If you spend time on Massachusetts tidal flats, you may encounter a clam that looks different from the familiar native quahog. Researchers are tracking sightings of the non-native Manila clam (Ruditapes philippinarum) along the New England coast and asking citizen scientists to report possible finds [3][4]. This guide explains what to record, how to note uncertainty, where to submit a report, and what to avoid so that your observation contributes useful data.
What to Record
Include the following details in your documentation:
- A clear photo showing the clam's hinge, lunule (the depression near the hinge), and the inner edge of the shell.
- Whether the clam was alive or dead (empty shell).
- An estimate of shell length (compare to a familiar object or use a ruler).
- The number of clams found at the same location.
- The exact location (e.g., beach name, GPS coordinates, or a description of the site).
If you are not sure about any of these details, note that uncertainty when you submit , incomplete data is still valuable.
Submission Checklist
Use this checklist to ensure your report is complete and safe.
| Step | Tools/Materials | Success Check | Stop/Escalate Condition |
|---|---|---|---|
| 1. Document the clam | Camera or smartphone; ruler or object for scale | Photo clearly shows hinge, lunule shape, and inner margin; notes on alive/dead, estimated length, and number of clams | If the clam is in a dangerous location (e.g., fast-moving water, unstable substrate) or you cannot safely take a photo, stop and record only the location and general description. |
| 2. Submit the report | iNaturalist app (or website) via the link on the WHOI Sea Grant or MIT Sea Grant sites | Report includes photo, alive/dead status, length estimate, number of clams, and location. You receive a confirmation (iNaturalist observation posted). | If you are unsure whether the clam is a Manila clam, still submit as "possible" and note uncertainty. Do not delay reporting. If you lack a photo, submit what you have and describe the shell. |
How to Label Uncertainty
Because Manila clams can be sold in seafood markets, some shells found on the shore may be discarded from meals rather than evidence of a living population [4]. If you are unsure whether the clam is a Manila clam, label your report as "possible" or "unconfirmed." Researchers will review your description and photo to make a determination. Do not discard the uncertainty , it helps them prioritize field verification.
Where to Find Current Official Reporting Channels
Researchers tracking Manila clams in Massachusetts, including those from WHOI Sea Grant and MIT Sea Grant, encourage citizen scientists to submit observations to iNaturalist (website or mobile app), a citizen science platform where observations are reviewed [3][4][5].
What Not to Do
- Do not assume the clam is a native quahog. The native Northern quahog (Mercenaria mercenaria) can be distinguished by its heart-shaped lunule and grooved inner margin, while the Manila clam has an oval lunule and a smooth inner margin [5].
- Do not disturb the site beyond what is necessary to take a photo. Avoid digging or removing clams unless you are certain they are dead and you have permission.
- Do not delay reporting because you are unsure. Submit your observation with a note about uncertainty , time-sensitive data helps researchers understand the seasonality of the species.
A Report Is Not Confirmation
Submitting a report does not mean the species is confirmed at your site. Researchers will review your observation and may follow up with additional surveys. The data contribute to a growing understanding of the Manila clam's distribution in New England [3][4]. Even if your report is later determined to be a misidentification, it provides valuable information about what people are finding on the shore.
References
[3] WHOI Sea Grant. "Help Track a Surprising New Arrival on Our Shores." https://seagrant.whoi.edu/manila-clams
[4] MIT Sea Grant. "On the Lookout for Non-Native Species: Investigating Manila Clams." https://seagrant.mit.edu/2025/09/18/on-the-lookout-for-non-native-species-investigating-manila-clams
[5] WHOI Sea Grant. "Be on the Lookout" (ID poster). https://seagrant.whoi.edu/wp-content/uploads/2025/12/manila-clam-id-poster.pdf