By Lauren Fliearman

Did you know that Mud Bay holds the largest patch of eelgrass (Zostra marina) in all of Kachemak Bay? While it may not look like much, eelgrass is one of the most important, and threatened, habitats in coastal ecosystems (Figure 1). Eelgrass prefer cooler shallow waters in the Northern Hemisphere, thriving in bays, estuaries, tidal flats and any other sheltered coastlines in the Northern Hemisphere. These plants anchor themselves into sandy or muddy sediment using a network of rhizomes- horizontal stems that spread beneath the surface, allowing eelgrass to form dense, meadow-like beds. 

Figure 1. Eelgrass (Zostra marina). (Photo © by Dr. Ross Whippo)

Because eelgrass depends on sunlight to grow, pristine water quality is essential for its survival. Pollution, sediment runoff, dredging and algal blooms can block sunlight from reaching the seafloor and quickly degrades eelgrass habitat. Recently there has been concern that the upcoming Homer Harbor Expansion may contribute to altering the water quality eelgrass needs to thrive by expanding the harbor further out into Kachamak Bay. Local biologists, ecologists and students with Kenai Peninsula Campus have been conducting research on eelgrass to further understand the importance of this species residing in the bay.

A study through Gulf Watch Alaska’s long-term ecosystem monitoring program has been surveying eelgrass beds in Kachemak Bay for about 15 years now.


“What we have found so far is that there is tremendous variability from bed to bed and year to year,” stated Dr. Brenda Konar, a professor affiliated with University of Alaska Fairbanks College of Fisheries and Ocean Sciences. “Also, we’ve noticed that the high and low abundance patterns are not synchronized across beds. Even in beds that are close to one another, one can have high percent coverage while the other has very low coverage in the same year. We still don’t know what drives, what seems to be these very local patterns.”


While these beds are observed to be variable, Dr. Konar also notes that the beds seem to be resilient to changes in environmental conditions from year to year. “Even when a bed becomes very sparse, it seems to bounce back in subsequent years,” she said.


Gulf Watch Alaska will continue to monitor eelgrass in Kachemak Bay to understand these fluctuation patterns in eelgrass coverage throughout the bay.  

The National Oceanic and Atmospheric Administration’s National Centers for Coastal Ocean Science (NOAA-NCCOS) based out of the Kasitsna Bay Lab have also started to conduct repeated surveys of eelgrass habitat in Mud Bay (Figure 2). Led by marine ecologist Dr. Ross Whippo, the surveys are designed to establish a baseline of eelgrass meadow extent and density and are currently the only surveys of their kind that are repeated multiple times a year in Mud Bay.


“The eelgrass in Mud Bay is an important habitat for many species, including migratory shorebird species that use it as a stopover in the spring,” he said. “Although we have information about the Mud Bay eelgrass meadow across multiple years, that information tends to be more of a ‘snapshot’ in time and collected once annually. Our surveys will hopefully provide additional detailed seasonal information about the overall size and density of the meadow, and how it might be changing through time.”


Dr. Whippo and his colleagues plan to expand their study. “We’ll be taking the same high-resolution approach we’re using in Mud Bay and translate it into other eelgrass meadows and kelp habitats, all the way out into Lower Cook Inlet,” he said. “Our goal is to create openly available seasonal vegetation maps for all of Kachemak Bay and identify trends as we collect more data, similar to the Washington State Department of Natural Resources Floating Kelp Indicator¹.” 

Figure 2. Mapping eelgrass distribution around Mud Bay. (Photo © by Dr. Ross Whippo)

Finally, students across the country through the Semester By the Bay (SBB) program are getting involved with eelgrass research during their duration in Alaska. Noble Moody, a SBB student with the Spring 2026 Conservation Ecology cohort, has been conducting research on the Pier One Beach located right behind the theater on the Homer Spit. The goal of this research is to confirm the presence of eelgrass beds in the area that are able to act as a foundational species.


“A foundation species is one that is not only in a specific habitat but builds the habitat both around and within it” Noble said. “The presence and density of Eelgrass alone is not enough to confirm this theory. It would require the interaction of animals displaying a variety of behaviors such as foraging, resting and traveling with the seagrass. As well as an increase in the bed’s overall health.”


Starting March 1, Noble has measured the eelgrass percent coverage, density and epiphyte load around Pier One to gather data for his project.


“Hopefully if it grows and comes back stronger when the ice disappears and spring temperatures return, then one can assume that the area is productive and healthy. Now this information is important because in all non-local aspects Pier One Beach is not on the map,” he said.


Moving forward, Noble hopes his research project will help expand what is already being done in Mud Bay. As seagrass beds are not just a foundation for animals that use it but for communities to build and maintain it. 

Protecting eelgrass is not only vital for species that depend on it, but also for thriving fisheries, stable coastlines and human communities. As pressures from global warming and human development continue to change marine ecosystems, understanding how these meadows change becomes increasingly important. Continued monitoring and community-driven research will be essential for identifying eelgrass trends in Kachemak Bay and guiding responsible management decisions, as we depend on these coastal ecosystems just as much as other marine organisms do. 

¹WADNR Floating Kelp Indicator