Low Dissolved Oxygen in Hood Canal

Home , Hood Canal

Hood Canal Watershed Hood Canal • 5 Major Rivers Dissolved Oxygen Program • 3 Counties • 54,000 Residents • 24,800 Homes

Jan Newton, Ph.D. Applied Physics Laboratory University of Washington

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Tuesday, September 16, 2003 The natural resources have great economic, recreational, commercial, and cultural value Hood Canal marine life struggling for oxygen By LISA STIFFLER SEATTLE POST-INTELLIGENCER REPORTER • 65-75% of the state’s Spot Shrimp are harvested from Hood Canal

• 500,000-600,000 pounds of Dungeness Crab are harvested annually in Hood Canal

Yesterday, the state Department of Fish and • The 2002 Geoduck quota was over Wildlife indefinitely closed commercial and 500,000 pounds… valued between $3-5 million recreational fishing throughout the canal for all finfish except salmon and trout, as well as octopus and squid… Source: WA Dept. of Fish and Wildlife Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Low oxygen in Hood Canal is not a new observation 2003 - UW: 1950’s observations (Collias et al., 1974 Washington Sea Grant) - UW-OSU 1970-80’s observations (e.g. Curl and Paulson, 1991, Puget • Low DO was found higher in water column Sound Research Conference Proceedings; Paulson, 1993, Mar. Chem.) • Another very sunny summer - PSAMP comparison of Ecology (90’s) and UW (50’s) data (Newton et al., 1995, Puget Sound Research Conference Proceedings) • 50,000 Shiner perch fish kill in June - Ecology’s “Washington State Marine Water Quality during 1998 through • Very low DO (anoxia) develops 2000” (Newton et al., 2001): • Substantial biota death observed by divers “Similar to our previous assessment (Newton et al., 1998a), four observations from the monitoring data indicate the possibility that DO • Another fish closure by WDFW in September conditions may be deteriorating in southern Hood Canal, that the spatial extent of low DO may be increasing northwards, and that • Very large fish kill in October eutrophication could be one of the processes contributing to this change. Impacts of other human activities (e.g., freshwater diversions) • HCDOP forms: work with ~20 entities to do what as well as natural cycles must also be fully evaluated.” is possible now and draft study plan for future • Hypoxia more frequent. • Northward increase in the horizontal extent of hypoxia. • Developed a website • High chlorophyll a concentrations observed when nutrient limitation of phytoplankton growth expected. • HCDOP Citizen Monitoring begins • Nutrient-addition experiments show that primary productivity was increased as much as three-fold (Newton et al., 1995).

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Sightings of fish kills on Hood Canal, October 8-10, 2003 WDFW observations W. Palsson What we know

Blackeyed gobies were found dead in a mat of decomposing material. • Hood Canal is exhibiting during 2003-04 the

This live spot prawn is a very unusual lowest oxygen concentrations on record. occurrence in shallow waters during the day. Many spot prawn are observed • Hood Canal, especially in south, has been Dead copper in shallow water during the low rockfish were dissolved oxygen event and many dead encountered prawns were also observed. showing a gradual increase in severity, mostly in waters between 5 and 40 persistence, and extent of low oxygen. feet in depth. • There are likely both human and natural processes involved. Which are most An astounding 80 copper rockfish influential needs to be quantified. were in this dense Most wolfeels were out of their school in water dens, which is uncommon. depths of less than Many were observed in water 20 feet. depth of less than 20 feet. Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Average Dissolved Oxygen Measurements – 1950s - 2004 Citizen Monitoring Time-series 8 Southern Hood Canal (DB to GB)

0 62 125 164 198 265 340 194 223 251 264 279 293 314 335 362

1952-3 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1965 1966 1998 1999 2000 2001 2002 2003 2004 Warner (UW) analysis of PRISM & UW Collias data Hannafious and Rose (HCSEG) analysis

UWOcean/ENVIR Historic 260 Data Winter 2006 (Collias et al.,Lecture 1974) 8 © 2006 UniversityEcology-PSAMP of Washington MonitoringDr. Jan Newton Data Where is Dissolved South Hood Canal - Sisters Point – HCB004 Oxygen a Problem?

Black=no data White=DO>5 mg/L Yellow=DO>5 and >3 mg/L Red=DO<3 mg/ L

North Hood Canal - Bangor – HCB006/8 Oxygen concentration and marine life…

good

OK bad real bad anoxic…no oxygen

The lower portion of the canal suffers from low DO levels for most of the year.

real bad…

…throughout year

• Area of low oxygen may be spreading north and • Seawater density stratification occupying greater volume. • Seawater flushing/circulation • Low oxygen present year-round. • Organic production and respiration • Hypoxia developing earlier in year. • Eutrophication/nutrient loading • Biological effects may be worsening. • Organic loading

Start with basics…. Source: J. Newton (UW), HCDOP Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Density structure can be two different ways: Organic (primary) production:

“stratified” “mixed”

WARM Lo nutrient Hi oxygen

FRESH Phytoplankton present

COLD Hi nutrient Lo oxygen “pycnocline”

SALTY No phytoplankton Respiration

{ CO2 + H2O C(H2O) + O2 }

sunlight nutrients Photosynthesis

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Oxygen structure can be two different ways: So why sub-surface low oxygen ? “stratified” “mixed”

• Light + nutrients algae HIGH OXYGEN • Algae accumulate and eventually settle to seabed WELL-MIXED • Organic material decomposition requires oxygen LOW OXYGEN

OXYGEN

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Which process dominates ? So why sub-surface low oxygen ? O2

• Light + nutrients algae Lo nutrient Hi oxygen P R • Algae accumulate and eventually settle to Phytoplankton present seabed • Organic material decomposition requires oxygen Hi nutrient Lo oxygen No phytoplankton . R Respiration • If water is stable, oxygen consumed at depth • If water is mixed/flushed, surface oxygen { CO2 + H2O C(H2O) + O2 } replenishes the deep oxygen concentration

Photosynthesis

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Hood looks like this: Hood Canal attributes

• Strong stratification – distinct layers maintained with different character Light (warmer, fresher) (the deep waters with low oxygen don’t get canal/river water mixed up) Dense (colder, salty) • High productivity – high organic load ocean water Intermediate (warming, freshening) water (that will be respired away during decomposition)

• Slow circulation – long residence time Dense (colder, salty) (the bulk of the waters are “old”; lots of ocean water respiration has occurred w/o PS or air contact) Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Compare residence times or “age” of And what about the oxygen ? waters

Light (warmer, fresher) O2 rich, Photosynthesis canal/river water NEW and air contact HIGH Low-ish O during Dense (cold, salty) 2 Lowest O2, isolated and ocean water Intermediate (warming, upwelling; higher old water with respiration freshening) water O2 else NEW OLDEST only LOWEST

Dense (cold, salty) Lower O2, respiration, ocean water no air contact MEDIUM LOW

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Add “new” nutrients from human Add carbon load: carcasses, activity: stormwater, agriculture, How do humans affect How do humans affect yard wastes, failing septic tanks, fertilized lawns, sewers, septic etc. this?? tanks, animals, etc. this??

Lo nutrient Hi oxygen Hi carbon Hi oxygen Phytoplankton present

Hi nutrient Lo oxygen Hi carbon Lo oxygen No phytoplankton Respiration Respiration Lo oxygen can Lo oxygen can get lower !!! get lower !!! { CO2 + H2O C(H2O) + O2 } { CO2 + H2O C(H2O) + O2 }

* * sunlight sunlight nutrients nutrients Photosynthesis Photosynthesis Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton What controls oxygen ? What controls oxygen ? WHAT SELECTS FOR LOW OXYGEN? WHAT SELECTS FOR LOW OXYGEN?

• Stratification • Stratification STRONG

• Organic production and respiration • Organic production and respiration HIGH • Flushing/circulation • Flushing/circulation SLOW

• Nutrient or carbon loading • Nutrient or carbon loading OCCURING

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton What could cause lower oxygen in Hood Canal attributes: Hood Canal ?

• Stratification STRONG • Stronger stratification – distinct layers maintained with different character • Organic production and respiration – Less mixing HIGH • Higher productivity – high organic load • Flushing/circulation SLOW – More nutrients, light, stable environment • Slower circulation – long residence time • Nutrient or carbon loading – Less density driven circulation OCCURING Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton What about eutrophication? Hood has high production: Primary Production (mg C m-2 d-1) >1000-2000 >2000-3000 30 >3000-4000 1500 >4000-5000 n=8 Nutrient addition 25 2186

causes 20 2340 1983 substantially 2360 n=30 15 more primary ambient 2900 10 spike production 3225 n=19 5 4625 n=19 ~3000 0

8754.2480192162917701.8097730613424930.9274728426491069.423152762342368.253683719929727.13584053346718 3412 Newton et al., 1995 Newton et al., 2000 ~2000 n=5 x 80

Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Ocean/ENVIR 260 Winter 2006 Lecture 8 © 2006 University of Washington Dr. Jan Newton Nutrient sensitivity Hypotheses on possible causes for the lower % increase in oxygen concentrations in Hood Canal: integrated prod’n • Changes in production or input of organic matter, due to <5 naturally better growth conditions such as increased sunlight or >5-15 other climate factors; >15-25 4 • Changes in production or input of organic matter, due to >25-35 naturally better growth conditions such as increased nutrient availability; 9 15 • Changes in production or input of organic matter, due to human- 10 caused loading of nutrients or organic material; • Changes in ocean properties, such as seawater density that 13 affects flushing of the Canals waters, oxygen concentration, or nutrients in the incoming ocean water; 28 • Changes in river input or timing from natural causes (e.g., drought) or from human actions (e.g., diversion) that affect both 32 flushing and mixing in the Canal. 11 15 • Changes in weather conditions, such as wind direction and speed, which affect the flushing and/or oxygen concentration distribution. Newton et al., 2000