Clements Shellfish Ecology Lab

Last week we spent some time on the water sampling bivalves on the Richibucto River. We hit >200 sampling stations over the course of three days and used a Venturi pump to sample the near shore benthos, identifying and counting all bivalves.

This is part of an ongoing, multi-year effort to gather bay-scale understanding of bivalve populations in the southern Gulf of St. Lawrence. Ultimately, the data will be used to derive a contemporary baseline of regional species densities, generate local species distribution models, and feed into bay-scale carrying capacity models for informing bivalve aquaculture.

Today we're doing something a little different!

We're out in the Northumberland Strait running preliminary trials using a drop camera system to test whether we may be able to emloy video surveys on scallop beds for stock assessment purposes.

So far, so good! We have some nice video footage of the benthos here and can see plenty of scallops along our drift transects.

Next, we will annotate the species we see in the videos, count scallops and their predators, and attempt to measure the scallops' shell heights.

Taking a page from the book of Bryce Stewart and trying to .

The first picture is an image that someone shared in a public clamming group, meant to try and educate group members on the anatomy of a clam shell. Looks reasonable at first glance and the scientific words are generally accurate.

But if you take a minute to look closely, it's nothing more than AI generated slop that is grossly incorrect.

The first tell is the overall look, but the most obvious tell is the "m" in umbo; it is not a correctly formatted m.

I fixed it in the second photo.

Please stop trusting AI and instead seek information from experts and credible sources.

AI is very often wrong, and if you don't know how to prompt it precisely, accurately, and completely it will lead you astray.

This example may be harmless (although we shellfish ecologists don't think it is!), but the same sloppiness applies to information that isn't so benign.

The manila clam (Ruditapes philippinarum) is one of the most successful marine invaders globally, but has remarkably failed to invade the east coast of North America.

That is, until now...

In this paper, we document the establishment of R. philippinarum in eastern North America, with Boston as the apparent epicentre of the invasion.

With its arrival here, the species has now completed its circumglobal journey and has established itself on every major coast in the Northern Hemisphere.

https://link.springer.com/epdf/10.1007/s10530-026-03861-z?sharing_token=BXUk11yBaDmhkKo_aC5jGfe4RwlQNchNByi7wbcMAY4EpkHsqLXkCmRvebxLUz0Jx-42HQDAbdts6XtfLO8qWfpPsXNMZVF06SAHuOX9I-bgUakTe_ydIfVIloOggprRic5e1k9scWIhXbiUjRO6yMlQYzcvoABtOGKJvn8ELgg%3D

A new paper from our group, in collaboration with Dr. Brian Beal at the University of Maine at Machias and the Downeast Institute, provides a contemporary understanding of soft-shell clam fecundity and places it firmly in the context of current fishery regulations (legal size limits).

We developed a novel method to study fecundity-at-size for soft-shell clams from the Gulf of St. Lawrence and the Gulf of Maine, confirming that larger, older female clams produce exponentially more eggs than smaller, younger clams, and that the viability of those eggs does not decrease with size/age. To put this into perspective, we found that a single 65mm clam produces, on average, as many eggs as 30, 50mm clams (50mm = current legal size limit).

We also show that while current legal size limits are above the size at 50% maturity, the clams that they protect produce very few eggs. In contrast, implementing upper legal size limits have the potential to drastically increase female reproductive stock, and coupling this upper limit with a reduced minimum size limit (40 mm) would provide similar reproductive benefits with only marginal temporary reductions in fishery yields.

Finally, an interesting finding of the study relates to the observed size range of soft-shell clams between the two systems. Clams in the Gulf of Maine tend to get much larger (>100mm) than those in the Gulf of St. Lawrence, which rarely reach 80mm length. This stark difference in life history strategies speaks to the need for regionally-tailored management strategies that take into account local biology.

Ultimately, our paper provides promising evidence that maximum size limits have the potential to increase reproductive stock for soft-shell clams in eastern North America. Given the ubiquitous decline of soft-shell clam fisheries across the east coast, such a strategy may be worth exploring, Furthermore, with many clam fisheries declining worldwide, this approach warrants investigation for other species, as clam fisheries globally are predominately managed using minimum legal size limits.

You can read the paper for free here: https://doi.org/10.1016/j.fishres.2026.107780

New paper out this morning in Global Change Biology Communications.

We show that warming waters in the Gulf of St. Lawrence (GSL), driven by anthropogenic climate change, are likely driving an increased risk of outbreaks of Vibrio parahaemolyticus—a naturally-occurring bacterium in shellfish that can result in food-borne illness when shellfish are consumed raw.

The work was led by Will Chapman, an outstanding undergraduate student at Mount Allison University that I had the pleasure of working with through a collaboration with Dr. Josh Kurek.

Will used a random-forest modelling approach based on sea surface temperature, salinity, chlorophyll-a, and >2400 Vibrio archival tests to develop a 25-year hindcast of Vibro outbreaks in the GSL (1998-2023).

He found that the risk of Vibrio outbreaks has increased by ~7% since 1998 and that this increased risk was predominantly driven by warming waters.

More evidence of shifting ecological conditions in the GSL as a result of climate change.

Rapidly Warming Waters Drive Vibrio parahaemolyticus Abundance in a Northern Gulf Vibrio parahaemolyticus (Vp) has been identified as a highly responsive bacterium to climate change, with increasing outbreaks and human impacts as marine waters warm. We identified an increase in Vp...

The Hunter and the Hunted

If you've ever walked along a beach and picked up some shells, you may have noticed that some have these perfectly round holes with inner and outer edges to them.

It may be tempting to assume someone drilled these to make jewelery, but these holes are actually the telltale traces made by predatory moonsnails!

Snails (including moonsnails) have a specialized organ called a radula, that is lined with calcareous teeth that are specially designed for the type of food a particular snail species eats. Moonsnail radulas are built to drill through hard shells.

To aid in the drilling process, moonsnails secrete an acid that helps dissolve the shells of its prey. Nonetheless, depending on the thickness of the prey shell, drilling can take upwards of an entire day—talk about working for your meal! Once the shell is penetrated, that acidic stuff helps break down the prey tissue and the moonsnail can gobble it up.

You might also note that these holes are almost always found in the same location on the shells of particular prey species. This is due to the way that moonsnails handle and manipulate their prey once they catch them—they do so to minimize the chances of the prey escaping, so the holes are most often in the same location within a prey species.

What's also cool is that the size of the hole is proportional to the size of the moonsnail that made it, so us marine scientists can use beach collected shells of their prey to study aspects of their feeding ecology. Furthermore, because mollusc shells are easily preserved in the fossil record, we can use moonsnail holes in fossil molluscs to study their predatory behaviour in deep time, providing unique insights into predator-prey evolution across geologic timescales. Even cooler is that these snails are super cannibalistic—they eat each other all. the. time.

During Jeff's undergraduate research back in 2009-2010, he applied this forensic approach to study moonsnail predation back in Cape Breton under the exceptional supervision of Tim Rawlings. Part of that research was documenting the diversity of prey species that moonsnails consume in northeastern North America. Moonsnail feeding ecology never wanders far from his mind, and he recently conducted a small independent study using iNaturalist to revisit that published diet breadth he documented over 15 years ago now. (Stay tuned for the super cool results from that endeavour!)

So, while he walked the shores of Cap Lumiere Beach with the dogs and his partner Jenna after work today, he couldn't help but poke around for some drillholes along the waterline. Some very cool finds!

First couple of images are the northern moonsnail (Euspira heros). Prey species found at Cap Lumiere today, in photographic sequence, include common periwinkles (Littorina littorea), a wedgeclam (Mesodesma arctatum), a surfclam (Spisula solodissima), and a blue mussel (Mytilus edulis complex).

A new paper from our group was published today in the journal Ecosphere.

In this paper, we show that artificial oyster reefs comprised of concrete cinder blocks can successfully recover lost epibenthic ecosystem services in large bare patches of fragmenting eelgrass beds.

Using these results, we contend that artificial oyster reefs can help facilitate more successful outcomes for eelgrass restoration given the right background conditions.

This work represents a 5+ year research effort and provides a nice example of ecological facilitation - where the co-occurrence of different foundational habitats that provide similar services can mutually benefit one another.

More importantly, this work was co-developed through a strong collaboration with the Lennox Island First Nation, with the ultimate goal of providing the community with an accessible tool for restoring culturally and ecologically significant habitat within their traditional territory.

You can read the paper for free here: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.70626

We're gearing up for next week's join conference of the Atlantic Canada Coastal and Estuarine Science Society and Bay of Fundy Ecosystem Partnership at Mount Allison University in Sackville, NB!

Brooke-Lyn will be presenting her most recent results on using siphon holes for assessing clam populations, while Jeff will be presenting one the ecological effects of the recent MSX outbreak, as well as a meta-analysis related to soft-shell clam s*x ratios.

We're very much looking forward to a week of science in Sackville!

Back in December, Jeff led an editorial in the journal Conservation Physiology that provided some candid tips and tricks to peer reviewers for writing constructive reviews.

But peer review is a two-way street!

In this follow-up editorial, we provide candid tips and tricks to authors for constructively responding to reviewer comments.

Collectively, we hope these two pieces pieces provide useful guidance for authors and reviewers at various career stages to uphold collegial and constructive peer review.

Tips and tricks for addressing and responding to peer reviews Although peer review is the fundamental process that strengthens the scientific method (Lock, 1985; Rowland, 2002), it is hindered by several well-recogniz