Raccoons’ Amazing Use of Water

 

Flora and Fauna Fridays

A weekly entry about the life of our estuary and watershed.

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by Erik Baard

HarborLAB volunteers (including a little one, Lily) recently spotted snow tracks at the GreenLaunch. Not our usual guard cat prints. The fingers weren’t webbed. At first we thought we might have fresh evidence of our resident muskrat. The tracks led up and down our growing native habitat slope from the water to the uplands, so that made sense. Ah, but there was no tail line. That leaves us with raccoon!

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Similar animal tracks. Credit: Lawrence Wade, The Old Naturalist

 

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Raccoon forepaw. Credit: Gaby Muler via Wikimedia Commons. 

The lack of webbing is very unusual for mammals in the order carnivora. What makes raccoon paws absolutely unique, however, is their sensitivity. More than 60% of the sensory perception areas of the raccoon’s cerebral cortex is given to touch. A raccoon’s dexterous fore paws are covered in tiny sensory spikes. The density raccoon pressure sensitive cells (called mechanoreceptor cells) is quintuple that of most mammals, matched only by primates like humans.

The primacy of their fore paws is reflected in the species’ names, including proto-Algonquin via Powhatan ahrah-koon-em (“one who scratches or rubs with its hands”) and part of the Latin one given by Carl Linnaeus (lotor or “washer”). The myth that raccoons wash their hands or food is rooted in amateur observations of their actual use of water: when submerged the sensory micro-bristles soften and become even more sensitive. A raccoon dips objects in water, fully submerging its paws, to even more acutely feel its surfaces. This video of a raccoon accidentally dissolving his treat of cotton candy is for only the most stone-hearted.

Even prolonged time in cold water doesn’t seem to diminish this sensitivity. Naturally this helps them to find small creatures, eggs, and some plants to eat in aquatic or muddy environments. Their fur is also well adapted to repel water.

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Once raccoons have learned of food sources, they won’t soon forget. In laboratory tests they remembered complex tasks for years afterward. Their ability to recall, problem solve, and think abstractly ranks them with Rhesus monkeys in evaluations of animal intelligence. So, say hello to our smart new neighbor! Maybe a furry new volunteer?

Naked Gobies in Newtown Creek

Flora and Fauna Fridays

A weekly entry about the life of our estuary and watershed.

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Naked Goby. (Smithsonian Environmental Research Center.)

 

by Erik Baard

Skinny dipping in the Newtown Creek Superfund Site might seem unwise, particularly in February, but it’s a way of life for naked gobies (Gobiosoma bosc). These very small, bottom-dwelling fish of the Eastern Seaboard and Gulf states are extremely common yet rare to see. That’s a shame because gobies — one of the most diverse families of fish, with over 2,000 species — have rich and fascinating lives packed into typically less than four inches and four years.

Ecologists for city, state, and federal agencies did encounter naked gobies in early studies to profile the life and pollutants of what became HarborLAB’s home waterway. They discovered an abundance of goby eggs at the mouth of the creek but not further in, indicating that spawning happened where cleaner East River waters swirled in with each tidal cycle. No surprise given that naked gobies and their eggs and spawn are often found in the fish-protecting screens covering intake tubes at the nearby Ravenswood Power Plant. Bear in mind, however, that this is opposite of the natural state of affairs. Fish normally lay eggs and spawn in sheltered areas outside the swift main channel of waterways. The East River is dredged, constricted by landfill, and edged with bulkheads that make for even faster currents. The slower-moving four-mile stretch of the Newtown Creek should by rights be the East River’s nursery.

As it is, only adult “gobies were prevalent in the mid-section of the Creek,” according to the Fish and Wildlife Service report linked above. Still, what a testament to this species’ hardiness, given that the creek bed (commonly described as being like “black mayonnaise”) is sedimented with toxins and stripped of naked gobies’ natural habitat of oyster beds and salt grass clusters. Females prefer to lay their amber-colored eggs into empty oyster shells. In the Newtown Creek, they make do with rock, crumbled concrete bulkheads, partly interred plastic trash, bottles, and other debris. In the winter, they bury themselves into that poisonous black mayonnaise.

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(South Florida Water Management District)

Naked gobies feed on worms and small crustaceans, which concentrate in their tissue the toxins of a century of oil spills, refinery and tannery effluents,  and illegal dumping.  Cloaked by the muck and the murk, these “naked” prey fish for better known species like striped bass, eels, and bluefish are still taking no chances. The species is scaleless and camouflaged in green and brown blotches. Their eyes are close together, atop the head. At a glance they look like lizards. The young are translucent.

Naked goby pelvic fins have evolved to fuse into suction cups, a neat trick for anchoring themselves. Scientists have noted that gobies can remember how to navigate complicated obstacle courses for at least 40 days, and judge and remember spatial relationships, useful for hopping from tidal pool to tidal pool. Some cousin species of goby have also evolved complex behaviors and symbiotic relationships. For example, one species climbs waterfalls that to human scale is the equivalent of climbing Mt. Everest three times over — check out this video! Others groom the parasites off larger fish. Another enjoys an “Odd Couple” relationship with a large burrowing shrimp. The fish and crustacean cohabitate and deposit eggs in the same burrow. They touch each other (with tail and antennae respectively) constantly to know if the other is agitated or retreating, relying on each other’s complementary senses. And we are still discovering new species of goby!

 

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Naked Gobi range. 

Sweet Sweep of the Creek!

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HarborLAB’s Newtown Creek Sweep, part of the Riverkeeper Sweep event at sites from NYC to Albany.

HarborLAB volunteers, environmental science students from CUNY LaGuardia Community College, and a mix of visitors from other schools and walks of life had a fantastic time tending to the Newtown Creek on Saturday! Our work was part of the annual Riverkeeper Sweep of Hudson River and estuary sites from New York City to Albany. Our Newtown Creek home base is a waterway so blighted with pollution that it qualifies for the US Environmental Protection Agency’s Superfund cleanup program.

HarborLAB’s Newtown Creek Sweep had two basic components, cleaning and gardening. We offered a variety of activities so that people of all ages and abilities could participate. More than 30 people helped over the course of the day. We were especially grateful to have educators among us to add learning to the labor. Holly Porter-Morgan, Diana Szatkowski, Harald Parzer, and Thomas Dieter brought knowledge and encouragement to our students and volunteers.

The core of the program was removing plastics from our shoreline and the creek itself. Volunteers wend their way through broken bulkheads and boat lines to pick trash from the shores while our canoes went out in two waves to scoop up litter, mostly plastic bottles and bags. These smaller items filled seven large trash bags. Larger hauls included a lawn mower, two chairs, a 55-gallon steel drum, a bird feeder, and antiquated electronic sound systems.

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We’re under no delusion that our cleanups will remove the tonnage necessary for an ecosystem rebound, but the exercise educates people about the severity of the plastics problem. So what works if picking up plastics is a measure that’s too little, too late? Recycling is also an inadequate solution by itself because it requires a great amount of energy (often from carbon-releasing fossil sources) and sustained administrative focus. With petroleum and other commodity prices low, private carters in New York City are recycling even less material than usual despite New York City’s public commitment to eliminating waste. While a reduction in unthinking, rampant consumerism is laudable, instilling new virtues across the culture will be a slow process. Real penalties and enforcement for littering will help a bit, but not enough. That leaves voters and activists to demand a reduction in wasteful packaging at the design and production stage. We must also push to eliminate combined sewer overflows, which gulch marine debris as well as pathogens and other pollutants.

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Gardening was also a big part of the day, and is a huge part of HarborLAB’s work. Volunteers — especially a group from New Hyde Park High School — made thousands of native pokeweed seed balls that we’ll distribute as we land at rest stops on our harbor journeys across to stabilize shorelines, buffer storm surges and waves, feed birds, and sustain pollinators. Those up for heavier lifting helped restore our shoreline by layering cocoa husks from MAST Brothers Chocolate with burlap sacks, kitchen scraps, and soil in a system called “lasagna composting.” This fresh soil covers a broken brick substrate that mimics the glacially transported rocks of our region. The resulting slop will be planted with staghorn sumac, pokeweed, goldenrod, milkweed, and other indigenous species, and footed by smooth cordgrass and shellfish. Some of these species are already making headway. We were delighted to see that our dozens of shadbush saplings were fruiting copiously and our hackberry and American persimmon are also thriving. Our raised bed and container-grown dessert cultivars are doing great too, including apricots, apples, pears, and figs.

We’re tremendously grateful to all who came and helped, and to Riverkeeper for creating this unifying event and helping direct volunteers to sites.

 

 

 

Spartina, Sumac, and Kid Power!

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HarborLAB partnered with Citizens Committee for New York City and Neuberger Berman for a company day of “Celebration and Service” at the Hunters Point Community Middle School. Volunteers partnered with science teacher Mary Mathai for hands-on education about shoreline habitat restoration. HarborLAB has a longstanding relationship with the school, conducting seed gathering field trips, providing lectures about water quality, and other services. Special thanks to HarborLAB volunteer Diana Szatkowski for making this newest activity a success!

Our first focus was Spartina alterniflora, or smooth cordgrass. HarborLAB Executive Director Erik Baard gave a brief presentation on this saltwater marsh species, which is a bedrock of our coastal ecosystem. We discussed how landfill, runoff pollution, invasive species introduced humans, and other modern impacts have reduced acreage in New York City to less than 10% of historic coverage. Invertebrates shelter within the grass, feeding herons and other shore birds. The complex root systems of spartina marshes anchor sand and mud, stabilizing shorelines. Dense foliage reduces wave and wakes, protecting property and lives. This nearly eliminated grass uniquely sustains a butterfly species, the Saffron skipper.

To restore spartina to HarborLAB’s shore on the Newtown Creek, we’re creating pods made from burlap bags supplied by MAST Brothers Chocolate. Students learned about how burlap is made of fibers drawn from jute, another marsh plant in South Asia, and how generations ago the fibers were softened with whale oil (and now vegetable oils and sometimes mineral oil). We filled the burlap bags with sand, bundled them, and later we’ll slice holes in the tops. Then we’ll place plugs of spartina seedlings in the holes. Our seedlings are provided by the Greenbelt Native Plant Center, a facility operated by the Natural Resources Group of the NYC Department of Parks and Recreation. Those seedlings will be ready in June.

Students and volunteers then made seed balls from cocoa husks, natural red clay, a bit of sand, and velvety red staghorn sumac seeds. Sumac is another important species for our region’s shorelines. It grows with very little water and produces berry-like drupes that sustain many birds. Seedballs replicate endozoochory, or seed dispersal by animal droppings.

The Citizens Committee for New York City and Neuberger Berman were vital to the program because it’s otherwise difficult to have adequate volunteer staffing on a weekday. The students benefited from the greater adult-to-minor ratio in safety, attention ,and encouragement.