The River to Reef Connection
From the Field: Preddy Creek Cleanup
Preddy Creek flows into the Rivanna, then the James, the Chesapeake Bay and finally the Atlantic. Here's founder Ken Smith on a cleanup at the creek, because everything that reaches the reef starts upstream.
Why We Start at the Creek
Researchers at Penn State and the Virginia Institute of Marine Science modeled what happens to plastic carried by rivers into the Chesapeake Bay, including the James and the Rappahannock. About 94% of it washed up on Bay shorelines instead of reaching the ocean. Half landed within one to two weeks, most of it close to where it entered.
On the Rappahannock (fed by the Rapidan), nearly all of it stayed along the river's own banks. The trash in our rivers doesn't disappear; it piles up on our own shores. That's why Oceans4Us starts upstream: cleaning creeks and rivers is the most direct way to stop plastic before it ever reaches the reef. $2 from every item sold goes to the River to Reef Fund to do exactly that.
Source: López et al., “Estuaries as Filters for Riverine Microplastics,” Frontiers in Marine Science (2021)
What We Pour on the Land Doesn’t Stay There
Plastic is only half the story. Every storm also washes fertilizer, manure, oil and sewage off the land and into our creeks. Rivers carry all of it downstream.
The Fertilizer Gap: about 50%
Crops take up only about half of the nitrogen fertilizer spread on fields worldwide. Rain carries much of the rest into groundwater and streams as “nutrient pollution.”
Source: Lassaletta et al., Environmental Research Letters (2014)
Close to Home: Agriculture Is the Bay’s Largest Source
Farms and animal operations supply about 40% of the nitrogen, 45% of the phosphorus and 60% of the sediment reaching the Chesapeake Bay, more than any other source. Stormwater from roads, roofs and lawns adds roughly another fifth.
Source: Chesapeake Bay Program
Dead Zones: 500+ Worldwide
Those nutrients feed algae blooms. When the algae die, bacteria break them down and use up the oxygen, leaving water too low in oxygen for fish, crabs and oysters. More than 500 coastal sites worldwide now suffer from it. The Gulf of Mexico’s dead zone measured 4,402 square miles in 2025, a below-average year, and its five-year average is still more than double the 2035 cleanup target. Here at home, up to 20% of the Chesapeake Bay and its tidal rivers was low on oxygen at the June 2024 peak.
Sources: Breitburg et al., Science (2018); NOAA (2025); Virginia Institute of Marine Science
Urban Runoff and Sewage
Runoff from land puts more oil into North American waters each year than tanker spills do. And aging U.S. sewer systems that combine stormwater and sewage release an estimated 850 billion gallons of untreated wastewater every year when heavy rain overwhelms them.
Sources: National Research Council, Oil in the Sea III (2003); U.S. EPA Report to Congress on Combined Sewer Overflows (2004)
From the Watershed to the Reef
01 The Watershed Highway: Creeks and rivers act like conveyor belts, carrying litter, microplastics and nutrient runoff downstream into the Bay and out to the coast.
02 Catch It Upstream: Pulling plastic off creek banks and riverfronts stops it before it breaks into microplastics that can’t be recovered.
03 Protect the Source: Real ocean conservation starts with protecting the waterways that feed it, from mountain streams to the open sea.