Michael Harte

A Review of Urban Water Body Challenges and Approaches: (1) Rehabilitation and Remediation

AbstractWe review how urbanization alters aquatic ecosystems, as well as actions that managers can take to remediate urban waters. Urbanization affects streams by fundamentally altering longitudinal and lateral processes that in turn alter hydrology, habitat, and water chemistry; these effects create physical and chemical stressors that in turn affect the biota. Urban streams often suffer from multiple stressor effects that have collectively been termed an “urban stream syndrome,” in which no single factor dominates degraded conditions. Resource managers have multiple ways of combating the urban stream syndrome. These approaches range from whole-watershed protection to reach-scale habitat rehabilitation, but the prescription must be matched to the scale of the factors that are causing the problem, and results will likely not be immediate because of lengthy recovery times. Although pristine or reference conditions are far from attainable, urban stream rehabilitation is a worthy goal because appropriate act...

A Review of Urban Water Body Challenges and Approaches: (2) Mitigating Effects of Future Urbanization

AbstractPreviously we examined how degraded urban streams can be rehabilitated, with emphasis on identifying solutions that match the scale of the problems (Hughes et al. 2014). Our findings showed that rehabilitation techniques are challenging but that some environmental benefits can nearly always be obtained regardless of existing conditions. Although rehabilitation is useful in many present-day situations, biologists need to consider the future and think about ways of preventing or reducing future environmental damage. We need to reduce future damage because urban areas are likely to expand greatly over the next century; if historical patterns continue, the number and length of streams experiencing urban stream syndrome will increase, with resulting high repair costs. However, there are several ways of avoiding or mitigating damage that are not only cost effective but provide benefits to humans and urban ecosystems.

Combining and aggregating environmental data for status and trend assessments: challenges and approaches

Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short- and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable techniques and statistically aggregated for new assessments. By doing so, they can increase the (1) use of available data and (2) the validity and reliability of the assessments. Increased awareness of the difficulties inherent in combining and aggregating data for local- and regional-level analyses can increase the likelihood that future monitoring efforts will be modified and/or planned to accommodate data from multiple sources.

Optimal Rebuilding of Fish Stocks in Different Nations: Bioeconomic Lessons for Regulators

Under the rubric of sustainable fisheries, nations are mandated to rebuild overfished stocks. Although rebuilding strategies are almost universally directed by the available biological information, approaches vary depending on fishery laws, management objectives, and technical guidelines. For example, rebuilding schedules in the United States are primarily designed to achieve rapid rebuilding of biomass and spawning stocks consistent with the biological characteristics of the resource. In contrast, New Zealand has greater flexibility in rebuilding stocks in order to consider economic, social, and cultural needs. In this paper we investigate potential economic costs to the fishery that result by limiting the US managers flexibility in choosing a recovery trajectory. Using numerical models for moderate-and long-lived stocks, the analysis reveals that depending on productivity of the stock and the discount rate, extending the rebuilding timeframe can substantially increase annual harvests and economic benefits. The results underscore the importance of economic analysis in crafting flexible rebuilding schedules that account for the unique characteristics of the fisheries, including economic and social needs.

Evaluation of dungeness crab pots as platforms of opportunity for ocean-observing research

Oregon Fishermen in Ocean Observing Research is a cooperative research program between ocean scientists and fishermen. Dungeness crab fishermen attach sensor packages (temperature and dissolved oxygen) to crab pots, which serve as platforms of opportunity for ocean observing. The goals of this study are to determine if: (1) fishermen and scientists involved in ocean observing are favorably disposed to the continued use of platforms of opportunity in ocean observing; (2) The quality of data produced from instrumentation attached to platforms of opportunity is similar to that produced from more traditional ocean observing platforms; and (3) The use of crab pots to deploy temperature and dissolved oxygen sensors off the Oregon Coast compares favorably to more traditional ocean observing platforms when assessed against important criteria for operational performance such as spatial and temporal coverage and cost. Results to date indicate that the OrFIOOR program is successful in all three of these regards.

Cheap rugged autoreporting bottom-positioned oxygen/temperature sensors (CRABPOTS) for industry/tribal/academic collaboration

The Oregon Fishermen in Ocean Observing Research (OrFIOOR) program is a collaboration between Oregon State University researchers and commercial Dungeness crab fishermen in Oregon and Washington which utilizes fishing gear (crab pots) as sensor platforms of opportunity. The program was started in 2005 using small temperature sensors and has since expanded to include observations of near bottom dissolved oxygen. To provide better near real-time products to the fishermen participating in the project and research interested in hypoxia data, we propose a number of technology improvements to the current dissolved oxygen units which will automate data collection using wireless communications and improve sensor endurance through hardware enhancements.