Summary In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmars... more Summary In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world‐wide meta‐analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta‐analysis shows that both trial survival and seagrass popula...
Seagrasses, a functional group of marine flowering plants rooted in the world's coastal oceans, s... more Seagrasses, a functional group of marine flowering plants rooted in the world's coastal oceans, support marine food webs and provide essential habitat for many coastal species, playing a critical role in the equilibrium of coastal ecosystems and human livelihoods. For the first time, the probability of extinction is determined for the world's seagrass species under the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. Several studies have indicated that seagrass habitat is declining worldwide. Our focus is to determine the risk of extinction for individual seagrass species, a 4-year process involving seagrass experts internationally, compilation of data on species' status, populations, and distribution, and review of the biology and ecology of each of the world's seagrass species. Ten seagrass species are at elevated risk of extinction (14% of all seagrass species), with three species qualifying as Endangered. Seagrass species loss and degradation of seagrass biodiversity will have serious repercussions for marine biodiversity and the human populations that depend upon the resources and ecosystem services that seagrasses provide.
Susan Lynn Williams (1951-2018) was an exceptional marine ecologist whose research focused broadl... more Susan Lynn Williams (1951-2018) was an exceptional marine ecologist whose research focused broadly on the ecology of benthic nearshore environments dominated by seagrasses, seaweeds, and coral reefs. She took an empirical approach founded in techniques of physiological ecology. Susan was committed to applying her research results to ocean management through outreach to decision-makers and resource managers. Susan's career included research throughout the USA in tropical, temperate, and polar regions, but she specialized in tropical marine ecology. Susan's scholarship, leadership, and friendship touched many people, leading to this multi-authored paper. Susan's scholarship was multi-faceted, and she excelled in scientific discovery, integration of scientific results, application of science for conservation, and teaching, especially as a mentor to undergraduate and graduate students and postdoctoral scholars. Susan served in a variety of leadership positions throughout her career. She embodied all facets of leadership; leading by example, listening to others, committing to the "long haul," maintaining trust, and creating a platform for all to shine. Susan was an important role model for women in science. Susan was also a loyal friend, maintaining friendships for many decades. Susan loved cooking and entertaining with friends. This paper provides an overview of the accomplishments of Susan in the broad categories of scholarship, leadership, and friendship.
Proceedings of the National Academy of Sciences of the United States of America, May 30, 2023
Global change has converted many structurally complex and ecologically and economically valuable ... more Global change has converted many structurally complex and ecologically and economically valuable coastlines to bare substrate. In the structural habitats that remain, climate-tolerant and opportunistic species are increasing in response to environmental extremes and variability. The shifting of dominant foundation species identity with climate change poses a unique conservation challenge because species vary in their responses to environmental stressors and to management. Here, we combine 35 y of watershed modeling and biogeochemical water quality data with species comprehensive aerial surveys to describe causes and consequences of turnover in seagrass foundation species across 26,000 ha of habitat in the Chesapeake Bay. Repeated marine heatwaves have caused 54% retraction of the formerly dominant eelgrass ( Zostera marina ) since 1991, allowing 171% expansion of the temperature-tolerant widgeongrass ( Ruppia maritima ) that has likewise benefited from large-scale nutrient reductions. However, this phase shift in dominant seagrass identity now presents two significant shifts for management: Widgeongrass meadows are not only responsible for rapid, extensive recoveries but also for the largest crashes over the last four decades; and, while adapted to high temperatures, are much more susceptible than eelgrass to nutrient pulses driven by springtime runoff. Thus, by selecting for rapid post-disturbance recolonization but low resistance to punctuated freshwater flow disturbance, climate change could threaten the Chesapeake Bay seagrass’ ability to provide consistent fishery habitat and sustain functioning over time. We demonstrate that understanding the dynamics of the next generation of foundation species is a critical management priority, because shifts from relatively stable habitat to high interannual variability can have far-reaching consequences across marine and terrestrial ecosystems.
Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Depth profiles and percent cover estimated for Zostera and Ruppia at Plum Tree Island transects. ... more Depth profiles and percent cover estimated for Zostera and Ruppia at Plum Tree Island transects. . •. • • Depth profiles and percent cover estimates for Zostera and Ruppia at Browns Bay transects. .. . •. •. • Depth profiles and percent cover estimates for Zostera and Ruppia at Ware Neck transects. • •. •. .. . • Depth profiles and percent cover estimates for Zostera and Ruppia at East River transects. ,. .. .. • • Depth profiles and percent cover estimates for Zostera and Ruppia at Horn Harbor transects.. .. • •. . Delineation of SAV bed, zones of similar vegetation and position of transects at the Vaucluse Shores area •• Depth profiles and percent cover estimates for Zostera and Ruppia at Vaucluse Shores transects, .
Aerial surveys of coastal habitats can uniquely inform the science and management of shallow, coa... more 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.
Description/Abstract Chesapeake Bay, one of the world's largest estuaries, has exper... more Description/Abstract Chesapeake Bay, one of the world's largest estuaries, has experienced deterioration of water quality from nutrient enrichment, resulting in anoxic or hypoxic conditions and declines in living resources. Determination of relationships between water ...
Chesapeake Bay has undergone profound changes since European settlement. Increases in human and l... more 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.
... of Mid-Atlantic Coast of the USA: Challenges in Conservation and Restoration Robert J. Orth &... more ... of Mid-Atlantic Coast of the USA: Challenges in Conservation and Restoration Robert J. Orth & Scott R. Marion & Kenneth A. Moore & David J. Wilcox ... Page 2. conservation and restoration in the last two decades (Kenworthy et al. 2006). ...
Anthesis and seed production in Zostera marina L. were studied in three areas of the Chesapeake B... more Anthesis and seed production in Zostera marina L. were studied in three areas of the Chesapeake Bay from January to June 1980. Inflorescence primordia with distinguishable anthers and pistils were first observed in February when water temperature was 3 ° C. Development of the reproductive shoots in the field continued after February as water temperature rose, with the first evidence of pollen release in mid-April (water temperature 14.3 ° C). Stigmata loss was first observed in samples taken in late April at two of the areas as water temperatures averaged above 16 ° C. Pollination was complete at all locations by 19 May and anthers were no longer present. Few reproductive shoots were found on 3-5 June and seed release was assumed to be complete by this time (water temperature 25 ° C). The density of flowering shoots ranged from 11 to 19% of the total number of shoots, producing an estimated 8127 seeds m-'. Comparison of flowering events with other areas along a latitudinal gradient from North Carolina to Canada indicated that reproductive events occurred earlier in the most southern locations and at successively later dates with increasing latitude.
Eleven years of eelgrass Zostera marina seed additions conducted in a coastal bay system where Z.... more Eleven years of eelgrass Zostera marina seed additions conducted in a coastal bay system where Z. marina had not been reported since 1933 have resulted in rapid Z. marina expansion beyond the initially seeded plots. From 1999 through 2010, 37.8 million viable seeds were added to 369 individual plots ranging in size from 0.01 to 2 ha totaling 125.2 ha in 4 coastal bays. Subsequent expansion from these initial plots to approximately 1700 ha of bay bottom populated with Z. marina through 2010 is attributable to seed export from the original plots and subsequent generations of seedlings originating from those exports. Estimates of annual patch vegetative expansion showed mean estimated diameter increasing at varying rates from 10 to 36 cm yr −1 , consistent with rhizome elongation rates reported for Z. marina. Water quality data collected over 7 yr by spatially intensive sampling, as well as fixed-location continuous monitoring, document conditions in all 4 bays that are adequate to support Z. marina growth. In particular, median chlorophyll levels for the entire sampling period were between 5 and 6 µg l −1 for each of the bays, and median turbidity levels, while exhibiting seasonal differences, were between 8 and 9 NTU. The recovery of Z. marina initiated in this coastal bay system may be unique in seagrass recovery studies because of how the recovery was initiated (seeds rather than adult plants), how rapidly it occurred (years rather than decades), and the explicit demonstration of how one meadow modulated water clarity and altered sediments as it developed and expanded. Our results offer a new perspective on the role seeds can play in recovery dynamics at large spatial scales. KEY WORDS: Seeds. Germination. Seedling establishment. Zostera marina. Virginia coastal bays Resale or republication not permitted without written consent of the publisher OPEN PEN ACCESS CCESS Contribution to the Theme Section 'Eelgrass recovery' 179 Continuous WQ Station D a ta fl o w T ra c k D e lm a r v a P e n in s u la Atlantic Ocean C h e s a p e a k e B a y Start Oyster Sand Shoal Inlet Great Machipongo Inlet
Summary In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmars... more Summary In coastal and estuarine systems, foundation species like seagrasses, mangroves, saltmarshes or corals provide important ecosystem services. Seagrasses are globally declining and their reintroduction has been shown to restore ecosystem functions. However, seagrass restoration is often challenging, given the dynamic and stressful environment that seagrasses often grow in. From our world‐wide meta‐analysis of seagrass restoration trials (1786 trials), we describe general features and best practice for seagrass restoration. We confirm that removal of threats is important prior to replanting. Reduced water quality (mainly eutrophication), and construction activities led to poorer restoration success than, for instance, dredging, local direct impact and natural causes. Proximity to and recovery of donor beds were positively correlated with trial performance. Planting techniques can influence restoration success. The meta‐analysis shows that both trial survival and seagrass popula...
Seagrasses, a functional group of marine flowering plants rooted in the world's coastal oceans, s... more Seagrasses, a functional group of marine flowering plants rooted in the world's coastal oceans, support marine food webs and provide essential habitat for many coastal species, playing a critical role in the equilibrium of coastal ecosystems and human livelihoods. For the first time, the probability of extinction is determined for the world's seagrass species under the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. Several studies have indicated that seagrass habitat is declining worldwide. Our focus is to determine the risk of extinction for individual seagrass species, a 4-year process involving seagrass experts internationally, compilation of data on species' status, populations, and distribution, and review of the biology and ecology of each of the world's seagrass species. Ten seagrass species are at elevated risk of extinction (14% of all seagrass species), with three species qualifying as Endangered. Seagrass species loss and degradation of seagrass biodiversity will have serious repercussions for marine biodiversity and the human populations that depend upon the resources and ecosystem services that seagrasses provide.
Susan Lynn Williams (1951-2018) was an exceptional marine ecologist whose research focused broadl... more Susan Lynn Williams (1951-2018) was an exceptional marine ecologist whose research focused broadly on the ecology of benthic nearshore environments dominated by seagrasses, seaweeds, and coral reefs. She took an empirical approach founded in techniques of physiological ecology. Susan was committed to applying her research results to ocean management through outreach to decision-makers and resource managers. Susan's career included research throughout the USA in tropical, temperate, and polar regions, but she specialized in tropical marine ecology. Susan's scholarship, leadership, and friendship touched many people, leading to this multi-authored paper. Susan's scholarship was multi-faceted, and she excelled in scientific discovery, integration of scientific results, application of science for conservation, and teaching, especially as a mentor to undergraduate and graduate students and postdoctoral scholars. Susan served in a variety of leadership positions throughout her career. She embodied all facets of leadership; leading by example, listening to others, committing to the "long haul," maintaining trust, and creating a platform for all to shine. Susan was an important role model for women in science. Susan was also a loyal friend, maintaining friendships for many decades. Susan loved cooking and entertaining with friends. This paper provides an overview of the accomplishments of Susan in the broad categories of scholarship, leadership, and friendship.
Proceedings of the National Academy of Sciences of the United States of America, May 30, 2023
Global change has converted many structurally complex and ecologically and economically valuable ... more Global change has converted many structurally complex and ecologically and economically valuable coastlines to bare substrate. In the structural habitats that remain, climate-tolerant and opportunistic species are increasing in response to environmental extremes and variability. The shifting of dominant foundation species identity with climate change poses a unique conservation challenge because species vary in their responses to environmental stressors and to management. Here, we combine 35 y of watershed modeling and biogeochemical water quality data with species comprehensive aerial surveys to describe causes and consequences of turnover in seagrass foundation species across 26,000 ha of habitat in the Chesapeake Bay. Repeated marine heatwaves have caused 54% retraction of the formerly dominant eelgrass ( Zostera marina ) since 1991, allowing 171% expansion of the temperature-tolerant widgeongrass ( Ruppia maritima ) that has likewise benefited from large-scale nutrient reductions. However, this phase shift in dominant seagrass identity now presents two significant shifts for management: Widgeongrass meadows are not only responsible for rapid, extensive recoveries but also for the largest crashes over the last four decades; and, while adapted to high temperatures, are much more susceptible than eelgrass to nutrient pulses driven by springtime runoff. Thus, by selecting for rapid post-disturbance recolonization but low resistance to punctuated freshwater flow disturbance, climate change could threaten the Chesapeake Bay seagrass’ ability to provide consistent fishery habitat and sustain functioning over time. We demonstrate that understanding the dynamics of the next generation of foundation species is a critical management priority, because shifts from relatively stable habitat to high interannual variability can have far-reaching consequences across marine and terrestrial ecosystems.
Public reporting burden for the collection of information is estimated to average 1 hour per resp... more Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.
Depth profiles and percent cover estimated for Zostera and Ruppia at Plum Tree Island transects. ... more Depth profiles and percent cover estimated for Zostera and Ruppia at Plum Tree Island transects. . •. • • Depth profiles and percent cover estimates for Zostera and Ruppia at Browns Bay transects. .. . •. •. • Depth profiles and percent cover estimates for Zostera and Ruppia at Ware Neck transects. • •. •. .. . • Depth profiles and percent cover estimates for Zostera and Ruppia at East River transects. ,. .. .. • • Depth profiles and percent cover estimates for Zostera and Ruppia at Horn Harbor transects.. .. • •. . Delineation of SAV bed, zones of similar vegetation and position of transects at the Vaucluse Shores area •• Depth profiles and percent cover estimates for Zostera and Ruppia at Vaucluse Shores transects, .
Aerial surveys of coastal habitats can uniquely inform the science and management of shallow, coa... more 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.
Description/Abstract Chesapeake Bay, one of the world's largest estuaries, has exper... more Description/Abstract Chesapeake Bay, one of the world's largest estuaries, has experienced deterioration of water quality from nutrient enrichment, resulting in anoxic or hypoxic conditions and declines in living resources. Determination of relationships between water ...
Chesapeake Bay has undergone profound changes since European settlement. Increases in human and l... more 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.
... of Mid-Atlantic Coast of the USA: Challenges in Conservation and Restoration Robert J. Orth &... more ... of Mid-Atlantic Coast of the USA: Challenges in Conservation and Restoration Robert J. Orth & Scott R. Marion & Kenneth A. Moore & David J. Wilcox ... Page 2. conservation and restoration in the last two decades (Kenworthy et al. 2006). ...
Anthesis and seed production in Zostera marina L. were studied in three areas of the Chesapeake B... more Anthesis and seed production in Zostera marina L. were studied in three areas of the Chesapeake Bay from January to June 1980. Inflorescence primordia with distinguishable anthers and pistils were first observed in February when water temperature was 3 ° C. Development of the reproductive shoots in the field continued after February as water temperature rose, with the first evidence of pollen release in mid-April (water temperature 14.3 ° C). Stigmata loss was first observed in samples taken in late April at two of the areas as water temperatures averaged above 16 ° C. Pollination was complete at all locations by 19 May and anthers were no longer present. Few reproductive shoots were found on 3-5 June and seed release was assumed to be complete by this time (water temperature 25 ° C). The density of flowering shoots ranged from 11 to 19% of the total number of shoots, producing an estimated 8127 seeds m-'. Comparison of flowering events with other areas along a latitudinal gradient from North Carolina to Canada indicated that reproductive events occurred earlier in the most southern locations and at successively later dates with increasing latitude.
Eleven years of eelgrass Zostera marina seed additions conducted in a coastal bay system where Z.... more Eleven years of eelgrass Zostera marina seed additions conducted in a coastal bay system where Z. marina had not been reported since 1933 have resulted in rapid Z. marina expansion beyond the initially seeded plots. From 1999 through 2010, 37.8 million viable seeds were added to 369 individual plots ranging in size from 0.01 to 2 ha totaling 125.2 ha in 4 coastal bays. Subsequent expansion from these initial plots to approximately 1700 ha of bay bottom populated with Z. marina through 2010 is attributable to seed export from the original plots and subsequent generations of seedlings originating from those exports. Estimates of annual patch vegetative expansion showed mean estimated diameter increasing at varying rates from 10 to 36 cm yr −1 , consistent with rhizome elongation rates reported for Z. marina. Water quality data collected over 7 yr by spatially intensive sampling, as well as fixed-location continuous monitoring, document conditions in all 4 bays that are adequate to support Z. marina growth. In particular, median chlorophyll levels for the entire sampling period were between 5 and 6 µg l −1 for each of the bays, and median turbidity levels, while exhibiting seasonal differences, were between 8 and 9 NTU. The recovery of Z. marina initiated in this coastal bay system may be unique in seagrass recovery studies because of how the recovery was initiated (seeds rather than adult plants), how rapidly it occurred (years rather than decades), and the explicit demonstration of how one meadow modulated water clarity and altered sediments as it developed and expanded. Our results offer a new perspective on the role seeds can play in recovery dynamics at large spatial scales. KEY WORDS: Seeds. Germination. Seedling establishment. Zostera marina. Virginia coastal bays Resale or republication not permitted without written consent of the publisher OPEN PEN ACCESS CCESS Contribution to the Theme Section 'Eelgrass recovery' 179 Continuous WQ Station D a ta fl o w T ra c k D e lm a r v a P e n in s u la Atlantic Ocean C h e s a p e a k e B a y Start Oyster Sand Shoal Inlet Great Machipongo Inlet
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