CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 NOTE TO REVIEWERS: THIS DOCUMENT PRESENTS THE RESULTS OF WORK TO DATE BY A TEAM OF ALL SIX STATES, DC AND EPA REGIONAL AND HEADQUARTERS WATER QUALITY STANDARDS PROGRAM MANAGERS IN DEFINING A REFINED SET OF CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES REFLECTIVE OF BAY LIVING RESOURCE NEEDS AND HABITATS. THE TIDAL WATER DESIGNATED USES PRESENTED HERE SHOULD BE VIEWED AS WORKING DRAFTS SUBJECT TO CHANGE DURING THE PLANNED MULTISTAGE REVIEW PROCESS. WE ENCOURAGE COMMENTS, IDEAS, RECOMMENDATIONS, AND EXPRESSIONS OF CONCERN FOCUSED PARTICULARLY ON THE APPROACH TAKEN TO CHARACTERIZE THE DIFFERENT DESIGNATED USES AND ESTABLISH THE BOUNDARY DELINEATIONS BETWEEN THE FIVE DESIGNATED USES. APPENDIX A. Refined Designated Uses for the Chesapeake Bay and Tidal Tributary Waters Acknowledgments These Chesapeake Bay tidal waters designated uses were derived through the collaborative efforts of the Chesapeake Bay Water Quality Standards Coordinators Team: Rich Batiuk, U.S. EPA Chesapeake Bay Program Office; Jerusalem Bekele, District of Columbia Department of Health; Iibby Chatfield, West Virginia Environmental Quality Board; Rich Eskin, Maryland Department of the Environment; Tom Gardner, U.S. EPA Office of Water (Criteria); Jean Gregory, Virginia Department of Environmental Quality, Denise Hakowski, U.S. EPA Region 3; Elaine Harbold, U.S. EPA Region 3; Wayne Jackson, U.S. EPA Region 2; Jim Keating, U.S. EPA Office of Water (Standards); Larry Merrill, U.S. EPA Region 3; Gary Miller, U.S. EPA Region 3; Joel Salter, U.S. EPA Office of Water (Permits); John Schneider, Delaware Department of Natural Resources and Environmental Control; Mark Smith, U.S. EPA Region 3; Scott Stoner, New York Department of Environmental Conservation; and Carol Young, Pennsylvania Department of Environmental Protection. Without the contributions of well over a hundred individuals listed as authors or technical contributors to various syntheses of Chesapeake Bay living resource habitat requirements over the past two decades, the scientific basis for a set of designated uses tailored to Chesapeake Bay tidal habitats and species would not have been forged. Their collective contributions are hereby fully acknowledged. Background Existing state designated uses applied to Chesapeake Bay and tidal tributary waters change across jurisdictional borders even for the same water body, the uses don't reflect natural conditions, and are not specific enough to allow water quality criteria tailored to different ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 habitats. The 2000 Chesapeake Bay Agreement and a subsequent six state/DC/EPA memorandum of understanding challenged the Bay watershed jurisdictions to "by 2010, correct the nutrient- and sediment-related problems in the Chesapeake Bay and its tidal tributaries sufficiently to remove the Bay and the tidal portions of its tributaries from the list of impaired waters under the Clean Water Act" (Chesapeake Executive Council, 2000). These agreements included commitments to "define the water quality conditions necessary to protect aquatic living resources" by 2001 and having the jurisdictions with tidal waters "use their best efforts to adopt new or revised water quality standards consistent with the defined water quality conditions" by 2003. Against this backdrop of a renewed commitment to restore Bay water quality, in part, through adoption of a consistent set of Chesapeake Bay water quality criteria as state standards, it was determined that the underlying tidal water designated uses must be refined to better reflect the restored Bay water quality conditions. In refining the tidal water designated uses, five considerations were applied: - the designated uses must reflect a limited, select set of publicly understandable habitats and intended aquatic life uses of those habitats; - habitats used by common sets of species and life stages should be identified and delineated as separate designated uses; - natural variations in water quality must be directly reflected in the delineation of the designated uses; - seasonal uses of different habitats need to be factored into the designated uses; and - the designated uses should be selected so that the Chesapeake Bay criteria for dissolved oxygen, water clarity and chlorophyll a could be tailored to support each unique designated use. The resultant conceptual illustration of a set of refined tidal water designated uses addressing these considerations is presented in Figure A-l. This appendix describes a set of five refined tidal water designated uses and defines the boundaries between "migratory spawning and nursery," "shallow water," "open water," "deep water," and "deep channel" habitats. Accurate delineation of where to apply these tidal water designated uses is critical as the Chesapeake Bay water quality criteria, particularly the Bay dissolved oxygen criteria, will be applied differentially over time and space to the different designated use habitats. The publication of two extensive syntheses of the physical, water quality, and biological habitat requirements of a set of commercially, recreationally and ecologically important target species and communities laid the foundation from which these refined tidal water designated uses were first conceived, then built (Chesapeake Bay Living Resource Task Force 1987; Funderburk et al. 1991). Only when coupled with analyses of the extensive Chesapeake Bay Water Quality Monitoring Program data base, now spanning 16 years, could the refined tidal 2 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 water designated uses described below be documented and delineated across all tidal water habitats without constraints by artificial jurisdictional borders. Chesapeake Bay Tidal Waters Designated Uses Migratory Spawning and Nursery The migratory spawning and nursery designated use is the propagation and growth of balanced indigenous populations of ecologically, recreationally, and commercially important anadromous, semi-anadromous, and tidal fresh resident fish species inhabiting spawning and nursery grounds from February 15th through June 10th. Designated Use Rationale Based on the commitment within the 1987 Chesapeake Bay Agreement to "develop and adopt guidelines for the protection of water quality and habitat conditions necessary to support the living resource found in the Chesapeake Bay," a list of target species were identified (Chesapeake Executive Council, 1987). Included on that list of targeted species were striped bass, American shad, hickory shad, alewife, blueback herring, white perch, and yellow perch These anadromous and semi-anadromous fish were selected on the basis of their "commercial, recreational, aesthetic, or ecological significance and the threat to sustained production due to population decline or serious habitat degradation"(Chesapeake Bay Living Resources Task Force 1988). Chesapeake Bay tidal waters support spawning areas and juvenile nurseries for a host of anadromous and semi-anadromous fish, important to not only maintaining Chesapeake Bay fishery populations, but also those of the entire East Coast for species like striped bass. The eggs, larvae, and early juveniles of anadromous and semi-anadromous species have often more sensitive habitat quality requirements than other species and life stages (Funderburk et al. 1991; Jordan et al. 1992). For these reasons, the combined "migratory spawning and nursery" habitats were delineated as a refined tidal water designated use for Chesapeake Bay. Designated Use Boundary Delineation The upper and lower boundaries of the "migratory spawning and nursery" designated use are defined by the upper extent of tidally influenced waters down river/down Bay to the lower reach of existing spawning and nursery habitats defined through a composite overlay of all targeted anadromous and semi-anadromous fish species' spawning/nursery habitats (Figure A-2). The designated use extends horizontally from the intertidal zone across the water body to the adjacent intertidal zone and vertically down into the water column, either to the measured 3 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 depth of the upper pycnocline boundary or, in the absence of a measured pycnocline, all the way to the tidal tributary or mainstem Bay bottom sediments. During the February 15th through June 10th time period, the "migratory spawning and nursery" designated use encompasses the "shallow water" and "open water" designated use habitats (see shaded sections in Figure A-l). Therefore, the horizontal and vertical delineations for the "migratory spawning and nursery" designated use directly matches with those of the "shallow water" and "open water" designated uses. To generate these boundaries, the habitat distribution maps listed in Table A-l drawn from the Habitat Requirements for Chesapeake Bay Living Resources - Second Edition (Funderburk et al. 1991) were overlaid. When a single species had multiple habitat distribution maps for related life stages, the maps were merged into a single coverage. After merging where necessary, the individual species maps were overlaid and the number of overlapping habitat maps were counted and visually displayed (Figure A-3). The striped bass habitat distribution maps used in this overlay process were originally titled "Striped Bass Chesapeake Bay Spawning Reaches and Spawning Rivers". The source of the spawning reach distributions were research and monitoring findings synthesized by Setzler- Hamilton and Hall (1991). However, the mapped extent of the nursery areas, termed spawning rivers in the original map, were based on Maryland and Virginia legislative definitions, not fisheries survey findings. Follow up discussions were held with Herb Austin and Deane Estes, Virginia Institute of Marine Science, and Eric Durelle, Maryland Department of Natural Resources, all fishery scientists responsible for their respective state's juvenile striped bass seine surveys. Based on comparison of long term Maryland and Virginia seine survey data with the legislatively defined extent of early juvenile nursery habitat, the primary nursery areas for young of the year striped bass were delineated. Even though juvenile striped bass can be found throughout a broader range of Maryland and Virginia tidal waters, the highest concentrations of early juvenile life stage striped bass are found in the primary nursery areas illustrated in Figure A-2 in the spring to early June time frame (e.g., Austin et al. 2000). Critical Support (food, shelter) Comm unities Spawning adults and the resultant larvae and early juvenile fish depend on an array of phytoplankton, zooplankton, bottom dwelling worms and clams, and forage fish as prey within the "migratory spawning and nursery" designated use habitat during these critical life stages (numerous references cited in Funderburk et al. 1991) The presence of underwater grasses in the shallow reaches of the designated use habitat are essential to providing a source of shelter for young juveniles as well as a location of concentrated prey species. Seasonal Use Application The "migratory spawning and nursery" designated use applies from February 15th through June 10th. From June 11th through February 14th, the shallow water and open water designated uses apply to these same habitats (see Figure A-l). The defined season for application of the use 4 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 is based on a composite of the full range of spawning periods and timing of when early juveniles leave the nursery areas for all the target anadromous and semi-anadromous species. Adult yellow perch migrate from downstream stretches of tidal water to spawning areas in less saline upper reaches in mid-February through March (Richkus and Stroup 1987; Tsai and Gibson 1971). By early June, young of the year juvenile striped bass begin to move shoreward, spending the summer and early fall in shoal water less than six feet deep (Setzler-Hamilton et al. 1981). As juveniles grow, they move progressively down river out of the nursery areas (Boreman and Klauda 1988; Dey 1981; Setzler-Hamilton et al. 1981). The February 15th date was selected to reflect the initiation of the yellow perch spawning season with the June 10th date selected to reflect the time when many striped bass juveniles are heading down river/down Bay beyond the lower boundaries of the designated use. Applicable Chesapeake Bay Water Quality Criteria From February 15th through June 10th, the "migratory spawning/nursery" dissolved oxygen criteria, "shallow water" water clarity criteria, and "shallow/open water" chlorophyll a criteria apply to the "migratory spawning/nursery" designated use habitats. See Chapters M, IV, and V, respectively, for more details on the individual criteria. Shallow Water The "shallow water" designated use is the propagation and growth of balanced, indigenous populations of ecologically, recreationally, and commercially important fish, shellfish and underwater grasses inhabiting shallow water habitats. Designated Use Rationale The "shallow water" designated use is designed to protect a wide array species like largemouth bass and pickerel inhabiting tidal fresh and low salinity habitats to speckled sea trout (juvenile) in higher salinity areas to blue crabs that inhabit shallow water habitats covering the full range of salinities encountered in Chesapeake Bay and its tidal tributaries. Underwater grasses, a critical community protected by the designated use, provides a source of shelter and food that makes shallow water habitats so unique and integral to the productivity of the Bay ecosystem. The many Chesapeake Bay species, which depend on these shallow water habitats at some point during their life cycle (numerous references cited in Funderburk et al. 1991), have specific habitat requirements while within these shallow habitats, the best example being underwater grasses. Given the unique nature of these habitats and their critical importance to the Chesapeake Bay ecosystem, "shallow waters" were delineated as a refined tidal water designated use for Chesapeake Bay. Designated Use Boundary Delineation Tidally influenced waters from the intertidal zone out to the two meter depth contour, as measured at mean low water along all Chesapeake Bay and tidal tributary shorelines, defines the upper and lower boundaries for the "shallow water" designated use (Figure A-4). The two meter 5 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 depth contour was selected principally on the basis of being the depth to which underwater Bay grasses could be restored in many of the tidal tributaries and mainstem Bay shallow water habitats. Although historical underwater grass beds in Chesapeake Bay probably grew to 3 meters or more, the 2 meter depth contour was chosen following an extensive evaluation of grass bed distributions in the past 30 years and anticipated restoration of light levels required to restore viable shallow water habitats out to the 2 meter depth (Batiuk et al. 1992; Dennison et al. 1993; Batiuk et al. 2000). The intertidal zone was selected as the upper boundary for the "shallow water" designated use as some species of underwater grass can grow up into the intertidal zone (Batiuk et al. 2000; Koch 2001). The 2 meter depth contour GIS coverage delineating the "shallow water" designated use is accessible via the Chesapeake Bay Program web site's data hub at http://www.chesapeakebay.net. [EDITOR'S NOTE: ADDITIONAL DOCUMENTATION ON THE 2 METER DEPTH CONTOUR COVERAGE AND HOW IT WAS DEVELOPED WILL BE ADDED IN THE NEXT DRAFT.] Critical Support (food, shelter) Comm. unities Phytoplankton, zooplankton, forage fish, and bottom dwelling worms and clams are food for a wide array of fish, crab, and molluscan shellfish species inhabiting shallow water habitats during part or all of their life stages. Water quality criteria necessary to fully support the "shallow water" designated use must provide for the survival, growth and successful propagation of quality prey communities in sufficient quantities. Applicable Bay Water Quality Criteria The "shallow water/open water" dissolved oxygen criteria apply all year round, the applicable salinity regime-based chlorophyll a criteria apply only during the spring (March-May) and summer (July-September) time frames, and the applicable salinity regime-based water clarity apply during the appropriate Bay grasses growing season (April to October for tidal fresh, oligohaline and mesohaline habitats and March to May and September to November for polyhaline habitats). See Chapters III, IV, and V, respectively, for more details on the individual criteria. Open Water The "open water" designated use is the propagation and growth of balanced, i ndigenous populations of ecologically, recreationally, and commercially important fish and shellfish species inhabiting open water habitats. Designated Use Rationale Given the natural temperature and salinity stratification of the open water column and the 6 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 direct influence of this stratification on the relative distribution of Chesapeake Bay species, waters located above the pycnocline can support a different community of species than deeper waters during the late spring to early fall time frame. Several well known species that inhabit the opens waters of the Chesapeake Bay and its tidal tributaries are menhaden, striped bass, and bluefish. The habitat requirements and prey need of these species are also different from species and communities inhabiting less oxygenated, deeper water habitats. (See the "deep water's" Designated Use Rationale section below for relevant information on the effects of natural water column stratification.). Based on these natural conditions and how they influence the distribution of Bay species, "open waters" were delineated as a refined tidal water designated use for Chesapeake Bay. Designated Use Boundary Delineation The boundaries for the "open water" designated use are tidally influenced waters extending horizontally from the two meter depth contour (measured at mean low water) (Figure A-5) across the water body to the adjacent two meter depth contour and vertically down into the water column to either to the measured depth of the upper pycnocline boundary or, in the absence of a measured pycnocline, to the bottom sediments (Figure A-6). Where a measured pycnocline is present but does not represent a barrier to oxygen replenishment, the open water designated use will extend all the way down to the bottom sediments (Figure A-7). In part of the mainstem Bay south of the mouth of the Rappahannock River, the "open water" designated use habitat extends all the way down to the bottom. Although this region can exhibit relatively strong stratification, it exhibits little dissolved oxygen deficiency. Proximity to the mouth of Chesapeake Bay allows for continuous replenishment of subpycnocline waters with oxygenated ocean water (Figure A-8). [EDITOR'S NOTE: OTHER PRELIMINARY ANALYSES INDICATE THAT DELINEATION OF THIS AREA SHOULD BE POSSIBLY AS FAR SOUTH AS A LINE DRAWN FROM THE BACK RIVER ACROSS THE BAY TO THE CHERRYSTONE INLET. FURTHER FOLLOW UP ANALYSES OF BOTH THE 16 YEAR BAY WATER QUALITY MONITORING PROGRAM DATA RECORD AND BAY WATER QUALITY MODEL MANAGEMENT SCENARIOS TO BE RUN THIS SUMMER/FALL WILL BE UNDERTAKEN TO CONFIRM THE AREAS WITHIN THE MAINSTEM BAY AND TIDAL TRIBUTARIES WHERE THE OPEN WATER DESIGNATED USE EXTENDS ALL THE WAY TO THE BOTTOM IN THE PRESENCE OF STRATIFIED CONDITIONS.] Critical Support (food, shelter) Comm unities Water column dwelling phytoplankton, zooplankton, and forage fish constitute the major prey for the species that inhabit the Bay's open waters (numerous references cited within Funderburk et al. 1991). Water quality criteria necessary to fully support the "open water" 7 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 designated use must provide for the survival, growth and successful propagation of quality prey communities in sufficient quantities. Applicable Bay Water Quality Criteria The "shallow water/open water" dissolved oxygen criteria apply all year round and the applicable salinity regime-based chlorophyll a criteria apply only during the spring (March-May) and summer (July-September) time frames to the open water designated use habitats. See Chapters III and V, respectively, for more details on the individual criteria. Deep Water The "deep water" designated use is to protect the propagation and growth of balanced, indigenous populations of ecologically, recreationally, and commercially important fish and shellfish species inhabiting deep water habitats. Designated Use Rationale In a eutrophic system such as Chesapeake Bay, excess organic matter settles to the bottom where it fuels microbial activity (e.g., Malone et al. 1986; Tuttle et al. 1987). The more fuel, the more oxygen consumed and, where replenishment is restricted, the more severely oxygen depleted is the water. There is evidence that hypoxic and anoxic conditions existed in the deeper waters of the Bay prior to European settlement (Cooper and Brush 1991). These same data give strong evidence that anthropogenic activity has increased the frequency and severity of oxygen deletion in the Bay (Zimmerman and Canuel 1999). Many parts of the Bay become vertically stratified seasonally because of depth-related density differences within the water column. These differences in density are caused primarily by differences in salinity and, to lesser degree, temperature. Fresh water flowing from the rivers tends to float on top of denser saline water moving in from the ocean, and the gravitational force of the down-Bay or down-river flow of freshwater causes a wedge of deeper, saltier water to move up-Bay, up-river. Vertically, at some point in the water column, a zone of maximum density difference is reached, sufficient to inhibit or prevent exchange between water above and below it. This region is called the region of the pycnocline. In the summer months, respiration by organisms living below the pycnocline can deplete concentrations of dissolved oxygen. Because waters below the pycnocline are isolated from surface waters, dissolved oxygen levels can decrease until they are stressful or lethal to higher organisms. Formation of the pycnocline is a natural process and not directly related to man's influence. Where stratification is common, the pycnocline generally forms at about the same depth, within a meter or two, every year. It is generally shallower at the mouths of rivers and the Bay and deeper at the heads of rivers and the bay. The effect of the pycnocline is also not the same everywhere in the Bay and is influenced by local characteristics such as bathymetry, 8 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 vertical and horizontal circulation patterns, and proximity to the ocean and fall line. In some parts of the Bay and rivers, these factors create a more complex stratification pattern: a second pycnocline is formed lower in the water column, dividing the water column into three layers. If a region is contained by both the pycnocline above and by bathymetry laterally, it is even more isolated from oxygen-replenishing water. In contrast, below-pycnocline areas below the Potomac River to the mouth of the Bay are continuously replenished by flow from the ocean and, therefore, naturally should not show extreme low dissolved oxygen effects from being isolated from surface waters. Bay anchovy is a target species whose egg and larval life stages are found within the pycnocline waters (Keister et al. 2000; Rilling and Houde 1999; MacGregor and Houde 1996). Blue crabs, oyster, softshell clam, hard clam, spot, croaker, flounder, and catfish are all species that inhabit the near bottom waters within the deep water habitats (references cited within Funderburk et al. 1991). These species have oxygen requirements that are different from species inhabiting shallow and open water column habitats. Where they feed as well as the distribution of their eggs and larvae, in the case of bay anchovy, are strongly influenced by natural features of the water column like the pycnocline. "Deep water" was delineated as a refined tidal water designated use for Chesapeake Bay based combination of the unique nature of the pycnocline region as an important living resource habitat as well as the transitional nature of the water quality conditions-temperature, salinity and dissolved oxygen—between the warmer, less saline, more oxygenated surficial open water and the physically segregated, cooler, more saline, often oxygen depleted deep channel waters. Designated Use Boundary Delineation "Deep water" designated use waters are defined as the tidally influenced waters located between the measured depths of the upper and lower boundaries of the pycnocline in areas where a measured pycnocline is present and represents a barrier to oxygen replenishment (Figures A-8 and A-9). There will be circumstances where "deep waters" extend from the upper boundary of the pycnocline to the sediment bottom where a lower boundary of the pycnocline is not calculated due to the depth of the water column. Critical Support (food, shelter) Comm unities Bottom dwelling worms and clams and reef inhabiting forage fish are all important food sources for the fish and crabs inhabiting deep water habitats. Water quality criteria necessary to fully support the "deep water" designated use must provide for the survival, growth and successful propagation of quality prey communities in sufficient quantities. Applicable Bay Water Quality Criteria The "deep water" dissolved oxygen criteria apply from May through September whereas 9 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 "shallow water/open water" dissolved oxygen criteria apply from October through April in "deep water" designated use habitats. Deep Channel The "deep channel" designated use is to provide a refuge for balanced, indigenous populations of ecologically, recreationally, and commercially important fish species that depend on deep channel habitats for overwintering from October through April; and, from May through September, the propagation and growth of benthic infaunal and epifaunal worms and clams that provide food for bottom feeding fish and crabs. Designated Use Rationale During the first winter of life, populations of five important Chesapeake Bay species- white perch, striped bass, Atlantic croaker, shortnose sturgeon, and Atlantic sturgeon-are constrained to oligohaline and mesohaline regions (<20 ppt) in the upper Chesapeake Bay mainstem. As juveniles during their first winter of life, these species are expected to seek out warmer temperatures that occur in deeper channel waters below the thermocline. From October through April, the deep channel habitats in the upper Bay adjacent to shallower summer and fall time habitats should be considered important nursery habitats for young-of-the-year juvenile white perch, striped bass, and Atlantic croaker (Pothoven et al. 1997) as well as Atlantic and shortnose sturgeon (Miller et al. 1997; Secor et al. 2000; Welsh et al. 2000). During the coldest months, the interaction between temperatures and salinity tolerances may result in a habitat bottleneck ("habitat squeeze") forcing distributions of the juveniles into these deep channel habitats seeking preferred temperatures. Unpublished data from the Maryland Environmental Service indicate that a thermocline separating warmer deeper waters from colder overlaying waters typically occurs at a 10 to 20 meter depth in the deep channel during the months of October to February. In Chesapeake Bay, researchers have determined the oxygen minimum to be in the subpycnocline waters at the head of the deep trough in the northern Bay during the late spring to early fall time frame (Smith et al. 1992). Isolated from aerated surface water, oxygen concentrations in this region are the net result of excess oxygen consumption from nutrient inputs over oxygen additions from advected ocean waters from far down-Bay. North of this region, the trough shallows quickly and bottom waters become oxygenated as they mix with aerated waters in the shoals. South of this region, subpycnocline waters are re-oxygenated through mixing with oxygenated oceanic waters entering through the Bay mouth Given the physical nature of the deep trough region leading to naturally severe oxygen depletion during the summer as well as its unique refuge habitat role during cooler months of the year, the "deep channel" was delineated as a refined tidal water designated use for Chesapeake Bay. 10 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 Designated Use Boundary Delineation "Deep channel" designated use waters are defined as tidally influenced waters at depths below the measured lower boundary of the pycnocline over and within isolated deep channels (Figure A-l 0). In the mainstem Chesapeake Bay, the "deep channel" designated use habitat is located along the deep central trough running north-south from the Chesapeake Bay Bridge near Annapolis to the region near the mouth of the Potomac River (see Figure A-8). The "deep channel" is defined laterally by bathymetry of the trough and vertically by the lower boundary of the pycnocline above and the bottom sediments below. [EDITOR'S NOTE: WORK IS UNDERWAY TO DOCUMENT AND MAP OUT OTHER POSSIBLE DEEP CHANNEL DESIGNATED USE HABITATS IN THE LOWER POTOMAC RIVER, THE SHIPPING ENTRANCE CHANNELS TO THE PATAPSCO RIVER/BALTIMORE HARBOR, THE LOWER RAPPAHANNOCK, AND POSSIBLY OTHER TIDAL RIVERS. MAPS AND ACCOMPANYING DOCUMENTATION WILL BE PROVIDED IN THE NEXT DRAFT OF THE TIDAL WATERS DESIGNATED USES DOCUMENT.] These deep channels are sinks for excess organic material fueling oxygen consumption and they are isolated from surface and oceanic sources of oxygen replenishment. Vertical stratification in combination with gravitational and horizontal circulation often cause severe oxygen deficiency to be manifested, when present, not as a gradually declining gradient, but by a rapid drop-off in oxygen, beginning just below the pycnocline and extending to the bottom (Smith et al. 1992). Within the "deep channel" designated use, specific areas are delineated as a seasonal anoxic region where conditions of extremely low (<1 mg/L) and no oxygen (<0.2 mg/L) conditions are likely to persist throughout even under the best management conditions that can be achieved. The seasonal anoxic region is defined generally as the deep bottom waters of the central trough in the mainstem Bay described above. This includes subpycnocline waters below about the 14 meter depth contour near the Bay Bridge where the deep trough begins sloping down to below the 20 meter depth contour further south where the trough deepens and maintains the deep depth to just below the mouth of the Potomac. The differences in depth as one heads south from the Chesapeake Bay Bridge down the Bay towards the Potomac River mouth is due to a gradual deepening of the depth of the pycnocline. [EDITOR'S NOTE: OVER THE COURSE OF THE SUMMER AND FAT J,, A SERIES OF CHESAPEAKE BAY WATER QUALITY MODEL MANAGEMENT SCENARIOS ARE PLANNED TO BE RUN WHICH, ALONG WITH ADDITIONAL ANALYSIS OF THE 16 YEAR BAY WATER QUALITY MONITORING DATA RECORD, WILL BE USED TO MORE SPECIFICALLY DEFINE AND MAP OUT THE MAXIMUM EXTENT OF THE 11 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 SEASONAL ANOXIC REGION. ADDITIONAL DOCUMENTATION AND MORE SPECIFIC MAPS WILL BE INCLUDED IN THE NEXT DRAFT OF THE TIDAL WATERS DESIGNATED USE DOCUMENT. WE SPECIFICALLY INVITE COMMENT ON HOW TO BEST DEFINE AND APPLY THE SEASONAL ANOXIC REGION.] Critical Support (food, shelter) Comm unities Bottom dwelling worms and clams provide are the principal food source to bottom dwelling and feeding crabs and fish in the deep channel. Water quality criteria necessary to fully support the "deep channel" designated use must provide for the survival of these prey communities. Applicable Bay Water Quality Criteria The "deep channel" dissolved oxygen criteria apply from May through September and the "shallow water/open water" dissolved oxygen criteria apply from October through April in "deep channel" designated use habitats. In the seasonal anoxic region, there will be periods from May through September when the "deep channel" dissolved oxygen criteria will be unattainable. Implementation Procedures [EDITOR'S NOTE: THE DESIGNATED USE IMPLEMENTATION PROCEDURES WILL BE FURTHER FLESHED OUT OVER THE COURSE OF THE SUMMER. PLEASE IDENTIFY IMPLEMENTATION ISSUES NOT OUTLINED BELOW. THE ULTIMATE OBJECTIVE IS TO DEVELOP A SET OF PROCEDURES THAT WILL BE ADOPTED AND USED CONSISTENTLY ACROSS ALL BAY TIDAL WATERS BY THE STATES WITH TIDAL WATERS.] Formally Delineating the Designated Use Boundaries Migratory Spawning and Nursery Table A-2 provides the specific navigational aids and landmarks as well as GIS coordinates delineating the down river/down Bay lower boundary of the "migratory spawning and nursery" designated use across all applicable tidal waters.... [EDITOR'S NOTE: THE INFORMATION FOR TABLE A-2 IS CURRENTLY BEING GENERATED BY THE CHESAPEAKE BAY PROGRAM OFFICE'S GIS TEAM AND WILL BE CONFIRMED BY MD, VA, DC, AND DE FISHERY SCIENTISTS THIS SUMMER. THE COMPLETE DETAILED TABLE WILL BE PUBLISHED IN THE NEXT DRAFT OF THE TIDAL WATER DESIGNATED USE DOCUMENT.] [SOURCE OF THE GIS COVERAGE TO BE ADDED AND DOCUMENTED.] 12 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 Shallow Water [SOURCE OF THE GIS COVERAGE TO BE ADDED AND DOCUMENTED.] Open Water/Deep Water/Deep Channel [DETAILS AND ASSOCIATED PROGRAMMING FOR CALCULATING THE UPPER AND LOWER BOUNDARIES OF THE PYCNOCLINETO BE ADDED AND DOCUMENTED.] Seasonal Anoxic Region [SOURCE OF THE GIS COVERAGE TO BE ADDED AND DOCUMENTED.] Bay Criteria Implementation by Designated Use 13 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 References Batiuk, R.A., P. Berg^trom, M. Kemp, E. Koch, L. Murray, J.C. Stevenson, R. Bartleson, V. Carter, N.B. Rybicki, J.M. Landwehr, C. Gallegos, L. Karrh, M. Naylor, D. Wilcox, K.A. Moore, S. Ailstock, and M. Teichberg. 2000. Chesapeake Bay submerged aquatic vegetation water quality and habitat-based requirements and restoration targets: a second technical synthesis. CBP/TRS 245/00 EPA 903-R-00-014. USEPA Chesapeake Bay Program, Annapolis, MD. Batiuk, R., R. Orth, K. Moore, J. C. Stevenson, W. Dennison, L. Staver, V. Carter, N. Rybicki, R. Hickman, S. KollarandS. Bieber. 1992. Submerged aquatic vegetation habitat requirements and restoration targets: a technical synthesis. CBP/TRS 83/92. USEPA Chesapeake Bay Program, Annapolis, MD. Chesapeake Executive Council. 2000. 2000 Chesapeake Bay Agreement, Annapolis, MD. Chesapeake Executive Council. 1987. Chesapeake Bay Agreement. Annapolis, MD. Chesapeake Bay Living Resources Task Force. 1987. Habitat requirements for Chesapeake Bay living resources: a report from the Chesapeake Bay Living Resources Task Force. Chesapeake Bay Program, Annapolis, MD. Cooper, S.R. and G.S. Brush 1991. Long term history of Chesapeake Bay anoxia. Science, 254: 992-996. Dennison, W. C., R. J. Orth, K. A. Moore, J. C. Stevenson, V. Carter, S. Kollar, P. W. Bergstrom and R. A. Batiuk. 1993. Assessing water quality with submersed aquatic vegetation. Habitat requirements as barometers of Chesapeake Bay health. Bioscience. 43: 86-94. Funderburk, S.L., J.A. Mihursky, S.J. Jordan, and D. Riley (eds.).1991. Habitat requirements for Chesapeake Bay living resources: second edition. Chesapeake Research Consortium, Solomons, MD. Koch, E.W. 2001. Beyond light: physical, geological, and geochemical parameters as possible submersed aquatic vegetation habitat requirements. Estuaries. Jordan, S.J., C. Stenger, M. Olson, R. Batiuk, and K. Mountford.1992. Chesapeake Bay dissolved oxygen goal for restoration of living resource habitats: a sythesis of living resource requirements with guidelines for their use in evaluating model results and monitoring information. CBP/TRS 88/93. Chesapeake Bay Program, Annapolis, MD. 14 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 Keister, J.E., E.D. Houde and D.L. Breitbuig. 2000. Effects ofbottom-layer hypoxia on abundances and depth distributions of organisms in Patuxent River, Chesapeake Bay. Mar. Ecol. Prog. Ser. 205:43-59. MacGregor, J. and E.D. Houde. 1996. Onshore-offshore pattern and variability in distribution and abundance of bay anchovy Anchoa mitchilli eggs and larvae in Chesapeake Bay. Marine Ecology Progress Series 138: 15-25. Malone, T.C., W.M. Kemp, H.W. Ducklow, W.R. Boynton, J.H. Tuttle, and R.B. Jonas. 1986. Lateral variation in the production and fate of phytoplankton in a partially stratified estuary. Mar. Ecol. Prog. Ser., 32: 149-160. Miller, T.J., J. Stone, and E.A. Sadler. 1997. Chapter 2: Gill net surveys, p. 34-63. In: T.J. Miller, (ed.) Assessment of fish community structure near Site 104. UMCES CBL 97-123. Report to the Maryland Environmental Service, Annapolis, MD. Pothoven, SA., S.B. Brandt, J.M. Jech, and J.L. Home. 1997. Chapter 3: Fish abundance, size and species composition: Kent Island Site 104, p. 78-125. In: T.J. Miller, (ed.) Assessment of fish community structure near Site 104. UMCES CBL 97-123. Report to the Maryland Environmental Service, Annapolis, MD. Rilling, G.C. and E.D. Houde. 1999. Regional and temporal variability in distribution and abundance of bay anchovy (Anchova mitchilli) eggs and larvae in the Chesapeake Bay. Estuaries 22(4): 1096-1109. Secor, D.H. and T.E. Gunderson. 1998. Effects of hypoxia and temperature on survival, growth, and respiration of juvenile Atlantic sturgeon, A cipenser oxyrinchus. Fish. Bull. 96: 603-613. Setlzer-Hamilton, E.M. and L.W. Hall, Jr. 1991. Striped bass. In: Funderburk, S.L., J.A. Mihursky, S.J. Jordan, andD. Riley (eds.). Habitat requirements for Chesapeake Bay living resources: second edition. Chesapeake Research Consortium, Solomons, MD. Smith, D.E., M. Leffler, and G. MacKiernan. 1992. Oxygen dynamics in the Chesapeake Bay: A synthesis of recent research. Maryland and Virginia Sea Grant Programs. College Park, MD. Tuttle, J.H., R.B. Jonas, and T.C. Malone. 1987. Origin, development, and significance of Chesapeake Bay anoxia, In Contaminant Problems and Management of Living Chesapeake Bay Resources, S.K. Majumdar, L/W. Hall, Jr. and K.M.Austin eds. Pennsylvania Acad. Sci. Philadelphia, PA, 442-472. 15 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 Welsh, S.A., J.E. Skjeveland, M.F. Mangold, and S.M. Eylver. 2000. Distribution ofwild and hatchery-reared Atlantic sturgeon in the Chesapeake Bay, MD. Biology, Management, and Protection of Sturgeon Symposium, EPRI, Palo Alto, CA. Zimmerman, A.R. and E.A. Canuel. 2000. A geochemical record of eulrophication and anoxia in Chesapeake Bay sediments: anthropogenic influence on organic matter composition. Marine Chemistry, 69: 117-137. 16 ------- CHESAPEAKE BAY TIDAL WATERS DESIGNATED USES WORKING DRAFT No. 1 July 3, 2001 Table A-l. Migratory spawning and nursery habitat distribution maps used in the delineation of the migratory spawning and nursery designated use. Alewife spawning and nursery Alewife nursery American shad spawning and nursery American shad nursery Hickory shad spawning and nursery Herring spawning and nursery Herring nursery Striped bass spawning reaches Striped bass spawning rivers White perch nursery White perch spawning Yellow perch spawning and nursery Source: Funderburk et al. 1991. 17 ------- |