries due to naturally occurring seasonal blooms.” Bricker, S.B., et al., 1999

“These particular systems are influenced by inflows of upwelled

• ceanic water which is

low in dissolved oxygen, and therefore contributes to dissolved oxygen problems which might

• therwise be attributed

to human influence.”

Bricker et al., 2007

?

Differences between Hood Canal and Puget Sound

Near Admiralty Inlet Within Hood Canal

“ORCA” buoy data Devol, Ruef (UW)

Water quality impacts from eutrophication

• Dependent on stratification

no light no nutrients Stratified: Well-mixed: O2 debt Spring: Summer: no light

32 28 13 10 15 9 4 11 15

% increase in integrated prod’n

<5 >5-15 >15-25 >25-35

Newton et al., 2000

32/ 79 28/78 13/17 10/16 15/20 9/14 4/11 11/ 152 15/ 51

% increase in integrated / surface prod’n

<5 / <10 >5-15 / >10-30 >15-25 / >30-50 >25-35 / >50-70 >35 / >70

Newton et al., 2000

Hood Canal Vertical stratification strong

20 40 60 80

20 40 60

20 40 60 80

50 100

Chl a (ug/L)

21 Oct 1999 18 Aug 1999

Jan Feb Mar Apr May Sep Aug Jul Jun Dec Nov Oct Jan Feb Mar Apr May Sep Aug Jul Jun Dec Nov Oct

Annual cycle

2006

• 100

100 200 300 400 500 600

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percent increase in surface production

Admiralty Central Hood South Hood

Hood Canal

Newton et al., 2000

South Sound

Phytoplankton blooms appear spatially variable and dynamic

Surface chl Surface NO3

Albertson et al., 2002

• 100

100 200 300 400

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percent increase in surface production

Carr Nisqually Case Hammersley Totten

South Sound

Newton et al., 2000

Effect of nutrient spike

• 1000
• 500

500 1000 1500 2000 2500 O-98 J-99 M-99 M-99 J-99 A-99 S-99 O-99 J-00 M-00 M-00 J-00 J-00 A-00 S-00

Delta Production

(mg C m-2 d-1)

Point Wells Admiralty Inlet West Point

2000 4000 6000 8000 10000 12000 S-98 D-98 A-99 J-99 O-99 F-00 M-00 A-00 N-00

Production

(mg C m

• 2 d-1)

Main Basin

Strong temporal variability

Nakata & Newton 2004

• 100

100 200 300 400

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percent increase in surface production

West Point Point Wells Admiralty Inlet Possession Sound

Main Basin

Newton et al., 2000

Regional patterns

• Hood Canal: 1.0 - 1.5 kg C m-2 y-1

– highest P, B, ~ constant nutrient sensitivity

• South Sound: 0.7 - 1.1 kg C m-2 y-1

– high and variable P, B, nutrient sensitivity

• Main Basin: 0.8 kg C m-2 y-1

– dynamic and moderate P, B, variable nutrient sensitivity

• Strait of Juan de Fuca: 0.5 kg C m-2 y-1

– lowest P, B, strong ocean influence

Problems

• Not all basins work the same, so our

monitoring needs to be distributed.

• Within a basin, there can be strong spatial

variation

• Can be strong temporal variation
• What does a nutrient concentration really

mean?

• Do we understand the system?
• How will things be changing?

Sources of N to Puget Sound

• Land

– ground water – surface water: rivers, streams, storm water, etc. – point sources: sewage, industrial

• Water

– recycled from consumers: zpk, fish, benthos, etc. – flux from marine sediments – import from other marine areas: ocean, etc.

• Air

– atmospheric nitrogen equilibrium with water – rain – fallout of particles

Ocean Atmosphere Groundwater Rivers Surface ? % ? % ? % ? % ? % ? % ‘Storage’ Benthic ? % Watershed ? % Upward flux to photic zone ? %

Load estimates:

20 - 40 - 60 - 0-

Lower Hood Canal 3.2 Freshwater input (incl. 2.4 from septics) 9.5 Denitrification removal 40 84 Transport in* 28.5 Transport out* 9 dNO3/dt Union Belfair

Lower Hood Canal N-Budget (Mt/mo; JJAS):

39.5 dPN/dt

Concentration x flow = flux !

Nitrate Currents

The answer you get depends on how you sample…

Ocean Atmosphere Groundwater Rivers Surface ? % ? % ? % ? % ? % ? % ‘Storage’ Benthic ? % Watershed ? % Upward flux to photic zone ? %

Load estimates:

Respiration and Decay (R) : [O2] CH2O + O2 CO2 + H2O + nutrients Photosynthesis (P) : [O2] CO2 + H2O + nutrients CH2O + O2 Nutrients Stratification Devol 2003

Photosynthesis (P) : [O2] CO2 + H2O + nutrients CH2O + O2 Respiration and Decay (R) : [O2] CH2O + O2 CO2 + H2O + nutrients Nutrients Stratification Photosynthesis (P) : [O2] CO2 + H2O + nutrients CH2O + O2 Devol 2003 Euphotic zone

Problems

• Not all basins work the same, so our

monitoring needs to be distributed.

• Within a basin, there can be strong spatial

variation

• Can be strong temporal variation
• What does a nutrient concentration really

mean?

• Do we understand the system?
• How will things be changing?

Monthly solar radiation SeaTac airport (48N)

Ebbesmeyer

Variation in spring bloom

N2 Chlorophyll Solar 2005 2006 2007 Ruef

Interannual variation

Eisner et al., 1997

PNW estuaries have strong influence from climate

Global influence on:

• cean conditions

watershed conditions local weather

NASA SeaWiFS Image

<0% 0-30% 30-49% 50-69% >70%

Percent change in stratification

(10-y mean – Oct 00-Sep 01/10-y mean)

Mean = 56%

Joint Effort to Monitor the Strait (JEMS)

JEMS line

fresher, warmer water from Puget Sound and Georgia Basin flowing

• ut

colder, salty water from Pacific Ocean flowing in North Canada South U.S.A.

Flow in Strait of Juan de Fuca:

Thomson, 1994

S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A 20 40 60 80 100 Depth (m) Geostrophic Velocity (cm/s)

• 60
• 5
• 5
• 40
• 40
• 4
• 30
• 30
• 30
• 30
• 20
• 20
• 2
• 20
• 20
• 20
• 20
• 20
• 20
• 20
• 20
• 10
• 10
• 1
• 1
• 10
• 10
• 1
• 1
• 1
• 1
• 1

2000 2001 2002

Geostrophic Velocity (cm/sec)

Low River Flow

Weak Density Gradient Decreased Outflow Velocity Water stays in Puget Sound longer

Four-fold difference in speed

• f inland water outflow.

(this means how fast the water flows

• ut the Strait)

Newton et al., 2003

Conclusions

• Drought period increased the salinity of

estuarine waters, leading to higher density surface layer and weaker stratification.

• Higher salinity surface waters with weaker

vertical density gradient result in decreased

• utflow velocity and longer residence time

in estuary.

• Implications for oxygen, phytoplankton

blooms, trophic transfer, and transport or retention of larvae, species, and pollutants need further investigation.

Deep Salinity: Precipitation:

wet dry wet

Carr @ 35 m Twanoh @ 25 m

Ruef et al., 2017 Marine Waters Overview

Solutions?

• More focus on mechanisms

– Fluxes

• Sustain long-term monitoring

– Plankton, rates

• Keep finding time for analysis

– Including models

Thank you !