National Park Service

State of the Park Reports

State of the Park Report for Salem Maritime National Historic Site

Natural Resources

Derby Wharf extends ½ mile into Salem Harbor and is a popular resource for public recreation and interpretation.
Derby Wharf extends ½ mile into Salem Harbor and is a popular resource for public recreation and interpretation.

The crisp ocean air and salt water of the park waterfront, and scenic views including wildlife on the waters of Salem Harbor, are part of the experience of Salem Maritime NHS. Ecological habitats in the park are limited to the shoreline, a small lawn and beach next to Derby Wharf, and patches of vegetation among the developed landscape. However, the interaction between the ocean and the historic wharf and waterfront buildings is one of the defining features of the park, and the predicted threat of sea level rise and increasing storm intensity will continue to be a central management challenge into the future.

View list of natural resource information sources

The Status and Trend symbols used in the summary table below and throughout this report are summarized in the following key. The background color represents the current condition status, the direction of the arrow summarizes the trend in condition, and the thickness of the outside line represents the degree of confidence in the assessment. In some cases, the arrow is omitted because data are not sufficient for calculating a trend (e.g., data from a one-time inventory or insufficient sample size).

Condition Status Trend in Condition Confidence in
Assessment
Condition of resource warrants significant concern Warrants Significant Concern Condition is improving Condition is Improving High confidence in the assessment High
Condition of resource warrants moderate concern Warrants Moderate Concern Condition is unchanging Condition is Unchanging Medium confidence in the assessment Medium
Resource is in good condition Resource is in Good Condition Condition is deteriorating Condition is Deteriorating Low confidence in the assessment Low

Examples of how the symbols should be interpreted:

Resource is in good condition; condition is improving; high confidence in the assessment. Resource is in good condition; condition is improving; high confidence in the assessment.
Condition of resource warrants moderate concern; condition is unchanging; medium confidence in the assessment. Condition of resource warrants moderate concern; condition is unchanging; medium confidence in the assessment.
Condition of resource warrants significant concern; trend in condition is unknown or not applicable; low confidence in the assessment. Condition of resource warrants significant concern; trend in condition is unknown or not applicable; low confidence in the assessment.
Air Quality Condition of resource warrants significant concern; condition is unchanging; medium confidence in the assessment.
Indicators of Condition Specific Measures Condition Status/Trend Rationale
Ozone Annual 4th-Highest 8-Hour Concentration Condition of resource warrants significant concern; condition is unchanging; high confidence in the assessment. The estimated ozone level for 2005–2009 at Salem Maritime NHS was 76.4 parts per billion (ppb), which warrants significant concern based on NPS Air Resource Division benchmarks. Although Salem Maritime NHS does not fall within a county designated by the EPA as non-attainment for ground-level ozone standard of 8-hour average concentration of 75 ppb, the 8-hour average ozone frequently exceeded the EPA ozone standard in 10 of the 11 years where data are available (1998 to 2008) (US EPA 2010, air data website). For 2000–2009, ozone levels at the monitoring site representing Salem Maritime NHS remained unchanged (NPS ARD 2013).
Wet Deposition Sulfur Wet Deposition Condition of resource warrants significant concern; trend in condition is unknown or not applicable; high confidence in the assessment. For 2005–2009, estimated sulfur wet deposition was 4.5 kilograms per hectare per year (kg/ha/yr), which warrants significant concern based on NPS ARD benchmarks. Adequate data are not available to calculate the trend (NPS ARD 2013).
Nitrogen Wet Deposition Condition of resource warrants significant concern; trend in condition is unknown or not applicable; high confidence in the assessment. For 2005–2009, estimated nitrogen wet deposition was 3.5 kilograms per hectare per year (kg/ha/yr), which warrants significant concern based on NPS ARD benchmarks. Adequate data are not available to calculate the trend (NPS ARD 2013).
Visibility Haze Index Condition of resource warrants moderate concern; condition is improving; high confidence in the assessment. For 2005–2009, estimated average visibility in Salem Maritime NHS was 6.8 deciviews (dv) above natural conditions, which warrants moderate concern based on NPS ARD benchmarks. For 2000–2009, visibility improved both on the 20% clearest days and 20% haziest days (NPS ARD 2013).

⇑ To Top of Page

The Status and Trend symbols used in the summary table below and throughout this report are summarized in the following key. The background color represents the current condition status, the direction of the arrow summarizes the trend in condition, and the thickness of the outside line represents the degree of confidence in the assessment. In some cases, the arrow is omitted because data are not sufficient for calculating a trend (e.g., data from a one-time inventory or insufficient sample size).

Condition Status Trend in Condition Confidence in
Assessment
Condition of resource warrants significant concern Warrants Significant Concern Condition is improving Condition is Improving High confidence in the assessment High
Condition of resource warrants moderate concern Warrants Moderate Concern Condition is unchanging Condition is Unchanging Medium confidence in the assessment Medium
Resource is in good condition Resource is in Good Condition Condition is deteriorating Condition is Deteriorating Low confidence in the assessment Low

Examples of how the symbols should be interpreted:

Resource is in good condition; condition is improving; high confidence in the assessment. Resource is in good condition; condition is improving; high confidence in the assessment.
Condition of resource warrants moderate concern; condition is unchanging; medium confidence in the assessment. Condition of resource warrants moderate concern; condition is unchanging; medium confidence in the assessment.
Condition of resource warrants significant concern; trend in condition is unknown or not applicable; low confidence in the assessment. Condition of resource warrants significant concern; trend in condition is unknown or not applicable; low confidence in the assessment.
Water Quality Condition of resource warrants moderate concern; trend in condition is unknown or not applicable; low confidence in the assessment.
Indicators of Condition Specific Measures Condition Status/Trend Rationale
Pathogens Enterococci per 100 ml Condition of resource warrants moderate concern; trend in condition is unknown or not applicable; low confidence in the assessment. Enterococci in outflow from the Derby Wharf storm drain has been sampled regularly since 2006 by the Salem Sound Coastwatch, Clean Beaches and Streams program. Levels following rain events routinely exceed the EPA standard (Enterococcus <104 CFU/100mL for single sample, or if the geometric mean of the most recent five samples <35 CFU/100mL). However, the storm drain outflow mixes with Salem Sound ocean water. Any exposure of people at Derby beach to water would likely be in the mixed water, which is very likely to have lower Enterococcus levels. The open ocean water has not been tested, thus no trend can be established at this time. Learn more »

⇑ To Top of Page

The Status and Trend symbols used in the summary table below and throughout this report are summarized in the following key. The background color represents the current condition status, the direction of the arrow summarizes the trend in condition, and the thickness of the outside line represents the degree of confidence in the assessment. In some cases, the arrow is omitted because data are not sufficient for calculating a trend (e.g., data from a one-time inventory or insufficient sample size).

Condition Status Trend in Condition Confidence in
Assessment
Condition of resource warrants significant concern Warrants Significant Concern Condition is improving Condition is Improving High confidence in the assessment High
Condition of resource warrants moderate concern Warrants Moderate Concern Condition is unchanging Condition is Unchanging Medium confidence in the assessment Medium
Resource is in good condition Resource is in Good Condition Condition is deteriorating Condition is Deteriorating Low confidence in the assessment Low

Examples of how the symbols should be interpreted:

Resource is in good condition; condition is improving; high confidence in the assessment. Resource is in good condition; condition is improving; high confidence in the assessment.
Condition of resource warrants moderate concern; condition is unchanging; medium confidence in the assessment. Condition of resource warrants moderate concern; condition is unchanging; medium confidence in the assessment.
Condition of resource warrants significant concern; trend in condition is unknown or not applicable; low confidence in the assessment. Condition of resource warrants significant concern; trend in condition is unknown or not applicable; low confidence in the assessment.
Shoreline / Waterfront Condition of resource warrants moderate concern; condition is deteriorating; low confidence in the assessment. Brief - Derby Wharf
Indicators of Condition Specific Measures Condition Status/Trend Rationale
Flooding Frequency of flooding events Condition of resource warrants moderate concern; condition is deteriorating; low confidence in the assessment. Flooding impacts waterfront cultural resources such as Derby Wharf. Condition Status/Trend is based on anecdotal reporting from facility managers. Improved elevation data is required to quantify status and trend. Over the 86 year record for the NOAA tide gauge at Boston, MA sea level has risen by 22.6 cm (10 in.), and is projected to accelerate in the future. Sea level along the North Atlantic coast of U.S. is rising at a faster rate than elsewhere on U.S. coast (Sallenger et al. 2012).

⇑ To Top of Page

Last Updated: October 31, 2013 Contact Webmaster