Climate Change Sensitivity Database
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» Marine: Deltas and Estuaries
Marine: Deltas and Estuaries
Submitted by Jorge Tomasevic on Fri, 2012-06-01 09:59
Direct sensitivities to changes in temperature and precipitation:
There are two ways to consider a system's direct sensitivity to changes in temperature and precipitation; 1) Does the system inhabit a relatively narrow climatic zone(s) (making it more sensitive)? and 2) Does the system show large changes in composition or structure in response to relatively small changes in temperature or precipitation (making it more sensitive) or conversely, would it take much larger changes in temperature and precipitation to elicit a change in composition or structure (i.e., a less sensitive system)?
How sensitive is this system to temperature (means and extremes):
Confidence in the direct sensitivity to changes in temperature and precipitation:
How sensitive is this system to precipitation (means and extremes):
Marine systems were assessed during a March 2012 workshop of experts. 1. Impacts related to changes in air temperature The pollen record from the Holocene provides information that reduces the uncertainty about the effects of climate change on this system. This information may be particularly useful to assess impacts on estuarine systems. Increases in air temperature could cause more drying, especially in low tide systems (e.g. eel grass and epiphytes desiccation may increase). Low marsh is very sensitive while high marsh is less so. Scrub shrub and forested wetlands are relatively resilient. May loose a few certain species, but since there’s no dominant species (it’s a complex and large assemblage), the overall functionality is likely to be resilient to air temperature increase. These systems are sensitive to the rate and the timing of the change. 2. Impacts related to changes in precipitation Precipitation itself won’t change much. Fresh water inflow will be more influential. But since most of these systems have been cut off from natural freshwater inflows due to land use/river alterations, they are more resilient to changes. These systems might lose some invasive species like reed canary grass because increased salinity in summer.
More sensitive systems will show larger changes in composition or structure in response to small changes in indirect factors, such as disturbance regimes. Conversely, it would take much larger changes in these factors to elicit a change in composition or structure in less sensitive systems.
How sensitive is this system on one or more indirect factors:
Confidence in the sensitivity to indirect factors:
Please select all indirect factors upon which this habitat is sensitive:
Marine systems were assessed during a March 2012 workshop of experts. The following are the individual scores that each expert identified (first number is sensitivity and the second is the associated confidence): * Water temperature (6, 4) * water chemistry (5, 2) * sea-level rise (4, 4) * flooding (3, 4) * coastal erosion: (1-5, 3), * wave action (1-5, 3) * currents (1, 1) * storms (1-5, 3) * disease (emphasis on eelgrass? and parasites) (5, 1). Water temperature: it is a major factor driving physiology and respiration. It highly influences the sensitivity of the system. Also, water chemistry may be affected, increasing acidification. Sea level rise (SLR): Sediment discharge will make east side of Puget Sound different than the Olympic Peninsula. Discharge is going up, and sediment delivery will go up. For example, Padilla Bay has eroded because of loss of sediment delivery resulting on cut off from Skagit River. It is likely that SLR may create an opportunity to add estuary habitat in some places. Flooding: fresh water flooding is beneficial for estuarine systems, because it delivers sediment and nutrients, large woody debris, etc. Synergistic effects of multiple factors acting together have not been considered (e.g. Hood canal ocean intrusion of low oxygen water getting over the sill with SLR and high tide and storm, then it gets stuck there changes the ecology of the system). Coastal erosion: most of these systems are well protected. Flats that are exposed are more vulnerable (e.g. Skagit, Snohomish). Outer flats (score 5 above) are more sensitive than protected areas (score 1 above). Wave action: same as coastal erosion. Currents: not relevant to Estuarine systems. Disease: Eelgrass wasting disease is affected by temperature and salinity. Increased stress will also increase disease rates and susceptibility, while increased temperature will likely have a net increase in propensity for disease. Parasites should be bundled with disease. Overall there is high uncertainty of the effects that this factor will have on the systems.
Sensitivity to impacts of other stressors:
To what degree do other, non‐climate‐related threats to the system make it more sensitive to climate change:
Confidence in the degree to which non‐climate‐related threats affect the systems’ sensitivity to climate change:
Please select all of the stressors that make the system more sensitive to climate change::
Other, please describe in Comments below
Marine systems were assessed during a March 2012 workshop of experts. Other: water regulation, aquaculture. Coastal development is high on this system. Land use change in watershed affects both pollution and hydrology. Other factors such as water regulation and aquaculture (60% of Willipa bay flats are affected by aquaculture) also play a role on the overall sensitivity of this system.
Are there other critical factors that have not been addressed that will likely make this system more sensitive to climate change?*
Please include any other factor that you may consider critical to understand the potential response of this system to climate change that was not represented with the previous questions. If no other factors apply, please leave it blank but specify your confidence associated with this question.
Collectively, to what degree do these factors make the system sensitive to climate change:
Confidence in the degree to which these factors make this system sensitive to climate change:
What weight should these factors have on the overall sensitivity of this system to climate change:
Marine systems were assessed during a March 2012 workshop of experts. Population change and a change in local/regional policies. Public attitudes/values regarding adaptation Synergistic effects.
Overall User Ranking
This question is not included in the sensitivity score.
Overall User Ranking:
In your opinion, how would you rank the overall sensitivity of this system to climate change:
Confidence in your overall assessment of the sensitivity of this system to climate change:
Marine systems were assessed during a March 2012 workshop of experts. Experts would assign a 4 for a more adaptive capacity and a 5 for systems with less adaptive capacity; also considering variability in public policies, attitudes and values Since these systems can handle wide variations in climatic conditions, climate change is a moderate threat. Although, it depends on how humans manage the systems and whether we reduce the anthropogenic stressors. If these systems are opened up and restored by removing dikes, they’ll be even more resilient and functional. Those systems that are less able to get sediment are much more vulnerable. Also those experiencing higher rates of sea level rise. Coastal erosion could influence these systems. Puget Sound systems will be less sensitive than coastal systems. Lagoons have high biomass, but low diversity. Few species can tolerate extremes of variation found in lagoons. There are different kinds of currents: o Cal current vs. other: hypoxia events may be driven by these. o Local tidal currents should stay the same. o Wind driven currents may change, and this important because of mixing. These systems are well adapted to variability, but human imposed changes can push it over the edge.
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