Co-creating and evaluating a citizen science program for monitoring submerged aquatic vegetation in Chesapeake Bay (original) (raw)
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Submersed Aquatic Vegetation in Chesapeake Bay: Sentinel Species in a Changing World
BioScience, 2017
Chesapeake Bay has undergone profound changes since European settlement. Increases in human and livestock populations, associated changes in land use, increases in nutrient loadings, shoreline armoring, and depletion of fish stocks have altered the important habitats within the Bay. Submersed aquatic vegetation (SAV) is a critical foundational habitat and provides numerous benefits and services to society. In Chesapeake Bay, SAV species are also indicators of environmental change because of their sensitivity to water quality and shoreline development. As such, SAV has been deeply integrated into regional regulations and annual assessments of management outcomes, restoration efforts, the scientific literature, and popular media coverage. Even so, SAV in Chesapeake Bay faces many historical and emerging challenges. The future of Chesapeake Bay is indicated by and contingent on the success of SAV. Its persistence will require continued action, coupled with new practices, to promote a healthy and sustainable ecosystem.
Distribution of Submerged Aquatic Vegetation in the Chesapeake Bay and Tributaries - 1985
1986
Effective cooperation by so many different types of governmental agencies in arranging, during a comparatively short developmental time frame, a comprehensive survey-mapping project of this scope is noteworthy. More and more emphasis is being placed on tracking SAV because of its perceived usefulness as an indicator of potential and actual improvement in the Chesapeake Bay's water quality and the correlated balance of living resources. Acknowledgement would not be complete without high commendation for the citizens and Maryland charterboat captains who took part in an unusual pilot program to provide "groundtruthing" of SAV beds to be used in conjunction with interpretation of the 1985 photography. The Citizens' Program for the Chesapeake Bay and the Chesapeake Bay Foundation, together with the U.S. Fish and Wildlife Service, organized nearly 150 citizens to report locations of grass beds around the Bay. In addition, about fifteen members of the Maryland Charterboat Association, funded by Maryland DNR, participated in the ground truthing program and contributed valuable information on location of grassbeds. The entire 1985 program, though arranged on relatively short notice, promised great potential benefits (from both informational and participational standpoints) that an expanded 1986 ground truthing program was organized. vi There are certain people who have made a project like this a real possibility. In addition, the production of such a report required the dedication of numerous technicians, artists and photographers. The following people deserve a note of thanks: Bert Brun,
2009
Broad declines in Chesapeake Bay submerged aquatic vegetation (SAV) populations that were first observed in the late 1960s and 1970s prompted the initiation of a comprehensive aerial mapping program to assess the status of the resource. This mapping program which began in 1978 has continued on an annual basis since 1984. The imagery used has primarily consisted of high resolution black and white photographs taken at a scale of 1:24,000. Mapping missions have been flown under guidelines addressing frame overlap, tidal stage, seasonal plant development, sun angle, atmospheric transparency, water turbidity and wind speed and direction to maximize SAV bed signatures. Currently 173 flight lines, which cover approximately 3,800 flight line km, are photographed and mapped for SAV each year. Scanned aerial photography images are geo-rectified and orthographically corrected to produce a series of aerial mosaics at 1 m resolution. The SAV beds are interpreted on-screen using in a GIS environment. Extensive ground survey data is also collected to verify the SAV photo-interpretation. A bay wide analysis of SAV distributions since the 1930s was also undertaken with archival aerial photographs using similar procedures to develop a composite historical coverage of SAV. Both the current and historical mapping results have been used for a variety of purposes. The composite historical coverages have been used to set SAV restoration goals and direct SAV restoration efforts. In addition, analyses of the historical SAV growth and bay bathymetry have been used to set seasonal water clarity targets for shallow water historically vegetated SAV areas throughout the bay. Comparisons of current SAV mapping results with historically based restoration targets are used annually to provide important indexes of bay condition and trends that are used to assess the effectiveness of nutrient and sediment reduction strategies for the bay and its watershed. In addition, the photographic imagery and the resultant SAV delineations have been widely used by managers to identify and minimize direct impacts to the SAV.
Estuaries and Coasts, 2019
Aerial surveys of coastal habitats can uniquely inform the science and management of shallow, coastal zones, and when repeated annually, they reveal changes that are otherwise difficult to assess from ground-based surveys. This paper reviews the utility of a longterm (1984-present) annual aerial monitoring program for submersed aquatic vegetation (SAV) in Chesapeake Bay, its tidal tributaries, and nearby Atlantic coastal bays, USA. We present a series of applications that highlight the program's importance in assessing anthropogenic impacts, gauging water quality status and trends, establishing and evaluating restoration goals, and understanding the impact of commercial fishing practices on benthic habitats. These examples demonstrate how periodically quantifying coverage of this important foundational habitat answers basic research questions locally, as well as globally, and provides essential information to resource managers. New technologies are enabling more frequent and accurate aerial surveys at greater spatial resolution and lower cost. These advances will support efforts to extend the applications described here to similar issues in other areas.
2002
Seagrasses along with many other species of freshwater rooted submerged macrophytes in Chesapeake Bay (collectively called SAV) underwent serious declines in population abundances in the 1970s and have not as yet rebounded to previous levels. Cooperative efforts by scientists, politicians, federal and state resource managers, and the general public have developed policies and plans to protect, preserve and enhance SAV populations of Chesapeake Bay. , as well as federal and state guidelines for protecting SAV communities from direct human impacts such as dredge and fill operations. The foundation for many of these management efforts has been the recognition of the habitat value of SAV to many fish and shellfish, and the elucidation of linkages between water quality conditions and the continuing occurrence of SAV as established by minimal water quality habitat requirements for growth and survival. Because of these linkages, the distribution of SAV in the Bay and its tidal tributaries is being used as an initial measure of progress in the restoration of living resources and water quality. Restoration targets and goals have been established to link demonstrable improvements in water quality to increases in SAV abundance. The major challenge facing the Chesapeake Bay community will be to restore SAV habitat and ecosystem functions to historic levels. However, the recent success in the development of policies, plans, regulations and laws highlighting the importance of SAV communities in Chesapeake Bay and their protection and restoration, is an excellent example of effective communication linkages and adaptive management principles between scientists, resource managers, politicians and the public in the Chesapeake Bay region. Only through these interactions will SAV restoration become a reality.
Estuaries, 2004
We developed an algorithm for calculating habitat suitability for seagrasses and related submerged aquatic vegetation (SAV) at coastal sites where monitoring data are available for five water quality variables that govern light availability at the leaf surface. We developed independent estimates of the minimum light required for SAV survival both as a percentage of surface light passing through the water column to the depth of SAV growth (PLW min ) and as a percentage of light reaching leaves through the epiphyte layer (PLL min ). Values were computed by applying, as inputs to this algorithm, statistically derived values for water quality variables that correspond to thresholds for SAV presence in Chesapeake Bay. These estimates of PLW min and PLL min compared well with the values established from a literature review. Calculations account for tidal range, and total light attenuation is partitioned into water column and epiphyte contributions. Water column attenuation is further partitioned into effects of chlorophyll a (chl a), total suspended solids (TSS) and other substances. We used this algorithm to predict potential SAV presence throughout the Bay where calculated light available at plant leaves exceeded PLL min . Predictions closely matched results of aerial photographic monitoring surveys of SAV distribution. Correspondence between predictions and observations was particularly strong in the mesohaline and polyhaline regions, which contain 75-80% of all potential SAV sites in this estuary. The method also allows for independent assessment of effects of physical and chemical factors other than light in limiting SAV growth and survival. Although this algorithm was developed with data from Chesapeake Bay, its general structure allows it to be calibrated and used as a quantitative tool for applying water quality data to define suitability of specific sites as habitats for SAV survival in diverse coastal environments worldwide.
Distribution of Submerged Aquatic Vegetation in the Chesapeake Bay and Tributaries - 1984
1985
Crown density scale for estimating SAV bed density Location of 3 zones and 21 major sections in the Chesapeake Bay for delineation of SAV. •. • •. .. • •. Location of quadrangles along transition of Potomac River for SAV study conducted by NVCC. •. • Location of vegetation sampling transects in the tidal and transition portion of the Potomac River conducted by uses in 1983 and 1984. . •. .. .. • • .
Open-file report /, 1998
The U.S. Geological Survey has been cooperating with other scientists under the auspices of the Interstate Commission on the Potomac River Basin to utilize existing data from the tidal Potomac River and Estuary for investigating linkages among living resources (primary producers, consumers) and abiotic components of the environment. Because the distribution and abundance of submersed aquatic vegetation in the tidal Potomac River and Estuary are controlled largely by light availability, the first step in investigating linkages with submersed aquatic vegetation is to examine the correlations that exist among vegetative cover, discharge, water quality and weather, all of which can affect light availability directly or indirectly. Growing season (April-October), spring (April-June), and summer (July-August) correlations are presented along with figures demonstrating the significant relationships among variables. INTRODUCTION The ecosystem of the Chesapeake Bay, the Nation's largest estuary, has been adversely affected during the past several decades by eutrophication caused by excessive nutrients entering the bay. Nutrient loading has been identified as the primary cause of periods of hypoxia that kill or stress living resources in parts of the bay. Additionally, high nutrient and sediment loads have decreased water clarity and consequently are largely responsible for the decline in submersed aquatic vegetation (SAV) that form the base of the food chain and provide critical habitat for finfish, shellfish, and waterfowl. The mission of the U.S. Geological Survey's (USGS) Chesapeake Bay Ecosystem Program is to provide information to a broad community of policy makers, resource managers, scientists, and private citizens working on the restoration of the Chesapeake Bay. As part of this mission, USGS scientists collect and analyze data on current and historical nutrient and sediment loads in the drainage basin of the Chesapeake Bay and determine linkages between hydrologic parameters and the distribution and abundance of SAV in the Potomac River drainage basin. Light is the primary factor controlling the distribution and abundance of SAV in the Chesapeake Bay and its tributaries (Batiuk and others, 1992; Carter and others, 1994; Carter and Rybicki, 1990). Light availability for SAV photosynthesis and growth is affected by water-column components such as total suspended solids (TSS) and chlorophyll-a (Carter and Rybicki, 1990). Additionally, epiphytic growths on the leaves and stems of SAV further reduce light availability for photosynthesis. Eutrophication causes an increase in the abundance of phytoplankton and thus increases chlorophyll-a, TSS, and epiphyte loads. Weather (precipitation, windspeed, available sunshine) also affects the amount of light available for photosynthesis and thus the distribution and abundance of SAV (Carter and others, 1994). The USGS is cooperating with other scientists under the auspices of the Interstate Commission on the Potomac River Basin (ICPRB) to utilize existing data from the tidal Potomac River and Estuary for investigation of linkages among primary producers, consumers, water-quality and weather parameters, and discharge.