nena masthead
NENA Home Staff & Editors For Readers For Authors

The Fish Assemblage Structure of the Saco River Estuary
Nathan B. Furey and James A. Sulikowski

Northeastern Naturalist, Volume 18, Issue 1 (2011): 37–44

Full-text pdf (Accessible only to subscribers.To subscribe click here.)

 

Access Journal Content

Open access browsing of table of contents and abstract pages. Full text pdfs available for download for subscribers.



Current Issue: Vol. 30 (3)
NENA 30(3)

Check out NENA's latest Monograph:

Monograph 22
NENA monograph 22

All Regular Issues

Monographs

Special Issues

 

submit

 

subscribe

 

JSTOR logoClarivate logoWeb of science logoBioOne logo EbscoHOST logoProQuest logo

2011 NORTHEASTERN NATURALIST 18(1):37–44 The Fish Assemblage Structure of the Saco River Estuary Nathan B. Furey1,2,* and James A. Sulikowski1 Abstract - The Saco River estuary is a narrow estuary in southern Maine, for which the fauna has not been described in nearly 30 years. Beach seining, otter trawling, and beam trawling were conducted between April and October of 2007 and 2008 to assess seasonal variation in fish assemblage structure. Twenty-four species were observed over the two sampling seasons, and nearly all species were at lengths indicative of juvenile age. Clupea harengus (Atlantic Herring), Pseudopleuronectes americanus (Winter Flounder), Anguilla rostrata (American Eel), Microgadus tomcod (Atlantic Tomcod), Pomatomus saltatrix (Bluefish), and Osmerus mordax (Rainbow Smelt) are either commercially or recreationally valuable, while Acipenser oxyrynchus oxyrynchus (Atlantic Sturgeon), Alosa aestivalis (Blueback Herring), and Rainbow Smelt are federally listed species of concern. Substantial historical assemblage changes were observed, including both the loss of commercially important species and the addition of species of concern. Regular monitoring of estuarine habitats is necessary to identify changes in assemblages and to better understand potential drivers of ecosystem change. Introduction The Saco River estuary is a small estuarine environment in Biddeford, ME. To our knowledge, only one published study (Reynolds and Casterlin 1985) has described the nekton of the Saco River estuary. Reynolds and Casterlin (1985) sampled the entire extent of the Saco River and its surrounding coastal waters with otter trawl, seine, bottom grab, hook and line, plankton net, and hand net, and although effort was not quantified, the authors noted that sampling occurred throughout all seasons of the years of 1979 to 1982. While more recent studies have examined Saco River geology and hydrography (Brothers et al. 2008, FitzGerald et al. 2002, Kelley et al. 2005), the estuary’s flora and fauna have not been described in nearly 30 years. The present study aimed to describe the fish assemblage of the Saco River estuary over a twoyear period (20 April 2007 to 2 December 2008) to determine nursery ground potential and identify possible assemblage changes since the previous study (Reynolds and Casterlin 1985). Methods Field-site description Sampling occurred in the Saco estuary at the mouth of the Saco River (43°27.5'N, 70°22'W) (Fig. 1). Two jetties extend 1.5 km into Saco Bay to form 1Marine Sciences Department, University of New England, 11 Hills Beach Road, Biddeford, ME 04005. 2Current address - Department and Wildlife and Fisheries Science, Texas A and M University- Galveston, 5007 Avenue U, Galveston, TX 77551. *Corresponding author - n.b.furey@gmail.com. 38 Northeastern Naturalist Vol. 18, No. 1 the Saco River mouth. Sampling occurred between the jetties as well as on a shallow, sandy portion of the estuary known as Freddy Beach (Fig. 1). The estuary ranges between 200 and 350 m in width and is characterized by sand and rock bottoms, and little vegetation. The Saco River has a discharge rate of greater than 85 m3/s (USGS 2009). Under normal conditions, the estuary’s salinity is stratified by salt wedge presence, and experiences a mean tidal range of 2.7 m (FitzGerald et al. 2002). Sampling sites were chosen to ensure that estuarine water was being sampled, rather than pure fresh- or saltwater. Sampling gear A 2-mm square mesh beach seine, 14 m long and 2 m high, was used to sample Freddy Beach (Fig. 1). Three replicate seines, approximately 100 m in length, were performed between low and mid-tide weekly in 2007 and twice weekly in 2008. A small otter trawl (6 m wide and 25-mm mesh) and beam trawl (2 m wide and 3-mm mesh) were towed between the jetties on a bimonthly basis in 2007 and weekly in 2008 from the 7-m (23-ft) University of New England research vessel Llyr. The use of trawls allowed for the sampling of waters deeper than those attainable by seine, and the beam trawl was used to sample areas close to the jetties rather than the deeper channel. The current study focused on the estuarine portion of the river, coinciding with Stations 4 and 5 of Reynolds and Casterlin (1985). Data collection Sampling began in April 2007 and ended in October 2008. In both 2007 and 2008, sampling occurred from April through October. All captured fish were identified to species and enumerated. For every sampling event where at least 100 Figure 1. Location of the Saco River estuary system in eastern Biddeford, ME. Star denotes Freddy Beach where beach seines occurred. Trawls occurred between jetties as outlined by rectangle. 2011 N.B. Furey and J.A. Sulikowski 39 fish of a species were captured, a subsample of 50 individuals was measured for total length (TL). To approximate the age of observed species as either juvenile or adult, mean lengths of fish species were compared to average adult and juvenile sizes found in literature specific to the Gulf of Maine. To assess potential changes in the fish assemblage, the presence of each species was compared to those observed by Reynolds and Casterlin (1985). Results Overall Twenty-four fish species were observed in the Saco River estuary over the course of the 2-year study (Tables 1, 2), and Alosa aestivalis (Blueback Herring), Menidia menidia (Atlantic Silverside), Clupea harengus (Atlantic Herring), Osmerus mordax (Rainbow Smelt), and Ammodytes americanus (Sand Lance) were the five most dominant species. More species were observed with seine (23) than either beam trawl (8) or otter trawl (9). Size (TL) Sizes of observed fish during the study ranged from a minimum of 8 mm TL (Atlantic Silverside) to a maximum of 1200 mm TL (Acipenser oxyrinchus Table 1. Full nomenclature of all 24 fish species observed in the study. Common name Scientific name Authority Bluefish Pomatomus saltatrix L. Largemouth Bass Micropterus salmoides (Lacèpede) Striped Mullet Mugil cephalus L. Red Hake Urophycis chuss (Waldbaum) Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus Mitchill American Eel Anguilla rostrata Laueur Atlantic Herring Clupea harengus L. Alewife Alosa pseudoharengus (Wilson) Cunner Tautogolabrus adspersus (Walbaum) Winter Flounder Pseudopleuronectes americanus Walbaum Yellow Perch Perca flavescens (Mitchill) Blueback Herring Alosa aestivalis Mitchell Windowpane Scophthalmus aquosus (Mitchill) Pumpkinseed Lepomis gibbosus (L.) Rainbow Smelt Osmerus mordax Mitchell Atlantic Tomcod Microgadus tomcod Walbaum Northern Pipefish Syngnathus fuscus Storer Sand Lance Ammodytes americanus Dekay Atlantic Silverside Menidia menidia L Mummichog Fundulus heteroclitus heteroclitus (L.) Threespine Stickleback Gasterosteus aculeatus L. Banded Killifish Fundulus diaphanus (Lesueur) Ninespine Stickleback Pungitius pungitius occidentalis Cuvier Fourspine Stickleback Apeltes quadracus Mitchill 40 Northeastern Naturalist Vol. 18, No. 1 Table 2. Overall mean total lengths (TL) and standard deviations (SD) for all 24 fish species observed in the study. Also given are average and maximum adult TL (or standard length, SL, when noted) cited in scientific literature for each species. Asterisk (*) denotes source is as cited in Collette and Klein-MacPhee 2002. An “X” in “Present” indicates the species was previously observed within the estuarine portion of the river that matches the current study’s extent (Stations 4 and 5, Reynods and Casterlin 1985). Seine (mm) Otter trawl (mm) Beam trawl (mm) Literature value (mm) Common name Present Mean SD Mean SD Mean SD Average Max Source* Bluefish 66.21 5.88 113 NA NA NA NA 1150 Collette and Klein-MacPhee 2002 Largemouth Bass 61.00 40.22 NA NA NA NA NA 970 Page and Burr 1991 Striped Mullet 55.27 17.42 NA NA NA NA NA 600 McDonough and Wenner 2003* Red Hake 75.50 10.29 NA NA NA NA NA 500 Musick 1967* Atlantic Sturgeon NA NA 1132.50 95.46 NA NA 880–2000 NA Damon-Randall et al. 2010 American Eel X 52.00 0.82 NA NA 85 43.84 NA 1200 Bigelow and Shroeder 1953* Atlantic Herring 48.50 5.74 52.12 6.96 38 3.46 NA 430 Collette and Klein-MacPhee 2002 Alewife 56.27 8.26 NA NA 46.63 10.65 NA 300 Ross 1991* Cunner 11.50 NA NA NA NA NA 150–250 NA Bigelow and Shroeder 1953* Winter Flounder X 71.35 55.19 131.47 52.12 134.75 29.47 NA 580 Fields 1988* Yellow Perch 25.00 NA NA NA NA NA NA 400 Page and Burr 1991 Blueback Herring 43.38 14.73 66.14 6.84 NA NA NA 300 Ross 1991* Windowpane 56.58 19.34 123.55 48.03 NA NA 250–305 NA Bigelow and Shroeder 1953* Pumpkinseed 49.00 NA NA NA NA NA NA 400 Page and Burr 1991* Rainbow Smelt 49.68 13.18 49.21 6.45 NA NA 180–230 NA Collette and Klein-MacPhee 2002 Atlantic Tomcod X 41.87 9.49 NA NA 33.35 21.57 228–300 NA Collette and Klein-MacPhee 2002 Northern Pipefish 102.64 51.28 NA NA 148.33 28.04 NA 305 Nichols and Breder 1927* Sand Lance X 68.26 27.67 60.00 27.55 58.71 9.48 NA 168 Nizinski et al. 1990* Atlantic Silverside 68.56 20.30 44.62 4.44 NA NA 105 NA Conover and Ross 1982* Mummichog 46.76 13.11 NA NA NA NA NA 100 Able 1990* Threespine Stickleback 31.03 16.46 NA NA NA NA 40–70 NA Collette and Klein-MacPhee 2002 Banded Killifish 44.03 8.78 NA NA NA NA 152–178 NA Clemmer and Schwartz 1964 Ninespine Stickleback 33.22 4.18 NA NA NA NA 35–55 SL 76 Scott and Scott 1988*; Ayvazian and Krueger 1992* Fourspine Stickleback 30.50 7.51 NA NA 53.50 3.53 23–44 NA Blouw and Hagen 1984* 2011 N.B. Furey and J.A. Sulikowski 41 oxyrinchus [Atlantic Sturgeon]). All but three observed fish (2 Atlantic Sturgeon and 1 Pseudopleuronectes americanus Walbaum [Winter Flounder]) were less than 250 mm TL. Except one Winter Flounder (TL = 552 mm), all individuals captured with seine were less than 200 mm TL. All fish observed by beam trawl were between 16 mm and 166 mm TL, and besides two Atlantic Sturgeon, all fish observed by otter trawl were less than 300 mm TL. When compared to literature examining the size of northwest Atlantic fishes, only 3 species—Gasterosteus aculeatus (Threespine Stickleback), Apeltes quadracus (Fourspine Stickleback), and Pungitius pungitius occidentalis (Ninespine Stickleback)—were not considered to be juvenile (Table 2). Discussion Twenty-four fish species were observed in the Saco River estuary over a 2-year period, and nearly all species observed were at juvenile lengths. Atlantic Herring, Winter Flounder, Anguilla rostrata (American Eel), Microgadus tomcod (Atlantic Tomcod), Pomatomus saltatrix (Bluefish), and Osmerus mordax (Rainbow Smelt) are either commercially or recreationally valuable. In addition, the Alosa pseudoharengus (Alewife), Atlantic Sturgeon, Blueback Herring, and Rainbow Smelt are federally listed as species of concern (NMFS 2009). Of these economically valuable and threatened species, four (Blueback Herring, Alewife, Winter Flounder, and Rainbow Smelt) were observed over multiple months, indicating that their presence was not an anomaly. All of these species were observed as juveniles, indicating the estuary’s value as a nursery ground. The number of fish species observed within the Saco River estuary (24) is comparable to other Maine estuaries, including Penobscot Bay (22) (Lazzari and Tupper 2002), Wells Harbor (24) (Ayvazian et al. 1992), Kennebec Point (27) (Lazzari et al. 1999), the Weskeag River (22) (Lazzari 2002), and Casco (25) and Muscongus bays (24) (Lazzari 2002). Furthermore, the estuaries of Penobscot Bay, Wells Harbor, Kennebec Point, and Casco Bay are of greater width and volume than the studied Saco River estuary. Only two of these compared studies, however, included beach seines as sampling gear (Ayvazian et al. 1992, Lazzari et al. 1999). The other aforementioned studies collected fish via beam trawl, otter trawl, or throw traps. Because the species observed, along with their abundance, can be affected by gear type (Rozas and Minello 1997), comparing species richness among these ecosystems is difficult. Regardless, these comparisons describe the Saco River estuary as ecologically valuable to the region despite its relatively modest size. Substantial differences exist between the fish assemblage observed by Reynolds and Casterlin (1985) and that observed in the current study (Table 2). Of the five most abundant species in the current study, only Sand Lance was observed by Reynolds and Casterlin (1985). An additional six species (Fundulus heteroclitus heteroclitus [Mummichog], Urophycis chuss [Red Hake], Scophthalmus aquosus [Windowpane], Fourspine Stickleback, Threespine Stickleback, and Ninespine 42 Northeastern Naturalist Vol. 18, No. 1 stickleback) were common to both studies, but were only observed by Reynolds and Casterlin (1985) outside of the current study’s sampling area. Notable species that were only observed in the current study include Alewife, Atlantic Sturgeon, Blueback Herring, and Rainbow Smelt, all of which are federal species of concern (NMFS 2009). Both Leucaraja erinacea Mitchill (Little Skate) and Pollachius virens L. (Pollock) were observed by Reynolds and Casterlin (1985) within the estuary, but not in the current study. Both of these species are commercially important in the Gulf of Maine. Comparisons to historical data can identify at-risk species (Smith et al. 2008), and regular monitoring will allow for identification of possible drivers of assemblage change. Continual monitoring of estuarine habitats should be a priority for conservationists and managers alike, given the observed loss of commercially important species, and the apparent additions of at-risk species observed in the Saco River estuary in a period of less than 30 years. Acknowledgments We would like to thank Tim Arienti, Marie Quinlan, Angela Cicia, Andrew Wargo, and Devin Flawd for assisting in field work. This project was supported by the University of New England Biological Sciences Honors Program, the University of New England College of Arts and Sciences (CAS), and the University of New England Provost’s Faculty Grant Program. This manuscript represents MSC contribution number 32. Literature Cited Able, K. 1990. Life-history patterns of salt marsh killifishes in New Jersey. Bulletin of the New Jersey Academy of Science 35:23–30. Ayvazian, S., and W. Krueger. 1992. Lateral plate ontogeny of the North American Ninespine Stickleback, Pungitius occidentalis. Copeia 1992:209–214. Ayvazian, S.G., L.A. Deegan, and J.T. Finn. 1992. Comparison of habitat use by estuarine fish assemblages in the Acadian and Virginian zoogeographic provinces. Estuaries 15(3):368–383. Bigelow, H.B., and W.C. Schroeder. 1953. Fishes of the Gulf of Maine. Fisheries Bulletin, US 53:1–577. Blouw, D., and D. Hagen. 1984. The adaptive significance of dorsal spine variation in the Fourspine Stickleback, Apeltes quadracus. III. Correlated traits and experimental evidence on predation. Heredity 53:371–382. Brothers, L., D. Belknap, J. Kelley, and C. Janzen. 2008. Sediment transport and dispersion in a cool-temperate estuary and embayment, Saco River estuary, Maine, USA. Marine Geology 251:183–194. Clemmer, G., and F.J. Schwartz. 1964. Age, growth, and weight relationships of the Striped Killifish, Fundulus majalis, near Solomons, Maryland. Transactions of the American Fisheries Society 93:197–198. Collette, B.B., and G. Klein-MacPhee. (Eds). 2002. Bigelow and Schroeder’s Fishes of the Gulf of Maine. 3rd Edition. Smithsonian Institute, Washington, DC. 748 pp. Conover, D., and M. Ross. 1982. Patterns in seasonal abundance, growth, and biomass of the Atlantic Silverside, Menidia menidia, in a New England estuary. Estuaries 5:275–286. 2011 N.B. Furey and J.A. Sulikowski 43 Damon-Randall K., R. Bohl, S. Bolden, D. Fox, C. Hager, B. Hickson, E. Hilton, J. Mohler, E. Robbins, T. Savoy, and A. Spells. 2010. Atlantic Sturgeon research techniques. NOAA Technical Memorandum NMFS NE 214. 19 pp. National Marine Fisheries Service, Woods Hole, MA. Fields, B. 1988. Winter Flounder, Pseudopleuroncetes americanus. Pp. 103–104, In J. Penttila and L.M. Dery (Eds.). Age-determination methods for northwest Atlantic species. NOAA Technical Report NMFS No. 72. Woods Hole, MA. FitzGerald, D., I. Buynevich, R. Davis, Jr., and M. Fenster. 2002. New England tidal inlets with special reference to riverine-associated inlet systems. Geomorphology 48:179–208. Kelley, J., D. Barber, D. Belknap, D. FitzGerald, S. van Heteren, and S. Dickson. 2005. Sand budgets at geological, historical, and contemporary time scales for a developed beach system, Saco Bay, Maine, USA. Marine Geology 214:117–142. Lazzari, M.A. 2002. Epibenthic fishes and decapod crustaceans in northern estuaries: A comparison of vegetated and unvegetated habitats in Maine. Estuaries 25(6A):1210–1218. Lazzari, M.A., and B. Tupper. 2002. Importance of shallow-water habitats for demersal fishes and decapod crustaceans in Penobscot Bay, Maine. Environmental Biology of Fishes 63:57–66. Lazzari, M.A., S. Sherman, C.S. Brown, J. King, B.J. Joule, S.B. Chenoweth, and R.W. Langton. 1999. Seasonal and annual variations in abundance and species composition of two nearshore fish communities in Maine. Estuaries 22(3A):636–647. McDonough, C.J., and C.W. Wenner. 2003. Growth, recruitment, and abundance of juvenile Striped Mullet (Mugil cephalus) in South Carolina estuaries. Fisheries Bulletin 101:343–357. Musick, J. 1967. Designation of the hakes, Urophycis chuss and Urophycis tenuis, in ICNAF statistics. International Commission for the Northwest Atlantic Fisheries, Dartmouth, NS, Canada. Research Document No. 67/76. Nichols, J., and C. Breder, Jr. 1927. The marine fishes of New York and southern New England. Zoologica, NY 9:1–192. Nizinski, M., B. Collette, and B. Washington, 1990. Separation of two species of sand lances, Ammodytes americanus and A. dubius, in the western North Atlantic. Fishery Bulletin 88:241–255. National Marine Fisheries Service (NMFS). 2009. Proactive Conservation Program: Species of Concern- Office of Protected Resources- NOAA Fisheries. Available online at http://www.nmfs.noaa.gov/pr/species/concern/. Accessed 22 March 2009. Page, L., and B. Burr. 1991. A Field Guide to Freshwater Fishes. Houghton Mifflin Company, New York, NY. 432 pp. Reynolds, W., and M. Casterlin. 1985. Vagile macrofauna and the hydrographic environment of the Saco River Estuary and adjacent waters of the Gulf of Maine. Hydrobiologia 128:207–215. Ross, M. 1991. Recreational Fisheries of Coastal New England. University of Massachusetts Press, Amherst, MA. 279 pp. Rozas, L.P., and T.J. Minello. 1997. Estimating densities of small fishes and decapod crustaceans in shallow estuarine habitats: A review of sampling design with focus on gear selection. Estuaries 20:199–213. 44 Northeastern Naturalist Vol. 18, No. 1 Scott, W., and M. Scott. 1988. Atlantic Fishes of Canada. Canadian Bulletin of Fisheries and Aquatic Sciences 219. 731 pp. Smith, K.L., I.C. Flores, and C.M. Pringle. 2008. A comparison of current and historical fish assemblages in a Caribbean island estuary: Conservation value of historical data. Aquatic Conservation: Marine and Freshwater Ecosystems 18:993–1004. United States Geological Survey (USGS). 2009. USGS surface-water annual statistics for the nation. Available online at http://nwis.waterdata.usgs.gov/nwis/uv?site_ no=01066000. Accessed 22 February 2009.