Resilience of aquatic systems: Review and management implications.

Our understanding of how ecosystems function has changed from an equilibria-based view to one that recognizes the dynamic, fluctuating, nonlinear nature of aquatic systems. This current understanding requires that we manage systems for resilience. In this review, we examine how resilience has been defined, measured and applied in aquatic systems, and more broadly, in the socioecological systems in which they are embedded.

Bioextractive Removal of Nitrogen by Oysters in Great Bay Piscataqua River Estuary, New Hampshire, USA.

Eutrophication is a challenge to coastal waters around the globe. In many places, nutrient reductions from land-based sources have not been sufficient to achieve desired water quality improvements. Bivalve shellfish have shown promise as an in-water strategy to complement land-based nutrient management.

Structured Decision Making to Meet a National Water Quality Mandate.

Water quality criteria are necessary to ensure protection of ecological and human health conditions, but compliance can require complex decisions. We use structured decision making to consider multiple stakeholder objectives in a water quality management process, with a case study in the Three Bays watershed on Cape Cod, Massachusetts. We set a goal to meet or exceed a nitrogen load reduction target for the watershed and four key objectives: minimizing economic costs of implementing management actions, minimizing the complexity of permitting management actions, maximizing stakeholder acceptability of the management actions, and maximizing the provision of ecosystem services (recreational opportunity, erosion and flood control, socio-cultural amenity).

Developing qualitative ecosystem service relationships with the Driver-Pressure-State-Impact-Response framework: A case study on Cape Cod, Massachusetts.

Understanding the effects of environmental management strategies on society and the environment is critical for evaluating their effectiveness, but is often impeded by limited data availability. In this article, we present a method that can help scientists to support resource managers' thinking about social-ecological relationships in coupled human and natural systems. Our method aims to model qualitative cause-effect relationships between management strategies and ecosystem services, using information provided by knowledgeable participants, and the tradeoffs between strategies.

A resilience framework for chronic exposures: water quality and ecosystem services in coastal social-ecological systems.

Water quality degradation is a chronic problem which influences the resilience of a social-ecological system differently than acute disturbances, such as disease or storms. Recognizing this, we developed a tailored resilience framework that applies ecosystem service concepts to coastal social-ecological systems affected by degraded water quality. We present the framework as a mechanism for coordinating interdisciplinary research to inform long-term community planning decisions pertaining to chronic challenges in coastal systems.

Role of Shellfish Aquaculture in the Reduction of Eutrophication in an Urban Estuary.

Land-based management has reduced nutrient discharges; however, many coastal waterbodies remain impaired. Oyster "bioextraction" of nutrients and how oyster aquaculture might complement existing management measures in urban estuaries was examined in Long Island Sound, Connecticut. Eutrophication status, nutrient removal, and ecosystem service values were estimated using eutrophication, circulation, local- and ecosystem-scale models, and an avoided-costs valuation.

Development of a reference coastal wetland set in Southern New England (USA).

Various measures of plants, soils, and invertebrates were described for a reference set of tidal coastal wetlands in Southern New England in order to provide a framework for assessing the condition of other similar wetlands in the region. The condition of the ten coastal wetlands with similar hydrology and geomorphology were ranked from least altered to highly altered using a combination of statistical methods and best professional judgment. Variables of plants, soils, and invertebrates were examined separately using principal component analysis to reduce the multidimensional variables to principal component scores.

The influence of suburban land use on habitat and biotic integrity of coastal Rhode Island streams.

Watershed land use in suburban areas can affect stream biota through degradation of instream habitat, water quality, and riparian vegetation. By monitoring stream biotic communities in various geographic regions, we can better understand and conserve our watershed ecosystems. The objective of this study was to examine the relationship between watershed land use and the integrity of benthic invertebrate communities in eight streams that were assessed over a 3-year period (2001-2003).

Denitrification enzyme activity of fringe salt marshes in New England (USA).

Coastal salt marshes are a buffer between the uplands and adjacent coastal waters in New England (USA). With increasing N loads from developed watersheds, salt marshes could play an important role in the water quality maintenance of coastal waters. In this study we examined seasonal relationships between denitrification enzyme activity (DEA) in salt marshes of Narragansett Bay, Rhode Island, and watershed N loadings, land use, and terrestrial hydric soils.

Comparison of in vitro-cultured and wild-type Perkinsus marinus. III. Fecal elimination and its role in transmission.

Perkinsus marinus, a pathogen of the eastern oyster Crassostrea virginica, is transmitted directly among oysters. Previous studies found viable P. marinus parasites in the feces and pseudofeces of oysters within hours of injection with parasites, suggesting that the parasite may be voided from live oysters and subsequently dispersed in the water column.

Comparison of in vitro-cultured and wild-type Perkinsus marinus. II. Dosing methods and host response.

Endoparasites must breach host barriers to establish infection and then must survive host internal defenses to cause disease. Such barriers may frustrate attempts to experimentally transmit parasites by 'natural' methods. In addition, the host's condition may affect a study's outcome.

Comparison of in vitro-cultured and wild-type Perkinsus marinus. I. Pathogen virulence.

Perkinsus marinus is a highly contagious pathogen of the eastern oyster Crassostrea virginica. Until recently, transmission studies have employed wild-type parasites isolated directly from infected oysters. Newly developed methods to propagate P.