Bellingham Bay - Biological Components and Ecological Processes. State of the Bay Research Symposium Bellingham, WA

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1 Bellingham Bay - Biological Components and Ecological Processes State of the Bay Research Symposium Bellingham, WA

2 Ecosystem context Phytoplankton Nutrient inputs Salmon Salmon Intertidal communities Nutrient inputs Mississippi River/GOM Watershed Nutrient Task Force

3 Session Speakers Nearshore Salmon Habitat (Eric Beamer) Intertidal Communities - Seagrass (Marco Hatch) - Seastars (Ben Miner) Dissolved oxygen/hypoxia (Jude Apple) Mississippi River/GOM Watershed Nutrient Task Force

4 Oxygen, nutrient and plankton dynamics in Bellingham Bay Collaborative study by students and WWU and NWIC USDA Tribal Colleges Research Grants Program (TCRGP) National Science Foundation Centers for Ocean Sciences Education Excellence (COSEE)

5 Goals of Bellingham Bay Study 1. Identify spatial and temporal extent of low dissolved bottom water in Bellingham Bay. 2. Identify drivers of low dissolved oxygen Stratification Organic matter delivery from phytoplankton growth Nutrient inputs

6 History of low DO in Bellingham Bay Evidence of hypoxic waters reported by Lummi fishermen (2005) Northwest Indian College Nooksack River Bellingham Lummi Indian Reservation Nooksack Delta Bellingham Bay PPWW Jason Seber, Lummi fisherman and NWIC Student

7 Investigating Oxygen Dynamics Drop in dissolved oxygen concentrations typically begin in late June and persist through late August Decrease in bottom water dissolved oxygen concentrations at BB2 and BB3 during summer DO (mg/l) 6 BB02 BB /01 7/07 7/14 7/28 8/02 8/04 Lance Brockie (NWIC)

8 Investigating Oxygen Dynamics High resolution transects of water column profiles in Bellingham Bay. Conducted during summer 2011 and COSEE PRIME Intern Sarah DeLand (WWU)

9 Summary of patterns in bottom water DO Hypoxic waters occur where bottom-water residence time is longer and organic matter deposition may be higher rather than in the deepest part of Bellingham Bay. Oxygen mapping (July 2011) LiDAR image courtesy of Eric Grossman (USGS) From Rubash and Kilanowski 2007 Volume of low DO (<4mgO 2 L -1 ) waters in July 2011 was 35.9 x10 6 m 3 (approx. 14,000 Olympic swimming pools)

10 Low DO is not limited to bottom waters Evidence of upward mixing of low DO bottom water into the water column (July 2011 and 2013) Natasha Christman (UW) 2013 Summer Research Internship Physical and microbial drivers of hypoxia in Bellingham Bay

11 Sub-surface sensor array deployment 10m 20m from bottom 10m from bottom Oxygen sensor and housing 1m from bottom Research Intern Natasha Christman (UW) retrieving subsurface sensor array

12 Sensor array data at 20m from bottom June 25 th July 24 th, 2015 Nooksack flow full moon (spring tides) DO (mg/l) 3 rd quarter (neap tides) Temperature

13 Recap on Oxygen Dynamics Timing of low dissolved oxygen in bottom waters is generally predictable each year (June Sept) Generally located in the north central region of Bellingham Bay in the region of lowest bottom water residence time. Low DO is driven by oxygen consumption associated with degradation of organic matter Despite this predictability Location of low DO in the water column is highly variable on short temporal/spatial scales ( snarks ) Intrusion of low DO water into the overlying water column associated with spring tides and turnover

14 Goals of Bellingham Bay Study 1. Identify spatial and temporal extent of low dissolved bottom water in Bellingham Bay. 2. Identify drivers of low dissolved oxygen Stratification Organic matter delivery from phytoplankton Nutrients

15 Drivers of hypoxia Export of organic matter Stratification Decomposition (oxygen consumption) Mississippi River/GOM Watershed Nutrient Task Force

16 Water column stratification Determined by evaluating difference in density between surface (0.5m) and 10m depths Highest degree of stratification in summer months. Influenced by temperature, river flow (salinity), and tidal mixing (e.g. spring tides in mid July) Average of all water column data for that sampling date Figure courtesy of Gabriela Zayas del Rio

17 Effect of carbon export on bottom water D.O. Conducted laboratory experiments using bottom water Bottom water oxygen consumption is carbon limited Respond quickly to carbon additions (e.g. sinking phytos) Data from SPMC COSEE Intern Natasha Christman ( )

18 Field observations corroborate carbon limitation Sinking phytos fuel decrease in bottom water DO July 10 July 17 July 24 Surface waters Pseudo-nitzschia Bottom waters none in bottom waters low surface abundance Data from work with Dr. Robin Kodner and Ciara Asamoto (WWU)

19 Recap Extent of hypoxia is generally predictable, but location in the water column is dynamic. Stratification and varies throughout the year Water column is more stratified in summer months Mixing from spring tides disrupts summer stratification Oxygen consumption (respiration) responds quickly to organic matter delivery Lab experiments show phytoplankton carbon can drive low DO Field observations reveal a link between bottom water oxygen consumption and sinking phytoplankton from the surface

20 Where to go from here? Work with modelers to integrate in situ measurements into existing circulation models Use models to predict transport of low DO waters into water column and nearshore habitats Reduce organic matter delivery and production Riverine input of woody debris Nutrient management to reduce phytoplankton blooms, considering timing of loading and nutrient ratios (e.g. Ecology Nooksack data)

21 Speakers to follow Lets move up into the food web Seagrass in Portage Bay. Marco Hatch, National Indian Center for Marine Environmental Research and Education at NWIC Sea Star Wasting Disease in Bellingham Bay and the Salish Sea, Ben Miner, Marine Ecologist at Western Washington University Juvenile Chinook Salmon Assessment of the Nooksack Estuary and Bellingham Bay Nearshore. Eric Beamer, Skagit River Cooperative

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