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Building regional threat-based networks for estuaries in the Western United States.

Merrifield MS, Hines E, Liu X, Beck MW - PLoS ONE (2011)

Bottom Line: To do this we classify estuaries into hierarchical networks that share similar threat characteristics using a spatial database (geodatabase) of threats to estuaries from land and sea in the western U.S. Our results show that very few estuaries in this region (16%) have no or minimal stresses from anthropogenic activity.The small number of un-threatened estuaries is likely not representative of the ecological variability in the region and will require working to abate threats at others.We think the identification of these estuary groups can foster sharing best practices and coordination of conservation activities amongst estuaries in any geography.

View Article: PubMed Central - PubMed

Affiliation: Department of Science and Planning, The Nature Conservancy, San Francisco, California, United States of America. mmerrifield@tnc.org

ABSTRACT
Estuaries are ecologically and economically valuable and have been highly degraded from both land and sea. Estuarine habitats in the coastal zone are under pressure from a range of human activities. In the United States and elsewhere, very few conservation plans focused on estuaries are regional in scope; fewer still address threats to estuary long term viability.We have compiled basic information about the spatial extent of threats to identify commonalities. To do this we classify estuaries into hierarchical networks that share similar threat characteristics using a spatial database (geodatabase) of threats to estuaries from land and sea in the western U.S. Our results show that very few estuaries in this region (16%) have no or minimal stresses from anthropogenic activity. Additionally, one quarter (25%) of all estuaries in this study have moderate levels of all threats. The small number of un-threatened estuaries is likely not representative of the ecological variability in the region and will require working to abate threats at others. We think the identification of these estuary groups can foster sharing best practices and coordination of conservation activities amongst estuaries in any geography.

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Dendrogram showing hierarchical division of estuary networks and agglomeration schedule.The hierarchical clustering identified nine substantive networks at a Euclidean distance of 2.5. Major divisions are by development (Network 2; d = 16), impaired inflows (Networks 1, 5, 8; d = 10), and approved shellfish growing areas (Networks 4; d = 7.5).
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pone-0017407-g004: Dendrogram showing hierarchical division of estuary networks and agglomeration schedule.The hierarchical clustering identified nine substantive networks at a Euclidean distance of 2.5. Major divisions are by development (Network 2; d = 16), impaired inflows (Networks 1, 5, 8; d = 10), and approved shellfish growing areas (Networks 4; d = 7.5).

Mentions: The hierarchical clustering identified nine substantive networks illustrated by the map in Figure 3 and the dendrogram in Figure 4. The properties of estuaries within the networkwere described by variable means (Table 2). Geographic summary statistics for each showed the distribution and magnitude of each network (Table 3). Close investigation of these tables andthe dendrogram reveal major divisions by development (Network 2; d = 16), impaired waterways (Networks 1, 5, 8; d = 10), and estuaries with substantial areas approved for shellfish and aquaculture (Network 4; d = 7.5). The remaining Networks: 3, 6, 7 and 9 are moderately impacted by single threats. Network 6 represents the overall lowest impact estuaries; however they cover a small proportion of the sample and area. Network 3 has low to moderate levels of all threats.


Building regional threat-based networks for estuaries in the Western United States.

Merrifield MS, Hines E, Liu X, Beck MW - PLoS ONE (2011)

Dendrogram showing hierarchical division of estuary networks and agglomeration schedule.The hierarchical clustering identified nine substantive networks at a Euclidean distance of 2.5. Major divisions are by development (Network 2; d = 16), impaired inflows (Networks 1, 5, 8; d = 10), and approved shellfish growing areas (Networks 4; d = 7.5).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3046153&req=5

pone-0017407-g004: Dendrogram showing hierarchical division of estuary networks and agglomeration schedule.The hierarchical clustering identified nine substantive networks at a Euclidean distance of 2.5. Major divisions are by development (Network 2; d = 16), impaired inflows (Networks 1, 5, 8; d = 10), and approved shellfish growing areas (Networks 4; d = 7.5).
Mentions: The hierarchical clustering identified nine substantive networks illustrated by the map in Figure 3 and the dendrogram in Figure 4. The properties of estuaries within the networkwere described by variable means (Table 2). Geographic summary statistics for each showed the distribution and magnitude of each network (Table 3). Close investigation of these tables andthe dendrogram reveal major divisions by development (Network 2; d = 16), impaired waterways (Networks 1, 5, 8; d = 10), and estuaries with substantial areas approved for shellfish and aquaculture (Network 4; d = 7.5). The remaining Networks: 3, 6, 7 and 9 are moderately impacted by single threats. Network 6 represents the overall lowest impact estuaries; however they cover a small proportion of the sample and area. Network 3 has low to moderate levels of all threats.

Bottom Line: To do this we classify estuaries into hierarchical networks that share similar threat characteristics using a spatial database (geodatabase) of threats to estuaries from land and sea in the western U.S. Our results show that very few estuaries in this region (16%) have no or minimal stresses from anthropogenic activity.The small number of un-threatened estuaries is likely not representative of the ecological variability in the region and will require working to abate threats at others.We think the identification of these estuary groups can foster sharing best practices and coordination of conservation activities amongst estuaries in any geography.

View Article: PubMed Central - PubMed

Affiliation: Department of Science and Planning, The Nature Conservancy, San Francisco, California, United States of America. mmerrifield@tnc.org

ABSTRACT
Estuaries are ecologically and economically valuable and have been highly degraded from both land and sea. Estuarine habitats in the coastal zone are under pressure from a range of human activities. In the United States and elsewhere, very few conservation plans focused on estuaries are regional in scope; fewer still address threats to estuary long term viability.We have compiled basic information about the spatial extent of threats to identify commonalities. To do this we classify estuaries into hierarchical networks that share similar threat characteristics using a spatial database (geodatabase) of threats to estuaries from land and sea in the western U.S. Our results show that very few estuaries in this region (16%) have no or minimal stresses from anthropogenic activity. Additionally, one quarter (25%) of all estuaries in this study have moderate levels of all threats. The small number of un-threatened estuaries is likely not representative of the ecological variability in the region and will require working to abate threats at others. We think the identification of these estuary groups can foster sharing best practices and coordination of conservation activities amongst estuaries in any geography.

Show MeSH