Barnstable Harbor Field Trip

Marine Invertebrates Course

Barnstable Harbor Field Trip
26 Sept. 2005

Field Trip Report by Joanna and Liz

Individuals present: Stace Beaulieu, Jennifer Benoit, Kate Buckman, Joanna Gyory, Annette Hynes, Lauren Mullineaux, Elizabeth Orchard, and Kelly Rakow.

Weather conditions: The temperature hovered around 23° C (about 74° F). There was about 80-100% cloud cover. Humidity ranged from about 70-80%. The winds were out of the Southwest at about 30 km/h, with gusts up to 40 km/h.

Field trip summary: On Sept. 26, 2005 we took a trip to the Barnstable Harbor mudflats (Calves pasture) at low tide. We were on a quest to find molluscs of all kinds. There was a plethora of razor clams that greeted us with squirts wherever we stepped. Because we were getting stuck in the mud, we were forced to remove our shoes and brave the razor clam minefield. We did not like the quality of the mud, and apparently neither did the Mya. We only found them in the sandier sediments near the marsh grass.

Arthropods:
Green crab (Carcinus maenus)
Asian shore crab (Hemigrapsus sanguineus)
Hermit crabs
Lady crab (Ovalipes ocellatus)
Shrimp
Barnacles (Semibalanus balanoides)

Molluscs:
Mud snails (Ilyanassa obsoleta)
Oysters (Crassostrea virginica)
Soft shell clam (Mya arenaria)
Razor clam (Ensis directus)
Scallop (Argopecten irradians)
Periwinkle (Littorina spp.)
Moon snail (Lunatia heros)
Blue mussel (Mytilus edulus)
Ribbed mussel (Geukensia demissus)
Clam (Mercenaria sp.)
Oyster drill egg cases

Worms:
Nereid (Nereis virens)
Clymenella torquata
Opal worms (Arabella iricolor)

Porifera:
Red sponge (Microciona prolifera)

Non-invert:
American eel (Anguilla rostrata)

Careful walking amongst mud snails (Ilyanassa obsoleta)	Razor clam (Ensis directus) disappearing into the sediment	Mud snails (Ilyanassa obsoleta) attracted to dead razor clam (Ensis directus)
Kate overturns rocks to find hidden animals	In the upper intertidal, Asian shore crabs (Hemigrapsus sanguineus) hide under rocks	In the lower intertidal, overturning a rock revealed an eel, likely an American eel (Anguilla rostrata)
Lauren displays a stranded sponge (Microciona prolifera)	Kate and Stace hold the seine in the tidal flow	We only caught a green crab (Carcinus maenus) in the seine
Soft-shelled clam (Mya arenaria)	We were all astounded at the shooting jaws of this polychaete, possibly Nepthys sp.	Mud turned into quicksand in some parts of Calves Pasture
Crossing the tidal channel an hour after low tide	Tiny tracks outside of small burrow openings appeared to be made by Nereid polychaetes (Nereis virens)	Liz's back is evidence of our hard work in the marsh

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