Black Bears

Project of the Hudson River Estuary Program

Compiled and edited by Tom Lake, Consulting Naturalist

The 2024 glass eel sampling and research season in the estuary concluded this week as numbers dwindled to just a few. It began to feel a little like summer with rising water temperatures and increased salinity. Species diversity (variety) and species richness (numbers of each) increased dramatically with education and monitoring efforts (seines, pots, and traps). We also chanced to take a look at adjacent waters feeding the estuary.  

Highlight of the Week

5/22 – Esopus Meadows, HRM 87: Third-graders from Woodstock Elementary joined us for a program today. We made eight hauls of our seine, and the catch was impressive. Fish included white perch, banded killifish, golden shiners, an adult gizzard shad that measured 270 millimeters (mm), and many young-of-year bay anchovies.

However, the star of the show was a 400 mm (almost 16-inches) Atlantic needlefish. We had caught smaller needlefish here before, possibly young-of-year, most about 70 mm.
– Eli Schloss

[Atlantic needlefish is one of two members of Belonidae (Needlefishes) in the estuary, the other being the houndfish (Tylosurus crocodilus). The associated Latin and common names, “needle” and “crocodile” are both suggestive and descriptive. Atlantic needlefish are found in coastal and inshore waters from New England to South America and were formerly designated as a temperate to tropical marine species in the Hudson River.

Natural selection designed the unmistakable Atlantic needlefish to be the consummate predator. They are primarily sight-feeders with more than 20% of their adult length taken up by slender tooth-studded jaws A ventrally-adjusted lateral-line allows needlefish to drift on the surface, hunt for prey, and still maintain an air-water interface. They can reach nearly two-feet in length and will frequently leap out of the water and swap ends in pursuit of prey.

J.R. Greeley, in his A Biological Survey of the Lower Hudson Watershed (1937), considered needlefish to be rare. He noted that they spawn in salt water even though his survey found immature needlefish as far upriver as Ulster Park (river mile 87). In 1984, Steve Stanne and John Mylod caught a young-of-year Atlantic Needlefish (50 mm) in a seine at Kingston Beach, and juvenile needlefish are occasionally seined up at Norrie Point in Staatsburg.

These catches strongly suggested that Atlantic needlefish, heretofore assumed in the literature to be marine or brackish-water spawners, may have adapted to freshwater. Estuaries, with all their dynamism and vagaries, have proven to be laboratories for aquatic resiliency. Today they are designated as a seasonally resident marine species. Tom Lake]

Atlantic needlefish

Atlantic needlefish – courtesy of Tom Lake

Natural History Entries

5/18 – Essex County, HRM 284: Last week we reported Mike Corey identifying a Lincoln’s sparrow in Minerva. While Mike’s sighting was genuine, we erred in including a photo of a song sparrow. To repair that mistake we have attached a Lincoln’s sparrow with this entry. 
– Tom Lake

Lincoln's sparrow

Lincoln’s sparrow – courtesy of Simon Kiacz

5/18 – Albany County, HRM 143: Two days ago, on our weekly May Thursday morning bird walk at the DEC’s Five Rivers Environmental Education Center in Delmar, Doug Steele found a Lawrence’s warbler, a rare hybrid between a blue-winged warbler and a golden-winged warbler. This bird was seen and photographed by many birders across the next several days.
– Scott Stoner, Hudson-Mohawk Bird Club

Lawrence's warbler

Lawrence’s warbler – courtesy of Scott Stoner

Fish of the Week

5/18 – Hudson River Watershed: Fish-of-the-Week for Week 270 is the Atlantic thread herring (Opisthonema oglinum), number 32 (of 237) on our Hudson River Watershed List of Fishes. If you would like a copy of our list, e-mail:

Atlantic thread herring (Opisthonema oglinum) is a marine fish and one of nine members of its family, the herrings (Clupeidae), documented for the watershed, five of which belong to the sub-Family Alosine: Atlantic menhaden, alewife, hickory shad, American shad, and blueback herring.

Atlantic thread herring are native to subtropical and temperate shallow coastal waters of the western Atlantic from the Cape Cod to the Gulf of Mexico and south to Brazil. They are a thin fish—blue dorsally, silver ventrally. In the field, they can be identified by the long last ray of their dorsal fin—as great as their body depth. They feed by filtering plankton (mainly copepods) but also take small fish and crustaceans and can get to be 380 mm in length.

Opisthonema oglinum was added to our Hudson River Watershed List of Fishes in September 2019; it had been a drought summer, and the Tappan Zee was warm and salty (8.4 parts-per-thousand). A crew from the DEC Region 3 Fisheries Unit (Robert Adams Russ Berdan, Emilie Hickox, Justin Herne, Colleen Parker) deployed their 200 x 10-foot seine at Philipse Manor (river mile 28) and caught a myriad of interesting and rather exotic fishes. Among them were five Spanish mackerel, a lookdown (jack family), and an inshore lizardfish. But the prize was 779 young-of-year Atlantic thread herring (60-97 mm), a new species for the watershed.

Prior to 2019, local records were very sparse. Briggs and Waldman (Marine Fishes of the New York Bight, 2002), call Atlantic thread herring rare. Bigelow & Schroeder (Fishes of the Gulf of Maine, 1953) note they are occasionally found as far up the coast as Cape Cod. Ichthyologist T.H. Bean recounts in 1903 of “a great run in Gravesend Bay [Brooklyn] that lasted two weeks.” Bob Schmidt found two Atlantic thread herring from Long Island Sound (1938), in the Collection of Fishes at the New York State Museum. None were reported in the last 3-4 decades, until now.
– Tom Lake

[Note: One-inch equals 25.4 millimeters (mm). Tom Lake]

Atlantic thread herring

Atlantic thread herring – courtesy of Tom Lake

5/19 – Hudson River Watershed: With legs spread as far apart as avianly possible to clasp nearby bulrushes and cattails, marsh wrens are heard far more often than seen. Their distinctive reedy, gurgling song is like no other. John J. Audubon compares its “song, if song I may call it… [to]… the grating of a rusty hinge.”  While admittedly it’s not the most musical song, it is varied (males learn 50-200 song types) and is sung with gusto continuously throughout the day and sometimes night to stake out territory and to attract a mate.

Equally impressive as the number and constancy of their songs is the number of nests male marsh wrens build—at least a half dozen dummy nests for every breeding nest used by a female.  Why expend this kind of energy? Several theories exist: the dummy nests serve as shelter for newly fledged young, as replacement nests if breeding nest is destroyed, as a decoy for predators, and possibly the number of nests may serve as an indicator of the male’s vigor or quality of his territory, or both.
– Mary Holland

Marsh wren

Marsh wren – courtesy of Mary Holland

5/20 – Yonkers, HRM 18: Our research and education team at the Sarah Lawrence Center for the Urban River at Beczak took our seine to the beach at low tide this morning for six hauls. It was a day for invertebrates with young-of-season blue crabs (40), all less than 40 mm, as high count. Others included grass shrimp (16), comb jellies, and two live eastern oysters (Crassostrea virginica), the native oyster to eastern North America.

The highlight among the fishes was an uncommon seaboard goby (Gobiosoma ginsburgi), as well as a winter flounder. Young-of-year bay anchovy was high count with 13 (70-80 mm), and white perch (75-130 mm) completed the catch. The river was 65 degrees Fahrenheit (F), salinity was 5.6 parts-per-thousand (ppt), and the dissolved oxygen (DO) was 8.3 parts-per-million (ppm).
– Jason Muller, Olivia Love, Aika Lankard, Amber Stumer, Katie Lamboy

[Crab measurements (size) are calculated in millimeters (mm) point-to-point across their carapace. Tom Lake]

Seabord goby

Seabord goby – courtesy of Barnegat Bay Association

5/20 – Manhattan, HRM 1-2: Our River Project Staff went to check our research gear (pots and traps) that we deploy from Piers 40 and Pier 26 in Hudson River Park as part of our ongoing fish ecology survey. We found a good catch that included an American eel (350 mm), three tautog (145-180 mm), an oyster toadfish (235 mm), and one winter flounder (150 mm).

We also had a catch that we had not seen in our area for more than a decade: an introduced, and certainly invasive, Chinese mitten crab (Eriocheir sinensis). This was only our second catch; the last one occurred more than a decade ago. The crab was large (50 mm) but clawless, likely due to sharing a trap with the previously mentioned, notorious crab-predator, oyster toadfish.

Lacking their distinctive claws, the mitten crab identification was confirmed by the 4-4-4 pattern of marginal spines on the crab’s carapace (4 on the left, 4 between the eyes, 4 on the right). The collected crab was placed in ethanol to be used as an educational specimen in the River Project Wetlab. We hope this remains a rarely encountered species, but we will continue to be on the lookout.
– Toland Kister, Sierra Drury

[The invasive Chinese mitten crab (Eriocheir sinensis) is native to the estuaries of China where it is highly regarded in the market. It is believed they were introduced to the U.S. in the 1980s in San Francisco Bay.

Mitten crabs are catadromous, meaning that they spend much of their life in freshwater, then return to higher salinities to reproduce. The salinity gradients of east coast estuarine systems like the Chesapeake Bay, Delaware Bay, and the Hudson River are nearly ideal for them. Adult mitten crabs have a carapace width of about three-inches, but six of its eight legs are almost twice as long, giving them an almost “spider crab” look. Unlike the native blue crab, a swimming crab, mitten crabs are “burrowing crabs,” much like our mud crabs only many times larger. They have a generalist diet, varied in prey, and their potential ecological impact on east coast estuaries is still unknown. Tom Lake]

[Our most recent mitten crab record for the estuary occurred on February 19, 2023, when Chris Bowser and John Mylod collected a small (6.0 mm carapace width) mitten crab in a fyke net they had set for glass eels. There are not many, but they are still around in small numbers. Bob Schmidt]

Chinese mitten crab

Chinese mitten crab – courtesy of Peter Park

5/20 – Governors Island, Manhattan: Our Billion Oyster Project staff and interns checked the eleven minnow pots we deploy off Pier 101 in the Upper Bay of New York Harbor. Today our traps held a black sea bass (60 mm) and a cunner, also known colloquially as a bergall or chogie (98 mm). 
– Natalie Kim, Madison O’Brien, Omisha Hossain

5/21 – Albany County, HRM 143: The DEC’s Five Rivers Environmental Education Center at Delmar never seems to fail in providing amazing wildlife from songbirds to waterfowl to today’s entry, a bobcat (Lynx rufus). This was not the bobcat’s first appearance at the Five Rivers EEC, we had seen it several times recently. 
 – Denise Hackert-Stoner, Hudson-Mohawk Bird Club


Bobcat – courtesy of Scott Stoner

5/21 – Yonkers, HRM 18: Our research and education team at the Sarah Lawrence Center for the Urban River at Beczak made a day of it on the river with three programs, two with our seine and one with the fyke net we had set in the Beczak tidemarsh.

We began this morning with nine hauls at high tide (not the best tide), with invaluable assistance from a class of pre-schoolers from Eliza Corwin Frost School in Bronxville. One of our standard fishes, mummichog, a killifish, 60-116 mm, was high count (9). Tiny blue crabs (8), not much more than a month from hatching, none larger than 30 mm, were next. Other fishes included bay anchovy and white perch. The river was 64 degrees F, salinity was 5.7 ppt, and the dissolved oxygen (DO) was 8.5 ppm.
– Emily Orr, Christina Edsall, Olivia Love, Aika Lankard

In midday, our research and education team visited the Beczak tidemarsh at low tide to check our fyke net. Two glass eels (and one elver, class of 2023) told us the season was still limping along. Invertebrates included a blue crab, two grass shrimp, and five mud crabs. The river had warmed to 66 degrees F, salinity was 5.4 ppt, and the dissolved oxygen (DO) was 8.6 ppm.
– Jason Muller, Mireia Rosenblum-Martin, Zoe Wolf, Amber Strumer

Our research and education team concluded our day on the river by seining six hauls at low tide (much better tide). Grass shrimp (22) was high count followed by blue crab (10-65 mm). However, the fishes really showed up led by bay anchovy, white perch, mummichog, and a young-of-year summer flounder (30 m). Still, the biggest surprise was four Atlantic tomcod (55-65 mm).

The river was still 65 degrees F, salinity was 5.4 ppt, and the dissolved oxygen (DO) was 8.6 ppm. 
– Jason Muller, Mireia Rosenblum-Martin, Amber Strumer, Zoe Wolf

[Bigelow and Schroder’s Fishes of the Gulf of Maine (1953) cite the general range of Tomcod (Microgadus tomcod) as “… northern Newfoundland to Virginia.” They are one of eight members of the cod family (Gadidae) found in the Hudson River estuary. Tomcod spawn in late fall through late winter in the cold water, often under the ice in the Hudson River, thus earning them the nickname “frost fish,” a Dutch Colonial colloquialism. Tomcod numbers in the river have been declining over the last few decades and being a boreal species, Global Warming has been suggested as a possible cause. Tom Lake]

Atlantic tomcod

Atlantic tomcod – courtesy of Andrew Martinez

5/21 – Staten Island, New York City. We have come to the end of another glass eel sampling season. I want to commend everyone’s interest and intrepid spirit, especially early in the season when the water was very cold. Together, we collected, counted, and moved 13,071 migrating glass eels, in 54 sampling days, upstream above the Mill Pond Dam, our best count ever.

The transported immature American eels will remain in Richmond Creek for more than ten years, after which most of our middle-school aged volunteers will have finished high school and even college. Sometime later, the eels will leave for the Sargasso Sea, a place where they hatched from eggs and left as Leptocephali larvae many years ago.

Among the highlights of our season include the earliest arrival date since we began in 2012, as well as the largest seasonal count of glass eels to date. Our biggest daily catches seemed to coincide with the new moon.
–  Bob Bauman

Glass eels

Glass eels – courtesy of Chris Bowser

5/22 – Yonkers, HRM 18: Our research and education team at the Sarah Lawrence Center for the Urban River at Beczak, accompanied by second-grade class from Hostos School in Yonkers, carried our seine to the beach for nine hauls of our net.

Not surpassingly, blue crab (14) was high count, all small, young of the season, less than 30 mm carapace width. Every other element of our catch came in as one each: white perch, yearling striped bass, grass shrimp, mud crab, and one small unidentified herring. The river was 65 degrees F, salinity was 4.3 ppt, and the dissolved oxygen (DO) was 8.7 ppm.
– Jason Muller, Emily Orr, Olivia Love, Aika Lankard

5/22 – Manhattan, HRM 1-2: Our River Project Staff went to check our research gear (pots and traps) that we deploy from Pier 40 and Pier 26 in Hudson River Park as part of our ongoing fish ecology survey. We had a similar catch two days ago, an American eel (350 mm) and one oyster toadfish (80 mm). The new fish for today was a lined seahorse (65 mm). 
– Toland Kister, Maggie Zhen, Laila Ortiz

Oyster toadfish

Oyser toadfish – courtesy of Chris Bowser

5/22 – Nassau County: My daughter and I went fishing off a pier in Long Island Sound today at Glen Cove. We came across a substantial school of Atlantic Mackerel (up to 15-inches) feeding on small sand eels (American sand lance, Ammodytes americanus). We caught a bunch, kept a few, and released so many more. The day was made more special because it was during a daddy-daughter fishing trip! 
– Peter Park, Elliana Park

[Atlantic mackerel (Scomber scombrus) is a gorgeous, rather fusiform fish. They winter off the Carolinas and then migrate north in spring to summer in New England waters north of Cape Cod. Their wavy-lined color pattern likely provides some adaptive defense against predators such as bluefish and striped bass, as it mimics the natural light-bending aspect of water in motion masquerading their presence. For years, Atlantic mackerel has been a model for many types of artificial fishing lures (green-black and silver mottled mackerel finish). Tom Lake]

[Long Island Sound is an entry and exit pathway for migrating Hudson River fishes, a tributary of sorts. While not ordinarily thought of as part of the Hudson River watershed, like Raritan Bay, Long Island Sound, via the East River, is major ecological contributor. Tom Lake]

Atlantic mackerel

Atlantic mackerel – courtesy of Peter Park

5/23 – Hudson River Watershed: Among indigenous peoples, full moons have long been labeled with fanciful names that are rooted in oral traditions, indigenous memories, and ethnographic accounts. Among Mohican people, whose ancestral homeland lies wholly within the Hudson River watershed, the May full moon is known as the Planting Moon, Aʔkeʔaat Neepãʔuk, in the Mohican dialect.

Tribal translations of full moons pre-date colonization and generally reflect the seasonality of the lunar phase. Moon phases, in fact, were used by indigenous people as measurements of time.
– Larry Madden, Stockbridge-Munsee Band of Mohican Indians

5/23 – Norrie Point, HRM 85: With this morning’s low tide the water was just barely stippled with water chestnut (Trapa natans) seedlings reaching up to the surface. The stippling will soon become a green haze, and within a month the surface of the shallow cove will be covered with large leafy rosettes. In the meantime, a trio of ospreys put on a fishing clinic. “Strike one!” as a fish hawk plunged feet first with nothing to show, followed by “Strike two!” a minute later. But the third dive was a home run, and an osprey emerged from the river with a yellow perch secured in its talons. 
– Chris Bowser

5/23 – Yonkers, HRM 18: Our research and education team at the Sarah Lawrence Center for the Urban River at Beczak visited our tidemarsh this morning at mid-tide to check our fyke net that we had set overnight. It felt rewarding to find two glass eels in the net along with grass shrimp and mud crabs. This was to be our final check of the season. At the end of the day, we removed the fyke net. The river was 66 degrees F, salinity was 7.5 ppt, and the dissolved oxygen (DO) was 7.6 ppm. 
–  Jason Muller, Zoe Wolf, Olivia Love, Aika Lankard

5/24 – Manhattan, HRM 1-2:  Our River Project Staff went to check our research gear (pots and traps) that we deploy from Piers 40 and Pier 26 in Hudson River Park as part of our ongoing fish ecology survey. The river was a bit inundated with debris after yesterday’s rain coupled with moon tides and currents. For the third day this week, our catch was dominated by oyster toadfish (180 mm) and tautog (“blackfish”), one of which was an adult at 380 mm. 
– Toland Kister, Sierra Drury

5/24 – Yonkers, HRM 18: Our research and education team at the Sarah Lawrence Center for the Urban River at Beczak compiled our data for our late-winter and spring 2024 glass eel season.

  • We collected 5,777 glass eels across 83 days which topped our previous record of 3,571 in 2022 (our seasonal average is 2,000 glass eels over eleven seasons).
  • Over 18 weeks (our longest season) we had 18 days with at least 100 eels caught. Our seasonal average is around six.
  • We caught our first glass eel on January 31, our earliest catch ever.
  • During our first seasons of sampling (2014 – 2018) we averaged 763 glass eels per season. Since then, our average has been 3,237 per season.

– Jason Muller

[The NYSDEC sincerely thanks Jason and all of our community science volunteers that helped out with the Eel Project this spring. Your work contributes very important data to coast-wide studies…and eels are just plain fascinating! -Chris Bowser]

Glass eels

Glass eels – courtesy of Tom McDowell

Atlantic mackerel

Atlantic mackerel – courtesy of Peter Park

Spring 2024 Natural History Programs and Events

Saturday, June 1: World Fish Migration Lower Hudson and Harbor Fish Count

World Fish Migration Day (WFMD) is a global celebration to create awareness about the importance of migratory fish and free-flowing rivers. On World Fish Migration Day, organizations from around the world coordinate their own event around the common theme of: Connecting Fish, Rivers, and People. Environmental organizations of the Lower Hudson and Harbor have come together to put on our own family-friendly, free fishing events for the public to engage in the wonders of the Hudson River!

Event times vary by site (Piermont to Staten Island), so please check the details.

Science Saturdays at Norrie Point Environmental Education Center

Norrie Point Environmental Education Center will be hosting “Science Saturdays”. Events are free and open to the public. Learn more about Science Saturday events.

Upcoming events:

  • June 8, 11 a.m.-1 p.m.: Get Outdoors Day
  • July 13, 10 a.m.-12 p.m.: Animal Saturday

Hudson River Lesson Plans

Explore our collection of Hudson River lesson plans, videos and online activities to support hand on investigations of the Hudson River in your classroom.

Volunteer for the Hudson River Striped Bass Cooperative Angler Program

Do you fish for striped bass in the Hudson River? Whether you catch-and-release or take home a keeper, you can be part of the Cooperative Angler Program. Share your fishing trip information and help biologists understand and manage our striped bass fishery.

Here’s how it works:

  • Fill out a logbook we provide or record your trips on your smartphone using DEC’s Hudson River online logbook (PDF) whenever you fish on the tidal Hudson River (by boat or on the shore);
  • Record general location, time, gear used, what you caught (or if you didn’t catch anything); and
  • Return the logbook when you are done fishing.

Join today! For more information on the angler program and instructions on installing the Survey123 App to access the online logbook, visit Hudson River Cooperative Angler webpage or email

Note: If you primarily fish for striped bass in New York waters south of the George Washington Bridge, the DEC has a separate Striped Bass Cooperative Anglers Program.

Volunteer for the Hudson River Eel Project

We are seeking volunteers to help study eels in streams of the Hudson River estuary! Volunteers check specialized nets for young transparent “glass eels” as they enter freshwater from their spawning grounds over 1,000 miles away in the Atlantic Ocean. Eels are counted, weighed, and released upstream, and environmental conditions are recorded. Sample sites include streams from NYC to near Albany, and all gear is provided.

If you’re interested in participating, email and include where you live and a little bit about yourself, so we can match you with the best nearby site. For more information, visit the Hudson River Eel Project webpage.

Hudson River Miles

The Hudson is measured north from Hudson River Mile 0 at the Battery at the southern tip of Manhattan. The George Washington Bridge is at HRM 12, the Tappan Zee 28, Bear Mountain 47, Beacon-Newburgh 62, Mid-Hudson 75, Kingston-Rhinecliff 95, Rip Van Winkle 114, and the Federal Dam at Troy, the head of tidewater, at 153. The tidal section of the Hudson constitutes a bit less than half the total distance—315 miles—from Lake Tear of the Clouds to the Battery. Entries from points east and west in the watershed reference the corresponding river mile on the mainstem.

To Contribute Your Observations

The Hudson River Almanac is compiled and edited by Tom Lake and emailed weekly by DEC’s Hudson River Estuary Program. Share your observations by e-mailing them to

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Helpful Resources

National Oceanic and Atmospheric Administration online tide and tidal current predictions are invaluable when planning Hudson River field trips. For real-time information on Hudson River tides, weather, and water conditions from sixteen monitoring stations, visit the Hudson River Environmental Conditions Observing System website.

DEC’s Smartphone app for iPhone and Android is now available at New York Fishing, Hunting, and Wildlife App.