Blog # 305 Where Does Orpheus Fish?

 2Winter walking on the gravel outwash, littoral zone off Salt Point, courtesy of Susan F. Ruoff. 

Every winter, Cayuga Lake’s water level is drawn down three feet to protect landowners’  investments and prevent flooding. This draw-down gives us an opportunity to walk on a part of the lake that is usually underwater—the nearshore littoral zone. Limnologists  divide the lake into life zones depending on how much sunlight each zone receives—the  littoral and limnetic zones receive the direct light while the lower profundal and benthic  zones receives little to no light. The amount of light in the different zones determines the  plants and animals that can live there.  

The littoral zone at Salt Point and Myers Park, as seen in the photos, doesn’t look like  much when exposed to the air, just a “lifeless” gravel bar. Once it is underwater, the  gravel bar comes to life with plants and animals overwintering in the mud and gravel. 

Right now, as spring advances, the lake is gradually being brought up to normal levels  and the littoral zone is slipping back out of sight. Once back under the waves, it  becomes a vital life zone of the lake. 

The realm of the fish and the Osprey. 

Vision is key to Ospreys locating fish and they do so most effectively in the well-lite  littoral and limnetic zones. Ospreys are always fighting buoyancy, the thing that  prevents them from diving deeper than three feet as they fish. Unlike the cormorant, 

The lake is divided into zones based on how much light they receive.

discussed in Blog # 303 Cayuga’s Snakebird, Osprey can only plunge underwater to a  depth of three feet due to their waterproofed feathers—and this is plunging 40 mph.  Osprey feathers naturally trap air in the microstructures of their feathers. These air  pockets are sealed by the waterproof uropygial oil layer applied to the feathers during  daily preening. 

In good weather, Osprey fish in two areas of Cayuga Lake: the near shore or littoral zone and the middle of the lake or limnetic zone. Because of its narrow and deep  topography, Cayuga Lake has ample littoral zones on the north and south ends, but few  shallow shelves on its sides by tributaries. One such place is the mouth of Salmon  Creek where Ophelia and Orpheus make their home on Salt Point.  

Flying over the limnetic zone, Orpheus picks up fish that are swimming near the water’s  surface. Many fish, large and small, swim in this plankton-rich zone; the smallest of fish  finding protection in the algae and drifting plankton. In the littoral zone, Orpheus can  often see the catfish and suckers on the bottom and target them. Perch and sunfish are  also plentiful in this shallow area as well as other hungry predators. In bad weather, it is  harder to see in the waves and many birds fish in the calmer tributaries entering the  lake. Orpheus uses Salmon Creek when visibility in the lake is low. 

Rich life in the littoral zone of the lake. 

The outwash from the Salmon Creek forms a gravel bar littoral zone at its mouth. This  area is rich in plants, giving off oxygen and producing the energy base for this aquatic  ecosystem. Energy-rich algae and macroinvertebrates provide food for countless  macroinvertebrates, such as crustaceans, insect nymphs, and crayfish. Tiny vertebrates 

such as tadpoles and larval fish also thrive here making it the perfect nursery for the  lake’s fish. 

Gravel bar formed by Salmon Creek. Salt Point (L) and Myers Park (R), courtesy of Susan F. Ruoff. Outwash littoral at Salmon Creek, Salt Point is in the center,  

Myers Park to the left , courtesy of Susan F. Ruoff.

This year we are doing to study the fish Orpheus brings to his family to eat based on  photographs, discarded bones, and the nest cam footage. The basic species in their  diet are known, but the specific amounts have yet to be catalogued. Hopefully, we will  be able to calculate the energetics and nutritional benefits of each fish but that involves  a great deal of guestimation of the fishes’ length and weight. The study will also give us  an idea of the distribution of the fish in the lake. 

Thanks to Sue Runoff for taking these images of Salmon Creek and Salt Point with her  drone, showing the extent of the exposed littoral zone in the winter. 

Eyes to the sky!  

Candace 

Candace E. Cornell  

Friends of Salt Point & 

Cayuga Osprey Network  

Lansing, NY  

cec222@gmail.com 

HELP PROTECT OSPREYS: 

• Keep a distance (100-300 feet) from active nests in the breeding season. If an  animal vocalizes when you are near, you are too close! BACK OFF IMMEDIATELY. • Carry binoculars to view wildlife from a distance. 

• Help keep local waters clean and healthy. Preserve and clean shorelines. • Recycle or dispose of used fishing line and other tangleable materials hazardous to  Ospreys and other aquatic animals. 

• Volunteer to monitor Osprey nests with the Cayuga Osprey Network. Write to:  cec222@gmail.com.  

EYES ON OSPREYS 

WATCH! 

Salt Point Osprey Nest Cam 2021 

READ! 

On Osprey Time—a blog on the Ospreys of Salt Point

VISIT! 

Cayuga Lake Osprey Trail

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