sea creatures show up in the Ocracoke surf
By PAT GARBER
There is slimy stuff all over the beach!”
the last weeks of May, beachgoers and sport fishermen at Ocracoke’s
ocean beaches came across an oddity that few recognized.
strange kind of slimy grass” was how one fisherman described it. “Gooey
strings resembling frog eggs” was someone else’s comment.
organisms floated in the surf, entangling fishermen’s lines so that
they couldn’t fish. Swimmers pulled them out of their hair, remarking
on their gelatinous quality with a disgusted “Yuck!” They washed up on
the beaches in rafts. Some thought they might be shark or skate eggs or
a kind of jellyfish. Others wondered if they were an invasive species
about to wreak havoc on Carolina ecosystems, but few knew what they
Park Service ranger Jessica Caldwell had come across them before, in
late spring of 2004, when she was working up the beach near Bodie
Island. She identified them as salps, or salpa, and she explained that
the aquarist at the North Carolina Aquarium on Roanoke Island, Heather
Bates, had recognized them when they started showing up on beaches in
2004. She assured everyone that they were harmless.
are fascinating barrel-shaped, free-floating tunicates, which despite
their appearance have no relationship to the primitive jellyfish they
resemble. They belong to the same phylum as human beings and other
vertebrates -- Chordata. They have primitive spinal chords or
notochords, as well as muscles, primitive nervous systems, and brains.
They have, according to William W. Kirby-Smith, a marine ecologist at
the Duke University Marine Lab at Beaufort, an eye around their brain
which collects light but does not form images, and are “our
closest-related relative among invertebrates.”
are closely related to the Ascidians, known as sea squirts or sea
grapes, which are often found clinging to dock pilings and other
underwater objects. But whereas sea squirts are sessile, attaching
themselves to one spot and staying there the rest of their lives, salps
are planktonic animals, never settling down anywhere.
common in many seas, including the temperate waters of the eastern
seaboard of the United States, salps are most prolific in the Southern
Ocean, near Antarctica, where their numbers sometimes supersede those
of the abundant krill. They are often seen at the surface of offshore
waters, either singly or in long string colonies such as the ones
observed at Ocracoke. And while they do not come ashore often, onshore
waves and currents may wash them in. They are, according to Kenneth
Gosner’s “Atlantic Seashore Guide,” infrequent visitors but may
sometimes be found in abundance.
Ocracoke was obviously one of those times.
salps that washed ashore in 2004 were identified as Thalia democratica,
a species described as transparent with a blue spot at one end. It is
probable that the salps at Ocracoke this year are the same species.
While each individual organism is less than one inch long, the chains
they form can be several meters in length.
feed by pumping water through their bodies and straining out the
phytoplankton that form their diet. They have complex and fascinating
life cycles, with alternation of sexual and asexual stages, or
generations. The two stages look quite different, though they exist
together in the sea. The solitary phase, known as an oozoid, is a
single barrel-shaped animal which reproduces asexually (without a
mate). It produces chains of individual animals known as blastzoids
which are hermaphrodites, which means they change sexes and reproduce
Harbison, a marine biologist from Woods Hole Oceanographic Center,
described how, when responding to large phytoplankton (algal) blooms,
salps multiply rapidly. Female salps produce an embryo that buds an
aggregate, which is female. The “mother” salp then grows testes and
becomes male, releasing sperm which fertilizes the aggregate. The
entire cycle takes less than two days.
as their presence may be to beachgoers, salps play an important
ecological role in the ocean. By feeding on the phytoplankton in algal
blooms, they reduce outbreaks which might otherwise wreak havoc on
ocean ecosystems . When there is a large bloom, they multiply faster
than any other multi-cellular animal and reduce the size of the bloom.
Salps also play a role in the ocean food chain by providing dinner
(themselves) for fish, sea turtles, and jellyfish.
scientists think that the organisms called salps may actually be useful
in counteracting predicted rises in global temperatures.
sinking bodies of salps and their fecal pellets carry carbon to the sea
floor, and when in great abundance can alter the ocean’s carbon cycle
and change its biological pump.
in Australia and other countries support this possibility.
LiveScience.com reported on July 20, 2006, that “gummy bears (salps)
fight global warming,” and ABC Radio, The World Today’s Nov. 17, 2008
edition said that “jelly blobs (salps) may hold the key to climate
change.” They theorize that if enough salps carry carbon to the ocean
floor, the heat trapped by carbon in the atmosphere could be
So, even if
salps clog up your fishing line and slide into your hair, give the
creatures the credit and admiration they deserve.