Each species of shellfish requires a different gauge for determining legal size.  Proper size metal rings, a combined length and width flat gauge, or a stainless steel set of three gauges are all locally available.  Be sure to carry the appropriate gauges with you at all times when shellfishing.  Having sublegal shellfish in your possession that you intend to cull later is not a legal practice and is subject to a fine.  The size limitations are strictly enforced to assure quality, size, and shape for next year’s catch and to protect the breeding stocks for next year’s spawn.  

Be sure to tie your gauges securely by a convenient length line to your basket, jacket, or belt.  Use the gauges consistently to ensure there is no doubt about the size of your catch.  A Shellfish Officer will be glad to show you how to measure your catch with the different gauges.  Measuring devices other than the “official” commercially available types are not encouraged.  The Shellfish Officer’s gauges make the final determination with respect to the legality of any catch.  

      1). Oyster Gauges:  Either a three inch ring (inside diameter) or the combined gauge that is three inches long serve to measure oyster length.  Be sure your oysters do not pass through the ring or are longer than the flat gauge.  If you are uncertain please return it to the water, as possession of short oysters can lead to a fine.

      2). Quahaug Gauges:  To be of legal size, a quahog must be one inch thick at the hinge.  he flat gauge with the one inch wide slot in the middle or the one inch caliper gauge works well for this purpose.  A two inch long quahaug is almost certain to be one inch thick. Therefore, a two inch ring (inside diameter) also functions well as a gauge when scratching for littlenecks.  

      3)  Soft Shell or Steamer Clam Gauges:  A legal steamer is two inches long. Here the two inch ring is most useful.  You can also use the two inch long slot in the flat combined gauge for this purpose, although it is somewhat awkward. 

4). Gauges for other Species:  The two inch quahaug ring serves equally well to measure the required two inch length for razor clams.  There are no size limits on mussels, conchs (whelks), or cockles.  Sea or surf clams must be five inches long, and can easily be measured with a small ruler.  Scallops are not measured for size.  These may be legally taken if a discernable raised growth ring is present.  Ask your Shellfish Officer for clarification on this requirement if you are gathering scallops.