Physical alteration, habitat loss, water withdrawal, pollution, land use change,
overexploitation, and the introduction of nonnative species together negatively influence
freshwater ecosystems. Due to these stresses, freshwaters are ranked among the most at
risk systems worldwide (Malmqvist and Rundle, 2002). Protected areas (PAs), defined as
an area of land and/or sea especially dedicated to the protection and maintenance of
biological diversity as well as natural and associated cultural resources and managed
through legal or other effective means (IUCN, 1994), are an emerging tool for the
protection of biodiversity and natural resources. Despite the well‐documented threatened
status of freshwater ecosystems, terrestrial targets have received far more attention and
resources in the designation of PAs (Abell et al., 2007). However, because many terrestrial
PAs include freshwater components, use fluvial systems as borders, or affect freshwaters
downstream, it is important to understand the role that terrestrial PAs play in freshwater
conservation (Abell et al., 2007; Herbert et al., in press). The goal of our study was to
investigate the conservation potential of terrestrial PAs. As such, using Federal‐ and Stateowned
PAs within the Northern Lake Michigan, Lake Huron, and Straits of Mackinac
Ecological Drainage Unit of the State of Michigan (TNC, 2001), we evaluated two broad
attributes of PAs: (1) the effect of containing land in an undeveloped condition on
downstream freshwater key environmental attributes (KEAs: biotic composition,
connectivity, hydrologic regime, physical habitat and energy regime, and water quality),
and (2) the ability of managers to identify and mitigate negative anthropogenic influences
on KEAs.
Our first objective was to determine the effect of total area under protection by terrestrial
PAs on KEAs. To do so, data was collected on eight response variables representative of the
five KEAs which included: NO2 + NO3 concentration, total phosphorus concentration, free
flowing stream miles, average rate of flow response, low flow expectation, habitat quality
score, fish index of biotic integrity, and percent of fish considered intolerant to
anthropogenic stress. Next, using Geographic Information Systems (GIS), catchments
derived from individual response variable datum locations were delineated and the total
percent of land in protection within each catchment was calculated. Finally, the
relationship between response variable values and percent land protected was determined
using linear regressions. We found significant (p<0.05) decreases in NO2 + NO3
concentration and average rate of flow response with increasing area of catchment in
protection, suggesting that by keeping land in a natural state, PAs can contribute to
lowering nitrogen concentrations and reducing stream flashiness downstream. We also
found significant increases in the percent of fish considered intolerant to anthropogenic
stress with increasing area of catchment in protection, suggesting PAs may contribute to

enhancing the total number of environmentally sensitive fish. No significant relationship
was found between PAs and total phosphorus concentration, free flowing stream miles, low
flow expectation, habitat quality score, or fish index of biotic integrity.
Our second objective was to determine how PA management attends to freshwater
conservation. To do so, we randomly selected eleven Federal‐ and State‐owned PAs
located within the Northern Lake Michigan, Lake Huron, and Straits of Mackinac Ecological
Drainage Unit of the State of Michigan and conducted PA management questionnaires and
interviews, based on IUCN’s “Evaluating Effectiveness: A Framework for Assessing
Management of Protected Areas” guidelines (Hockings et al., 2006) and the principles of
integrated water resource management (IWRM; Global Water Partnership, 2009). This
process identified what PA managers perceived to be greatest internal (within PA) and
external (outside of PA) threats to freshwater KEAs within PAs and what specific activities
PA managers conducted to protect or restore KEAs. The alignment between threats and
activities was then determined as a measure of management’s attendance to freshwater
conservation. This analysis revealed that management processes are, with a few
exceptions, complementary to identified threats to freshwater systems. However, while
our findings suggest positive alignment between management activities and identified
threats, the informality of collaborative processes and absence of robust freshwater
monitoring programs indicate that management is not fully engaged in IRWM, which limits
the capacity for adaptive management.
Our third objective was to determine the relative influences of management and catchment
stressors on KEAs. Using previously delineated response variable catchments, we
organized response variable values by the study PAs contained within their catchments,
and calculated PA‐specific response variable scores (Response Variable Score). Next, using
the same response variable catchments, we calculated a measure of catchment condition
(Catchment Condition Score). Finally, using results from PA management questionnaires,
we quantified the degree of activity potentially affecting KEA response variables
(Management Activity Score). Catchment Condition Scores and Management Activity
Scores were then compared to Response Variable Scores to identify instances where PA
management activities were successful in mitigating the effects of catchment stressors on
KEAs (Scenario 1) and instances where catchment stressors had an overriding effect on
management activities (Scenario 2). The two Scenarios were observed in nearly identical
proportions across KEAs and PAs, suggesting that both management activities and
catchment stressors vary in their ability to affect freshwater KEA values. However,
Scenario 1 was observed more than Scenario 2 for water quality, while the opposite was
observed for biotic composition and hydrologic regime, suggesting management activities
may be more successful in mitigating the effects of catchment stressors specific to nutrient
concentrations. Our results suggest that terrestrial PAs likely contribute to some components of freshwater
KEAs by protecting land from development and through certain management activities.
However, further research is warranted to more extensively track the effect of the
interaction of anthropogenic stressors and management activities on freshwater systems.
If terrestrial protection were sufficient to secure freshwater integrity, we would expect the
majority of indicators to be favorably related to total percent protected. Since only three of
eight response variables showed the expected relationship, our findings do not support the
assumption that watershed protections are synonymous with maintenance of freshwater
KEAs.
Our approach provides a framework for evaluating and tracking key freshwater outcomes
while addressing the interacting factors of human‐induced stress and management
attempts to mitigate these stresses. Furthermore, our approach holds utility for any
managing entity attempting to produce favorable outcomes for freshwater systems. Future
applications of this approach can be tailored to include a different set of management
activities, catchment stressors, and response variables, depending on the context of the PA
and what data are available for use.