Nantucket Bay Scallops

  • Veliger
    Scallops start as free swimming larvae called veligers.
  • Settling Scallop
    They grow and settle out of the water column.
  • Developing Spat
    Scallops settle onto vegetation and are called spat.
  • Scallop Settled
    The spat have to avoid predation to grow into adults.
  • Spat Bag Set-up
    We use spat bags to determine when scallops spawn each summer.
  • Tying spat bags
    Spat bags get tied onto a line with buoys and anchors.
  • Deploying spat bags
    Spat bags are deployed in several locations in Nantucket harbor.
  • Collected spat bag
    Every two weeks they are pulled up and spat (baby scallops) counted.
  • scallops
    Bags contain between a few and a few thousand tiny scallops!
  • Nubs
    2013 nub scallops from field work in October
  • Measuring scallops
    Nub scallops are measured and counted. These will reproduce next summer.

Nantucket Bay Scallops, Argopecten irradians irradians (Lamarck 1819), add around two million dollars to the Nantucket economy each winter. The adductor muscle that opens and closes the two shells in the live animal is a delicacy and Nantucket is one of the last places where wild bay scallops are regularly harvested. Since 2003, the Maria Mitchell Association (MMA) and Nantucket Shellfish Association (NSA) have collaborated on a long-term study of the Nantucket Bay Scallop to understand scallop longevity, reproduction and survival and habitat preferences of the bay scallop. The scallop research program has been very important to our understanding of the timing of spawning of the wild scallop population in Nantucket Harbor.  Currently, MMA Research Associate, Dr. Peter Boyce oversees the research and the students who assist with it.

Current Research

Congratulations Dr. Valerie Hall!

Dr. Hall successfully defended her PhD dissertation on January 31, 2014 at UMass Val Hall with her dissertation presentation.Dartmouth’s School of Marine Science and Technology (SMAST).  Titled Impact of the second seasonal spawn on reproduction, recruitment, population, and life history of the northern bay scallop, her work is based on several years of scallop monitoring, field experiments, and lab work in and around Nantucket Harbor.

A large part of her work is trying to understand the influence of nub scallops in the population. Scallops usually reproduce twice a summer; there is an early spawn around late June and a late spawn that occurs late in the summer or early fall. Scallops produce in the late spawn are referred to as “nubs” because they are very tiny their first fall.

Only about 40% of the nubs Val Hall with her dissertation committee after successfully defending her dissertation.reproduce the following spring; the rest wait until their second spring. In the second spring, Val has found that they are able to reproduce equally well compared to the early spawned scallops. Nub scallops may be very important in maintaining the scollop population under harvesting pressure or detrimental environmental conditions. For example, in 2009 an algal bloom or “rust tide” wiped out much of the early summer spawned larvae but the late spawned larvae were fine.

Dr. Hall’s accomplishment is a major milestone in the Maria Mitchell Association’s/Nantucket Shellfish Association’s Bay Scallop Research Project. She was assisted by her doctoral committee, the SMAST program, Val Hall collecting data on bay scallops for her dissertation.and her colleagues Dr. Bob Kennedy (MMA Senior Research Fellow), Dr. Peter Boyce (MMA Research Associate), and Tara Riley (Nantucket Town Shellfish Biologist).

The Nantucket Shellfish Association and the Nancy Sayles Day Foundation have been generous financial supporters of the Bay Scallop Research Project. Their support and the work of dozens of MMA interns and volunteers have been critical to the success of the project.

Student Mentoring and Research Program

Dr. Peter Boyce, Research Associate at the MMA, continues research on the spawning times of bay scallops and what factors affect scallop spat and larvae. Assisting him each summer are several high school interns who each work on their own project while helping with regular field work.  Projects include spat bag placement, mud crab predation on young scallops, and effects of rain on scallop success.

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