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  • Tara Crutchfield

Sea & Shoreline

We are surrounded by water, both fresh and salt. What happens when an aquatic ecosystem becomes unbalanced or worse? We sat over coffee with Sea & Shoreline President and Partner Carter Henne to discuss seagrass solutions, saving Crystal River, and how you can help keep Florida water bodies clean. 

Winter Haven-born biologist Carter Henne lives in Polk County with his wife, Dr. Michelle Henne, and their two dogs. The avid angler and outdoorsman grew up on Lake Daisy. “It was interesting to see Lake

Daisy go from a really undeveloped lake to a developed lake and the changes that went along with that,” he reflected. In high school, he co-founded the Winter Haven Competitive Bass Fishing Team – the first in the country. “It allowed me to get my competitive side out in a sport that I really loved,” Henne said.

Henne attended the University of South Florida, where he obtained a degree in Biology. The Polk County boy who ‘loved the water’ and getting his hands dirty was fixated on aquaculture. “I thought that by farming fish, you’d be able to save the world. You don’t see chickens or cows going extinct anytime soon,” he said. In college, he interned at the Florida Fish and Wildlife Research Institute (FWRI) and started farming redfish, sea trout, and blue crab for the state. “I loved it, but there wasn’t a clear career path to stay in the country and do aquaculture.” As he learned more about habitat restoration, he dove head-first into working as the Chief Biologist and Project Manager with Seagrass Recovery, Inc. In 2014, he joined Sea & Shoreline Founder and Partner Jim Anderson in his efforts to restore rivers, lakes, lagoons, and estuaries and “pioneer innovative technologies that help to ensure the long-term success of restoration projects.” Henne serves as the lead biologist, partner, and president for Sea & Shoreline.

Since 2014, the Florida-based aquatic restoration firm has grown from six to 100 employees and counting. Henne attributes this to apt timing and a resounding need for their services. His primary responsibilities are restoration project acquisition and management and the ensured growth of Sea & Shoreline. Henne’s first success metric is hiring new people and “pouring love” into their team. “It means we’re doing something correctly, and we’re providing a benefit to the communities. We’re providing a service that people want, and we’re effectively doing it if they continue to rehire us, and we’re able to grow.”

The company’s mission is to restore aquatic ecosystems, with an emphasis on seagrass and the vital part it plays in cleaning the water, stabilizing sediment, sequestering harmful nutrients that cause algae, and providing food and habitat for fish and animals. Sea & Shoreline is the largest seagrass restoration company in the world and, until last year, the only commercial seagrass nursery. Sea & Shoreline has planted over one million seagrass plants in Florida waterways. In addition to their submerged aquatic vegetation/seagrass restoration, the company offers services including dredging, propeller scar restoration, oyster reefs, wetland plants, living shorelines, coral reefs, mitigation banks, wave attenuation devices, surveying and mapping, and vegetated retaining walls. Henne said, “You can’t feed yourself on biology alone. I tell everyone, ‘We do marine contracting to pay for our seagrass addiction.’”

Sea & Shoreline has grown outside of the Sunshine State into the Carolinas, Louisiana, and most recently, acquired licensing in the U.S. Virgin Islands. Their focus is to serve the southeast coastal and Caribbean for now. Sea & Shoreline have refined their restoration process, with Henne describing their projects as a sort of “cut, paste, repeat,” adding, “There are environmental issues surrounding water, water quality, development, and growth. How do you do that responsibly?”


The cause is essential for animals, the environment, and humans. As Sea & Shoreline states, “All life depends on water to survive. When these ecosystems become unbalanced, they pose health risks to not only humans but also to plants and animals that rely on the water to live.” According to Henne, ninety percent of all commercially derived seafood depends on a seagrass meadow for some point in its lifecycle. “One acre of seagrass is worth roughly $50,000 a year back to ecosystem services, back to the state whether that’s commercial fishing, recreational fishing, habitat, sediment stabilization, [or] nutrient buffering.”

As for the human health concern unbalanced ecosystems pose, he invoked Florida’s largest lake. “Lake Okeechobee needs 26,000 acres of submerged aquatic vegetation to function as a wetland. After Hurricane Irma, it had less than 6,000 acres,” Henne said. “All those nutrients go from a plant to phytoplankton which is algae. Then you saw these phytoplankton blooms going east and west out of the St. Lucie and Caloosahatchee estuaries.” The algae’s Microcystis toxin caused health concerns.

Red tide is another example. Though red tide is a naturally occurring phenomenon, Henne explained, “When those red tides kill fish, those dead fish wash into backend canals. They sink, they rot, and create anoxic conditions. [That] creates algal blooms, which further reduces seagrass. Then you lose those ecosystem services. [...] It’s the death by a thousand cuts. An ounce of prevention is worth a pound of cure. We’re trying to get ahead of some of these environmental disasters, calamities, issues.”

Submerged plants, namely seagrass, are the tool Sea & Shoreline uses to address these issues, which also has a marked economic impact. During a relatively small project, about $50,000, Sea & Shoreline planted in a Martin County stormwater canal. “It had the same effects of water quality filtration as a $5M stormwater pond,” Henne said. The project was an added benefit to those communities to be able to filter their water economically. “It’s my job to be able to A: Identify the benefits. And B: articulate them,” he said.

 Sea & Shoreline has worked to temper its habitat restoration methods. Seagrass mitigation projects of the past were going for about a million dollars an acre. “It was cost-prohibitive to use on restoration. But we’ve been working on refining the process, and we’re sub $50,000 an acre right now. […] If you think about seagrass being worth somewhere between $20,000 to $50,000 of ecosystem services back to the state every year, you’ve got a one to three-year return on investment.”

 Seagrass is a veritable Swiss army knife for aquatic habitat restoration. In one function, it acts as a nursery for fish, Henne explained. “Seawater is about 32 parts per thousand (ppt) salinity. Freshwater is zero ppt. Juvenile fish need to stay around 9-15 ppt salinity. That’s why these rivers and the upper parts of these bays are so important because it’s the nursery ground for all these juvenile fish. One acre of seagrass supports 40,000 fish and 50 million small invertebrates. It protects them, and it provides food for them.”

Seagrasses also filter out water quality. Henne used the example of going inside after a barefoot walk along the beach. If you walk across the tile floor, your feet will remain sandy. But, if you walk across the carpet, it will scrape that sand from your feet. “That’s what seagrasses are doing,” Henne said. “They’re sequestering all the suspended particles out of the water column, and then they’re stabilizing the seabed.”

 It’s hard to see the trajectory of a waterbody going from an algae-dominated system to a plant-dominated system. “I can’t tell you when it does it or what the exact acreage is – but when you see the flip, it’s apparent,” Henne said. “That day when you can see the switch go to the positive side is incredibly fulfilling.”


Though Sea & Shoreline provides a niche service, the company touches many components of the Florida lifestyle. Clients approach the organization seeking various solutions to environmental issues. The Angler Action Foundation, for example, is planting to increase fisheries. In Martin County, the aim was to sequester sediments and clarify water before it goes into the Indian River Lagoon, and in Crystal River, they worked to beat algal blooms.

Henne called Crystal River a center point for merging issues – endangered species management, invasive species management, algal blooms, water quality, and “how do we deal with coastal communities and how they interact with what’s natural and what’s not natural?”

A waterbody exists in two stable states, Henne explained – either a plant-dominated or algae-dominated system. Crystal River was a plant-dominated system until the climatic impact of the 1993 “no-name storm,” which sent a saltwater plume, killing all the hydrilla in its system and switching it to an algae-dominated system. “It couldn’t recover because now there were dense algal blooms, there was muck on the bottom, and any plant that was there, the manatee would come by and rip it out,” Henne said. Seagrasses are manatee’s primary food source. “It’s not the manatee’s fault,” he added. Whenever a sea cow came by to eat, they would pull the plant up from the soft bed. If the ground were harder, the manatee would eat the leaves, leaving the plant for its leaves to grow back.

 “Save Crystal River was formed as a response to government oversight,” Henne said. “It was a small, tight-knit community of locals. U.S. Fish and Wildlife started taking over and cutting off access to different parts of the bay, and the residents that grew up there didn’t like that.” Save Crystal River is a non-profit, grassroots organization on a mission to address the damage done by human and environmental factors that had made the river inhospitable for sea life and recreation alike. The community banded together to raise funding for land acquisition and restoration. Save Crystal River raised funding in Tallahassee for a demonstration project which included a vacuuming out of all the algal bloom, the macroalgae on the bottom, and the muck. Sea & Shoreline reduced it to a hard mineralized substrate and planted native eelgrass. “It was tough going in the beginning. The problem is scale,” Henne said. The project showed success, so Save Crystal River returned to Tallahassee and raised more funding.

“They got everyone in line behind a cohesive mission,” said Henne. “That’s critical for any large-scale transformational change in a water body.” Six years later, the project is ongoing. Sea & Shoreline restored over 80 acres which have rippled into over 200 acres of naturally recruited native, dense submerged plants throughout the system. “Now the manatees have something to eat. The water clarity went from about 2-3 feet in visibility. Now it’s upwards of 20-30 feet,” Henne said.

 Crystal River is Sea & Shoreline’s second largest project, beaten out in scale only by their current Caloosahatchee project, which will be over 100 acres of directly planted submerged vegetation.

Perhaps more important than the restoration itself will be ongoing efforts to protect that work. Crystal River is a hot spot for people moving to Florida from out of state. Unaware of the river’s condition years earlier and the exhaustive work to restore it, new residents are calling to remove the seagrasses. “Ongoing education is critical to maintaining Florida in some semblance of balance,” Henne said. “We’ve effectively turned back the hands of time from predevelopment era to developed, and now they’ve done all the septic to sewer conversions, all the fertilizer ordinances, all the things we talk about. […] Now they’re on a good track for sustainability.”

 With its abundance of rolling seagrass meadows, Henne said of the Crystal River Project, “It’s the poster child for manatee health now.”


In a state divided on a great many issues – protecting our natural spaces has proven uncontentious. Polk County saw that with last year’s rally behind and passage of the Environmental Lands Acquisition and Management Referendum, thanks in no small part to Polk Forever, a nonpartisan political committee of volunteers.

 Communities, both red and blue, are opting to tax themselves in the name of conservation. In a November 17, 2022, article titled “Florida’s Green Wave,” Conservation Florida President and CEO Traci Deen wrote, “Voters in Polk, Brevard, Indian River, Alachua, Pasco, and Nassau counties turned out during a surprise November hurricane to cast a vote for wild Florida. These counties join Collier, Volusia, and Manatee in passing recent measures that support natural resource protection.”

Henne noted, “It’s apolitical because we now have to sleep in the bed we’ve made.” Altruism and duty to the environment aside, the issue has become a common ground because it makes economic sense. According to the Indian River Lagoon Basin Management Action Plan, “the return on investment from achieving water quality and seagrass restoration goals is 33 to 1,” for that project. Investments in improved water quality and seagrass beds mean considerable economic benefits for the region.

In 2016, Brevard County voted to impose a ½ cent sales tax providing almost $500M for wastewater infrastructure projects and aquatic restoration over ten years. Part of that sales tax goes to the Save Our Indian River Lagoon Program, which is “designed to address excess nitrogen and phosphorus pollution to the Indian River Lagoon through various projects to reduce pollution inputs, remove legacy loads of pollution, and restore natural filtration systems,” according to It is estimated that this program will bring in up to $542M in revenue over ten years.

Natural spaces, specifically coastal communities, are embedded in Florida’s economy and lifestyle. “Tourism is a main driver of the economy, and if people aren’t coming to the state because of bad water quality – it becomes a return on investment [issue]. […] Everyone understands that an investment in the environment, an investment in education, an investment in good law enforcement is just good for communities all around,” Henne said.


Wondering what you can do to keep Florida water bodies clean? Sea & Shoreline shared a few easy ways you can help reduce polluted runoff from homes:

Properly dispose of hazardous household items by checking with your county waste management service to find out what hazardous materials they accept.

Reduce or eliminate the use of fertilizers and chemical herbicides and pesticides.

Make sure to check your septic system annually.

Make a rain garden in a low-lying area planted with native species that can handle wet soil to help reduce flooding and erosion and filter runoff.

Always remember to clean up after your pet.

To learn more about Florida’s ecosystems, Carter Henne recommends the “Naturally Florida” podcast hosted by Shannon Carnevale and Lara Milligan. And for those curious about marine science – the “So You Want to Be a Marine Biologist?” podcast. You don’t have to be a biologist to slow the issues that Sea & Shoreline work to ameliorate. Small changes make the most significant difference. Education, policy, and leading by example are key. “There are no silver bullets in this,” Henne said. “It’s a game of net sums.”

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