The York River: a Brief Review of Its Physical, Chemical and Biological Characteristics
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W&M ScholarWorks Reports 1986 The York River: A Brief Review of Its Physical, Chemical and Biological Characteristics Michael E. Bender Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/reports Part of the Aquaculture and Fisheries Commons, Marine Biology Commons, Natural Resources and Conservation Commons, and the Terrestrial and Aquatic Ecology Commons Recommended Citation Bender, M. E. (1986) The York River: A Brief Review of Its Physical, Chemical and Biological Characteristics. Virginia Institute of Marine Science, William & Mary. https://doi.org/10.21220/V5JD9W This Report is brought to you for free and open access by W&M ScholarWorks. It has been accepted for inclusion in Reports by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. The York River: A Brief Review of Its Physical, Chemical and Biological Characteristics ·.by · Michael E. Bender .·· Virginia Institute of Marine Science School ofMar.ine Science The College of William and Mary Gloucester, Point; Virginia 23062 The York River: A Brief Review of Its Physical, Chemical and Biological Characteristics by · Michael E. Bender Virginia Institute of Marine Science School of Marine Science The College of William and Mary Gloucester Point, Virginia 23062 LIST OF FIGURES Figure Page 1. The York River . 5 2. The York River Basin (to the fall line) .. 6 3. Mean Daily Water Temperatures off VIMS Pier for 1954- 1977 [from Hsieh, 1979]. • . 8 4. Typical Water Temperature Profiles in the Lower York River approximately 10 km from the River Mouth . 10 5. Typical Seasonal Salinity Profiles Along the York River. 11 6. Salinity Distribution along the York During March, July and October 1982 • • ~ . • . • • . • 12 7. Salinity and Di.ssolved Oxygen During Periods of Strati- fication and·Destratification, August 1981, 1982 . 14 8. Salinity Distributiori Al~ng the Axis of the York- August 1982 [from Ruzecki & Evans, 1985] . • . 15 9. Surface to Bottom Dissolved Oxygen Differences vs Tidal Range - York River Approximately 10 km From the Mouth. 17 10. Surface to Bottom Dissolved Oxygen Differences (May - September) from 1972 - 1981 Approximately 10 km from the River Mouth. • . • . 19 11. Surface and Bottom Phosphate Concentrations in the Lower York (monthly moving averages over 3 years) [calculated from Jordan et al., 1975]. • • • 20 12. Surface and Bottom Nitrogen Concentrations in the Lower York (monthly moving average over 3 years) [calculated from Jordan et al., 1975]. 22 13. Sampling Stations for Water Quality and Plankton [from Jordan et al., 1975] .......... 28 14. Seasonal Abundance of Dinoflagellates, Cryptophytes and Diatoms in the lower York [from Jordan et al., 1975] 29 15. Temporal Distributions of Nine Dinoflagellate Species 1973-74 [from Jordan et al., 1975] ...•...•. 30 i ----~- --- ----------·--------··-- --------·----~---·------··-···-----· LIST OF FIGURES (continued) Figure Page 16. Seasonal Occurrence of Dominant Zooplankton in the Lower York [modified from Jordan et al., 1975] • . • . • . 32 17. Seasonal Abundance of Four Common Polychaete Species vs Substrate [from Virnstein, 1975] . 37 18. Sampling Stations of Hinde for Benthic Invertebrates [from Hinde, 1976] .........•....... 38 19. Benthic Species Diversity (H1) vs Sampling Location [from Hinde, 1976] ............... 40 20a,b,c. York River Oyster Habitat [from Haven et al., 1981] .. 44,45,46 21. Hard Clam Densities in the Lower Chesapeake Bay [from Haven and Loesch, 1975] ....•...•.. 48 22. Hard Clam Densities in t~e Lower York and Poquoson Flats [from Haven and Loesch, 1975] ....... 50 23. York River - Catch Per Unit Effort - Striped Bass, White Perch, Atlantic Croaker and Spot [from Wojcik and Austin, 1982]. • . 55 24. York River - Catch Per Unit Effort - Weakfish, American Shad, Summer Flounder, Hogchoker and Channel Catfish [from Wojcik and Austin, 1982] . • . 57 25. York River - Catch per Unit Effort - White Catfish, Bay Anchovy and American Eel [from Wojcik and Austin, 1982]. 58 26. Beach Seine and Trawl Sampling Stations [from Jordan et al., 1975]. 59 27. Seasonal Occurrence of 10 Fish Species [from Jordan et al., 1975]. 61 28. Number of Fish Species vs. Year, Month and Strata [from Jordan et al., 1975] . 62 29. Seasonal Sand Shrimp Abundance vs. Cross Sectional Strata, April 1972- December 1974 [from Jordan et al., 1975]. 64 30. Seasonal Sand Shrimp Abundance vs. Longitudinal Strata, April 1972- December 1974 [from Jordan et al., 1975]. 65 i i 31. Number of Fish Species vs. Cross-sectional Strata, April 1972 - December 1974 [from Jordan et al ., 1975]. 67 32. Number of Fish Species vs. Longitudinal Strata, April 1972- December 1974 [from Jordan et al., 1975]. 68 33. York River Commercial Catch (1963-81) Finfish (total) A1 ewi fe, Blue Crabs and Hard Clams • . • • . 71 34. York River, Commercial Catch (1963-81) Swellfish, Croaker, Spot and Grey Trout. • . • . 72 35. York River, Commercial Catch (1963-81) Bluefish, Striped Bass, American Shad and Oysters (from private grounds} . 73 36. Moving Averages (3) of Concentrations of Precipitated Coprecipitated and Organic Copper in the <63-um Fraction of Sediments from the York River Estuary [from Huggett et a1 • , 197 4] . • . • . 83 37. Moving Averages (3) of Concentrations of precipitated Coprecipitated and Organic Zinc in the <63-um Fraction of sediments from the York River Estuary [from Huggett et al., 1974] . .....: .............. 84 38. The Distribution of Copper in Oysters From Virginia's Major Rivers [from Huggett et al., 1974] ...... 85 iii LIST OF TABLES Table Page 1. Diversity and Descriptive Statistics of Benthic Communities in the Lower York [from Hinde, 1981] . • . • • . • . 41 2. Aromatic Hydrocarbons in Sediments [from Voudrias, 1981] . 80 3. York River Aliphatic Hydrocarbons [from Hinde, 1981] . 81 4. Copper, Cadmimum and Zinc Levels in Oysters [data from State Health Department] • . • . • . 86 iv 1 Executive Summary The purpose of this paper is to provide an overview of the physical, chemical and biological characteristics of the York River, Virginia. The river is formed by the confluence of the Mattaponi and Pamunkey rivers at West Point, Virginia. It is tidal over its entire length and flows to the western shore of Chesapeake Bay. The salinity structure and chemical characteristics of the lower York River are extremely dynamic. Stratification of the water column in summer months causes oxygen depletion in the deeper waters of the river and nutrients are regenerated during these periods. Episodes of stratification and destratification are, related to the neap-spring tidal cycle. Low oxygen tensions in the deeper portions of the river, during periods .. : of stratification, limit fish and crab populations in these areas and may 'cause mortalities of benthic fauna. The extent to which the nutrients that are regenerated are utilized phytoplankton is not known with certainty. However, there are indications that the nutrients are rapidly assimilated by phytoplankton in the York and in other estuaries exhibiting destratification cycles. Insufficient historical data precludes an analysis of whether the degree of oxygen depletion in the deeper segments of the York has changed with time. Data collected over the last 10 years do not indicate a deterioration in conditions, however, prior to 1970 data are too sparse to make comparisons. The conditions which result in oxygen depletion are natural but the degree of depletion can be augmented by man's activities that contribute oxygen demanding wastes and/or nutrients. 2 Phytoplankton populations in the river vary seasonally, their most striking feature being the sproadic occurrence of "red tides" caused by blooms of various species of dinoflagellates. These motile, non-toxic organisms can develop very dense populations with chlorophyll levels exceed ing 100g/l. A bay wide decline in submerged aquatic vegetation has been observed over the last 15 years. The declines in areal coverage by these plants began in the upstream areas and have progressed "down-river." Communities in the York have declined in a similar manner. Although the exact cause of the declines is not known it is believed due to increased turbidity levels resulting from erosion and increased phytoplankton growth. Copepods are th~ most consistently abundant members of the zooplankton community but larval stages of. decapods, molluscs and polychaetes are also important. Benthic animal populations are dominated by polychaete worms. The type of substrate present plays an important role in determining community structure. Oyster populations in the lower river are limited by disease and predators. Commercial harvests come mainly from private grounds located upstream where average salinities are less than 15°/oo. The lower river supports a hard clam fishery of 10-20 patent tong boats. Landings reported for the river average about 200,000 pounds/year. Fish populations of the York are composed of resident, anadromous and catadromous species. As in the Bay proper, populations of many important species have shown dramatic fluctuations in abundance as a function of time. The causes of these population fluctuations are known for only a few species. 3 Finfish are harvested commercially in the York by pound nets, fixed and drift gill nets, fish traps and by haul seining. Major species include; bluefish, grey trout, croaker, spot, flounder, eels, striped bass and American shad. Large fluctuations in landings for individual species occur with