Hudson River Almanac July 21 - July 28, 2009
It was a week of mitten crabs and snakeheads, unfortunate and sobering reminders of the threats of alien species to twenty-first century Hudson Valley ecosystems. Fortunately, Dave Nelson reminds us that we still have wild places in which to escape, if only for a short while.
HIGHLIGHT OF THE WEEK
7/18 - Town of Jewett, Greene County, HRM 113: While hiking the Black Dome Range of the Catskills, I was struck by a number of things: how beautiful a hermit thrush sounds at close range; an American toad at the very peak of Thomas Cole Mountain; the number of garter snakes I saw sunning themselves on rocks along the path on a rare sunny, warm day; and perhaps most significantly, the number of hikers I did not see on the same. In more than nine miles of trail, I ran into only three small groups of hikers. While I thoroughly enjoyed the peace, quiet, solitude, and views, part of me worried that the lack of hikers might be symptomatic of the much-touted nature-deficit disorder.
- Dave Nelson
NATURAL HISTORY NOTES
7/21 - Newcomb, HRM 302: I stop checking our bluebird boxes once the chicks are a couple of weeks old because they could be startled and jump out, fledging early. This would decrease their chances of survival since they are not really ready to fly. But the nest boxes are empty, so I presumed that they have all left home and were now out and about with the parents learning how to be bluebirds. I saw two monarchs this morning. It has been a pretty barren butterfly summer since the tiger swallowtails disappeared.
- Ellen Rathbone
7/21 - Brooklyn, New York City: St. John's and Red Hook Recreation Centers (both of Brooklyn) participated in seining programs at the cove in Brooklyn Bridge Park offered through a partnership with Brooklyn Bridge Park Conservancy and The Coastal Marine Resource Center. Our catch included sand shrimp (Crangon septemspinosa) and shore shrimp (Palaemonetes spp. including specimens of two species that were gravid), winter flounder, Atlantic silverside, northern pipefish, comb jellies and snails. In one haul we caught four different species of crab: lady, blue, green, and hermit. We also had a great haul for an algae lesson. The children became experts classifying sea lettuce, rockweed and Grinnell's pink leaf into their respective green, brown, and red algae groups.
- Cynthia Fowx
7/22 - Slate Hill, Orange County, HRM 58: Last summer, an aggressive, invasive fish species called the northern snakehead was found in Ridgebury Lake and surrounding ponds. The NYS DEC treated the lake with a chemical called rotenone, killing off the fish as it was the only practical way to stop the invasive threat. However, a few weeks ago, two adult snakeheads were found in a swampy, weedy area below nearby Valentine Pond. That area may be treated again, in a limited manner.
- Heather Yakin
[While the northern snakehead is not a threat to human health or safety, it is an aggressive predator that has the potential to prey on and compete with native fishes. Left unchecked, this predatory invasive is likely to rapidly expand its population and territory with real and negative economic impacts to the Hudson River watershed fisheries while causing potentially irreversible harm to rare and endangered species and natural communities. NYSDEC Region 3 Fisheries.]
7/22 - Queens, New York City: One of my Queens College graduate students recently electro-shocked an eleven pound snakehead from Flushing Meadow Lake.
- John Waldman
[The northern snakehead is a predatory fish native to China, northern Korea, and Japan. It is a desirable food fish in its native range. Snakeheads have been found in several areas of the United States and there is a recent paper describing its spread in the Potomac River. There are legitimate concerns about the effect that this large predator can have on the environment. They are capable of reproducing in New York waters. These are very tough fish that can live in poor water quality. They have an accessory breathing apparatus and can survive out of water for several days at moderate temperatures. Bob Schmidt.]
7/22 - Manhattan, HRM 9: We caught an unusual, for us, fish in a blue crab pot set twenty feet deep in the Harlem River at 150th street. The fish was released.
- Mauricio Gonzalez
[Mauricio sent a digital photo. Marcha Johnson (NYC Parks), Bob Schmidt, and John Waldman helped us make a pretty definitive identification that this was a native oyster toadfish (Opsanus tau). These are a handsome fish with strong sharp teeth that they use to crush shellfish and are quite common in the salty and brackish waters of the lower estuary and New York Harbor. Tom Lake]
7/23 - Manhattan, HRM 5.5: With our trawl net down for only for 3 minutes, the Clearwater made a remarkable catch of at least 25 hogchokers, 4 spotted hake, 2 more blue crab, and a 10-inch summer flounder.
- Captain Samantha Heyman
[Last week Clearwater captain Samantha Heyman recounted her crew's struggle to measure an American eel. Here are two suggestions for measuring eels from Almanac reader Paul A. Moccio: He suggests putting the eel in a bucket with a modest amount of ice, being careful not to shock the fish. Add small amounts of ice until the eel gets lethargic, its metabolism slowed enough so that you can get an accurate measurement. If handled with care, eels are easily resilient enough to recover soon after being removed from the icy water. For eels that exceed the length of your measuring stick, use a length of twine. Tom Lake.]
7/23 - Staten Island, New York City: Last year I located the single dried stem of pinesap in a small park on Staten Island. Mentioning it casually to a friend at a local herbarium, he told me of its significance. Apparently the species hadn't been seen on the island in more than 70 years. So this year I went out with a mission, only to be disappointed when the plant was relocated and already past bloom. Not to be denied, I marched off to see if others were in the area. I had just about given up when, behind an old stump, a glint of bright apricot yellow brought me face to face with an additional five stems, in perfect shape, just emerging from the leaf litter.
- Dave Taft
[Pinesap is a saprophyte that contains no chlorophyll. Since it cannot obtain energy from sunlight to produce its own food, it acquires sustenance from organic matter in the soil. They are found on sandy, dry old woodland floors among the leaf litter and leaf mold. Tom Lake.]
7/24 - Poughkeepsie, HRM 75.5: I entered the Fall Kill looking for live mitten crabs so when I saw a crab sitting out in the flowing water, I was excited. It jetted away from me sideways but I saw enough to realize it was a blue crab (3 inch wide carapace). I was taking the water temperature at the start of tidewater when I noticed a carp (8-10 lb.) swimming into the stream. It saw me and fled. I found a newly excavated hole under a moveable rock and when I flipped it, there was a female mitten crab (42 mm) that tried to escape to no avail. Farther upstream I also found a shed mitten crab exoskeleton. It seems like all the neat animals in the Hudson River run away from me, except for the shed exoskeleton.
- Bob Schmidt
7/25 - Newcomb, HRM 302: I went for a walk this morning to see the flowers of late July. Among those I met were meadowsweet and spotted knapweed, which is considered an invasive. Most of our roadside plants are not native, and it is easy to see how they spread, thanks to all the traffic along our roadways. Then there was white sweet clover, one of my favorite roadside plants. There's just something appealing about the slender spires. Next was a yellow flower that I have always called evening primroses, but true evening primroses open in the evening. If you see an "evening primrose" open during the day, it is most likely a sundrop. Asters are notoriously difficult to key out. I did not have my field guide with me but the one I came upon was probably a cornel-leaved aster. Another of my roadside favorites is birdsfoot trefoil. When I was a kid, my favorite crayon was "lemon yellow," and this non-native flower is the embodiment of that color. Even on gray days its bright yellow sings out - sunshine incarnate. Finally there were smaller purple fringed orchids blooming in the roadside ditch. There are fewer of them than last year, but they seem more robust. It could be they are enjoying all the extra rain we've had this summer.
- Ellen Rathbone
7/25 - Town of Wappinger, HRM 67: After an absence of nearly six weeks, the hummingbirds were back at the feeders: a male, a female, and what appeared to be an immature.
- Tom Lake
7/26 - Crugers, HRM 39: We should have realized when the weather map showed a bright red area heading our way that we were in for something big. The day had been muggy and warm and at 7:00 PM things began to change. Thick dark clouds rolled in bringing with them torrential rains, thunder and lightning. Within minutes, what was once a grassy area next to our house had turned into a muddy lake. There was so much rain that it looked like a "waterfall from the sky." Finally the curtain of water slackened its pace and the sun reappeared. Several neighborhood ponds overflowed their banks and joined making it appear as one huge pond. We had not seen a storm affect our area this way since Hurricane Floyd.
- Dorothy Ferguson, Bob Ferguson
7/27 - Knox, Albany County, HRM 153: The season's first call of a katydid this evening reminded us that summer is here, even though the cool temperature of our pond shocks us when we swim.
- Dave Nelson
7/27 - Hathaway's Glen Brook, HRM 63: A thorough midday check of this small brook and low tide beach produced no live mitten crabs or sheds (exoskeletons).
- Tom Lake
[The beach at Hathaway's Glen is one of those special places, like Brigadoon, that appears only at certain times. For Brigadoon, it was one day every 100 years; for Hathaway's Glen, it's twice a day at low tide. At high tide it disappears as the river floods up to the railroad bed. Tom Lake.]
7/28 - Saugerties, HRM 102: An immature bald eagle with a blue leg band hung around the Saugerties Lighthouse today. (The blue leg band signifies that it is a New York State bred eagle.)
- Frank Murphy
7/28 - Hathaway's Glen Brook, HRM 63: This small Orange County brook spills down the fall line into a short run to the river. Even with higher moon tides, the reach of tide is only a few hundred feet in length. The river shallows just outside the brook were 79 degrees F. A hundred feet away, just inside the brook, in the shade of cottonwoods and box elders where the tidepools teemed with fish, the water temperature was eleven degrees cooler at 68 F.
We hauled our 80-foot seine and caught several dozen mixed killifish, both mummichogs and gorgeous banded killifish, some nearly five inches long. I'd argue that there is not a prettier fish in the river than a courting male banded killifish, with iridescent blue, lavender and silver highlights in their bands. Our favorite name for the male killifish is "blue-banded mudminnow," a colloquialism coined by riverman Everett Nack. Slightly fewer in number were young-of-the-year striped bass (40-55 mm) and several small blue crabs (15-20 mm carapace width).
After letting the river rest for ten minutes, I put on a mask and snorkel and found some small beds of curly pondweed and wild celery just offshore. It was there that I could appreciate the limited effectiveness of a seine. In a sweep of this area we had caught maybe two dozen fish. As I hovered just above the bottom, I could see clouds of killifish doing figure eights in and out of the small aquatic oases.
- Tom Lake, A. Danforth