Continuous Monitoring Stations
Imagine Working 365 Days a Year.
Data from our Continuous Monitoring Stations
Harpswell Continuous Monitoring Station Daily Mean Graphs
Temperature
Water Water Temperature in Celsius (C)
The temperature of the water, measured in degrees Celsius. The growth, reproduction, and survival of marine life are influenced by temperature.
Salinity
Salinity in parts per thousand (ppt)
Salinity is the saltiness of seawater — the amount of salts dissolved in water, measured in parts per thousand. The open ocean averages 35 ppt (that is 3.5% saltiness) and the Casco Bay estuary typically ranges from 5 to 33 ppt. Salinity levels are influenced by tides and the volume of fresh water and runoff flowing into the Bay. Marine life in estuaries such as Casco Bay normally can tolerate a larger range of salinity than those living in the open ocean.
Dissolved Oxygen
Dissolved Oxygen in milligrams per liter (mg/L)
Dissolved oxygen (DO) measures how much oxygen is available to marine life. When the concentration of Dissolved Oxygen falls below 5.5 mg/L (5.5 milligrams of oxygen dissolved in one liter of seawater), fish and other marine life can become stressed. Dissolved Oxygen levels less than 2.0 mg/L may be life-threatening to marine animals.
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation is a measure of oxygen. When water holds all the oxygen it can at a given temperature and salinity, it is said to be 100% saturated. Dissolved Oxygen Percent Saturation compares the actual dissolved oxygen concentration compared to the theoretical 100% saturation of dissolved oxygen concentration under the measured temperature and salinity conditions.
Chlorophyll
Chlorophyll Fluorescence in micrograms per liter (µg/L)
Measurements of chlorophyll—the green pigment that enables plants to photosynthesize—provide an estimate of phytoplankton abundance. Phytoplankton are the tiny marine plants that are at the bottom of the ocean food chain.
pH
pH
pH is a measure of the acidity of seawater. As more carbon dioxide is absorbed by the ocean from the burning of fossil fuels and the decomposition of marine plants, the pH of the water drops, becoming more acidic. Ocean acidification threatens the ability of marine life such as clams, mussels, and oysters, to grow healthy shells. Pure fresh water has a pH of 7; typically, seawater pH is between 7.5 and 8.4. Casco Bay receives a lot of fresh water and runoff, resulting in lower pH measurements.
Partial Pressure of Carbon Dioxide
Partial Pressure of Carbon Dioxide in parts per million (pCO2)
Partial Pressure of Carbon Dioxide is a measure of the amount of Carbon Dioxide dissolved in the water, which varies with alkalinity, latitude, depth, and temperature. In addition, marine plants can add carbon dioxide to the water through respiration and remove it via photosynthesis. Dissolved Carbon Dioxide can also be exchanged with the atmosphere. Data on carbon dioxide, which has an impact on the acidity of our coastal waters, support our work to protect the health of Casco Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Total Alkalinity
Total Alkalinity* in millimoles per kilogram (mmol/kg)
Total Alkalinity is a measure of the buffering capacity of the water, indicating how resistant the ocean is to acidification.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Dissolved Inorganic Carbon
Dissolved Inorganic Carbon* in millimoles per kilogram (mmol/kg)
Dissolved Inorganic Carbon is the sum of the concentrations of Carbon Dioxide, Carbonate, and Bicarbonate in the water. This is one of the parameters that provides a more complete picture of acidification in the Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Omega Aragonite
Omega Aragonite* Omega Aragonite assesses the state of calcium carbonate in suspension in the water. Calcium carbonate is the material that marine life such as clams and oysters use to build their shells. When the level of Omega Aragonite in seawater falls below 1.5, it can be difficult for shell-bearing marine organisms to build and maintain their shells.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Turbidity
Turbidity
Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.
Yarmouth Continuous Monitoring Station Daily Mean Graphs
Temperature
Water Water Temperature in Celsius (C)
The temperature of the water, measured in degrees Celsius. The growth, reproduction, and survival of marine life are influenced by temperature.
Salinity
Salinity in parts per thousand (ppt)
Salinity is the saltiness of seawater — the amount of salts dissolved in water, measured in parts per thousand. The open ocean averages 35 ppt (that is 3.5% saltiness) and the Casco Bay estuary typically ranges from 5 to 33 ppt. Salinity levels are influenced by tides and the volume of fresh water and runoff flowing into the Bay. Marine life in estuaries such as Casco Bay normally can tolerate a larger range of salinity than those living in the open ocean.
Dissolved Oxygen
Dissolved Oxygen in milligrams per liter (mg/L)
Dissolved oxygen (DO) measures how much oxygen is available to marine life. When the concentration of Dissolved Oxygen falls below 5.5 mg/L (5.5 milligrams of oxygen dissolved in one liter of seawater), fish and other marine life can become stressed. Dissolved Oxygen levels less than 2.0 mg/L may be life-threatening to marine animals.
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation is a measure of oxygen. When water holds all the oxygen it can at a given temperature and salinity, it is said to be 100% saturated. Dissolved Oxygen Percent Saturation compares the actual dissolved oxygen concentration compared to the theoretical 100% saturation of dissolved oxygen concentration under the measured temperature and salinity conditions.
Chlorophyll
Chlorophyll Fluorescence in micrograms per liter (µg/L)
Measurements of chlorophyll—the green pigment that enables plants to photosynthesize—provide an estimate of phytoplankton abundance. Phytoplankton are the tiny marine plants that are at the bottom of the ocean food chain.
pH
pH
pH is a measure of the acidity of seawater. As more carbon dioxide is absorbed by the ocean from the burning of fossil fuels and the decomposition of marine plants, the pH of the water drops, becoming more acidic. Ocean acidification threatens the ability of marine life such as clams, mussels, and oysters, to grow healthy shells. Pure fresh water has a pH of 7; typically, seawater pH is between 7.5 and 8.4. Casco Bay receives a lot of fresh water and runoff, resulting in lower pH measurements.
Partial Pressure of Carbon Dioxide
Partial Pressure of Carbon Dioxide in parts per million (pCO2)
Partial Pressure of Carbon Dioxide is a measure of the amount of Carbon Dioxide dissolved in the water, which varies with alkalinity, latitude, depth, and temperature. In addition, marine plants can add carbon dioxide to the water through respiration and remove it via photosynthesis. Dissolved Carbon Dioxide can also be exchanged with the atmosphere. Data on carbon dioxide, which has an impact on the acidity of our coastal waters, support our work to protect the health of Casco Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Total Alkalinity
Total Alkalinity* in millimoles per kilogram (mmol/kg)
Total Alkalinity is a measure of the buffering capacity of the water, indicating how resistant the ocean is to acidification.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Dissolved Inorganic Carbon
Dissolved Inorganic Carbon* in millimoles per kilogram (mmol/kg)
Dissolved Inorganic Carbon is the sum of the concentrations of Carbon Dioxide, Carbonate, and Bicarbonate in the water. This is one of the parameters that provides a more complete picture of acidification in the Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Omega Aragonite
Omega Aragonite* Omega Aragonite assesses the state of calcium carbonate in suspension in the water. Calcium carbonate is the material that marine life such as clams and oysters use to build their shells. When the level of Omega Aragonite in seawater falls below 1.5, it can be difficult for shell-bearing marine organisms to build and maintain their shells.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Turbidity
Turbidity
Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.
Portland Continuous Monitoring Station Daily Mean Graphs
Temperature
Water Water Temperature in Celsius (C)
The temperature of the water, measured in degrees Celsius. The growth, reproduction, and survival of marine life are influenced by temperature.
Salinity
Salinity in parts per thousand (ppt)
Salinity is the saltiness of seawater — the amount of salts dissolved in water, measured in parts per thousand. The open ocean averages 35 ppt (that is 3.5% saltiness) and the Casco Bay estuary typically ranges from 5 to 33 ppt. Salinity levels are influenced by tides and the volume of fresh water and runoff flowing into the Bay. Marine life in estuaries such as Casco Bay normally can tolerate a larger range of salinity than those living in the open ocean.
Dissolved Oxygen
Dissolved Oxygen in milligrams per liter (mg/L)
Dissolved oxygen (DO) measures how much oxygen is available to marine life. When the concentration of Dissolved Oxygen falls below 5.5 mg/L (5.5 milligrams of oxygen dissolved in one liter of seawater), fish and other marine life can become stressed. Dissolved Oxygen levels less than 2.0 mg/L may be life-threatening to marine animals.
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation is a measure of oxygen. When water holds all the oxygen it can at a given temperature and salinity, it is said to be 100% saturated. Dissolved Oxygen Percent Saturation compares the actual dissolved oxygen concentration compared to the theoretical 100% saturation of dissolved oxygen concentration under the measured temperature and salinity conditions.
Chlorophyll
Chlorophyll Fluorescence in micrograms per liter (µg/L)
Measurements of chlorophyll—the green pigment that enables plants to photosynthesize—provide an estimate of phytoplankton abundance. Phytoplankton are the tiny marine plants that are at the bottom of the ocean food chain.
pH
pH
pH is a measure of the acidity of seawater. As more carbon dioxide is absorbed by the ocean from the burning of fossil fuels and the decomposition of marine plants, the pH of the water drops, becoming more acidic. Ocean acidification threatens the ability of marine life such as clams, mussels, and oysters, to grow healthy shells. Pure fresh water has a pH of 7; typically, seawater pH is between 7.5 and 8.4. Casco Bay receives a lot of fresh water and runoff, resulting in lower pH measurements.
Partial Pressure of Carbon Dioxide
Partial Pressure of Carbon Dioxide in parts per million (pCO2)
Partial Pressure of Carbon Dioxide is a measure of the amount of Carbon Dioxide dissolved in the water, which varies with alkalinity, latitude, depth, and temperature. In addition, marine plants can add carbon dioxide to the water through respiration and remove it via photosynthesis. Dissolved Carbon Dioxide can also be exchanged with the atmosphere. Data on carbon dioxide, which has an impact on the acidity of our coastal waters, support our work to protect the health of Casco Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Total Alkalinity
Total Alkalinity* in millimoles per kilogram (mmol/kg)
Total Alkalinity is a measure of the buffering capacity of the water, indicating how resistant the ocean is to acidification.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Dissolved Inorganic Carbon
Dissolved Inorganic Carbon* in millimoles per kilogram (mmol/kg)
Dissolved Inorganic Carbon is the sum of the concentrations of Carbon Dioxide, Carbonate, and Bicarbonate in the water. This is one of the parameters that provides a more complete picture of acidification in the Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Omega Aragonite
Omega Aragonite* Omega Aragonite assesses the state of calcium carbonate in suspension in the water. Calcium carbonate is the material that marine life such as clams and oysters use to build their shells. When the level of Omega Aragonite in seawater falls below 1.5, it can be difficult for shell-bearing marine organisms to build and maintain their shells.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Turbidity
Turbidity
Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.
Comparison of Harpswell, Yarmouth, and Portland Harbor Continuous Monitoring Station Data
Temperature
Water Water Temperature in Celsius (C)
The temperature of the water, measured in degrees Celsius. The growth, reproduction, and survival of marine life are influenced by temperature.
Salinity
Salinity in parts per thousand (ppt)
Salinity is the saltiness of seawater — the amount of salts dissolved in water, measured in parts per thousand. The open ocean averages 35 ppt (that is 3.5% saltiness) and the Casco Bay estuary typically ranges from 5 to 33 ppt. Salinity levels are influenced by tides and the volume of fresh water and runoff flowing into the Bay. Marine life in estuaries such as Casco Bay normally can tolerate a larger range of salinity than those living in the open ocean.
Dissolved Oxygen
Dissolved Oxygen in milligrams per liter (mg/L)
Dissolved oxygen (DO) measures how much oxygen is available to marine life. When the concentration of Dissolved Oxygen falls below 5.5 mg/L (5.5 milligrams of oxygen dissolved in one liter of seawater), fish and other marine life can become stressed. Dissolved Oxygen levels less than 2.0 mg/L may be life-threatening to marine animals.
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation (%)
Dissolved Oxygen Percent Saturation is a measure of oxygen. When water holds all the oxygen it can at a given temperature and salinity, it is said to be 100% saturated. Dissolved Oxygen Percent Saturation compares the actual dissolved oxygen concentration compared to the theoretical 100% saturation of dissolved oxygen concentration under the measured temperature and salinity conditions.
Chlorophyll
Chlorophyll Fluorescence in micrograms per liter (µg/L)
Measurements of chlorophyll—the green pigment that enables plants to photosynthesize—provide an estimate of phytoplankton abundance. Phytoplankton are the tiny marine plants that are at the bottom of the ocean food chain.
pH
pH
pH is a measure of the acidity of seawater. As more carbon dioxide is absorbed by the ocean from the burning of fossil fuels and the decomposition of marine plants, the pH of the water drops, becoming more acidic. Ocean acidification threatens the ability of marine life such as clams, mussels, and oysters, to grow healthy shells. Pure fresh water has a pH of 7; typically, seawater pH is between 7.5 and 8.4. Casco Bay receives a lot of fresh water and runoff, resulting in lower pH measurements.
Partial Pressure of Carbon Dioxide
Partial Pressure of Carbon Dioxide in parts per million (pCO2)
Partial Pressure of Carbon Dioxide is a measure of the amount of Carbon Dioxide dissolved in the water, which varies with alkalinity, latitude, depth, and temperature. In addition, marine plants can add carbon dioxide to the water through respiration and remove it via photosynthesis. Dissolved Carbon Dioxide can also be exchanged with the atmosphere. Data on carbon dioxide, which has an impact on the acidity of our coastal waters, support our work to protect the health of Casco Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Total Alkalinity
Total Alkalinity* in millimoles per kilogram (mmol/kg)
Total Alkalinity is a measure of the buffering capacity of the water, indicating how resistant the ocean is to acidification.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Dissolved Inorganic Carbon
Dissolved Inorganic Carbon* in millimoles per kilogram (mmol/kg)
Dissolved Inorganic Carbon is the sum of the concentrations of Carbon Dioxide, Carbonate, and Bicarbonate in the water. This is one of the parameters that provides a more complete picture of acidification in the Bay.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Omega Aragonite
Omega Aragonite* Omega Aragonite assesses the state of calcium carbonate in suspension in the water. Calcium carbonate is the material that marine life such as clams and oysters use to build their shells. When the level of Omega Aragonite in seawater falls below 1.5, it can be difficult for shell-bearing marine organisms to build and maintain their shells.
Please note: Over the last couple of years, the technology and methodology to measure ocean acidification have advanced. Friends of Casco Bay is part of a team testing these new technologies and methods. We will update these data as those experiments progress as we expect that the new methods will change some of our past calculations. If you have any questions please contact Mike Doan (mdoan [at] cascobay [dot] org) or Heather Kenyon (hkenyon [at] cascobay [dot] org).
Turbidity
Turbidity
Turbidity is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. The more total suspended solids in the water, the murkier it seems and the higher the turbidity.