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Juvenile river herring habitat use and marine emigration trends: comparing populations
ELECTRONIC SUPPLEMENTARY MATERIAL
Sara M. Turner1* and Karin E. Limburg1
1SUNY College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY 13210; *corresponding author, current: Integrated Statistics, NEFSC Narragansett Laboratory, 28 Tarzwell Drive, Narragansett, RI 02882,
Online Resource 1. Detailed watershed descriptions, population information, maps, and histograms of adult back-calculated marine emigration size distributions (red = alewife, blue = blueback herring). Stars approximate latitudes listed in Table 1.
East Machias, ME – This site is comprised of Hadley and Gardner lakes, approximately 10 km from the mouth of the Machias R. Both species are present in E. Machias; half of the alewife were collected in each lake, while blueback herring were all collected from Hadley Lake.
St. George R., ME – The river has multiple ponds and lakes along the accessible portion (50 km) that are believed to be used as spawning habitats for both species. All alewife were collected at the harvest station below reported spawning areas; most blueback herring were collected from the pond just below the limit to migration (the others were collected lower in the system).
Cocheco R., NH – An impassible dam blocks access just over 9 km upstream, although a natural falls approximately 0.8 km below the dam could be the barrier to migration (no studies have investigated if fish can pass the falls). Alewife were collected from the fish ladder on the first dam (3.6 km upstream). The mouth of the river is approximately 20 km from the ocean, near the Little Bay/ Great Bay estuary.
Oyster R., NH – The Oyster River is almost 16 km from the ocean, and passage is limited by an impassible dam (the second dam) approximately 7.5 km upstream, although passage to that point has not been confirmed; blueback herring were collected from the fish ladder on the first dam, approximately 4.4 km upstream. The mouth of the river is located at the entrance to the Little Bay/ Great Bay, which is a large tidal estuary.
Lamprey R., NH – The mouth of the Lamprey River is approximately 23.5 km from the ocean, off of the Great Bay estuary. Alewife were collected from the fish ladder approximately 2.9 km upstream; passage was limited until 2012 by an impassible dam about 5.8 km upstream (a fishway has been installed).
Exeter R., NH – The Exeter River is a tributary to the Great Bay estuary; while there is a fish ladder at the head-of-tide dam (approximately 9 km upstream), there have not been any firm observations of fish passing. Blueback herring were collected at the base of the dam.
Merrimack R., MA – Upstream passage on the Merrimack River is dependent on river flow; flows are often too high for the fish lift at the Essex Dam (the first dam on the river, almost 46 km upstream) to operate when river herring are migrating; blueback herring were collected below the first dam.
Mystic R., MA – The Mystic River is a small coastal system with two lakes approximately 11.7 km upstream; no passage into the upper lake was available at the time of fish collections (alewife and blueback herring were dipnetted from the spillway of the dam). The mouth of the river is in Boston Harbor, approximately 6.3 km from the ocean.
Town Brook, MA – Town Brook is a small coastal watershed; alewife can pass approximately 1.5 km upstream, and were collected less than 0.5 km upriver from the fish ladder at the first dam.
Nemasket R., MA – The Nemasket River is a tributary to the Taunton River, which originates in the Narragansett Bay. The mouth of the Nemasket R. is approximately 50 km up the Taunton River, and extends just over 18 km to the headponds where spawning occurs; alewife were sampled from the fish ladder at the mouth to the first pond.
Monument R., MA – The Monument River extends approximately 6 km from the Cape Cod Canal to the ponds where fish are thought to spawn. Alewife and blueback herring were collected from the fish ladder at the dam 0.2 km from the Canal.
Gilbert Stuart R., MA – Gilbert Stuart River is a tributary to the Pettaquamscutt River that originates near the mouth of Narragansett Bay; the head pond is approximately 10.6 km upstream, and alewife and blueback herring were collected just below the fish ladder to the pond.
Bride Brook, CT – Bride Brook is on the north side of Long Island Sound, and is roughly 3.6 km to its source, Bride Lake, where spawning occurs. Alewife were collected from a trap at the lake outlet to the brook.
Quinnipiac R., CT – Until 2012, when a fish ladder was installed on the Wallace Dam, alewife could only migrate approximately 26.8 km up the Quinnipiac River. The river originates on the northern side of Long Island Sound. Fish were collected below the dam.
Hudson R., NY – The mouth of the Hudson River is in New York Harbor (near the western end of Long Island), and there are no obstructions until the Federal Dam at Troy, approximately 260 km upstream (blueback herring enter the Mohawk River via the locks). Alewife and blueback herring were collected at Coxsackie, NY (rkm 201). The largest individuals may have over-wintered within the system.
Nanticoke R., DE – No obstructions are on the mainstem of the Nanticoke River (over 60 km). Alewife and blueback herring have been observed spawning above tidal influence in the system (approximately 40-50 km upstream), and spawning also occurs in two tributaries, where dams block pond access (both are head-of-tide dams).
Chowan R., NC – The mouth of the Chowan River is in Albemarle Sound, and it originates in Virginia (from the Meherrin, Blackwater, and Nottoway rivers). Monitoring is currently only conducted in North Carolina, and alewife and blueback herring have been observed using small tributaries lower in the watershed (e.g. Dillard’s Creek, approximately 23 km upstream).
Alligator R., NC – The Alligator River is located in Albemarle Sound, and a canal connects it to Pamlico Sound so it is high salinity at sink and source. The Alligator R. has a blueback herring population, but only alewife sample sizes were large enough for analyses.
Santee-Cooper R., SC – The Santee-Cooper system is comprised of two rivers that originate from Lake Marion, and both extend approximately 144 km from the ocean to the lake; obstructions make the lake the upstream extent of blueback herring access.
St. John’s R., FL – The St. John’s River in Florida is believed to be the southern extent of the two species distribution; the river extends over 400 km and includes many lakes. Blueback herring were collected more than 150 km upstream.
Online Resource 2. Mean freshwater and/or estuarine Sr:Ca and Ba:Ca ratios observed in otoliths for each species at each site, ordered from north to south. (See Table 1 for site codes; A = alewife; B = blueback herring)
Site / Species / Freshwater Sr:Ca (SD) / Freshwater Ba:Ca (SD) / Estuary Sr:Ca (SD) / Estuary Ba:Ca (SD)EMME / A / 1.5 (0.3) / 0.016 (0.004) / - / -
B / 1.3 (0.2) / 0.023 (0.005) / - / -
SGME / A / 1.8 (0.3) / 0.011 (0.003) / - / -
B / 1.3 (0.3) / 0.018 (0.008) / - / -
CONH / A / 3.0 (0.4) / 0.025 (0.008) / - / -
OYNH / B / 1.9 (0.7) / 0.028 (0.014) / - / -
LANH / A / 2.6 (0.5) / 0.034 (0.008) / - / -
EXNH / B / - / - / 3.1 (0.9) / 0.005 (0.002)
MRMA / B / 2.7 (1.1) / 0.013 (0.008) / 3.5 (0.8) / 0.029 (0.010)
MYMA / A / 1.3 (0.2) / 0.019 (0.007) / - / -
B / 1.0 (0.1) / 0.026 (0.008) / - / -
TBMA / A / 3.0 (0.3) / 0.056 (0.008) / 4.6 (0.5) / 0.127 (0.026)
NEMA / A / 3.1 (0.8) / 0.030 (0.014) / - / -
MTMA / A / 3.6 (0.6) / 0.066 (0.018) / 4.3 (1.5) / 0.076 (0.062)
B / 2.4 (0.6) / 0.127 (0.107) / - / -
GSRI / A / - / - / 6.3 (1.2) / 0.005 (0.004)
B / 1.4 (0.3) / 0.027 (0.007) / - / -
BBCT / A / 2.0 (0.3) / 0.041 (0.013) / 4.8 (1.2) / 0.017 (0.006)
QRCT / A / 1.0 (0.1) / 0.031 (0.009) / 3.1 (0.6) / 0.017 (0.003)
HUNY / A / 1.5 (0.2) / 0.018 (0.003) / - / -
B / 1.3 (0.2) / 0.015 (0.003) / - / -
NNDE / A / - / - / 4.8 (1.3) / 0.133 (0.050)
B / - / - / 3.7 (1.1) / 0.173 (0.082)
CHNC / A / 2.5 (1.0) / 0.048 (0.013) / 6.5 (1.6) / 0.057 (0.041)
B / 1.7 (0.3) / 0.084 (0.073) / 4.5 (1.6) / 0.070 (0.059)
AGNC / A / - / - / 6.7 (1.6) / 0.022 (0.012)
STSC / B / 2.1 (0.7) / 0.069 (0.026) / - / -
SJFL / B / 5.7 (1.0) / 0.012 (0.002) / 3.4 (0.6) / 0.010 (0.007)
Fig. 1 Examples of otolith chemistry patterns for different early life migration behaviors with Sr:Ca (solid line) on the left y-axis and Ba:Ca (dashed line) on the right y-axis. Thin dotted lines represent moving averages calculated using a regime detection algorithm. (a) Otolith chemistry data for an alewife from East Machias, Maine, USA that migrated directly from fresh water to the ocean. (b) Otolith chemistry data for an alewife from Town Brook, Massachusetts, USA that used freshwater and estuarine nursery habitats prior to emigrating to the ocean. (c) Otolith chemistry for an alewife from the Monument River, Massachusetts, USA that used only estuarine nursery areas (i.e. spent no time in fresh waters) and then emigrated to sea.
Fig. 2 Histograms of the total length (mm) at emigration to sea by species for alewife (upper panels) and blueback herring (lower panels) for different nursery habitat types (left panels = only freshwater nurseries; center panels = estuarine nurseries only; right panels = combined freshwater and estuarine nurseries).
Online Resource 3. Plots of otolith 87:86Sr against Sr:Ca for natal and marine periods for each site. Blue diamonds represent natal values and red squares indicate marine values. (EMME = E. Machias, ME; SGME = St. George R., ME; CONH = Cocheco R., NH; OYNH = Oyster R., NH; LANH = Lamprey R., NH; EXNH = Exeter R., NH; MRMA = Merrimack R., MA; MYMA = Mystic R., MA; TBMA = Town Brook, MA; NEMA = Nemasket R., MA; MTMA = Monument R., MA; GSRI = Gilbert Stuart R., RI; BBCT = Bride Brook, CT; QRCT = Quinnipiac R., CT; HUNY = Hudson R., NY; NNDE = Nanticoke R., DE; CHNC = Chowan R., NC; AGNC = Alligator R., NC; STSC = Santee-Cooper R., SC; SJFL = St. John’s R., FL)