Gulf River 2017

Here's why I'm involved in the Gulf River Project: I care about my surrounding environment and want to learn about the current state of the Gulf River. I also want to learn about all the scientific factors that effect the ecosystem of the Gulf River.(Greg Smith, at the pH meter, above.) 
What do students do?
Students invest their time in an educational environment, in either the lab or "on the front lines" of the Gulf River. Students who are "in the trenches" of the Gulf River are sampling during low tide on Wednesdays along four different sites to see if there is any variation depending on the location. Those who don't enjoy being knee deep in water can spend their time in the lab, using quality equipment to analyze the samples for important values.
Important values include
  • Dissolved oxygen-the amount of gasseous oxygen dissolved in the water. poor levels of dissolved oxygen can cause stress and lead to mass death of fish (What is Dissolved Oxygen? - Mobile Bay NEP)
  • Conductivity/Salinity-too much dissolved salt in water can cause vegetation to become unhealthy and die. very high salinity can also effect the ecosystem, as those who are stronger in salt resistance will assume dominance and be able to survive such conditions. the vegetation effected by this can also lead to a depletion of herbivores, leading to death of herbivores and predetors with a reduced food supply.(Salinity and water quality fact sheet)+(What is Conductivity? - Environmental Monitor - Fondriest Environmental)
  • Temperature- high temperature can result in decreased dissolved oxygen(
  • enterococcus bacteria-
  • pH-
  • Chlorophyll-a-

In 2016, CSCR students and staff began surveying shellfish in the Gulf. Click here to view the live, editable Gulf River Shellfish Survey map.

Project Sites:Gulf River from the Border St Bridge to Gannet Road in N. Scituate


Leaders: Ann Thomae, Ben Wetherill

 2016 Highlights:

  • 7 weeks of sampling
  • 4 sites
  • 2 samples per site per week
  • 56 total water samples collected


Each sample analyzed for…

  • Dissolved oxygen
  • Salinity / Conductivity
  • Temperature
  • Enterococcus bacteria
  • pH
  • Chlorophyll-a


Learned and started using a new test method for Nitrates


  • Lower detection limit of 0.04 mg/L vs. the previous method of 1 mg/L
  • Gulf River samples are in the range 0.05-0.2 mg/L, so this allows us to confidently assess concentrations



Gulf 2016 Preliminary Summary 

In general, the health of the Gulf looks very good. We still need time for the analysis of the data, but we have seen no data that reflects eutrophication conditions or nutrient contamination.

Dissolved oxygen – All DO values fell within the normal ranges for %saturation and mg/l. Only one or two samples where DO levels were abnormally low. Still need to assess what conditions might have caused them.

Chlorophyll-a – Chlorophyll levels seem to fluctuate within healthy ranges, with the highest values in shallow waters at low tides.

Nitrates – Nitrates are extremely low, meaning that nitrogen is probably being completely consumed by phytoplankton and algae. This could hint that nitrogen is a limiting nutrient in the Gulf and that phosphorous is in large supply. A future opportunity for us could be to start measuring phosphorous.

Bacteria – Bacteria counts are consistently very low everywhere except Hunters. We need to do more studies to evaluate the source of the bacteria at Hunters. This might require building CSCR staff and skills to differentiate animal and human bacteria.

The strong tidal flow is critical for the Gulf, and keeps it fairly well flushed and oxygenated. 

It is important for us to keep thinking about the Hunters Pond dam removal scheduled for fall 2017. Dr. Sara Grady and her colleagues at the state level may suggest protocols for us to test in the spring and summer of 2017 in order to develop baseline data for post dam removal comparison.