A Snowy Egret caught two Bay pipefish in quick succession along the shoreline next to the Hornet Soccer Field on Sunday, November 24. This sighting of the Snowy Egret catching a pipefish is evidence that eelgrass, a special status marine vegetation, is present in the harbor east of the ferry maintenance facility. Pipefish “do not wander far from the eelgrass bed where they were born,” according to Bay Nature magazine. Eelgrass is pipefish habitat, in part, because pipefish are able to avoid predators as their slender bodies blend in with the narrow blades of eelgrass.
Winter herring spawning also occurs in the vicinity, and eelgrass is prime vegetation on which herring eggs can attach.
Eelgrass is a flowering plant and needs sunlight to thrive, making the shallow waters between the Bay Trail and the harbor seal float ideal.
A foraging Great Blue Heron and a diving Western Grebe have also been spotted in this area holding a pipefish.
“Eelgrass is a highly productive species and is considered to be a ‘foundation’ or habitat forming species,” according the National Oceanic and Atmospheric Administration California Eelgrass Mitigation Policy. “Eelgrass contributes to ecosystem functions at multiple levels … and as sediment stabilizer and nutrient cycling facilitator. Eelgrass provides important foraging areas and shelter to young fish and invertebrates, food for migratory waterfowl and sea turtles, and spawning surfaces for invertebrates and fish such as the Pacific herring. […] In addition, eelgrass has the capacity to sequester carbon in the underlying sediments and may help offset carbon emissions,” states the eelgrass policy.
Shallow waters that support eelgrass are also considered special aquatic sites under the federal Clean Water Act.
Bay pipefish can be viewed in an aquarium display at the Crab Cove Visitor Center on McKay Avenue in Alameda.
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