1. Introduction to the ICEC/USNVC
Adapting to Changing Climate, Watersheds, and Ecological Interactions in the Delaware Estuary
Danielle Kreeger Science Director Partnership for the Delaware Estuary
Watershed discussion of cases study interactions, tipping points, disconnects, synergisms

2. Introduction to the ICEC/USNVC
To be discussed
The Delaware Estuary:
- types of ecological responses to climate change
- case study examples to watch in this “giant natural experiment”
Adaptation
- escalating interest
- Climate Ready Pilot
- vulnerability assessments
- management, policy challenges
- restoration or adaptation

3. Climate Change Adds Complexity to an Already Complex Landscape
Upper Watershed: “pristine” recreational area water supply for NYC Tidal River: 4th largest US urban center world’s largest freshwater port 70% of east coast oil Major industry buildup Lower Estuary: Water fowl, finfish, shellfish Horseshoe crab population
13,611 Square Miles

4. Seat of the Nation History as a “Working River”
1762 map showing Philadelphia on the Delaware River
Slides adapted from Jonathan Sharp, 2005

5. Also a “Living River”

6. Delaware Estuary

7. Introduction to the ICEC/USNVC

8. Climate Change in the Delaware Estuary
Introduction to the ICEC/USNVC
Climate Change in the Delaware Estuary
Natural Resource Responses
Disruption – species or community effects
Thresholds – non-linear bio responses
Disconnects – de-coupling ecological interactions
Synergisms – climate effects + other changes

9. Introduction to the ICEC/USNVC
Disruption
Likely Physical Changes
Temp
Sea Level Rise
Storms
Salinity
2. Example Effects on Resources
Drinking
Water
Uplands
Tidal Marshes
Shellfish
In 2006, my group prepared a white paper on the state of science and needs for science and management for our watershed.
This was a summary of the top-ten issues.
If this were the Chesapeake, we might see eutrophication and nutrients being at the to, for instance.
Because of the industrial history and population density, contaminants came out on top.
But note that tidal wetlands came in at #2. And others tie-in, such as linkages and relationships with sediment budgets, for example.

10. Introduction to the ICEC/USNVC
Species Range Shifts   

11. Opportunistic Invasive Species
Introduction to the ICEC/USNVC
Opportunistic Invasive Species

12. Introduction to the ICEC/USNVC
Will bio responses be linear?
Extent of Climate Change
Ecosystem Response
Abrupt Response
Threshold
Not necessarily…
Smooth Response
Ecosystem Response
Extent of Climate Change
Slide adapted from Carlos Duarte 12

13. Introduction to the ICEC/USNVC
Thresholds (Non-linear Responses)
Organisms, Populations: Hypoxia triggers stress, mortality
Species: Extinction is an Abrupt, irreversible Change
Slide adapted from Carlos Duarte 13

14. Harris, Nixon and Duarte, 2006. Estuaries and Coasts 29: 343–347
Introduction to the ICEC/USNVC
Global Example of Non-Linear Scaling: The Impact of Temperature Rise on Respiration and Heterotrophic Metabolism
Calculated using Metabolic models, a 4 ºC warming is predicted to:
increase net primary
production by 20%, but
increase oxygen
consumption by 43%
Seagrass Meadows
Effects are expected to be most severe in coastal ecosystems
Harris, Nixon and Duarte, Estuaries and Coasts 29: 343–347 14

15. Introduction to the ICEC/USNVC
Slide from Carlos Duarte
What are Ecological Thresholds?
Non linear shifts in ecosystem status
Tipping points or breaking points of the system
Once breached, ”recovery” may be slow or unlikely
Pressure
(Climate change)
Knowing where these tipping points are will be extremely valuable to set policy targets (Climate-driven Thresholds) 15

16. Introduction to the ICEC/USNVC
Example – Nutrients
The Expectation
Slide and principles, Duarte et al. (submitted)
Decreasing Nutrient Inputs
Increasing Nutrient Inputs
Chlorophyll
The Reality
Decreasing Nutrient Inputs
Increasing Nutrient Inputs
Chlorophyll
Ecosystem Trajectories Rarely Reverse Course
“Reference Values” are Dynamic
New Buffers Become Established to Reinforce New Steady States 16

17. Introduction to the ICEC/USNVC
Delaware Estuary Example: Oysters and Other Bivalve Shellfish
Well obviously, protect and conserve, wherever we have an opportunity
Measure natural capital and assign values to ecological service flows to increase wetland valuation (e.g. for NRDA)
From Rutgers HSRL

18. Introduction to the ICEC/USNVC
Salt Line Location
Oyster Disease and Salinity
From Rutgers HSRL
From DRBC
But as these data from the Rutgers Shellfish Lab show, population abundance measures not based on landings data show a different pattern.
These are Rutgers survey data from the upper Bay seed beds since the 1950’s.
You can see that this plot shows there was a rebound in numbers in the early 1970’s, but of course, the bottom line is that today’s numbers don’t look anything like the historical carrying capacity.

19. Salinity and Oysters
Eric Powell: A 2 parts per thousand increase in salinity over the seed beds is likely to push the oysters past a point of no return

20. Intertidal Niche Expansion?
Oyster Management Can they maintain (or be maintained) until they might see more optimal conditions?
No Help
Longer Growing Season
With Help
2 Recruitment Events
Intertidal Niche Expansion?
Point of No Return
Today
2030
2060
Historical data from Rutgers Haskin Shellfish Laboratory

21. Introduction to the ICEC/USNVC
Oyster Reef Revitalization
Eric Powell from the Rutgers lab recently estimated that in 2003 Delaware Bay (NJ seed beds only!) had 2 billion oysters.
I’ve measured average body sizes for oysters on reefs subject to commercial fishing to be 0.87 g DTW.
An average summer clearance rate was calculated from data in a recent report by Newell et al.
In summary, the total water processing by 2 billion oysters is estimated to be 11.2 billion liters per hour across the system (Note that you have probably severely discounted the total extant oyster population by as much as 50% by using Eric’s numbers that are only for a portion of the population in NJ)

22. Introduction to the ICEC/USNVC
Ecosystem Services
Why do we care about bivalves? Well, besides the commercial value of some of the species, they’re of critical importance for ecosystem services in many of the world’s aquatic systems. Like other suspension-feeding organisms living in different habitats worldwide, bivalves feed at the base of the food chain on a rich diet of microparticulate material.
In doing so, they can attain terrific population biomass and abundance, and were they do they are known to be functional dominant species that regulate key processes and provide essential habitat.

23. Clean Water Start No mussels 8 adult mussels
Slide from Catherine Gatenby, USFWS

24. Biofiltration Potential
Later
No mussels
8 adult mussels
Slide from Catherine Gatenby, USFWS

25. Marsh Mussels Freshwater Mussels CTUIR Freshwater Mussel Project
Living Shorelines 2008

26. Food Webs and Cooperative Networks
Introduction to the ICEC/USNVC
Disconnects – Decoupled Interactions
Food Webs and Cooperative Networks
Changes in phenology and or lags in range displacement with climate change
Changes in the timing of fish hatching relative to the proliferation of their predators may lead to population collapse
Slide from Carlos Duarte 26

27. Introduction to the ICEC/USNVC
Hypothetical Scenario: Decoupling of Horseshoe Crab Spawning and Shorebird Migration
Well obviously, protect and conserve, wherever we have an opportunity
Measure natural capital and assign values to ecological service flows to increase wetland valuation (e.g. for NRDA)
Website slides are from the Delaware Shorebird Project and the Horseshoe Crab Conservation Network

28. Introduction to the ICEC/USNVC
Synergisms – Climate & Other Changes Together
“… The interaction between climate change and habitat loss might be disastrous. During climate change, the habitat threshold occurs sooner. Similarly, species suffer more from climate change in a fragmented habitat.”

29. Hot Topics Land Use Change Ecological Flows Spills, NRDA Dredging
Withdrawals
Inundation, SLR
Horseshoe Crabs, Red Knots
Emerging Pollutants

30. Introduction to the ICEC/USNVC
Wetlands
So, there’s a lot of interest at the moment in what lessons we can learn from Katrina and Rita.
In many ways, the DE Estuary is much like the Gulf, with a high dependence on naturally high turbidity.
As channels are deepened, people are now asking whether this could increase net export of suspended sediments, for instance.

31. Introduction to the ICEC/USNVC
Tidal Wetlands
A Signature Trait of System
Near Contiguous Band
Diverse: Freshwater Tidal Marshes
Brackish Marshes
Salt Marshes
Ecological Values:
Structural
biodiversity
habitat for fish and wildlife
nurseries for imperiled taxa
Functional
food web
water quality
flood protection
Rutgers University
As I said, the tidal wetlands in our system are diverse, following this wide salinity gradient, ranging from fw tidal in the north to full salt marshes and salt brines in the southern areas.
Like all tidal marshes, these provide important ecological services. Indeed, due to their sheer vastness, combined with the backdrop of industry and major water quality challenges, many scientists consider these marshes to be our kidneys or lungs at the ecosystem level.
Concerns, like here in the Gulf, see level rise, combined with land subsidence and possibly increased storms, are seen as a major threat
There is a lot of interest at this time in the state of our sediments budgets.
Degradation and marsh die back

32. Introduction to the ICEC/USNVC
Degradation
This is the Athos I spill on Thanksgiving weekend, 2004.
Trash in our city parks.
Leachate from contaminated sites
There is no doubt these wetlands have faced a wide diversity of insults, and
There are reports that document many species of vegetation native to our fwt marshes are now extirpated from the system

33. Introduction to the ICEC/USNVC
Conversion: e.g., Freshwater Tidal Wetlands
Past and Present
Pre-Settlement ?
1973 (Patrick et al.) 2310 ha
1981 (NWI) ha (all classes)
597 ha (emergent)
1988 (Tiner & Wilen) 1000 ha
Estimated < 5% remains
Data tough to come by, but here is best estimate

34. Introduction to the ICEC/USNVC
1992
Tidal Wetlands
Concerns:
Degradation
Conversion & Loss
Sea level rise
Canary Creek Marsh, DE
2006
Seen at fixed locations
SLR with my own eyes
This affects our system in multiple ways – for example, salinity increase harms FWT wetlands, oyster reefs, etc.

35. Introduction to the ICEC/USNVC
Sea Level Rise and Erosion
Seen at fixed locations
and in aerial imagery
Courtesy D. Bushek, Rutgers
Combine SLR, possibly stronger and more frequent storms, larger open water bodies with high fetch, and we get rapid erosion.
This is a big problem, and often occurs in interior pond areas as well as along the high energy open shoreline.
Courtesy J. Gebert, ACOE

36. Introduction to the ICEC/USNVC
Tidal Wetlands
Concerns:
Degradation
Conversion & Loss
Sea Level Rise
Storms
Storms – we do get them, just not as frequent.
A cat 3 storm meandering into Delmarva and winding up the western side of the bay would be a bad scenario
With the tidal forcing

37. Introduction to the ICEC/USNVC
Tidal Wetlands
Concerns:
Degradation
Conversion and Loss
Sea Level Rise
Storms
Sediment budget
Living Shorelines 2008
We need sediment!
DE Estuary is naturally turbid, has a turbidity maximum in the middle estuary
But Chris Sommerfield at UDel recently pointed out that channel deepening could be altering the sediment profiles by increasing net export of TSS, effectively depriving/starving tidal marshes of their necessary sediments.

38. Introduction to the ICEC/USNVC
Sudden Wetland Dieback – Marsh Browning
Angola Neck – Rehoboth Bay, DE
Summer, 2006
Here’s another shot, and again see the green near the ditches.
I’ll talk about sediment budgets in a minute, but it does make you wonder if the ditching is altering the hydrology leading to pot-holing in the interior areas where sea level rise may offset sediment accretion rates
Slide from Chris Bason (Center for Inland Bays, DE)

39. Introduction to the ICEC/USNVC
Challenges
Introduction to the ICEC/USNVC
Disruption – direct effects
Disconnects – de-coupling effects
Thresholds – non-linear responses
Synergisms – climate + other changes
(But Let’s Be Positive) - Opportunities
Climate Change will be a giant Natural Experiment
Bivalve Shellfish and Tidal Marshes are ideal for studying climate change effects, and for testing adaptation strategies (adaptively)
Sea level, salinity, temperature and suspended sediment are important environmental factors for bivalves and marshes
Climate change will alter these environmental conditions
Land use change, channel deepening, and changes in freshwater inflow
are also likely to alter these conditions
How will bivalves and tidal wetlands respond to the combined effects?
How will their life-sustaining ecosystem services be altered?

40. Introduction to the ICEC/USNVC
So what can we do?
The Hapless Marsh

41. Plans for Adaptation Plans
Introduction to the ICEC/USNVC
Plans for Adaptation Plans
High Need
Escalating Interest
New Programs
Still.. Little On-the-Ground Action
Recent CSO Survey:
80% of coastal states plan to develop sea level rise adaptation plans
only 3 have made any progress
no standard approach
little federal coordination

42. Adaptation Needs (in addition to mitigation)
Introduction to the ICEC/USNVC
Adaptation Needs (in addition to mitigation)
Vulnerability – forecast and assess risks
Opportunity – identify activities that can help us maintain key natural resources that are vulnerable
Obstacles – identify potential barriers to action (e.g., interstate cooperation, data comparability, etc.)
Adaptation Plan – discrete recommendations for filling crucial information needs, capitalizing on the greatest opportunities, and overcoming obstacles

43. Introduction to the ICEC/USNVC
PDE Climate Ready Pilot
See poster by Cole et al.
Goal – perform a vulnerability assessment and adaptation plan for one or more case studies: tidal wetlands, shellfish, drinking water
Tasks
Vulnerability/Risk Assessment - inventory threats to natural resources using best judgment
Valuation - Assess natural goods and services that are at risk using a natural capital framework
Identify Options – List management response scenarios, including early warning monitoring needs, and prioritize adaptation options to safeguard resources at risk
Recommendations - Provide managers and policy-makers guidance on how to achieve greatest natural resource outcomes

44. PDE Climate Ready Approach
Introduction to the ICEC/USNVC
PDE Climate Ready Approach
Adaptive
Adaptation
Climate
Workgroup
Case Study
Subgroups
Prioritization
Outreach, Education, Messaging
Adaptation
Plan
Management
and Policy

45. PDE Climate Ready Pilot
Introduction to the ICEC/USNVC
PDE Climate Ready Pilot
Rigor - qualitative approach initially, but will identify future options and data needs for quantitative, geospatial-based assessments
Future
strengthen case study assessments by filling information needs
expand the approach to other critical natural resources
broaden the geographic applicability by working with other CRE pilots and NEP’s
develop “Adaptable Adaptation Plans” that can evolve as new information and feedbacks comes to light
(Contingent on public will and resources)

46. Introduction to the ICEC/USNVC
Lesson #1: Be Realistic
The Expectation
Slide and principles, Duarte et al. (submitted)
Decreasing Nutrient Inputs
Increasing Nutrient Inputs
Chlorophyll
If:
Ecosystem Trajectories Rarely Reverse Course
Reference Values are Dynamic
New Buffers Become Established to Reinforce New Steady States
Then:
In some cases, smart investments in ADAPTATION may yield greater long-term natural capital than “RESTORATION” to prior conditions
The Reality
Decreasing Nutrient Inputs
Increasing Nutrient Inputs
Chlorophyll 46

47. Introduction to the ICEC/USNVC
Tidal Wetlands Adaptation Planning Goal: Maximize long-term ecosystem health and resiliency
Tough Choices
Where will wetlands will be
converted to open water?
Where can we save them ?
Where is strategic retreat
the best option?
And what we’re here to discuss at this meeting – monitoring.
We really need to get serious about monitoring not only the extent of different wetland types, and assigning values to them, but also monitoring their health.
Why?

48. What Else Can We Do. 1. CCMP Implementation
What Else Can We Do? CCMP Implementation Continue our basic charge to restore, protect and conserve, but intelligently, accepting that in some cases the “optimal” condition is a moving target 2. Mitigation Work to slow climate change 3. Science Better understand, monitor, and predict likely consequences - disruption, disconnects, thresholds, interactions, +/- feedbacks 4. Ecosystem Modeling Explain the natural balance and functional importance of key linkages among primary resource components to be discussed in the Monday evening panel 5. Collaborate Work together to develop a coordinated adaptation strategy

49. - End -