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Monterey Bay National Marine Sanctuary
Condition Summary Table

Offshore Environment | Nearshore Environment | Estuarine Environment

Estuarine Environment

The following table summarizes the "State of Sanctuary Resources" section of this report. The first two columns list 17 questions used to rate the condition and trends for qualities of water, habitat, living resources, and maritime archaeological resources. The Rating column consists of a color, indicating resource condition, and a symbol, indicating trend (see key for definitions). The Basis for Judgment column provides a short statement or list of criteria used to justify the rating. The Description of Findings column presents the statement that best characterizes resource status, and corresponds to the assigned color rating. The Description of Findings statements are customized for all possible ratings for each question. Please see Appendix A for further clarification of the questions and the Description of Findings statements. The "State of Sanctuary Resources" section of the report provides a more thorough and detailed summary of the ratings and judgments described in this table.

Because of the considerable differences within the sanctuary between the offshore, nearshore, and estuarine environments, each question found in the State of the Sanctuary Resources section of this report was answered separately for each of these environments. Though many small estuaries occur along the central California coastline, only Elkhorn Slough is located inside the boundaries of the Monterey Bay National Marine Sanctuary.

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  Questions/
Resources
Rating Basis For Judgement Description Findings Sanctuary Response
WATER
1. Are specific or multiple stressors, including changing oceanographic and atmospheric conditions, affecting water quality?
Major alternations to tidal, freshwater, and sediment processes has increased the level of pollution and eutrophication; inputs of pollutants from agricultural and urbanized land sources. Selected conditions have caused or are likely to cause severe declines in some but not all living resources and habitats. Active water quality protection program is in place and involves coordination with regulatory programs, agriculture and municipalities to reduce inputs and impacts.
2. What is the eutrophic condition of sanctuary waters and how is it changing?
Low dissolved oxygen levels and high nutrient concentrations are observed but strong tidal flushing dilutes concentrations in main channel. Selected conditions may inhibit the development of assemblages and may cause measurable but not severe declines in living resources and habitats.
3. Do sanctuary waters pose risks to human health?
?
Elkhorn Slough and connected waterbodies are impaired by pesticides and pathogens. High levels of contaminants in harvested crustaceans and bivalves could pose a risk to human health. Selected conditions have caused or are likely to cause severe impacts, but cases to date have not suggested a pervasive problem.
4. What are the levels of human activities that may influence water quality and how are they changing?
?
Substantial inputs of pollutants from non-point sources, especially agriculture. Significant efforts over past ten years to implement best management practices and educate local land owners. No evidence yet of improving water quality due to changes in land management practices. Selected activities have resulted in measurable resource impacts, but evidence suggests effects are localized, not widespread.
HABITAT
5. What is the abundance and distribution of major habitat types and how is it changing?
Over 150 years of hydrologic alteration has resulted in substantial erosion and habitat conversion. Selected habitat loss or alteration has caused or is likely to cause severe declines in some but not all living resources or water quality. Active involvement in the Elkhorn Slough Tidal Wetland Project strategic planning and science teams. SIMoN program provides support for research projects in Elkhorn Slough, including monitoring tidal erosion and modeling hydrodynamics and sedimentation.
6. What is the condition of biologically structured habitats and how is it changing?
Severe reductions in the abundance of native structure-forming organisms from historic levels. Selected habitat loss or alteration has caused or is likely to cause severe declines in most if not all living resources or water quality.
7. What are the contaminant concentrations in monument habitats and how are they changing?
Numerous contaminants present and at high levels at localized areas with limited evidence of community level impacts; on-going input of currently applied pesticides and lack of attenuation of legacy pesticides. Selected contaminants may inhibit the development of assemblages and may cause measurable but not severe declines in living resources or water quality.
8. What are the levels of human activities that may influence habitat quality and how are they changing?
Past hydrologic changes, continued dredging and maintenance of water diversion structures, and input of agricultural non-point source pollution. Management activities have the potential to reduce the input of pollution. Selected activities warrant widespread concern and action, as large-scale, persistent and/or repeated severe impacts have occurred or are likely to occur.
LIVING RESOURCES
9.What is the status of biodiversity and how is it changing?
?
Changes in the relative abundance of some species associated with specific estuarine habitats. Overall trend cannot be determined. Selected biodiversity loss may inhibit full community development and function and may cause measurable but not severe degradation of ecosystem integrity. Partnered with Elkhorn Slough National Estuarine Research Reserve to create an early detection program for non-indigenous species. SIMoN program provides support for research projects on living resources in Elkhorn Slough, including characterization of the benthic and planktonic communities in the main channel and the fish and crab assemblages in shallow-water habitats.
10. What is the status of environmentally sustainable fishing and how is it changing?
There is limited take of shellfish and mudflat invertebrates in the lower slough as well as limited fishing and hunting. New state marine protected areas reduce or eliminate fishing. Extraction takes place, precluding full community development and function, but it is unlikely to cause substantial or persistent degradation of ecosystem integrity.
11. What is the status of non-indigenous species and how is it changing?
High percentage of non-native species, no known recent introductions. Non-indigenous species have caused or are likely to cause severe declines in ecosystem integrity.
12. What is the status of key species and how is it changing?
Abundance of native oyster, eelgrass, and salt marsh are substantially reduced compared to historic levels; continued loss and conversion of salt marsh. The reduced abundance of selected keystone species has caused or is likely to cause severe declines in some but not all ecosystem components, and reduce ecosystem integrity; or selected key species are at substantially reduced levels, and prospects for recovery are uncertain.
13. What is the condition or health of key species and how is it changing?
?
No direct measurements of health or condition have been made for eelgrass and oysters, and salt marsh. Not enough information to make a determination.
14. What are the levels of human activities that may influence living resource quality and how are they changing?
?
Impacts result from hydrologic modifications, inputs of pollutants from agriculture and development, introduction of non-indigenous species, harvesting, entrainment of larvae in power plant intakes; no clear overall trend in human activities. Selected activities have caused or are likely to cause severe impacts, and cases to date suggest a pervasive problem.
MARITIME ARCHAEOLOGICAL RESOURCES
15. What is the integrity of known maritime archaeological resources and how is it changing?
?
Very little is known for this area. Not enough information to make a determination. No current management efforts directed at the two known archaeological sites within sanctuary areas of Elkhorn Slough.
16. Do known maritime archaeological resources pose an environmental hazard and is this threat changing?
No known environmental hazards. Known maritime archaeological resources pose few or no environmental threats.
17. What are the levels of human activities that may influence maritime archaeological resource quality and how are they changing?
Existing human activities do not influence archaeological resources. Few or no activities occur that are likely to negatively affect maritime archaeological resource integrity.

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