Estuary Classification Revisited

This paper presents the governing equations of a tidally-averaged, width-averaged, rectangular estuary in completely nondimensionalized forms. Subsequently, we discover that the dynamics of an estuary is entirely controlled by only two variables: (i) the Estuarine Froude number, and (ii) a nondimensional number related to the Estuarine Aspect ratio and the Tidal Froude number. Motivated by this new observation, the problem of estuary classification is re-investigated. Our analysis shows that the two control variables are capable of completely determining the stratification at the estuary mouth, and therefore can specify the estuary type. The theoretical estuary classification scheme proposed in this paper is validated against real estuarine data collected from existing literature. Our classification scheme on comparison with the state-of-the-art theory shows significant improvement.Comment: 6 pages, 4 figure

Eelgrass Distribution in the Great Bay Estuary for 2014

See also: Eelgrass/Macroalgae Discussion Primer for TAC Activities 2016-2017 http://scholars.unh.edu/prep/355 Eelgrass (Zostera marina L.) is an essential habitat for the Great Bay Estuary (GBE) because it is the basis of an estuarine food web that supports many of the recreationally, commercially and ecologically important species in the estuary and beyond. Eelgrass provides food for ducks, geese and swans, as well as food, nursery habitat, and shelter for juvenile fish and shellfish. Eelgrass filters estuarine waters and improves water clarity, removing both nutrients and suspended sediments from the water column; its roots and rhizomes bind and hold sediments in place, thereby reducing turbidity. Historically, eelgrass has been the primary habitat in the Great Bay Estuary, for many decades covering the most area of any of the three major habitats: eelgrass, salt marsh, and mud flat. Eelgrass in the Great Bay Estuary is a vital resource to the State of New Hampshire’s marine environment, and eelgrass habitat is essential to the health of the estuary (Trowbridge 2006, Short 2014). The present report describes and interprets the eelgrass distribution, percent cover and biomass data collected in 2014 for the Great Bay Estuary. The report was written for the Piscataqua Region Estuaries Partnership (PREP), and covers the entire Great Bay Estuary, from the Atlantic Coast to the Great Bay, and including the estuarine portions of the tributaries

Environmental variables, pesticide pollution and meiofaunal community structure in two contrasting temporarily open/closed false bay estuaries

Environmental variables (including natural and anthropogenic stressors) and meiobenthic communities were sampled in a ‘natural’ (Rooiels) and a ‘disturbed’ (Lourens) estuary in the Western Cape, South Africa, bimonthly for 20 months. A primary aim of the study was to assess if the meiobenthic community structure is driven by different variables when comparing ‘natural’ versus ‘disturbed’ system. Due to the much smaller catchment of the Rooiels Estuary, many environmental variables were significantly different (p<0.001) from the variables in the Lourens Estuary, e.g. salinity, temperature, pH, total suspended solids, nitrate and depth. No pesticide concentrations were expected in the Rooiels Estuary due to the absence of agricultural development in the catchment. However, chlorpyrifos (8.9 µg/kg), prothiofos (22.0 µg/kg) and cypermethrin concentrations (0.42 µg/kg) were detected frequently, with the highest concentrations recorded during the summer months. Principal response curve analysis showed that temporal variability between sampling dates explained 42% of the variance in environmental variables and pesticide concentrations and spatial variability between the 2 estuaries explained 58%. Variables contributing most to the differences were higher concentrations of endosulfan, p,p-DDE and nitrate concentrations in the Lourens Estuary and larger grain size and higher salinity at the bottom in the Rooiels Estuary. In general the meiofaunal community in the Rooiels Estuary showed a significantly higher number of taxa (p<0.001), a significantly higher Shannon Wiener Diversity Index (

Eelgrass/Macroalgae Discussion Primer for TAC Activities 2016-2017

See also: Eelgrass Distribution and Biomass in the Great Bay Estuary for 2015 http://scholars.unh.edu/prep/354 Eelgrass Distribution in the Great Bay Estuary for 2014 http://scholars.unh.edu/prep/352/ The issue of eelgrass and macroalgae in the Great Bay Estuary (GBE) is extremely important and complex. The purpose of this document is to clarify issues and questions to make for a more productive and informed discussion

Eelgrass Distribution and Biomass in the Great Bay Estuary for 2015

See also: Eelgrass/Macroalgae Discussion Primer for TAC Activities 2016-2017 http://scholars.unh.edu/prep/355 Eelgrass (Zostera marina L.) is an essential habitat for the Great Bay Estuary (GBE) because it is the basis of an estuarine food web that supports many of the recreationally, commercially and ecologically important species in the estuary and beyond. Eelgrass provides food for ducks, geese and swans, as well as food, nursery habitat, and shelter for juvenile fish and shellfish. Eelgrass filters estuarine waters and improves water clarity, removing both nutrients and suspended sediments from the water column; its roots and rhizomes bind and hold sediments in place, thereby reducing turbidity. Historically, eelgrass has been the primary habitat in the Great Bay Estuary, for many decades covering the most area of any of the three major habitats: eelgrass, salt marsh, and mud flat. Eelgrass in the Great Bay Estuary is a vital resource to the State of New Hampshire’s marine environment, and eelgrass habitat is essential to the health of the estuary (Trowbridge 2006, Short 2014). The report was written for the Piscataqua Region Estuaries Partnership (PREP), and covers the entire Great Bay Estuary, from the Atlantic Coast to the Great Bay, and including the estuarine portions of the tributaries

2015 State of the Bay Report

The Casco Bay Estuary Partnership helps track and report on changing conditions within the Bay and its watershed. Every five years, in its State of the Bay report, the Partnership portrays how Casco Bay is faring—what trends are evident, what progress is visible, and what new challenges are emerging. By tracking indicators at regular intervals over decades, the Partnership helps identify the collective work needed to sustain the region. State of the Bay 2015, summarized here and detailed online at www.cascobayestuary.org/state-of-the-bay-2015, reveals a complex array of factors shaping the ecology and economy of the Casco Bay region. There’s a mix of encouraging news, interspersed with unsettling trends. The warming climate represents a vast and unpredictable driver of regional change—with hotter ocean and air temperatures, more frequent and extreme precipitation, and rising seas (already evident in flooding at extreme high tides). Indicators used in the past (and included in the 2015 report) do not fully account for the dynamic interplay of forces currently at work on Casco Bay. Future reports will include new indicators to help gauge the pace and impacts of far reaching change.https://digitalcommons.usm.maine.edu/cbep-state-of-the-bay/1000/thumbnail.jp

Habitat Restoration Case Studies in Casco Bay

These are a few of the projects implemented by some of the partners of the Casco Bay Estuary Project. To learn more about the Casco Bay Estuary Project Habitat Restoration Program and to explore partnership opportunities, visit: www.cascobayestuary.or