Green Harbor River Project Holly Williams Independent Study Whitman-Hanson Regional High School May 2008

The Green Harbor River is currently being studied to see how the tidal restriction affects the ecosystem. It is important to keep our rivers clean. You can help us out and take part in a great effort to protect our local areas.

The Green Harbor Project started in 2003 and is still underway. Reports contain water quality data including salinity, turbidity, dissolved oxygen, dissolved oxygen saturation, and surface pH. In the past three years a nekton species survey was taken to compare fish and crab catches for the harbor and river. I compiled a complete list of animal species recorded in the area from the reports. An example of 2005 data can be found at the end of this power point. In the following slides, graphs and tables of water quality averages of June, July, and August from will be presented. I will also point out what is most relevant and interesting. The dike was built in Green Harbor River in Marshfield Massachusetts in Since then the river has suffered from tidal restrictions.

What are these graphs and tables for? The reason for making these tables was to show the monthly averages of the data taken in the past five years. The purpose is to see if there are any trends caused by tidal restrictions and to compare yearly data. June, July, and August were chosen because during these months the river and harbor have been studied more intensely. Turbidity in river and harbor

Salinity in HarborSalinity in River Date 2003-July N/A August N/A June N/A July August June July August June July August June July August Summer average The salinity was determined by using a YSI-85 digital meter. A Sea Test Full Range Specific Gravity Meter manufactured by Aquarium Systems was also used to compare the data.

During May, June, and July of 2006 mean salinity was the lowest in the river because tide gate was not opened up until June. Then salinity rose gradually. Another variable is the rain patterns.

pH In HarborpH in River Date 2003-July N/A August N/A June N/A July August June July August June July August June July August 88 Summer Average 87.7 Rainfall typically lowers the pH in the river.

Harbor Secchi DepthRiver Secchi Depth Date(meters) 2003-June N/A 2003-JulyN/A AugustN/A JuneN/A JulyN/A AugustN/A June July August August June July August Summer Average The Secchi Dish shows the depth to which light can penetrate and is an indicator of the turbidity of the water. Note: Secchi readings cannot be taken except during slack tide so there is missing data.

Turbidity Data: June, July August Note: On graph, 1 is 2003, 5 is 2007 DateHarborRiver Yearly Average turbidity chart

Analyzing Turbidity. It is no surprise that in 2003 and 2004 the river was extremely turbid. During June, July, and August the tide gates were barely open. The river bottom is very muddy. Any disturbance to the mud such as rain or water flow disrupts the water making it dirtier. The river often looks like a brown coffee color. At times, after rain or when the gates are closed, you can see two to three meters down in the harbor. The harbor consistently has clearer water.

The scum on the water may represent that the water quality is poor.

Dissolved Oxygen (Mg/L) HarborDissolved Oxygen (Mg/L) River) Date 2003-July N/A August N/A June 9 N/A 2004-July August July August June July August June July August Summer Average 86.9 Dissolved Oxygen could be better, but progress has been made to improve the D.O. by increasing tidal flow especially in the last 2 years ( ).

Allowing more water into the river would significantly improve Green Harbor’s dissolved oxygen. On September 2, 2004 tide gates were closed so there was zero tidal induction until the next summer when one gate was blocked open.

Dissolved Oxygen Saturation in HarborD O Saturation in River Date 2005-July August June July August July August Summer Average Harbor D.O is higher on average than in the river.

Dissolved Oxygen data: June, July, August DateHarborRiver DO Average chart

Analyzing Dissolved oxygen Dissolved oxygen levels were probably low during the summer months in 2003 and 2006 because the water was extremely turbid with a brownish/red color which was most likely caused by the limited tidal flow. Suspended sediments block out sunlight that vegetation needs to photosynthesize: Without photosynthesis the oxygen levels will be low. Also, the warmer the water, the less oxygen there will be, and the temperatures were high because there was less mixing of cool ocean water in the river due to limited tidal induction. The brownish coloration of the water absorbs radiation at a higher rate then clearer waters which can cause the temperatures to rise. Dissolved oxygen was also effected because there is little rainfall in July and August. The gates were also barely open, allowing slight inflow of water.

Animal Survey for the Green Harbor River Project All species that have been recorded in the river and harbor Fish American Eel (Anguilla rostrata) R Banded Killifish (Fundulus diphanus) R Mummichog (Fundulus heteroclitus) H R Tautog (Tautogo onitis) H Winter Flounder juveniles (Pleuronectes americanus) H R Jack Family (Carabgudae) H Pumpkin Seed Sunfish (Cepomis gibbosus) R Three Spine Stickleback (Gasterosteus aculeatus) H R Four Spine Stickleback (Apeltes quadrucus) H R Atlantic Silverside (Menidia menidia)) H R Northern Pipefish (Syngnathus fuscus) R Menhaden (Brevoortia tyrannus) H White Perch (Morone americanus) R Sculpin (Scorpawniformes sp.) H Mollusks Periwinkles (Littorina littorea) H R Mussel juveniles (Mytilus edulis) H R? Softshell Clam juveniles (Mya arenaria) H R Worms Polychaetes H R Sea Worm; Nereid H R Nematodes R Annelids R

Plankton ( RIVER) Copepods (Calanus sp) Crab zoea and Mysis-zoea Ctenophore Barnacle cyprid and molts Ciliates Amphipod Corophiid Amphipod Gammarid Hydroid Diatoms; Navicula Cladospherans; Daphnia Rotifer Tunicates Veligers (Clam Larvae) Ostracod Mosquito molts Damselfly larva in water Birds Great Blue Heron (Florida caerulea) R Great Egret (Casmerodius albus) H R Double Crested cormorant (Phalacroc oraz auritus) H R Herring Gull (Larus argentatus) H R Swan R Swallow R Mallard (Anas platyrhynchos) R Red winged blackbird (Agelaius phoeniceus) R Pigeon (Columba livia) R Gulls (Larus sp.) R Osprey (Pandion haliaetus) R Kingfisher (Megaceryle alcyon) R Canada Geese (Branta Canadensis) R Robin (Turdus migratorius) R American wood cock (Scolopax minor) R Little blue Heron (Florida caerulea) R Green Heron (Butorides striatus) R

Algae (BOTH) Cladophora sp. - Algae that forms thick greenish/brown floating mats. Sea lettuce Ulva (Came in with tide; Growing on river bottom) Filamentous Green Algae- Wharf Creek- attached to bottom covered with brown algae Brown Algae (Phaeophyta) Golden algae (Prymnesium parvum) Tube Weed (Enteromorpha sp.) Fucus- (came in with tide- not growing on river side). Insects (RIVER) Dragon Fly Damselfly Horsefly Water boatman Beetle Mosquito Tiny flies Crustacea Green Crab (Carcinus maenas) H R Asian Shore Crab (Hemigrapsus sarguinus) H Grass Shimp (Palaemonetes sp.) H R Sand Shrimp (Crangon septemspinosa) H R Amphipods (Corophiid and Grammarid) H R Northern Rock Barnacles (Semibalanus balanoides) H R Horse Shoe Crab (Limulus polyphemus) H