Seaweeds play a major role in the marine ecosystem by providing nutrients, shelter, and habitat for numerous coastal biota.

We’re colating rare and historic data needed to inform scientific research and policy decisions. Without your support, seaweed species may disappear from the coast of Maine.



Field Guide to Maine Seaweeds

As of 2020, MNHO is in the early stages of producing a user-friendly, semi-technical field guide to the seaweeds of Maine aimed at making seaweed identification simple for outdoor enthusiasts and experienced biologists alike.  This project is in collaboration with local artist and seaweed naturalist Jordan Chalfant (more info).

The guide will feature a key to identification that is complete and specific enough to be useful to phycologists and professionals in the seaweed industry, but simple and clear enough to be easily usable by casual learners. The guide will include background information on seaweeds in Maine, descriptions of each species with an emphasis on characteristics that are simple to distinguish, updated taxonomy reflecting recent phylogenetic work, habitat, and, when possible, distribution and regional abundance.

The guide will also feature numerous visual components to aid identification including color photographs (both in the field to provide context and submerged with a neutral background to illustrate form), scans of pressed specimens, line drawings to isolate details, and paintings to capture features that define each species and exemplify the aesthetic of seaweeds.

Substantial preliminary work and collaboration with other seaweed researchers is necessary to lay the groundwork for this guide. Our first goal is to connect with local experts and archives to develop a database of historic seaweed records including herbarium specimens, historical references and reports, and observations. The second goal is to conduct field work to create a current inventory of Maine seaweeds including a library of digital photos for each species. Once that phase of the project is completed, our focus will be building the field guide with the intent of peer review before sending it out for publication. We estimate this project will take 5-10 years to complete.


Quick Key seaweed ID as seen in the Observer field journal.


Get Involved

Do you have experience identifying and photographing seaweeds or have an interest in learning?  MNHO needs motivated citizen scientists to help with this project.  Contact for more information on how you might be able to get involved. 



MNHO is actively looking for funding for the preliminary stages of this project: building a database of current taxonomy and synonymy
of Maine seaweeds and conducting field work in Washington and Hancock Counties to build complete species lists and collect photos.  If you are interested in supporting this project financially or have other ideas for funding opportunities, please contact


Photo: Chondrus crispus by Jordan Chalfant