June Riverkeeper Report

Arundel Rivers staff harvest underwater grasses on the Eastern Shore.

Out of the office and on the river! We are officially in full field season for the Riverkeeper Department. We are out monitoring our 35 tidal sites on the rivers every Wednesday, we collect bacteria samples from 30 sites by land every Thursday, and we are harvesting and processing underwater grass seeds the remainder of the week. Our response to emails and calls may be slower over the next 3 months, but rest assured it is because we are working hard to heal our local waterways. Here's a deeper look at these three programs this past month: 

Tidal Monitoring: Thank you to the over 130 people who attended our State of the Rivers Report Card Presentation at Homestead Gardens last month! We released our 2024 Report Card, which featured the results of 3 new types of data collected on our rivers: nitrogen, phosphorus, and algae. All three rivers received a grade of C this year. Looking at 2025 so far, June is where we start to see our bottom oxygen levels dip to unhealthy levels. We have started recording extremely low oxygen at multiple tributaries on the South River this month, including: Crab Creek, Route 2 Bridge, Riva Bridge, Upper River, and Glebe Creek. We saw similar patterns compared to this time last year. What is different than last year however is the salinity, which is higher this year than compared to last year. While harvesting grasses on the Eastern Shore this month, we began to encounter jellies- they're coming! 

Bacteria monitoring: We are about 5 weeks into our weekly bacteria monitoring program, where we test for harmful bacteria at popular community swimming locations. We have had a lot of rain recently, especially on Wednesdays or Thursday mornings, just before we collect the samples. This type of bacteria tends to increase after rain events, so we have seen a large number of failures with high bacteria counts so far this season. This is a good reminder to not swim after a rain event of 1/2 inch of rain or more. Our bacteria results are posted every Friday on our social media pages and swimguide.org. 

Underwater grasses: Have you seen the floating grasses on the rivers lately? It is likely horned pondweed! This is a native underwater grass that naturally breaks off and floats around this time of summer to spread its seed. The Riverkeeper Department staff joined MD Department of Natural Resources and ShoreRivers on the Eastern Shore earlier this month to harvest from a large bed of horned pondweed. The grasses will be taken to our turbulator at South River Farm Park to be processed and refined. The cleaned seed will be replanted in the South, West, and Rhode Rivers in an effort to restore grass beds. Remember we are trying to map where these grasses are growing, so let us know if you see a bed of grass while you're out on the river!