Future Research Needs

While many of the linkages involving zooplankton in the Hudson food web are known, uncertainty remains concerning their importance to populations. Are predator-prey interactions tightly coupled to the respective dynamics of individual populations or are these associations "loose" in the sense that specific trophic interactions have little affect on dynamics? Loose linkages could be the case if populations are highly omnivorous. In this view the estuary represents a dynamic feeding tableau with sufficient resources to support population growth. Exploitation is a matter of ever changing opportunities, and resources have little influence on populations. Alternatively, the highly repeatable dynamics of some populations (for example, Bosmina freyi) suggest there are structured interactions that determine population processes and that some of these are related to trophic effects. The Hudson probably contains both loose and tight trophic interactions and sorting the causes and consequences of these relationships remains a goal for future study.

Zooplankton by definition are animals in the water column and are often studied in isolation from interactions with benthic processes. Mero-planktonic animals, however, arise from the benthos and return there after a brief pelagic phase. More permanent members of the plankton have resting stages that reside in the bottom and shallows of the Hudson. These stages likely seed the blooms and population increases of many species. Further, planktonic animals retreat to the bottom or near-bottom environment as part of daily migrations probably to avoid visual predators but also to maintain position and retention within the estuary in association with tides. These few examples of benthic-pelagic interactions point to an area of limited knowledge. A more fully integrated understanding of zooplanktonrequires abetter appreciation of how benthic-pelagic interactions influence populations and food web interactions.

We have argued that zooplankton are a critical trophic linkage to fish in the Hudson and much of their functional significance in the ecosystem derives from this role. Fish populations are, however, quite variable. Large interannual variations are observed. In addition, populations vary substantially in time and space within a year and hence predation from fish on zooplankton may be highly episodic. The consequences of this presumably variable interaction between fish and zooplankton remain poorly understood. Means for measuring predatory mortality and variation in these rates are critical to testing many of the ideas posed in this chapter.


Adrian, R., Hansson, S., Sandin, B., De Stasio, B., and Larsson, U. 1999. Effects of food availability and predation on a marine zooplankton community-A study on copepods in the Baltic Sea. Internationale Revue der Gesamten Hydrobiologie 84:609-26.

Caraco, N. F., Cole, J. J., Findlay, S. E. G., Fischer, D. T., Lampman, G. G., Pace, M. L., and Strayer, D. L. 2000. Dissolved oxygen declines in the Hudson River associated with the invasion of the zebra mussel (Dreissena polymorpha). Environmental Science and Technology 34:1204-1210.

Caraco, N. F., Cole, J. J., Raymond, P. A., Strayer, D. L., Pace, M. L., Findlay, S. E. G., and Fischer, D. T. 1997. Zebra mussel invasion in a large, turbid, river: phytoplankton response to increased grazing. Ecology 78:588-602.

Chervin, M. B. 1978. Assimilation of particulate organic carbon by estuarine and coastal copepods. Marine Biology 49:265-75.

Chervin, M. B., Malone, T. C., and Neale, P. J. 1981. Interactions between suspended organic matter and copepod grazing in the plume of the Hudson River. Estuarine and Coastal Shelf Science 13: 169-83.

Christy, J. H., and Morgan, S. G.1998. Estuarine immigration by crab postlarvae: mechanisms, reliability and adaptive significance. Marine Ecology Progress Series 174:51-65.

Clark, J. F., Simpson, H. J., Bopp, R. F., andDeck, B. 1992. Geochemistry and loading history of phosphate and silicate in the Hudson Estuary. Estuarine and Coastal Shelf Science 34:213-233.

Cole, J. J., Caraco, N. F., and Peierls, B. L. 1992. Canphy-toplankton maintain a positive carbon balance in a turbid, fresh-water, tidal estuary? Limnology and Oceanography 37:1608-1617.

Cyr, H., Downing, J. A., Lalonde, S., Baines, S., and Pace,M. L. 1992. Sampling larval fish populations: choice of sample number and size. Transactions of the American Fisheries Society 121:35668.

Day, Jr., J. W, Hall, C. A. S., Kemp, W. M., and Yanez-Arancibia, A. 1989. Estuarine Ecology. NewYork: John Wiley & Sons.

Deason, E. E., and Smayda, T. J. 1982. Ctenophore-zooplankton-phytoplankton interactions in Narragansett Bay, Rhode Island, USA, during 1972-1977. Journal of Plankton Research 4: 203-217.

DeMott, W. R., and Gulati, R. D. 1999. Phosphorous limitation in Daphnia: Evidence from a long-term study of three hypereutrophic Dutch lakes. Limnology and Oceanography 44:1557-64.

Durbin, E. G., Durbin, A. G., Smayda, T. J., and Verity, P G. 1983. Food limitation of production by adult Acartia tonsa in Narragansett Bay, Rhode Island. Limnology and Oceanography 28:11991213.

Feigenbaum, D., and Kelly, M. 1984. Changes in the lower Chesapeake Bay food chain in the presence of the sea nettle Chrysaora quinquecirrha (Schy-phomedusa). Marine Ecology Progress Series 19: 39-47.

Findlay, S., Pace, M. L., Lints, D., Cole, J. J., Caraco, N. F., and Peierls, B. 1991. Weak coupling of bacterial and algal production in a heterotrophic ecosystem: The Hudson River estuary. Limnology and Oceanography 36:268-78.

Gasol, J. M., and Vaque, D. 1993. Lack of coupling between heterotrophic nanoflagellates and bacteria: A general phenomenon across aquatic systems. Limnology and Oceanography 38:657-65.

Grabe, S. A. 1978. Food and feeding habits of juvenile Atlantic tomcod, Microgadus tomcod, from Haverstraw bay, Hudson River. Fisheries Bulletin 76:89-94.

Grabe, S. A. 1996. Feeding chronology and habits of Alosa spp., (Clupeidae) juveniles from the lower Hudson River estuary, New York. Environmental Biology of Fishes 47:321-6.

Harvey, H. R., Ederington, M. C., and McManus, G. B. 1997. Lipid composition of the marine ciliates Pleuronema sp. and Fabrea salina: Shifts in response to changes in diet. Journal ofEukaryotic Microbiology 44:189-93.

Huntley, M. E., and Lopez, M. D. G. 1992. Temperature-dependent production of marine copepods: A global synthesis. American Naturalist 140:20142.

Hurst, T. P, and Conover, D. O.2001. Diet and consumption rates of overwintering YOYstriped bass, Morone saxatilis, in the Hudson River. Fisheries Bulletin 99:545-53.

Jonasdottir, S. H. 1994. Effects of food quality on the reproductive success of Acartia tonsa and Acartia hudsonica: laboratory observations. Marine Biology 121:67-81.

Kerfoot, W. C. 1980. Ecology and Evolution of Zooplankton Communities. Special Symposium Volume 3, American Society of Limnology and Oceanography, University Press of New England, Durham, New Hampshire.

Ki0rboe, T. 1998. Population regulation and role of mesozooplankton in shaping marine pelagic food webs. Hydrobiologia 363:13-27.

Kleppel, G. S. 1992. Environmental regulation of feeding and egg production by Acartia tonsa off southern California. Marine Biology 112:57-65.

Kremer, P. 1994. Patterns of abundance for Mnemiopsis in U.S. coastal water: a comparative review. ICES Journal of Marine Science 51:347-54.

Kunze, H. B. 1995. "Distribution and transport oflarvae within the Hudson River estuary." M. S. Thesis, State University of New York at Stony Brook, Stony Brook, New York.

Lampman, G. G., Caraco, N. F., and Cole, J. J. 1999. Spatial and temporal patterns of nutrient concentration and export in the tidal Hudson River. Estuaries 22:285-96.

Limburg, K. E. 1994. "Ecological constraints on growth and migration of juvenile American shad (Alosa sapidissima Wilson) in the Hudson River estuary, NewYork."Ph.D. Dissertation, Cornell University, Ithaca, New York.

Limburg, K. E., Pace, M. L., Arend, K. K. 1999. Growth, mortality, and recruitment of larval Morone spp. in relation to food availability and temperature in the Hudson River. Fisheries Bulletin 97:80-91.

Limburg, K. E., Pace, M. L., Fischer, D., and Arend, K. K. 1997. Consumption, selectivity, and use of zooplankton by larval striped bass and white perch in a seasonally pulsed estuary. Transactions of the American Fisheries Society 126:607-21.

Lints, D., Findlay, S. E. G., andPace, M. L. 1992. Biomass and energetics of consumers in the lower food web of the Hudson River, in C. L. Smith (ed.), Estuarine Research in the 1980s. Albany, NY: State University of New York Press, pp. 466-57.

Lonsdale, D. J., Cosper, E. M., and Doall, M. 1996. Effects of zooplankton grazing on phytoplankton size-structure and biomass in the lower Hudson River estuary. Estuaries 19:874-89.

MacIsaac, H. J., Sprules, W G., Johansson, O. E., and Leach, J. J. 1992. Filtering impacts of larval and sessile zebra mussels (Dreissena polymorpha) in western Lake Erie. Oecologia 92:30-9.

Mauchline, J. 1998. The biology of calanoid copepods, in Blaxter, J. H. S., Southward, A. J., and Tyler, P A. (eds.), Advances in Marine Biology, Vol. 33. San Diego, CA: Academic Press, pp. 1-710.

Mehner, T., and Thiel, R. 1999. A review of predation impact by 0+ fish on zooplankton in fresh and brackish waters of the temperate northern hemisphere. Environmental Biology of Fishes 56:169-81.

Merrell, J. R., and Stoecker, D. K. 1998. Differential grazing on protozoan microplankton by developmental stages of the calanoid copepod Eurytemora affinis Poppe. Journal of Plankton Research 20:289-304.

Omori, M., and Ikeda, T. 1984. Methods in Marine Zooplankton Ecology, New York: John Wiley & Sons.

Pace, M. L., Findlay, S. E. G., and Fischer, D. 1998. Effects of an invasive bivalve on the zooplankton community of the Hudson River. Freshwater Biology 38:103-116.

Pace, M. L., Findlay, S. E. G., and Lints, D. 1991. Variance in zooplankton samples: evaluation of a predictive model. Canadian Journal ofFisheries and Aquatic Science 48:146-51.

1992. Zooplankton in advective environments: The Hudson River community and a comparative analysis. Canadian Journal of Fisheries and Aquatic Science. 49:1060-9.

Sanders, R. W, and Wickham, S. A. 1993. Planktonic protozoa and metazoa: predation, food quality and population control. Marine Microbial Food Webs 7:197-223.

Sherr, E. B., and Sherr, B. F. 1987. High rates of consumption of bacteria by pelagic ciliates. Nature 325:710-711.

Simenstad, C. A., Small, L. F., and McIntire, C. D. 1990. Consumption processes and food web structure in the Columbia River estuary. Progress in Oceanography 25:271-97.

Stepien, J. C., Malone, T. C., and Chervin, M. B. 1981. Copepod communities in the estuary and coastal plume of the Hudson River. Estuarine and Coastal Shelf Science 13:185-95.

Stoecker, D. K., and Capuzzo, J. M. 1990. Predation on protozoa: its importance to zooplankton. Journal of Plankton Research 12:891-908.

Stoecker, D. K., and Govoni, J. J. 1984. Food selection by young larval gulf menhaden (Brevoortia pa-tronus). Marine Biology 80:299-306.

Stoecker, D. K., Verity, P. G., Michaels, A. E., and Davis, L. H. 1987. Feeding by larval and postlar-val ctenophores on microzooplankton. Journalof Plankton Research 9:667-83.

Strayer, D. L., Caraco, N. F., Cole, J. J., Findlay, S., and Pace, M. L. 1999. Transformation of freshwater ecosystems by bivalves: a case study in the Hudson River. BioScience 49:19-27.

Strayer, D. L., and Smith, L. C. 2001. The zoobenthos of the freshwater tidal Hudson River and its response to the zebra mussel (Dreissena polymorpha) invasion. Archive für Hydrobiologia Supplement 139:1-52.

Strayer, D. L., Hattala, K., and Kahnle, A. 2004. Effects of an invasive bivalve (Dreissena polymorpha) on fish in the Hudson River estuary. Canadian Journal of Fisheries and Aquatic Sciences 61:924-41.

Vaque, D., Pace, M. L., Findlay, S. E. G., and Lints, D. 1992. Fate of bacterial production in a heterotrophic ecosystem: Grazing by protists and metazoans in the Hudson Estuary. Marine Ecology Progress Series 89:155-63.

Wong, W. H., Levinton, J. S., Twining, B. S., and Fisher, N. 2003. Assimilation of micro- and mesozoo-plankton by zebra mussels: A demonstration of the food web link between benthic predators and zooplankton. Limnology and Oceanography 48:308-312.

0 0

Post a comment