Macrobenthic Ecology of a Sawdust-Bearing Substrate in the Penobscot River Estuary (Maine)

1973 ◽  
Vol 30 (4) ◽  
pp. 493-497 ◽  
Author(s):  
Wayne K. Shorey
Keyword(s):  
Macoma Balthica ◽  
River Estuary ◽  
Mya Arenaria ◽  
Index Number ◽  
Corophium Volutator ◽  
Number Of Species ◽  
Penobscot River ◽  
Shallow Station ◽  
Sandy Sediments ◽  
Number Of Individuals

The macrobenthos of sawdust-bearing substrates in the Penobscot River estuary (Maine) were sampled bimonthly from January through November 1968. The polychaete Scolecolepides viridis and the bivalves Macoma balthica and Mya arenaria dominated the sandy sediments of the shallow station. Prionospio malmgreni and Corophium volutator were dominant in the granular substrate of the deeper station. The population of the shallow station (1-m depth, mean low water) was seasonally more stable and had a higher mean monthly bio-index (number of individuals/number of species) than that of the deeper station (6-m depth, mean low water).

Effect of Sedimentation on Infaunal Invertebrate Populations of Cobequid Bay, Bay of Fundy

1981 ◽  
Vol 38 (6) ◽  
pp. 642-648 ◽  
Author(s):  
Ted R. Turk ◽  
Michael J. Risk
Keyword(s):  
Grain Size ◽  
Macoma Balthica ◽  
Fine Sand ◽  
Coarse Sand ◽  
Sediment Deposition ◽  
Mya Arenaria ◽  
Bay Of Fundy ◽  
Corophium Volutator ◽  
Tidal Power ◽  
Order Of Magnitude

Construction of a tidal dam in the upper reaches of the Bay of Fundy is expected to result in deposition of sediment. We investigated the effect of sediment deposition on populations of three major benthic species of the upper reaches: Corophium volutator, Macoma balthica, and Mya arenaria. In fences and boxes that induced deposition on intertidal mudflats, accumulation of 1.0–3.5 cm of sediment at rates of 1.9–10.2 cm/mo caused Corophium density to decrease sharply, usually by an order of magnitude. Macoma density was generally unaffected. In fishing weirs, mud that accumulated at 1.5 cm/mo to a mean depth of 5.2 cm supported normal Corophium densities. The effect of sedimentation on Mya depends strongly on grain size: LD50 was 24 cm for coarse sand, 6 cm for fine sand, and 3 cm for mud. Mya is able to burrow upward in accumulating coarse sand. Even moderate rates and depths of sediment deposition, particularly of fine sediment, could have a major adverse effect on existing Corophium and Mya populations.Key words: Bay of Fundy, tidal power, sedimentation, grain size, water content, Corophium volutator, Macoma balthica, Mya arenaria

scholarly journals Evidence of Life Cycle Diversity of River Herring in the Penobscot River Estuary, Maine

2021 ◽  
Vol 13 (3) ◽  
pp. 263-276
Author(s):  
Justin R. Stevens ◽  
Rory Saunders ◽  
William Duffy
Keyword(s):  
Life Cycle ◽  
River Estuary ◽  
River Herring ◽  
Penobscot River

Temporal patterns in the macrobenthic communities of the Hawkesbury estuary, New South Wales

1987 ◽  
Vol 38 (5) ◽  
pp. 607
Author(s):  
AR Jones
Keyword(s):  
Community Composition ◽  
Temporal Patterns ◽  
Single Species ◽  
Species Number ◽  
Community Patterns ◽  
Low Salinity ◽  
Number Of Species ◽  
South Wales ◽  
Physicochemical Factors ◽  
Number Of Individuals

Temporal patterns in number of species, number of individual animals and community composition of the soft-sediment zoobenthos of the Hawkesbury estuary are described and related to physicochemical factors. Replicate grabs were taken at 3-month intervals over 3 years (1977-1979) from sites located in three zones: the lower, middle and upper reaches. The number of species and number of individuals showed significant seasonal and annual differences in all zones. However, the pattern of these differences varied among sites and seasonal differences were not repeatable over years. Similarly, differences in community composition as revealed by classification were not seasonal. In the middle and lower reaches, these differences were apparently caused by the over- riding influence of non-seasonal climatic events, i.e. a major flood in 1978 and a drought throughout 1979. In the first two sampling following the flood, sample values for the numbers of both species and individuals were usually lowest and community composition was distinct from pre-flood and drought times. During the drought, the number of species was usually high and community composition relatively distinct. Whereas the number of species and community composition groupings were both significantly related to river discharge, the number of individuals was significantly correlated with temperature. All community variables were sometimes significantly related to salinity. The identity of numerically dominant species, as determined by Fager rankings, varied among times in both the lower and middle reaches. However, the polychaete Nephtys australiensis and the bivalve mollusc Notospisula trigonella were highest ranked overall in both zones. Community patterns in the low-salinity upper reaches differed from those further downstream by showing little change in numbers of species and community composition following the flood. Only the number of species was significantly correlated with any of the measured physicochemical variables, this being partly due to an influx of species during the drought. Furthermore, the upstream community was always dominated by the polychaete Ceratonereis limnetica and was thus the only community that could be characterised by a single species.

scholarly journals Comparing on site human and video counts at Igarapava fish ladder, south eastern Brazil

2006 ◽  
Vol 4 (2) ◽  
pp. 291-294 ◽  
Author(s):  
Mark D. Bowen ◽  
Simone Marques ◽  
Luiz G. M. Silva ◽  
Volney Vono ◽  
Hugo P. Godinho
Keyword(s):  
Fish Species ◽  
Accurate Method ◽  
Fish Passage ◽  
Southeastern Brazil ◽  
Human Observer ◽  
Full Spectrum ◽  
Prochilodus Lineatus ◽  
Number Of Species ◽  
Fish Ladder ◽  
Number Of Individuals

On site human observations and video images were collected and compared at the window of the Igarapava Dam fish ladder (IDFL), rio Grande , Southeastern Brazil, between March 1st and June 30th, 2004. We conducted four experiments with two humans (Observer 1 and Observer 2) observing fish passage in the IDFL window while a Sony 3CCD video camera (Observer 3) recorded fish passage at the same time. Experiments, each one hour in length, were distributed throughout the diel cycle using full spectrum lights. We identified fish species, the number of individuals for each species, and the real time that they passed. Counts from each human observer were compared to the video counts. The fish species most commonly observed in the window were - curimba (Prochilodus lineatus), mandi-amarelo (Pimelodus maculatus), piau-três-pintas (Leporinus friderici) and ferreirinha (Leporinus octofasciatus). The number of species and individuals were indistinguishable for the three observers. But, the number of species and individuals were significantly different among experiments. Thus, the three observers register the same number of species and count the same number of individuals even when these two response variables differ significantly among experiments. Based on these results, we concluded that the video count was an accurate method to assess fish passage at the IDFL.

scholarly journals Observations on the Fauna and Constituents of an Estuarine Mud in a Polluted Area

1932 ◽  
Vol 18 (1) ◽  
pp. 69-86 ◽  
Author(s):  
James H. Fraser
Keyword(s):  
Quantitative Analysis ◽  
Detailed Analysis ◽  
Food Chain ◽  
Macoma Balthica ◽  
Mya Arenaria ◽  
Polluted Area ◽  
Ecological Survey ◽  
Molluscan Fauna ◽  
Sand And Gravel ◽  
Mersey Estuary

1. An ecological survey of the fauna of Dingle Beach, Mersey Estuary, has been made.2. A detailed analysis of the constituents of the mud, sand and gravel is given.3. A quantitative analysis of the Molluscan fauna from a series of stations has been made.4. Type of ground and fauna at different tidal levels are correlated.Mya arenaria is only found in abundance where there are stones. Macoma balthica is abundant wherever there is thick mud.5. Dingle Beach is a type of Macoma community but differing markedly from the typical community described by Petersen as “d”.6. The importance of sewage in producing silt and the part played by sewage in the food chain are discussed.

Effects of Lunatia heros predation on the population dynamics of Mya arenaria and Macoma balthica in Maine, USA

1982 ◽  
Vol 69 (2) ◽  
pp. 187-193 ◽  
Author(s):  
J. A. Commito
Keyword(s):  
Population Dynamics ◽  
Macoma Balthica ◽  
Mya Arenaria

Mercury contamination of the Penobscot River Estuary, Maine, USA

2018 ◽  
Vol 639 ◽  
pp. 1077-1078 ◽  
Author(s):  
R.A. (Drew) Bodaly
Keyword(s):  
River Estuary ◽  
Mercury Contamination ◽  
Penobscot River

scholarly journals Is food supply for shellfish-eating birds in the western Wadden Sea affected by the between-species synchrony in year-to-year fluctuations of bivalve population parameters?

2019 ◽  
Vol 73 (1) ◽  
Author(s):  
J. J. Beukema ◽  
R. Dekker
Keyword(s):  
Food Supply ◽  
Macoma Balthica ◽  
Survival Rates ◽  
Mya Arenaria ◽  
System Stability ◽  
Individual Species ◽  
Late Winter ◽  
Important Species ◽  
Annual Biomass

Abstract For a better understanding of functioning and stability of ecosystems, it is important to know to what extent constituent species show similarity in their long-term fluctuation patterns, i.e. whether their numbers and biomass frequently show simultaneous peaks and lows. Synchronic peaks and lows of important species would enhance variability in the functioning of the entire system and might affect its stability. When fluctuation patterns of individual species are largely independent, their peaks and lows would tend to extinguish each other’s effect on overall parameters (such as total zoobenthic biomass), thus promoting system stability. A long-term (46 years) monitoring study of the macrozoobenthos in a large (50 km2) tidal-flat area revealed that the 4 most important bivalve species (3 suspension feeders: Cerastoderma edule, Mytilus edulis, Mya arenaria and 1 deposit/suspension feeder: Limecola (Macoma) balthica) frequently showed peak numbers of their recruits in the same years. The annual growth rates of the three suspension feeding species showed some synchrony as well. Annual survival rates, on the other hand, did not show any synchronization, wiping out the initial synchrony of numbers within less than 2 years. As a result, annual biomass values did not show any positive between-species correlations. Annual amounts of bivalves that are accessible as bird food rarely declined to levels below 5 g AFDW m−2 and showed limited (5 to 10 fold difference between maximal and minimal values) variation. Oystercatchers left the area quicker in late winter and showed increased death rates at very low levels of food supply. Total bivalve bird food did not show any significant long-term trend. However, biomass of Mya arenaria showed an increasing trend and that of Limecola balthica a declining trend.

Rhythmic activity of migrating juvenile American eels Anguilla rostrata

1988 ◽  
Vol 68 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Gail S. Wippelhauser ◽  
James D. McCleave
Keyword(s):  
River Estuary ◽  
Rhythmic Activity ◽  
Water Current ◽  
Anguilla Rostrata ◽  
Activity Rhythms ◽  
Tidal Water ◽  
Penobscot River ◽  
Tidal Stream ◽  
Glass Eels ◽  
Stream Transport

Glass eels of the American eel Anguilla rostrata (Lesueur) utilize selective tidal stream transport, a series of semidiurnal vertical migrations in phase with the tide, to migrate up the Penobscot River estuary, Maine, U.S.A., in the spring. Glass eels, freshly collected during their migration, exhibited rhythmic activity with circatidal periodicities when tested in groups in the presence of a water current under constant conditions in the laboratory. Freshly collected groups of eels which had already completed their migration through tidal water did not exhibit circatidal activity rhythms under the same conditions. The activity rhythms of groups of eels freshly caught in tidal water appeared to be entrained by a 12.5 h cycle of water current reversals, but not by a 10.0 h cycle of current reversals. In other entrainment experiments water collected on flood and ebb tides was alternately added to the experimental tanks every 5.0 h. Under these conditions groups of eels freshly caught in tidal water did not display any rhythmic activity. Only 2 of 100 glass eels, freshly collected from tidal and non-tidal water, which were tested individually in static tanks, exhibited rhythmic activity. The activity rhythms would allow an eel to time its vertical migrations in the estuary despite varying environmental conditions.

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